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Interfaces
and surfaces are where the action happens. Catalysis, molecular
recognition, charge transfer, polymerization and many other critical
processes take place at the boundary between one medium and another. With
the need to integrate new materials into devices, and applications ranging
from catalysis to sensors, medicine to self-cleaning surfaces, and displays
to lasers, fundamental and applied studies of surface and interface
processes and optimization are of critical importance in developing new
technology to meet today's challenges. The selection of recent research
articles presented below illustrates the vast potential of this
field.
For recent reviews, see
Anna Carlmark
Tailoring Cellulose Surfaces by Controlled Polymerization Methods [Talents & Trends]
To expand the utilization of cellulose beyond its traditional uses, it is necessary to modify the surface of the fibers. This paper summarizes the modification of cellulose by controlled polymerization methods such as ATRP, RAFT, ROP, and ROMP. The combination of the excellent properties of cellulose with functional polymers creates new materials of great potential in advanced material applications.
Macromol. Chem. Phys., Jun 14, 2013, DOI: 10.1002/macp.201300272
Francesca Lugli, Giulia Fioravanti, Denise Pattini, Luca Pasquali, Monica Montecchi, Denis Gentili, Mauro Murgia, Zahra Hemmatian, Massimiliano Cavallini, Francesco Zerbetto
And Yet it Moves! Microfluidics Without Channels and Troughs [Full Paper]
A simple and versatile procedure, based on the immersion method, is developed to fabricate chemical gradients on Si/SiO2 surfaces by using a silane self-assembly monolayer. The spontaneous motion of water droplet is demonstrated and the results are rationalized by dissipative particle dynamics simulations that shows that the intrinsic nature of the gradient affects the velocity of the motion.
Adv. Funct. Mater., Jun 14, 2013, DOI: 10.1002/adfm.201300913
Bomi Kim, Seong Cheol Hong, Seongho Jung, Jutaek Nam, Jiwon Bang, Sungjee Kim
Novel Synthesis of Porous Silver Nanostructures Using a Starch Template and Their Applications toward Plasmonic Sensors [Communication]
A novel method to prepare nanoporous silver structures (NPSs) is introduced. Soluble starch is used as the in situ template, and an aqueous AgNO3 solution is used as the silver precursor. The porous NPS film is introduced in a plasmonic sensor using the Kretschmann configuration. The obtained device responds well to environmental reflective-index changes.
Li-Wei Chou, Michael A. Filler
Engineering Multimodal Localized Surface Plasmon Resonances in Silicon Nanowires [Communication]
Multimodal plasmonic resonances: Silicon nanowires that contain multiple, dimensionally controlled, axially registered doped regions were synthesized and investigated by angle-dependent mid-infrared spectroscopy (see picture; P=partial pressure). The wires support mid-infrared multimodal localized surface plasmon resonances (LSPRs).
Angew. Chem. Int. Ed., Jun 13, 2013, DOI: 10.1002/anie.201301468
Mark Huijben, Gertjan Koster, Michelle K. Kruize, Sander Wenderich, Jo Verbeeck, Sara Bals, Erik Slooten, Bo Shi, Hajo J. A. Molegraaf, Josee E. Kleibeuker, Sandra van Aert, Jeroen B. Goedkoop, Alexander Brinkman, Dave H. A. Blank, Mark S. Golden, Gustaaf van Tendeloo, Hans Hilgenkamp, Guus Rijnders
Defect Engineering in Oxide Heterostructures by Enhanced Oxygen Surface Exchange [Full Paper]
Defect engineering of conducting interfaces in oxide LaAlO3–SrTiO3(001) heterostructures by incorporation of a strontium copper oxide nanolayer strongly reduces the impurity scattering, opening the door to high carrier mobility materials. This remote cuprate layer facilitates enhanced suppression of oxygen defects by reducing the kinetic barrier for oxygen surface exchange in the hetero-interfacial film system.
Adv. Funct. Mater., Jun 10, 2013, DOI: 10.1002/adfm.201203355
Sebastian Rauch, Klaus-Jochen Eichhorn, Dirk Kuckling, Manfred Stamm, Petra Uhlmann
Chain Extension of Stimuli-Responsive Polymer Brushes: A General Strategy to Overcome the Drawbacks of the “Grafting-To” Approach [Full Paper]
A general strategy to overcome the limits of the grafting-to approach concerning the intrinsic limitation of the grafting density, connected with a simultaneous improvement of the switching behavior of a temperature-responsive polymer brush, is reported. The thermal azide–alkyne cycloaddition reaction is used to perform a chain extension of alkyne-functionalized poly(N-isopropylacrylamide) (PNiPAAm) brushes with azide-functionalized PNiPAAm molecules to increase the molecular weight of the attached chains without changing the grafting density.
Adv. Funct. Mater., Jun 10, 2013, DOI: 10.1002/adfm.201300849
Wei Wang, Mao-Jie Zhang, Rui Xie, Xiao-Jie Ju, Chao Yang, Chuan-Lin Mou, David A. Weitz, Liang-Yin Chu
Hole–Shell Microparticles from Controllably Evolved Double Emulsions [Communication]
Hole in one! Hole–shell microparticles (blue, see picture) with controllable structures and flexible internal surfaces have been fabricated from W/O/W emulsions. These microparticles could be used as microcontainers for the controlled capture/release of molecules, microsphere classification/separation, confined cell culture, or as microreactors for catalysis.
Angew. Chem. Int. Ed., Jun 10, 2013, DOI: 10.1002/anie.201301590
Markus Lampimäki, Veronika Zelenay, Adéla Křepelová, Zhi Liu, Rui Chang, Hendrik Bluhm, Markus Ammann
Ozone-Induced Band Bending on Metal-Oxide Surfaces Studied under Environmental Conditions [Article]
Bind until you bend: Ozone-adsorption-induced band bending is observed on Ti- and Fe-oxide surfaces under dry and humid conditions. X-ray photoelectron spectroscopy results indicate that O3 adsorption and decomposition proceed via a mechanism including a reversibly adsorbed precursor. These results contribute to the fundamental understanding of O3 adsorption and decomposition mechanisms on oxides of environmental and technological relevance.
Kojirou Fuku, Ryunosuke Hayashi, Shuhei Takakura, Takashi Kamegawa, Kohsuke Mori, Hiromi Yamashita
The Synthesis of Size- and Color-Controlled Silver Nanoparticles by Using Microwave Heating and their Enhanced Catalytic Activity by Localized Surface Plasmon Resonance [Communication]
Silver nanoparticles (Ag NPs) of various colors were synthesized within the mesopore structure of SBA-15 by using microwave-assisted alcohol reduction. The charge density is partially localized on the surface of these Ag NPs owing to localized surface plasmon resonance. This charge localization results in them having enhanced catalytic activity under visible light irradiation compared to Ag NPs obtained by thermal processes.
Angew. Chem. Int. Ed., Jun 05, 2013, DOI: 10.1002/anie.201301652
En-Chiang Lin, Jun Fang, Se-Chul Park, Thomas Stauden, Joerg Pezoldt, Heiko O. Jacobs
Effective Collection and Detection of Airborne Species Using SERS-Based Detection and Localized Electrodynamic Precipitation [Communication]
Three different delivery concepts (standard diffusion, global electrodynamic precipitation, and localized nanolens-based precipitation) and three different SERS enhancement layers (a silver film, a nanolens-based localized silver nanoparticle film, and the standard AgFON) are compared. The nanolens concept is applied to increase the SERS signal: a factor of 633, when compared to a standard mechanism of diffusion, is observed.
Arunava Agarwala, Thangavel Subramani, Amir Goldbourt, David Danovich, Roie Yerushalmi
Facile Monolayer Formation on SiO2 Surfaces via Organoboron Functionalities [Communication]
More than they appear on the surface: The treatment of SiO2 nanoparticles under mild conditions with two organoboron derivatives led to boron-containing monolayers with different types of surface species (see picture) through the direct formation of Si-O-B bonds. The organoboron-modified SiO2 NPs showed selective reactivity towards diols.
Angew. Chem. Int. Ed., Jun 04, 2013, DOI: 10.1002/anie.201302655
Congrui Jin, Anand Jagota, Chung-Yuen Hui
Structure and Energetics of Dislocations at Micro-Structured Complementary Interfaces Govern Adhesion [Full Paper]
Poly (dimethylsiloxane) (PDMS) is used to fabricate micro-structured complementary surfaces by molding into a silicon master with micro-channel profiles patterned by photolithography. For each pair of complementary surfaces, dislocation defects are observed in the form of visible striations, and misalignment angle is found to be the key factor controlling dislocation distribution and adhesion strength. The ability to control the orientation and periodicity of dislocation patterns by changing misalignment angle makes this system eminently controllable.
Adv. Funct. Mater., Jun 03, 2013, DOI: 10.1002/adfm.201203337
Ashutosh Agarwal, Yohan Farouz, Alexander Peyton Nesmith, Leila F. Deravi, Megan Laura McCain, Kevin Kit Parker
Micropatterning Alginate Substrates for In Vitro Cardiovascular Muscle on a Chip [Full Paper]
Two new techniques to create chemical and structural heterogeneities within soft alginate substrates are presented and employed to engineer anisotropic cardiac and vascular smooth muscle monolayers. These micropatterned hydrogel substrates are ideally suited for building in vitro models of muscle contractility and tissue engineering applications as they recapitulate the mechanical properties of muscle microenvironment and their anisotropic structure.
Adv. Funct. Mater., Jun 03, 2013, DOI: 10.1002/adfm.201203319
Júlia Bognár, Júlia Szűcs, Zsanett Dorkó, Viola Horváth, Róbert E. Gyurcsányi
Nanosphere Lithography as a Versatile Method to Generate Surface-Imprinted Polymer Films for Selective Protein Recognition [Full Paper]
A versatile approach based on nanosphere lithography is proposed to generate surface-imprinted polymers for selective protein recognition. Nanogravimetric measurements demonstrate that the protein (avidin) coating of the nanospheres generates selective recognition sites for avidin on the surface of the PEDOT/PSS film. This methodology coupled with oriented conjugation of the macromolecular template to the nanospheres offers the possibility of site-directed imprinting.
Adv. Funct. Mater., Jun 03, 2013, DOI: 10.1002/adfm.201300113
Kane M. O'Donnell, Mark T. Edmonds, Juergen Ristein, Anton Tadich, Lars Thomsen, Qi-Hui Wu, Chris I. Pakes, Lothar Ley
Diamond Surfaces with Air-Stable Negative Electron Affinity and Giant Electron Yield Enhancement [Full Paper]
A robust, air-stable negative electron affinity diamond surface with giant secondary electron yield enhancement is introduced. Starting with oxidized diamond (100), lithium deposition and annealing induce a structural and electronic change to a negative electron affinity surface showing electron yield enhancement greater than 200.
Adv. Funct. Mater., Jun 03, 2013, DOI: 10.1002/adfm.201301424
Gerardo Hernandez-Sosa, Nils Bornemann, Ingo Ringle, Michaela Agari, Edgar Dörsam, Norman Mechau, Uli Lemmer
Rheological and Drying Considerations for Uniformly Gravure-Printed Layers: Towards Large-Area Flexible Organic Light-Emitting Diodes [Full Paper]
The interplay between surface tension, viscosity, and drying time of organic semiconducting inks is taken into account to fabricate homogeneous active layers for organic light-emitting diodes (OLEDs) by gravure printing. The optimal formulation of the ink is identified when its properties allow a film leveling time shorter that the critical “freezing” time.
Adv. Funct. Mater., Jun 03, 2013, DOI: 10.1002/adfm.201202862
Zhen Yuan Xia, Sergio Pezzini, Emanuele Treossi, Giuliano Giambastiani, Franco Corticelli, Vittorio Morandi, Alberto Zanelli, Vittorio Bellani, Vincenzo Palermo
The Exfoliation of Graphene in Liquids by Electrochemical, Chemical, and Sonication-Assisted Techniques: A Nanoscale Study [Full Paper]
The different exfoliation routes of graphite to produce graphene by sonication in solvent, chemical oxidation, and electrochemical oxidation are compared. The results obtained show the trade-off between exfoliation speed and preservation of graphene quality. A key step to achieve efficient exfoliation is to couple gas production and mechanical exfoliation on a macroscale with non-covalent exfoliation and preservation of graphene properties on a molecular scale.
Adv. Funct. Mater., Jun 03, 2013, DOI: 10.1002/adfm.201203686
Hsing-An Lin, Shyh-Chyang Luo, Bo Zhu, Chi Chen, Yoshiro Yamashita, Hsiao-hua Yu
Molecular or Nanoscale Structures? The Deciding Factor of Surface Properties on Functionalized Poly(3,4-ethylenedioxythiophene) Nanorod Arrays [Full Paper]
Nanorod arrays of functionalized poly(3,4-ethylenedioxythiophene) (PEDOT) are assembled by using an anodic alumium oxide template directly fabricated on gold-coated silicon wafers. These nanorod arrays are promising for organic electronic and biomedical applications. This approach allows a platform to understand the molecular and nanostructural effect on the surface wettability of these materials.
Adv. Funct. Mater., Jun 03, 2013, DOI: 10.1002/adfm.201203006
Mei Feng, Lin-Bao Luo, Biao Nie, Shu-Hong Yu
p-Type Beta-Silver Vanadate Nanoribbons for Nanoelectronic Devices with Tunable Electrical Properties [Full Paper]
Two basic building blocks including nano-field-effect transistor (nano-FET) and nano-Schottky barrier diode (nano-SBD) can be constructed, indicating the great potential of β-AgVO3 nanoribbons (NRs) for their applications in nanoelectronic devices.
Adv. Funct. Mater., Jun 03, 2013, DOI: 10.1002/adfm.201300413
P. K. Johnny Wong, Elmer van Geijn, Wen Zhang, Anton A. Starikov, T. Lan Anh Tran, Johnny G. M. Sanderink, Martin H. Siekman, Geert Brocks, Paul J. Kelly, Wilfred G. van der Wiel, Michel P. de Jong
Crystalline CoFeB/Graphite Interfaces for Carbon Spintronics Fabricated by Solid Phase Epitaxy [Full Paper]
Solid phase epitaxy of the amorphous alloy CoFeB is used to fabricate crystalline ferromagnet/graphite interfaces, which are of great interest for carbon spintronics but hardly achievable with conventional thin film deposition techniques. The heterointerface features a strong body-centred-cubic (110) texture and is free from boron accumulation upon crystallization, favorable for obtaining a high spin polarization at the CoFe/graphite interface.
Adv. Funct. Mater., Jun 03, 2013, DOI: 10.1002/adfm.201203460
Eva Blasco, Milagros Piñol, Luis Oriol, Bernhard V. K. J. Schmidt, Alexander Welle, Vanessa Trouillet, Michael Bruns, Christopher Barner-Kowollik
Photochemical Generation of Light Responsive Surfaces [Full Paper]
Patterned photoswitchable surfaces are prepared by employing a nitrile imine-mediated tetrazole ene cycloaddition (NITEC) photoinduced process in the presence of dipolarophiles based on photoresponsive azobenzene moieties. Trans-to-cis azobenzene isomerization of the surface allows for the spatially resolved tuning of the surface properties.
Adv. Funct. Mater., Jun 03, 2013, DOI: 10.1002/adfm.201203602
Xiaobin Xu, Huifeng Li, Dihan Hasan, Rodney S. Ruoff, Alan X. Wang, D. L. Fan
Near-Field Enhanced Plasmonic-Magnetic Bifunctional Nanotubes for Single Cell Bioanalysis [Full Paper]
Unique near-field enhanced plasmonic-magnetic bifunctional nanotubes are fabricated and their plasmonic properties are investigated by both experimentation and theoretical modeling. By leveraging the bifunctionality, a nanotube can be precisely transported to a single living Chinese hamster ovary (CHO) cell amidst many and its membrane chemistry (lipid and protein) is revealed with surface-enhanced Raman scattering (SERS) spectroscopy.
Adv. Funct. Mater., Jun 03, 2013, DOI: 10.1002/adfm.201203822
Steven Harris Wibowo, Edgar H. H. Wong, Adrian Sulistio, Stefanie N. Guntari, Anton Blencowe, Frank Caruso, Greg G. Qiao
Assembly of Free-Standing Polypeptide Films via the Synergistic Combination of Hyperbranched Macroinitiators, the Grafting-From Approach, and Cross-Chain Termination [Communication]
Cross-linked polypeptide-based films are fabricated via a novel and robust method employing surface-initiated ring opening polymerization of α-amino acid N-carboxyanhydrides (NCA-ROP). The judicious combination of amine-based hyperbranched macroinitiators and benzyl ester-protected NCA derivatives promotes network formation by cross-chain terminations, which allows the formation of stable cross-linked peptide-based capsules in a one-pot system.
Subramanyan Namboodiri Varanakkottu, Sajan Daniel George, Tobias Baier, Steffen Hardt, Martina Ewald, Markus Biesalski
Particle Manipulation Based on Optically Controlled Free Surface Hydrodynamics [Communication]
Microparticle manipulation: The photoisomerization of surfactants adsorbed at a gas–liquid interface drives a Marangoni flow that can be used for the trapping and manipulation of small particles. By switching the laser wavelength, a flow either into or away from the focal spot can be induced. The picture shows a microparticle trapped in the focal region by the inflow.
Angew. Chem. Int. Ed., May 31, 2013, DOI: 10.1002/anie.201302111
Weiwei Gao, Che-Ming J. Hu, Ronnie H. Fang, Brian T. Luk, Jing Su, Liangfang Zhang
Surface Functionalization of Gold Nanoparticles with Red Blood Cell Membranes [Communication]
Gold nanoparticles are enclosed in cellular membranes derived from natural red blood cells (RBCs) by a top-down approach. The gold nanoparticles exhibit a complete membrane surface layer and biological characteristics of the source cells. The combination of inorganic gold nanoparticles with biological membranes is a compelling way to develop biomimetic gold nanostructures for future applications, such as those requiring evasion of the immune system.
Daan van den Ende, Jan-Dirk Kamminga, Arjen Boersma, Thomas Andritsch, Peter G. Steeneken
Voltage-Controlled Surface Wrinkling of Elastomeric Coatings [Communication]
Wrinkling of elastomeric coatings by an electric field is reported. The associated changes in the coating's optical properties yield switchable mirrors and windows. The field Ec needed to induce wrinkling is a factor of 4.4 lower than the theoretically predicted value, which is attributed to space-charge injection.
Liang Lin, Xiangdong Tian, Senlian Hong, Peng Dai, Qiancheng You, Ruyi Wang, Lianshun Feng, Can Xie, Zhong-Qun Tian, Xing Chen
A Bioorthogonal Raman Reporter Strategy for SERS Detection of Glycans on Live Cells [Communication]
Direct detection of glycans on live cells using surface-enhanced Raman scattering (SERS) has been shown. A bioorthogonal Raman reporter was directly installed onto the monosaccharide analogs. Once metabolically incorporated into cell surface glycans, the Raman reporter was detected using SERS (see picture).
Angew. Chem. Int. Ed., May 23, 2013, DOI: 10.1002/anie.201301387
Kateryna Artyushkova, Plamen Atanassov
X-Ray Photoelectron Spectroscopy for Characterization of Bionanocomposite Functional Materials for Energy-Harvesting Technologies [Minireview]
See beneath the surface! Surface analysis of biologically relevant composites leads to an improved understanding of the chemistry of nanocomposite constituents and the interactions between them (see picture).
C. K. Pandiyarajan, Oswald Prucker, Barbara Zieger, Jürgen Rühe
Influence of the Molecular Structure of Surface-Attached Poly(N-alkyl Acrylamide) Coatings on the Interaction of Surfaces with Proteins, Cells and Blood Platelets [Full Paper]
The interaction of surfaces with biological species is largely controlled through the initial adsorption of proteins. Surface-attached hydrogel coatings can suppress protein adsorption and, subsequently, cell or blood platelet adhesion. The strong swelling of theses coatings excludes proteins either via size exclusion and/or via entropic shielding.
Macromol. Biosci., May 21, 2013, DOI: 10.1002/mabi.201200445
Wei Ye, Qiang Shi, Shing-Chung Wong, Jianwen Hou, Hengchong Shi, Jinghua Yin
Patterning Surfaces for Controlled Platelet Adhesion and Detection of Dysfunctional Platelets [Communication]
A patterned surface is fabricated based on controlled surface-initiated polymerization of monomer and degradation of the obtained polymer at the UV-exposed domains on the polymer surface with UV irradiation. Switching on and off of platelet adhesion on the polymer surface is realized with a precision down to single cell level. The dysfunctional platelets can be quantitatively detected based on the adhesive pattern.
Macromol. Biosci., May 21, 2013, DOI: 10.1002/mabi.201200463
Frank Thielbeer, Emma M. V. Johansson, Sunay V. Chankeshwara, Mark Bradley
Influence of Spacer Length on the Cellular Uptake of Polymeric Nanoparticles [Communication]
The influence of varying the length of the spacer, attached to polymer nanoparticles, on the formation of a protein corona and cellular uptake are studied. Although the composition of the protein corona is not affected by different spacer lengths, an influence on cellular uptake can be identified.
Macromol. Biosci., May 21, 2013, DOI: 10.1002/mabi.201200455
Peiyu Ge, Astrid J. Olaya, Micheál D. Scanlon, Imren Hatay Patir, Heron Vrubel, Hubert H. Girault
Photoinduced Biphasic Hydrogen Evolution: Decamethylosmocene as a Light-Driven Electron Donor [Article]
A weak but productive donor: Mechanistic and kinetic insights into light-driven biphasic hydrogen evolution in the presence of the weak electron donor decamethylosmocene , which on white-light illumination produces an excited-state species that can reduce organically solubilized protons (see picture), are obtained by gas chromatographic, cyclic voltammetric, and UV/Vis and 1H NMR spectroscopic analysis.
Alfredo González-Pérez, Juan M. Ruso
A Versatile Approach towards the Compaction, Decompaction, and Immobilization of DNA at Interfaces by Using Cyclodextrins [Article]
Die another DNA: The decompaction of the DNA/hexadecyltrimethylammonium bromide (CTAB) complex is strongly influenced by the concentration of β-cyclodextrin (CD) and by the reaction temperature, owing to a subtle balance between the hydration of the complex and the lower compressibility of the native structures. Moreover, the formation of self-assembled layers of β-CD/CTAB complexes on glass or mica surfaces facilitates the immobilization of DNA, either in its coil or globule conformations (see picture).
Hiromitsu Urakami, Ali Gorkem Yilmaz, Petre Osiceanu, Yusuf Yagci, Filipe Vilela, Maria-Magdalena Titirici
Facile Polymer Functionalization of Hydrothermal-Carbonization-Derived Carbons [Communication]
Facile “graft-to” cycloaddition-mediated polymer functionalization of hydrothermal carbonization (HTC)-derived materials is carried out by use of a dienophile-functionalized polymer. Masked maleimide terminated poly(ethylene glycol) (PEG) is used as a model dienophile containing polymer to graft onto the surface of the HTC material. Analysis of PEGylated carbons (Fourier transform infrared, elemental analysis, X-ray photoelectron spectroscopy, and dispersion studies) all indicate the successful surface modification.
Macromol. Rapid Commun., May 17, 2013, DOI: 10.1002/marc.201300209
David Pastré, Vandana Joshi, Patrick A. Curmi, Loic Hamon
Detection of Single DNA Molecule Hybridization on a Surface by Atomic Force Microscopy [Full Paper]
Hybridization between complementary single-stranded DNA (ssDNA) molecules loosely adsorbed on a mica surface is achieved by fine-tuning the composition of the hybridization buffer. The detection of single-molecule DNA hybridization events is performed by measuring the contour length of DNA in atomic force microscopy images.
Irem Kosif, Mengmeng Cui, Thomas P. Russell, Todd Emrick
Triggered In situ Disruption and Inversion of Nanoparticle-Stabilized Droplets [Communication]
Emulsion inversion, from water-in-oil (w/o) to oil-in-water (o/w), was accomplished by employing tetrahydropyran-containing ligands that undergo facile deprotection, converting the nanoparticles from hydrophobic to hydrophilic. These ligand-tailored nanoparticles were used to prepare w/o emulsions that were disrupted, and inverted, to o/w systems simply by lowering the solution pH. The inversion process could be triggered by light using a photoacid generator.
Angew. Chem. Int. Ed., May 13, 2013, DOI: 10.1002/anie.201302112
Sudarshan Kundu, Myong-Hoon Lee, Seung Hee Lee, Shin-Woong Kang
In Situ Homeotropic Alignment of Nematic Liquid Crystals Based on Photoisomerization of Azo-Dye, Physical Adsorption of Aggregates, and Consequent Topographical Modification [Communication]
In situ homeotropic alignment is achieved by photochromic trans- to cis-isomerization of an azo-dye doped in a nematic host. The augmented dipole moment of the cis-isomer formed under UV-irradiation expedites molecular assembly into crystalline aggregates. Subsequent deposition of the aggregates creates a roughened surface and induces an anchoring transition from the initial planar to a homeotropic alignment of the LCs.
Ruisheng Guo, You Yu, Zhuang Xie, Xuqing Liu, Xuechang Zhou, Yufan Gao, Zhilu Liu, Feng Zhou, Yong Yang, Zijian Zheng
Matrix-Assisted Catalytic Printing for the Fabrication of Multiscale, Flexible, Foldable, and Stretchable Metal Conductors [Communication]
Matrix-assisted catalytic printing (MACP) is developed as a low-cost and versatile printing method for the fabrication of multiscale metal conductors on a wide variety of plastic, elastomeric, and textile substrates. Highly conductive Cu interconnects (2.0 × 108 S/m) fabricated by MACP at room temperature display excellent flexibility, foldability, and stretchability.
Kurt W. Kolasinski, William B. Barclay
The Stoichiometry of Electroless Silicon Etching in Solutions of V2O5 and HF [Communication]
Performance by an oxidant in a leading role: In the electroless etching of silicon to form nanocrystalline porous-silicon thin films, the oxidant extracts one electron from the silicon valence band to initiate etching and then a second from the conduction band to suppress H2 formation. This discovery overturns the conventional wisdom regarding the role of the oxidant in stain etching, the stoichiometry of which was derived from the UV/Vis spectra shown.
Angew. Chem. Int. Ed., May 10, 2013, DOI: 10.1002/anie.201300755
Lequan Liu, Shuxin Ouyang, Jinhua Ye
Gold-Nanorod-Photosensitized Titanium Dioxide with Wide-Range Visible-Light Harvesting Based on Localized Surface Plasmon Resonance [Communication]
Broadband visible-light harvesting over TiO2 is achieved by introducing gold nanorods (Au NRs) as antennas based on localized surface plasmon resonance. Furthermore, surfactant removal is achieved by an HClO4 oxidative method. Not only transversal but also longitudinal plasma of Au NRs can induce photooxidation of 2-propanol, which extends the light harvesting to the near-infrared region. Scale bar: 10 nm.
Angew. Chem. Int. Ed., May 10, 2013, DOI: 10.1002/anie.201300239
Callie Fairman, Joshua Z. Ginges, Stuart B. Lowe, J. Justin Gooding
Protein Resistance of Surfaces Modified with Oligo(Ethylene Glycol) Aryl Diazonium Derivatives [Article]
Surface modification for protein resistance: Oligo(ethylene glycol) aryl diazonium derivatives electrochemically deposited on carbon and gold surfaces reduce non-specific protein adsorption (see picture). The influence of ligand length, distal end group, and ligand packing density on protein resistance is investigated. This approach could be used to produce stable antifouling layers for electrochemical biosensors.
Omar F. Zouani, Yifeng Lei, Marie-Christine Durrieu
Pericytes, Stem-Cell-Like Cells, but not Mesenchymal Stem Cells are Recruited to Support Microvascular Tube Stabilization [Communication]
An experimental model is introduced for the induction of endothelial cell (EC) tubulogenesis after 24 h of incubation on micropatterned polymer surfaces. Pericytes or mesenchymal stem cells are added separately to this system to evaluate their effect on tubular stabilization. In the absence of additional cells, the tubular structures are lost after 36 h. Addition of only pericytes, however, stabilizes the EC vasculogenic tubes.
Benjamin P. Brown, Loren Picco, Mervyn J. Miles, Charl F. J. Faul
Opportunities in High-Speed Atomic Force Microscopy [Review]
Developments in instrumentation for “high-speed AFM” (HSAFM) have been ongoing since the 1990s, and now nanometer resolution imaging and lithography at video rate is readily achievable. This review provides a summary of different approaches to and advances in the development of high-speed AFMs, highlights important discoveries made with new instruments, and discusses new possibilities for HSAFM in materials science.
Jung-Bum Kim, Jeong-Hwan Lee, Chang-Ki Moon, Sei-Yong Kim, Jang-Joo Kim
Highly Enhanced Light Extraction from Surface Plasmonic Loss Minimized Organic Light-Emitting Diodes [Communication]
Extremely high light out-coupling efficiency from a transparent organic light-emitting diode integrated with microstructures on both sides of the device is reported. The metal free device offers dramatically reduced surface plasmonic and intrinsic absorption losses. Moreover, high refractive index micro patterns with optimal light extraction condition are fabricated based on the well matched analysis of optical simulations.
Qian Liu, Li Jiang, Lin Guo
Precursor-Directed Self-Assembly of Porous ZnO Nanosheets as High-Performance Surface-Enhanced Raman Scattering Substrate [Communication]
Self-assembly of ZnO porous nanosheets with novel parallelogram morphology and high specific surface area is achieved by a one-pot alkalization reaction. The growth mechanism relies on the dual roles of the precursor: providing the building blocks and the assembling template concurrently. This porous structure with active surface defects serves as a high-performance semiconductor substrate for surface-enhanced Raman scattering (SERS).
Xiaoming Chen, Meng Zheng, Cheol Park, Changhong Ke
Direct Measurements of the Mechanical Strength of Carbon Nanotube–Poly(methyl methacrylate) Interfaces [Full Paper]
The interfacial strength between individual double-walled carbon nanotubes and poly(methyl methacrylate) is characterized using an in situ nanomechanical single-tube pull-out testing scheme inside a high-resolution electron microscope. These measurements reveal the shear lag effect on the nanotube–polymer interface and demonstrate that the effective interfacial load transfer occurs only within a certain embedded length.
Leo T. Varghese, Li Fan, Yi Xuan, Chookiat Tansarawiput, Sangsik Kim, Minghao Qi
Resistless Nanoimprinting in Metal for Plasmonic Nanostructures [Full Paper]
Direct imprinting of metal films by silicon molds without the need of resists or any intermediate layers is demonstrated using pressures of <4 MPa and temperatures of 25–150 °C. Three-dimensional metal structures with smooth and vertical sidewalls, down to sub-10 nm resolution, are generated in silver and gold films. Large-scale vivid images through extraordinary optical transmission and strong surface-enhanced Raman scattering substrates are realized quickly, repeatedly, and at a low-cost.
Charles Esnault, Nicolas Delorme, Guy Louarn, Jean-François Pilard
One-Pot in Situ Mixed Film Formation by Azo Coupling and Diazonium Salt Electrografting [Communication]
So simple: The in situ synthesis of an aryldiazonium salt and an azo-aryldiazonium salt by azo coupling from sulfanilic acid and aniline is reported. Formation of a mixed organic layer is monitored by cyclic voltammetry and atomic force microscopy. A compact mixed layer is obtained with a global roughness of 0.4 nm and 10–15 % vertical extension in the range 1.5–6 nm.
Adi Salomon, Shaojun Wang, James A. Hutchison, Cyriaque Genet, Thomas W. Ebbesen
Strong Light-Molecule Coupling on Plasmonic Arrays of Different Symmetry [Article]
The strong coupling of porphyrin J-aggregates to plasmonic nanostructures of different symmetry is investigated. The nanostructures of higher symmetry show the strongest interaction with the molecular layer. At high coupling strengths a new, weakly dispersive mode appears. These findings point to new ways for optimizing strong coupling and thereby realize its full potential for molecular and material science.
Waldemir Moura Carvalho, Jr. Diogo Volpati, Vitor A. Nunes Carvalho, Ricardo F. Aroca, Carlos J. L. Constantino, Flavio L. Souza
Large-Area Plasmonic Substrate of Silver-Coated Iron Oxide Nanorod Arrays for Plasmon-Enhanced Spectroscopy [Article]
Stand up straight! Vertically oriented α-Fe2O3 nanorod arrays are synthesized under hydrothermal conditions over a large area, as an active platform for surface-enhanced resonance Raman scattering (SERRS) and surface-enhanced fluorescence (SEF, see picture; LB=Langmuir–Blodgett layer of probe molecule). The morphology of the arrays is preserved after the surface is covered with a 6 nm Ag layer deposited by physical vapor deposition (PVD).
Xunda Feng, Ahmed Mourran, Martin Möller, Christian Bahr
AFM Study of Gibbs Films of Semifluorinated Alkanes at Liquid Crystal/Air Interfaces [Communication]
Forming micelles: The first in situ AFM study of Gibbs films of semifluorinated alkanes at liquid crystal/air interfaces is presented. The Gibbs films self-organize in a hexagonal close packing of surface micelles with shapes and lateral dimensions that are similar to micelles forming on aqueous and solid surfaces. It is concluded that he formation of surfaces micelles and their self-organization in large-area dense hexagonal arrays are intrinsic properties of semifluorinated alkane molecules.
Dong Lai Guo, Li Huey Tan, Zhi Peng Wei, Hongyu Chen, Tom Wu
Density-Controlled Synthesis of Uniform ZnO Nanowires: Wide-Range Tunability and Growth Regime Transition [Communication]
Jin-Hua Luo, Yun-Hong Zhang, Ze-Sheng Li
Adsorption of Water on an MgSO4(100) Surface: A First-Principles Investigation [Article]
Surface factors: The adsorption properties of water molecules on an MgSO4(100) surface are studied by using density functional theory (see picture). The configurations of water molecules adsorbed on atoms of the second and third atomic layers of MgSO4(100) are quite stable. In addition, water molecules preferentially adsorb onto a defective surface.
Hee Jin Jeong, Hae Deuk Jeong, Ho Young Kim, Seung Yol Jeong, Joong Tark Han, Geon-Woong Lee
Self-Organized Graphene Nanosheets with Corrugated, Ordered Tip Structures for High-Performance Flexible Field Emission [Full Paper]
Self-organized graphene nanosheets with corrugated, ordered tip structures ae fabricated by a straightforward self-assembly method. The size, uniformity of the arrays, and alignment of tips are successfully controlled by the viscosity of the graphene oxide/octadecylamine solution. The vertically aligned tip structures of graphene thin films fabricated on polymeric substrate show excellent field emission characteristics upon bending.
Maria Alba, Nicolas Pazos-Perez, Belén Vaz, Pilar Formentin, Moritz Tebbe, Miguel A. Correa-Duarte, Pedro Granero, Josep Ferré-Borrull, Rosana Alvarez, Josep Pallares, Andreas Fery, Angel R. de Lera, Lluis F. Marsal, Ramón A. Alvarez-Puebla
Macroscale Plasmonic Substrates for Highly Sensitive Surface-Enhanced Raman Scattering [Communication]
Modern-day wonders of the world: Nanostructured films of plasmonic pyramid arrays (see picture) were prepared by the simple stamping of preformed homogeneous nanocolloids. These materials show very high efficiency as optical enhancers and can be exploited for the design of quantitative, cheap, portable, and ultrasensitive optical sensors with excellent reversibility.
Phuc Nghia Nguyen, Gilles Waton, Thierry Vandamme, Marie Pierre Krafft
Behavior of an Adsorbed Phospholipid Monolayer Submitted to Prolonged Periodical Surface Density Variations [Communication]
Prolonged periodical variations of the surface density of a film of phospholipids adsorbed on the surface of an air bubble and in contact with a dispersion of phospholipid vesicles (orange) lead to accelerated phospholipid adsorption and lowering of the interfacial tension. The phenomenon is assigned to a coupling between the periodical variation of the surface density of the phospholipid at the interface and its dilute-to-condensed (LE-to-LC) phase transition.
Silvia Piperno, Elena Mirzadeh, Eran Mishuk, David Ehre, Sidney Cohen, Miriam Eisenstein, Meir Lahav, Igor Lubomirsky
Water-Induced Pyroelectricity from Nonpolar Crystals of Amino Acids [Communication]
Surface pyroelectricity: Centrosymmetric crystals of α-glycine display an anomalous quadrupole-like pyroelectric current. This observation implies the formation of water–glycine hybrid polar layers at the (010) faces of the α-glycine crystals (see picture).
Bizan N. Balzer, Markus Gallei, Moritz V. Hauf, Markus Stallhofer, Lorenz Wiegleb, Alexander Holleitner, Matthias Rehahn, Thorsten Hugel
Nanoscale Friction Mechanisms at Solid–Liquid Interfaces [Communication]
There's the rub: Friction of single polymers on solid bodies in a liquid environment was investigated. Apart from expected mechanisms, such as slip and stick, a third nanoscale friction mechanism exists that is independent of normal force, velocity, and adsorbed polymer length. A model is proposed for this mechanism that is based on measurements with various polymers on topographically and chemically nanostructured surfaces.
Danqing Liu, Xiaomin Xu, Yaorong Su, Zikai He, Jianbin Xu, Qian Miao
Self-Assembled Monolayers of Phosphonic Acids with Enhanced Surface Energy for High-Performance Solution-Processed N-Channel Organic Thin-Film Transistors [Communication]
Add an O: A new strategy for preparing solution-processed organic thin-film transistors (OTFTs) is based on enhancing the surface energy of self-assembled monolayers (SAMs) by inserting polar oxygen atoms into the long alkyl chain of phosphonic acids. SAMs of these phosphonic acids on a high-k metal oxide layer lead to solution-processed n-channel OTFTs with average field effect mobilities of up to 2.5 cm2 V−1 s−1 and low operational voltages.
Xinnan Wang, Yuyang Wang, Ming Cong, Haibo Li, Yuejiao Gu, John R. Lombardi, Shuping Xu, Weiqing Xu
Propagating and Localized Surface Plasmons in Hierarchical Metallic Structures for Surface-Enhanced Raman Scattering [Communication]
A highly ordered hierarchical periodic structure with large area is fabricated to support surface plasmon (SP) and surface-enhanced Raman scattering (SERS). This novel metallic submicro-nano structure exhibits a complex honeycomb-like geometry, which is confirmed in experiments to support both PSPs and LSPs. Multiple modes of SPs are expected to have co-enhanced Raman scattering, heralding the development of more sophisticated hybrid surface plasmonic nanodevices.
Yi Zhang, Tza-Huei Wang
Full-Range Magnetic Manipulation of Droplets via Surface Energy Traps Enables Complex Bioassays [Communication]
Manipulating droplets on an open surface promises an easier, more flexible, and more scalable platform of liquid control, than does microchannel-based fluidics. In this report, a surface-energy-trap-enabled magnetic droplet handling platform is introduced that is capable of comprehensive droplet manipulations, including droplet dispensing, transport, fusion, and particle extraction.
Aditya Savara, Wiebke Ludwig, Swetlana Schauermann
Kinetic Evidence for a Non-Langmuir-Hinshelwood Surface Reaction: H/D Exchange over Pd Nanoparticles and Pd(111) [Article]
Tell me how: The mechanism of hydrogen recombination on a Pd(111) single crystal and well-defined Pd nanoparticles is studied using pulsed multi-molecular beam techniques and the H2/D2 isotope exchange reaction. It is found that various kinetic models are required to account for the observed phenomena.
Hyungki Kim, Yoonkook Son, Chibeom Park, Jaephil Cho, Hee Cheul Choi
Catalyst-free Direct Growth of a Single to a Few Layers of Graphene on a Germanium Nanowire for the Anode Material of a Lithium Battery [Communication]
Direct growth of a single to a few layers of graphene on a germanium nanowire (Gr/Ge NW; see picture) was achieved by a metal-catalyst-free chemical vapor deposition (CVD) process. The Gr/Ge NW was used as anode in a lithium ion battery. This material has a specific capacity of 1059 mA h g−1 at 4.0 C, a long cycle life over 200 cycles, and a high capacity retention of 90 %.
Hong Xu, Elke Ghijsens, Subi J. George, Martin Wolffs, Željko Tomović, Albertus P. H. J. Schenning, Steven De Feyter
Chiral Induction and Amplification in Supramolecular Systems at the Liquid–Solid Interface [Article]
Sir, yes sir! Chiral induction and amplification in surface-confined supramolecular monolayers are investigated at the liquid–solid interface. Scanning tunneling microscopy proves that achiral molecules can self-assemble into globally chiral patterns through induction by chiral solvents or by a novel chiral amplification method.
Valdis Corradini, Alberto Ghirri, Andrea Candini, Roberto Biagi, Umberto del Pennino, Gianluca Dotti, Edwige Otero, Fadi Choueikani, Robin J. Blagg, Eric J. L. McInnes, Marco Affronte
Magnetic Cooling at a Single Molecule Level: a Spectroscopic Investigation of Isolated Molecules on a Surface [Communication]
A sub-monolayer distribution of isolated molecular Fe14(bta)6 nanomagnets is deposited intact on a Au(111) surface and investigated by X-ray magnetic circular dichroism spectroscopy. The entropy variation with respect to the applied magnetic field is extracted from the magnetization curves and evidences high magnetocaloric values at the single molecule level.
Yong Jun Li, Yongli Yan, Chuang Zhang, Yong Sheng Zhao, Jiannian Yao
Embedded Branch-Like Organic/Metal Nanowire Heterostructures: Liquid-Phase Synthesis, Efficient Photon-Plasmon Coupling, and Optical Signal Manipulation [Communication]
A novel approach to manipulating multiple optical signals at subwavelength scale is proposed in dendritic organic/metal nanowire heterostructures. The heterostructures are prepared by embedding Ag nanowires in fac-tris(2-phenylpyridine) iridium microwires during the self-assembly in liquid phase. Optical signals inputted from the organic waveguide can be selectively transferred to the predetermined subwavelength output ports based on the angular dependence of the photon-plasmon coupling.
Peter Sutter, Eli Sutter
Microscopy of Graphene Growth, Processing, and Properties [Feature Article]
Real-time surface microscopy and in situ spectroscopy can provide unique insight into graphene and other 2D materials on metal substrates. The power of in situ microscopy in realizing and probing important functionalities in 2D materials is illustrated by reviewing recent progress in understanding scalable graphene growth on metals, processing by selective chemistry at the graphene/metal interface, and important properties such as band structure, work function, etc.
Shu-Feng Hsieh, Dhimiter Bello, Daniel F. Schmidt, Anoop K. Pal, Aaron Stella, Jacqueline A. Isaacs, Eugene J. Rogers
Mapping the Biological Oxidative Damage of Engineered Nanomaterials [Full Paper]
Hyungsoon Im, Kyle C. Bantz, Si Hoon Lee, Timothy W. Johnson, Christy L. Haynes, Sang-Hyun Oh
Self-Assembled Plasmonic Nanoring Cavity Arrays for SERS and LSPR Biosensing [Communication]
Self-assembled plasmonic nanoring cavity arrays are formed alongside the curvature of highly packed metallic nanosphere gratings. The sub-10-nm gap size is precisely tuned via atomic layer deposition and highly ordered arrays are produced over a cm-sized area. The resulting hybrid nanostructure boosts coupling efficiency of light into plasmons, and shows an improved SERS detection limit. These substrates are used for SERS detection of the biological analyte, adenine, followed by concurrent localized surface plasmon resonance sensing.
Jia Huo, Marco Marcello, Ashesh Garai, Darren Bradshaw
MOF-Polymer Composite Microcapsules Derived from Pickering Emulsions [Communication]
Hollow composite microcapsules are prepared by the assembly of pre-formed nanocrystals of metal-organic frameworks (MOFs) around emulsion droplets, followed by interfacial polymerisation of the interior. The micropores of the MOF crystals embedded within a semipermeable hierarchically structured polymeric membrane are an effective combination for the retention of encapsulated dye molecules. Release can be triggered however by acid dissolution of the MOF component.
Guizhi Zhu, Shengfeng Zhang, Erqun Song, Jing Zheng, Rong Hu, Xiaohong Fang, Weihong Tan
Building Fluorescent DNA Nanodevices on Target Living Cell Surfaces [Communication]
DNA nanotrain: Anchoring of preformed fluorescent DNA nanodevices (NDs; see picture) and in situ self-assembly of fluorescent DNA NDs on target living cell surfaces are reported. The in situ self-assembly of the nanodevice was further shown on surfaces of living cells in cell mixtures. These DNA NDs exhibited fluorescence emission and underwent fluorescence resonance energy transfer (FRET) on living cell surfaces.
Sebastian Böcklein, Sebastian Günther, Joost Wintterlin
High-Pressure Scanning Tunneling Microscopy of a Silver Surface during Catalytic Formation of Ethylene Oxide [Communication]
The active state of a catalyst: A high-pressure scanning tunneling microscope (STM) was used to bridge the pressure gap for the Ag-catalyzed ethylene epoxidation. An active oxygen species on an Ag(111) single crystal was characterized under ultrahigh vacuum conditions. The same species was identified with STM in an ethylene/oxygen mixture (see picture). In the STM cell the formation of ethylene oxide was detected.
Ventsislav K. Valev, Jeremy J. Baumberg, Concita Sibilia, Thierry Verbiest
Chirality and Chiroptical Effects in Plasmonic Nanostructures: Fundamentals, Recent Progress, and Outlook [Progress Report]
Due to the recent development of bottom-up and top-down approaches for material design and fabrication at the nanoscale, giant chiroptical effects have been reported from plasmonic nanostructures. These effects are exhibited both in the linear and in the nonlinear optical regimes and are sensitive to the chirality of nanostructures, the chirality of the experiments and the chirality of light itself.
Yun Hao Lu, Hongmei Jin, Hongjun Zhu, Shuo-Wang Yang, Chun Zhang, Jian Zhong Jiang, Yuan Ping Feng
A Possible Reaction Pathway to Fabricate a Half-Metallic Wire on a Silicon Surface [Full Paper]
A possible way to fabricate a half-metallic sandwich molecular wire on a silicon surface is proposed using first-principle calculations. The magnetic state of this molecular wire is sensitive to the electric field and can be changed between two states. The hybrid system has very promising application in emerging molecular electronic or spintronic devices.
Graeme Williams, Qi Wang, Hany Aziz
The Photo-Stability of Polymer Solar Cells: Contact Photo-Degradation and the Benefits of Interfacial Layers [Full Paper]
Exposure of organic solar cells (OSCs) to light results in degradation in all OSC parameters, even in inert environments. The use of electron extraction layers (EELs) in between the organic layer and an Al layer can largely suppress contact photo-degradation and enhance OSC photo-stability. Lithium acetylacetonate, as a new EEL material, provides efficiency improvement on par with the ubiquitous LiF, but with some additional stability improvement.
Gernot Füchsel, Jean Christophe Tremblay, Tillmann Klamroth, Peter Saalfrank
Quantum Dynamical Simulations of the Femtosecond-Laser-Induced Ultrafast Desorption of H2 and D2 from Ru(0001) [Article]
Las-ing around: Quantum mechanical desorption induced by electronic transition simulations in 3D is reported to describe the recombinative desorption of H2 and D2 from Ru(0001) produced by low-intensity laser fields. The experimental trends at low laser fluences are well reproduced for the isotopic ratio and the translational and rotational energies. A single temperature is sufficient to characterize the energy distributions for all degrees of freedom.
James A. Hutchison, Andrea Liscio, Tal Schwartz, Antoine Canaguier-Durand, Cyriaque Genet, Vincenzo Palermo, Paolo Samorì, Thomas W. Ebbesen
Tuning the Work-Function Via Strong Coupling [Communication]
The tuning of the molecular material work-function via strong coupling with vacuum electromagnetic fields is demonstrated. Kelvin probe microscopy extracts the surface potential (SP) changes of a photochromic molecular film on plasmonic hole arrays and inside Fabry-Perot cavities. Modulating the optical cavity resonance or the photochromic film effectively tunes the work-function, suggesting a new tool for tailoring material properties.
Sungsook Ahn, Sung Yong Jung, Sang Joon Lee
Surface-Activated Nanoparticles for Controlled Light-Responsiveness [Full Paper]
Surface properties of functionalized nanoparticle (NPs) under different solvent conditions are modified by electron beam treatment. The specific surface layer (proximity length) of the NPs is activated, which modifies the NPs' light-responsiveness. For example, amine-functionalized NPs activated by the electron beam, exhibit UV-vis absorbance at the lower wavelength than that those without electron beam treatment. This NP activation technology is advantageous for effective light energy use.
Kumudu Mudiyanselage, Sanjaya D. Senanayake, Leticia Feria, Shankhamala Kundu, Ashleigh E. Baber, Jesús Graciani, Alba B. Vidal, Stefano Agnoli, Jaime Evans, Rui Chang, Stephanus Axnanda, Zhi Liu, Javier F. Sanz, Ping Liu, José A. Rodriguez, Darío J. Stacchiola
Importance of the Metal–Oxide Interface in Catalysis: In Situ Studies of the Water–Gas Shift Reaction by Ambient-Pressure X-ray Photoelectron Spectroscopy [Communication]
Where oxide and metals meet: The activation of an efficient associative mechanistic pathway for the water–gas shift reaction by an oxide–metal interface leads to an increase in the catalytic activity of nanoparticles of ceria deposited on Cu(111) or Au(111) by more than an order of magnitude (see graph). In situ experiments demonstrated that a carboxy species formed at the metal–oxide interface is the critical intermediate in the reaction.
Barbara A. J. Lechner, Holly Hedgeland, John Ellis, William Allison, Marco Sacchi, Stephen J. Jenkins, B. J. Hinch
Quantum Influences in the Diffusive Motion of Pyrrole on Cu(111) [Communication]
Classical diffusion—quantum barrier: On Cu(111), pyrrole diffuses in channels, hopping between adjacent bridge sites over a barrier above hollow sites. The motion of the center of mass can be described classically; however, the activation barrier arises from the quantum character of internal vibrational modes that are largely unexcited during the motion. The unique helium spin-echo experiment is indicated by the green sphere and arrows.
Heng Cao, Guoqiang Lin, Jinrong Yao, Zhengzhong Shao
Amphiphilic Polypeptides as a Bifunctional Template in the Mineralization of Calcium Carbonate at the Air/Water Interface [Full Paper]
A well-defined amphiphilic polypeptide, poly(glutamic acid)22-block-poly(alanine)8 (PGlu22-b-PAla8) is taken as organic additive to mediate the mineralization of CaCO3. Asymmetrical calcite particles with various shapes are obtained at the air/water interface and PGlu22-b-PAla8 acts as a bifunctional template in the mineralization process according to time-dependent observations.
Erhan Bat, Theo G. van Kooten, Martin C. Harmsen, Josée A. Plantinga, Marja J. A. van Luyn, Jan Feijen, Dirk W. Grijpma
Physical Properties and Erosion Behavior of Poly(trimethylene carbonate-co-ε-caprolactone) Networks [Full Paper]
Resorbable poly(trimethylene carbonate-co-ε-caprolactone) networks with a wide composition range are prepared by γ-irradiation of the corresponding linear polymers. It is shown that the network composition has a large effect on the mechanical properties as well as on the erosion behavior. These biocompatible networks are suitable for a variety of applications in medicine such as in drug delivery and tissue engineering.
Yaming Yu, Björn Heidel, Tamara Lourdes Parapugna, Sabine Wenderhold-Reeb, Bo Song, Holger Schönherr, Martin Grininger, Gilbert Nöll
The Flavoprotein Dodecin as a Redox Probe for Electron Transfer through DNA [Communication]
Flavin away: Dodecin binds oxidized flavins, whereas reduction of the bound flavin induces dissociation of the holoprotein into apododecin and free flavins. The stepwise reconstitution of dodecin on flavin-terminated ds-DNA monolayers showed that although electrochemical flavin reduction (i.e. electron transfer through DNA) was not possible, apododecin (gray circles) could be released by chemical reduction (see scheme).
Silke Gandor, Stephanie Reisewitz, Muthukumaran Venkatachalapathy, Giuseppe Arrabito, Martina Reibner, Hendrik Schröder, Katharina Ruf, Christof M. Niemeyer, Philippe I. H. Bastiaens, Leif Dehmelt
A Protein-Interaction Array Inside a Living Cell [Communication]
Taking the bait: Protein-interaction arrays were generated in living cells by the interaction of bait-presenting artificial receptor constructs (bait-PARCs) with micrometer-scaled antibody surface patterns (see figure). This method was applied to simultaneously monitor the interaction kinetics of a prey protein with two distinct bait proteins in individual living cells.
Tiffani M. Burt, Alex M. Jordan, LaShanda T. J. Korley
Investigating Interfacial Contributions on the Layer-Thickness-Dependent Mechanical Response of Confined Self-Assembly via Forced Assembly [Full Paper]
M. Salluzzo, S. Gariglio, X. Torrelles, Z. Ristic, R. Di Capua, J. Drnec, M. Moretti Sala, G. Ghiringhelli, R. Felici, N. B. Brookes
Structural and Electronic Reconstructions at the LaAlO3/SrTiO3 Interface [Communication]
A full understanding of the mechanism of the formation of a two-dimensional electron gas (2DEG) at the interface between insulating LaAlO3 (LAO) thin films and bulk SrTiO3 (STO) crystals is a prerequisite for the full exploitation of this class of materials. Here, by using a combination of advanced X-ray synchrotron-based spectroscopic and structural measurements, it is shown that a structural and electronic reconstruction of the interface occurs before the realization of the 2DEG.
Libo Ma, Shilong Li, Vladimir A. Bolaños Quiñones, Lichun Yang, Wang Xi, Matthew Jorgensen, Stefan Baunack, Yongfeng Mei, Suwit Kiravittaya, Oliver G. Schmidt
Dynamic Molecular Processes Detected by Microtubular Opto-chemical Sensors Self-Assembled from Prestrained Nanomembranes [Communication]
Opto-chemical sensors are prepared by self-assembly of SiO/SiO2 nanomembranes into microtube structures. Dynamic molecular processes of H2O and C2H5OH are detected on the surface of sub-wavelength-thin nanomembranes. Based on the perturbation theory, quantitative information of molecule layer changes is acquired. The nanomembrane-based molecular-sensing ability constitutes a versatile platform for the detection of diverse surface phenomena in a label-free fashion.
Min He, Qiaolan Zhang, Xiping Zeng, Dapeng Cui, Jing Chen, Huiling Li, Jianjun Wang, Yanlin Song
Hierarchical Porous Surface for Efficiently Controlling Microdroplets' Self-Removal [Communication]
Superhydrophobic porous surfaces with hydrophilic polymers adsorbed in pores are designed to control the coalescing behavior of microdroplets as well as their quick self-removal. The combination of chemical composition and surface structure are greatly important in the design of new materials for heat exchange, antifogging, and anti-icing.
Ville Liimatainen, Veikko Sariola, Quan Zhou
Controlling Liquid Spreading Using Microfabricated Undercut Edges [Communication]
A purely topographical method for controlling liquid spreading by using easy-to-fabricate undercut edges is reported. By periodic repetition of such edges, it is shown that multiple droplets can be patterned in well-controlled shapes, and highly anisotropic wetting can also be achieved at a large scale. Apparent contact angles close to 180° at the edge are shown, even for low surface tension liquids.
Weigao Xu, Nannan Mao, Jin Zhang
Graphene: A Platform for Surface-Enhanced Raman Spectroscopy [Review]
Graphene is a unique platform for surface-enhanced Raman spectroscopy (SERS). The multi-role of graphene played in SERS is overviewed, including as a Raman probe, as a substrate, as an additive, and as a building block of a flat surface for SERS. Apart from versatile improvements on SERS performance towards applications, graphene-involved SERS studies are also expected to shed light on the fundamental mechanism of the SERS effect.
Xiaoxia Yang, Zixuan Guan, Min Zeng, Jiake Wei, Wenlong Wang, Xuedong Bai
Facile Synthesis of Large-Area Ultrathin Hexagonal BN Films via Self-Limiting Growth at the Molten B2O3 Surface [Communication]
A self-limiting growth process based on the interface-controlled reaction of molten boron oxide (B2O3) with ammonia (NH3) is demonstrated for the facile and lost-cost synthesis of ultrathin (20–30 nm) crystalline hexagonal boron nitride (h-BN) films over large areas. The as-grown h-BN films are of high quality, being densely continuous, uniform and smooth, and highly transparent over a broad wavelength range.
Christian Wäckerlin, Kartick Tarafder, Jan Girovsky, Jan Nowakowski, Tatjana Hählen, Aneliia Shchyrba, Dorota Siewert, Armin Kleibert, Frithjof Nolting, Peter M. Oppeneer, Thomas A. Jung, Nirmalya Ballav
Ammonia Coordination Introducing a Magnetic Moment in an On-Surface Low-Spin Porphyrin [Communication]
Amazing ammonia: The molecular spin state of NiII porphyrin, supported on a ferromagnetic Co surface, can be reversibly switched between spin-off (S=0) and spin-on (S=1) states upon coordination and decoordination of the gaseous ligand NH3, respectively (see picture). This finding clearly indicates the possible use of the system as a single-molecule-based magnetochemical sensor and in spintronics.
Stefanie A. Sydlik, Timothy M. Swager
Functional Graphenic Materials Via a Johnson−Claisen Rearrangement [Full Paper]
The hydroxyl functionalities in graphene oxide (GO) are subjected to Johnson−Claisen rearrangement conditions, which trades the labile CO bond for a robust CC bond. Further functionalization allows for the synthesis of highly charged, water-soluble graphene. The negatively and positively charged graphenes (zeta potentials of –75 mV and +56 mV), are successfully used to build layer-by-layer (LBL) constructs.
Scott A. Mauger, Lilian Chang, Stephan Friedrich, Christopher W. Rochester, David M. Huang, Peng Wang, Adam J. Moulé
Self-Assembly of Selective Interfaces in Organic Photovoltaics [Full Paper]
It is shown that the metal capping electrode in an organic photovoltaic device affects the stratification of materials in the bulk heterojunction (BHJ) and that solvent additives can inhibit stratification. It is found that some metals can donate charge to (6,6)-phenyl-C61-butyric acid methyl ester (PCBM). The enrichment and charging of PCBM at the interface with the metal increases device power conversion efficiency.
Alice Pranzetti, Sophie Mieszkin, Parvez Iqbal, Frankie J. Rawson, Maureen E. Callow, James A. Callow, Patrick Koelsch, Jon A. Preece, Paula M. Mendes
An Electrically Reversible Switchable Surface to Control and Study Early Bacterial Adhesion Dynamics in Real-Time [Communication]
Bacterial adhesion can be controlled by applying electrical potentials to surfaces incorporating well-spaced negatively charged 11-mercaptoundecanoic acids. When combined with electrochemical surface plasmon resonance, these dynamic surfaces become powerful for monitoring and analysing the passage between reversible and non-reversible cell adhesion, opening new opportunities to advance our understanding of cell adhesion processes.
Christopher Bronner, Stephan Stremlau, Marie Gille, Felix Brauße, Anton Haase, Stefan Hecht, Petra Tegeder
Aligning the Band Gap of Graphene Nanoribbons by Monomer Doping [Communication]
A matter of doping: Graphene nanoribbons (GNRs) were generated through an on-surface bottom-up synthesis and selectively doped at their edges by introducing nitrogen atoms in the precursor monomers. While the size of the band gap of 2.8 eV remains almost unchanged upon N substitution, a linear shift of the band structure is observed and corresponds to n-type doping (see picture; CB=conduction band and VB=valence band).
Andrea Liscio
Scanning Probe Microscopy beyond Imaging: A General Tool for Quantitative Analysis [Article]
Precise estimates of properties such as surface roughness, height, electrical characteristics and surface potential are obtained from scanning probe microscopy images by means of a quantitative approach based on histogram analysis (see picture).
Solji Kim, Lilin Piao, Donghoon Han, Beom Jin Kim, Taek Dong Chung
Surface Enhanced Raman Scattering on Non-SERS Active Substrates and In Situ Electrochemical Study based on a Single Gold Microshell [Communication]
A single gold microshell, which was elaborately fabricated to carry numerous hot spots on its own surface, enabled the acquisition of the SERS spectra from the molecules on non-SERS active substrates such as Si/SiO2, ITO, and glass. A self-assembled monolayer of 11-mercaptoundecanols on the gold microshell offered an easy and reliable way to electrically insulate from the underlying flat Pt electrode and accomplish in situ monitoring the electrochemical reaction with minimal interference.
R. Sachan, V. Ramos, A. Malasi, S. Yadavali, B. Bartley, H. Garcia, G. Duscher, R. Kalyanaraman
Oxidation-Resistant Silver Nanostructures for Ultrastable Plasmonic Applications [Communication]
Reduced degradation (oxidation) of silver nanoparticles (NPs) is achieved by contacting Ag with immiscible Co NPs. The relative decay of the plasmon peak (plot) shows that pure Ag NPs (blue dashed curve) decay by 25% in ca 20 days, whereas AgCo NPs last about 10 times longer, requiring nearly five months for a similar decay (red solid curve). The TEM images for both Ag and AgCo were taken after 50 days of storage under ambient conditions.
Kyuwan Lee, Joseph Irudayaraj
Correct Spectral Conversion between Surface-Enhanced Raman and Plasmon Resonance Scattering from Nanoparticle Dimers for Single-Molecule Detection [Full Paper]
Jie Zeng, David Goldfeld, Younan Xia
A Plasmon-Assisted Optofluidic (PAOF) System for Measuring the Photothermal Conversion Efficiencies of Gold Nanostructures and Controlling an Electrical Switch [Communication]
“Photothermometer”: A PAOF system was constructed using a diode laser as the energy source, an aqueous suspension of plasmonic nanostructures as the photothermal transducer, and a glass capillary for measuring the volumetric expansion of the suspension (see picture). The suspension could be driven to move up the capillary by more than 30 mm and be used to control the operation of an electrical switch.
Hui Jiang, Keke K. Zhang, Jun Ye, Fengxia Wei, Peng Hu, Jun Guo, Chunyong Liang, Xiaodong Chen, Yang Zhao, L. E. McNeil, Wenping Hu, Christian Kloc
Atomically Flat, Large-Sized, Two-Dimensional Organic Nanocrystals [Communication]
Large-sized, 2D single crystals of perylene are grown by both solution-cast and physical vapor transport methods. The crystals have a atomically flat parallelogram morphology and the aspect ratios of the lateral extension compared to the thickness are up to 103. The atomically flat feature leads to good interface contact, making a single-crystal field-effect transistor with higher mobility. The mobility of atomically flat crystals can be 103–104 times higher than rough crystals.
Yifeng Lei, Omar F. Zouani, Lila Rami, Christel Chanseau, Marie-Christine Durrieu
Modulation of Lumen Formation by Microgeometrical Bioactive Cues and Migration Mode of Actin Machinery [Full Paper]
Peptide micropatterning on polymer surfaces are designed to control endothelial cell (EC) functions. ECs form tubular structures with a central lumen depending on both microgeometrical cues of peptide micropatterns and different migration modes of actin machinery on the peptide micropatterns.
Shagufta Naureen, Naeem Shahid, Reza Sanatinia, Srinivasan Anand
Top-Down Fabrication of High Quality III–V Nanostructures by Monolayer Controlled Sculpting and Simultaneous Passivation [Full Paper]
A novel post etch chemical process is developed to etch III–V materials with monolayer precision in an inverse epitaxial manner. The process, which also simultaneously passivates the surface, is applied to push the limits of top-down fabrication. InP-based high-optical quality nanowire arrays with aspect ratios more than 50 and nanostructures with new topologies are demonstrated.
Lola Gonzalez-García, Julian Parra-Barranco, Juan Ramón Sanchez-Valencia, Javier Ferrer, Mari-Cruz Garcia-Gutierrez, Angel Barranco, Agustín R. Gonzalez-Elipe
Tuning Dichroic Plasmon Resonance Modes of Gold Nanoparticles in Optical Thin Films [Full Paper]
SiO2 thin films prepared at glancing geometries are used as templates to grow gold nanoparticles that depict optical dichroism around the azimuthal and polar axis of the films and yield unprecedented possibilities for the encryption of optical information.
Younes Makoudi, Bulent Baris, Judicael Jeannoutot, Frank Palmino, Bruno Grandidier, Frederic Cherioux
Tailored Molecular Design for Supramolecular Network Engineering on a Silicon Surface [Communication]
An open-and-shut case: By using tailored molecules, the formation of open or close-packed supramolecular network can be achieved on a silicon-based surface. The role of molecule–molecule interactions and molecule–substrate interactions to control the geometry of organic network on semi-conductor surface is investigated.
Qingye Lu, Dongyeop X. Oh, Youngjin Lee, Yongseok Jho, Dong Soo Hwang, Hongbo Zeng
Nanomechanics of Cation–π Interactions in Aqueous Solution [Communication]
The first direct probing of the nanomechanics of cation–π interactions in aqueous media was accomplished by using a surface forces apparatus with complementary theoretical simulations. The tetraethylammonium (TEA) ion breaks the adhesion between poly-L-tryptophan (PTrp) and poly-L-lysine (PLL) with a 100 times higher sensitivity relative to the K+ ion (PS=polystyrene, PTyr=poly-L-tyrosine, and ACh=acetylcholine).
Hong-Ying Gao, Hendrik Wagner, Dingyong Zhong, Jörn-Holger Franke, Armido Studer, Harald Fuchs
Glaser Coupling at Metal Surfaces [Communication]
On-surface synthesis is a promising approach for constructing covalently bound nanostructures. However, the number of reliable chemical reactions suitable for on-surface chemistry is very limited. Arylalkynes can be coupled at various surfaces in a novel 2D Glaser coupling (see picture). This approach can be used for constructing conjugated materials directly on surfaces.
Liangliang Liu, Zhu Wang, Chunxu Pan, Wei Xiao, Kyeongjae Cho
Effect of Hydrogen on O2 Adsorption and Dissociation on a TiO2 Anatase (001) Surface [Article]
A single H adatom on an anatase (001) surface can lower dramatically the dissociation barrier of the O2 molecule (see picture; O2 blue, H green). With two H adatoms, O2 is also strongly adsorbed with O=O bond cleavage, but the system energy increases after dissociation.
Hossein Eslami, Bahram Jaafari, Nargess Mehdipour
Coarse Grained Molecular Dynamics Simulation of Nanoconfined Water [Article]
Bead up: A coarse-grained (CG) model for the simulation of nanoconfined water between graphene surfaces is developed (see picture). The constructed CG potentials are shown to be pore-size transferable, capable of predicting structural properties of confined water over a wide range of pore sizes. The model predicts the layering of water in contact with the surfaces and the solvation force is in complete agreement with the mixed-grained model.
Sandra Sänze, Aleksander Gurlo, Christian Hess
Monitoring Gas Sensors at Work: Operando Raman–FTIR Study of Ethanol Detection by Indium Oxide [Communication]
Gas sensors at work: The mode of operation of metal-oxide gas sensors can be studied by simultaneous measurement of the sensor response, adsorbates, changes in the metal-oxide material, and gas-phase composition by operando Raman–FTIR spectroscopy. Depending on the gas environment and temperature, for EtOH sensing by In2O3, a correlation has been found between the sensor signal, presence of adsorbates, oxidation state of the sensor material, and intensity of surface hydroxy groups.
Erica Ueda, Pavel A. Levkin
Emerging Applications of Superhydrophilic-Superhydrophobic Micropatterns [Progress Report]
Creating patterns of extreme wettability on surfaces leads to new functionalities and possibilities in a wide variety of applications. We highlight novel applications of superhydrophilic-superhydrophobic patterned surfaces that are currently being explored, from miniaturized cell and chemical screening platforms to surface tension confined microchannels for separation and diagnostic devices, and give an outlook on the progress in this field.
Michaël De Volder, A. John Hart
Engineering Hierarchical Nanostructures by Elastocapillary Self-Assembly [Review]
New insights in capillary interactions between nanofilaments have led to versatile and scalable methods to build complex structures that cannot be achieved by any other processing technique. Understanding the control of this process is conducive to the development of high-performance battery and capacitor electrodes as well as photovoltaics, electrical interconnects, and other smart materials.
Jose Luis Yagüe, Anna Maria Coclite, Christy Petruczok, Karen K. Gleason
Chemical Vapor Deposition for Solvent-Free Polymerization at Surfaces [Talents & Trends]
Josep Sedó, Javier Saiz-Poseu, Felix Busqué, Daniel Ruiz-Molina
Catechol-Based Biomimetic Functional Materials [Review]
Catechols participate in several natural processes and functions that range from the adhesive properties of marine organisms to the storage of certain metals ions. Accordingly, many scientists worldwide have been studying and mimicking these natural systems to develop new active materials and coatings. A detailed revision of a wide variety of relevant studies in this field is discussed in this Review.
Xiaoli Liu, Yajun Xu, Zhaoqiang Wu, Hong Chen
Poly(N-vinylpyrrolidone)-Modified Surfaces for Biomedical Applications [Review]
In this review, a brief introduction to surface modification using poly(N-vinylpyrrolidone) and its copolymers and their potential biomedical applications is presented. Some perspectives on future research in the areas are also discussed.
Francesco Zerbetto
Reverse Engineering of Monolayers and Nanopatterns [Research News]
In a molecularly decorated surface, the molecular tiles are “glued” to the surface by binding constants and possibly further “glued” to each other by cooperativity factors. At odds with mosaics, these “glues” come with the tiles and cannot be removed or supplemented. Binding polynomials quantify glue amounts from experimental data and may predict molecular self-organization on surfaces that can be exploited in organic (opto-)electronics.
Inseong Choi, Woon-Seok Yeo
Self-Assembled Monolayers with Dynamicity Stemming from (Bio)Chemical Conversions: From Construction to Application [Minireview]
Dynamic surfaces: Construction and applications of dynamic surfaces on which surface properties can be modulated by an external stimulus on user demand are reviewed, with focus on self-assembled monolayers with dynamicity that stems from (bio)chemical conversions on the surface in response to stimuli such as electrical potential, light, enzymes, and pH (see picture).
Shamil Shaikhutdinov, Hans-Joachim Freund
Metal-Supported Aluminosilicate Ultrathin Films as a Versatile Tool for Studying the Surface Chemistry of Zeolites [Concept]
Monolayer zeolite? The application of a variety of “surface-science” techniques to elucidate the surface structures and mechanisms of chemical reactions at zeolite surfaces has long been considered as almost impossible. The growth of a thin aluminosilicate film on a metal single crystal under controlled conditions results in adequate and well-defined model systems for zeolite surfaces.
Roald Hoffmann
Small but Strong Lessons from Chemistry for Nanoscience [Essay]
In a different light: In a provocative look at nanoscience, Nobel Laureate Roald Hoffmann considers the structural and electronic perplexities of dimensionality, the consequences of bond severance in nano-object formation, the implications of simple acid-base chemistry for stabilization of nanostructures, and what lessons might be learned from surface science on structural relaxation and reconstruction.
Gerhard Ertl
Molecules at Surfaces: 100 Years of Physical Chemistry in Berlin-Dahlem [Essay]
Scratching the surface: For over 100 years the interactions of molecules at surfaces have been studied at the Fritz Haber Institute of the Max Planck Society, Berlin. Nobel Laureate Gerhard Ertl looks back at some of the key developments in this time, and the people who made them.
Michèle Vignes-Adler
The Fizzling Foam of Champagne [Essay]
Bubble, bubble: Why does champagne bubble? Why does it stop bubbling? Does the vintage affect its fizz? Chemistry can answer these and other questions about the wine that is so often associated with celebrations and anniversaries.
Kailash C. Jena, Rüdiger Scheu, Sylvie Roke
Surface Impurities Are Not Responsible For the Charge on the Oil/Water Interface: A Comment [Correspondence]
The origin of the charge on oil/water interfaces that can be found from electrokinetic mobility measurements is a long-standing issue that has invoked different explanations. Sum frequency scattering (SFS) shows that impurities are likely not a general cause for the charge (see picture).
James K. Beattie, Angus Gray-Weale
Oil/Water Interface Charged by Hydroxide Ions and Deprotonated Fatty Acids: A Comment [Correspondence]
The effect of fatty acid impurities on the electrophoretic mobility of hexadecane in water emulsions is reinterpreted, occasioned by an error in the surface charge attributed to the fatty acids. The results are consistent with a surface charge contributed by both hydroxide ions and deprotonated fatty acids (see picture).
Kevin Roger, Bernard Cabane
Uncontaminated Hydrophobic/Water Interfaces Are Uncharged: A Reply [Correspondence]
Pure is uncharged: Uncontaminated hydrophobic interfaces, such as PMMA-H/water interfaces, are uncharged. If the macromolecules have instead ionizable carboxylic acid endgroups, such as PMMA-COOH, a surface charge similar to the contaminated oil/water interface is obtained.
Hien N. Pham, Amanda E. Anderson, Robert L. Johnson, Klaus Schmidt-Rohr, Abhaya K. Datye
Improved Hydrothermal Stability of Mesoporous Oxides for Reactions in the Aqueous Phase [Communication]
A simple and inexpensive approach is used to coat metal oxide surfaces (SBA-15) with thin films of carbon. These carbon films provide improved hydrothermal stability to oxides, such as silica and alumina, which are not otherwise stable at elevated temperatures in the presence of liquid water (see picture). Furthermore, the carbon film changes the surface chemistry of the support.
Thomas Lang, Kyriakos A. Eslahian, Michael Maskos
Ion Effects in Field-Flow Fractionation of Aqueous Colloidal Polystyrene [Feature Article]
Particle characterization by asymmetrical flow field-flow fractionation (AF-FFF) and thermal field-flow fractionation (ThFFF) in aqueous solution is highly affected by the electrolyte in the carrier liquid. In this feature article, the impact of salinity and ion specificity on fractionation behavior is discussed. Forces acting in the fractionation channel and electrostatic particle–particle and particle–wall forces are highlighted.
Govind V. Kaigala, Robert D. Lovchik, Emmanuel Delamarche
Microfluidics in the “Open Space” for Performing Localized Chemistry on Biological Interfaces [Review]
Space, the final frontier? Microfluidic technologies for controlling liquid dispensing and handling will become central for localizing (bio)chemical reactions/functions on biological interfaces. However, microfluidic systems must then operate in the “open space”, that is, without the sealed channels and chambers commonly used (see picture). The development of such open-space microfluidic technologies is reported.
Mengtao Sun, Hongxing Xu
A Novel Application of Plasmonics: Plasmon-Driven Surface-Catalyzed Reactions [Review]
Experimental and theoretical progress on surface-catalyzed reactions of p,p'-dimercaptoazobenzene (DMAB), produced from para-aminothiophenol (PATP) and 4-nitrobenzenethiol (4NBT), assisted by local surface plasmons (LSPs) and a plasmonic waveguide is reviewed. “Hot” electrons generated by surface plasmon decay play an important role in chemical reactions. A novel method to synthesize new molecules, assisted by local LSPs or plasmon waveguides at the nanoscale, is proposed.
Rajdeep Singh Payal, Sundaram Balasubramanian
Dynamic Atomic Force Microscopy for Ionic Liquids: Massless Model Shows the Way [Highlight]
Interface unveiled: A new massless model for use in dynamic atomic force microscopy experiments aids in the study of solid–liquid interfaces of viscous liquids.
Stephan Salzinger, Bernhard Rieger
Rare Earth Metal-Mediated Group Transfer Polymerization of Vinylphosphonates [Review]
Faster, higher, stronger,... simply better. True to the Olympic motto: late lanthanide metallocenes polymerize vinylphosphonates extremely fast (TOF up to 125 000 h−1) and give access to high-molecular-weight polymers. The reaction proceeds in a living fashion via a rare earth metal-mediated group transfer polymerization mechanism. Surface-initiated group transfer polymerization allows fast and efficient preparation of thick and uniform polymer brushes.
Gerhard Ertl, Hans-Joachim Lewerenz
Obituary: Dieter M. Kolb (1942–2011) [Essay]
Dongxing Wang, Wenqi Zhu, Yizhuo Chu, Kenneth B. Crozier
High Directivity Optical Antenna Substrates for Surface Enhanced Raman Scattering [Communication]
A two-dimensional array of gold optical antennas integrated with a one-dimensional array of gold strips and mirrors is introduced and fabricated. The experimental results show that this design achieves average surface-enhanced Raman scattering (SERS) enhancement factors as high as 1.2 × 1010, which is more than two orders of magnitude larger than optical antennas without the gold strips and gold mirror.
Angelina Yimei Lim, Jan Ma, Yin Chiang Freddy Boey
Development of Nanomaterials for SALDI-MS Analysis in Forensics [Research News]
The rapid development of nanomaterials as SALDI-assisting agents in SALDI-TOF-MS has greatly enhanced the capability of this analytical technique. This article describes the ingress of this technique into the field of forensic analysis.
Kai Wang, Kenneth B. Crozier
Plasmonic Trapping with a Gold Nanopillar [Concept]
Conventional optical tweezers, in which lasers are focused with microscope objectives, are limited in the trapping force they can exert on an object for a given laser power. In this Concept, the authors review the fundamentals of optical tweezers and describe an optical nanotweezer (see picture) that exceeds the performance limitations of conventional tweezers while avoiding thermal effects with a heat-sinking approach.
Long Chen, Yenny Hernandez, Xinliang Feng, Klaus Müllen
From Nanographene and Graphene Nanoribbons to Graphene Sheets: Chemical Synthesis [Minireview]
Of all shapes and sizes: Precise control over graphene synthesis is crucial for probing their fundamental physical properties and introduction into promising applications. In this Minireview, the recent progress that has led to the successful chemical synthesis of graphene with a range of different sizes and chemical compositions based on both top-down and bottom-up strategies is highlighted (see figure).
Xiangbo Meng, Xiao-Qing Yang, Xueliang Sun
Emerging Applications of Atomic Layer Deposition for Lithium-Ion Battery Studies [Review]
Atomic layer deposition (ALD) is a highly tunable technique for fabricating various nanostructured materials that can potentially be used in lithium-ion batteries (LIBs) as anodes, cathodes, or inorganic solid electrolytes. It is also a viable approach to coat electrode materials of LIBs for improved performance.
P. Manuel Diehm, Péter Agoston, Karsten Albe
Size-Dependent Lattice Expansion in Nanoparticles: Reality or Anomaly? [Minireview]
Increasing lattice parameters for nanoparticles of decreasing sizes have been reported for a large variety of materials. The authors summarize experimental results and examine the theoretical foundation of this seemingly anomalous behavior, revealing that negative surface stress is the decisive factor. The picture shows the local atomic strain in a hexagonal GaN nanoparticle (where the blue shades represent negative strains, or contraction, and the yellow–red ones denote positive strains, i.e., expansion).
Renjia Zhou, Jiangeng Xue
Hybrid Polymer–Nanocrystal Materials for Photovoltaic Applications [Minireview]
Hybrid materials for photovoltaics: The recent development of solution-processed hybrid polymer–nanocrystal photovoltaic cells is reviewed. The tailoring of colloidal nanocrystals and conjugated polymers as well as the manipulation of polymer–nanocrystal interfaces and device architectures are highlighted. The picture shows device structure and J–V characteristics of a hybrid photovoltaic device.
Xiaohua Liu, Jeremy M. Holzwarth, Peter X. Ma
Functionalized Synthetic Biodegradable Polymer Scaffolds for Tissue Engineering [Review]
Significant efforts have been made to develop functional biodegradable scaffolds for tissue regeneration that can enhance cell function and guide new tissue formation. This paper discusses the recent advancements of functionalizing synthetic biodegradable polymer scaffolds, focusing on polymer synthesis, surface modification, and cellular response on these functionalized scaffolds.
Matthew J. Hancock, Koray Sekeroglu, Melik C. Demirel
Bioinspired Directional Surfaces for Adhesion, Wetting, and Transport [Feature Article]
Recent developments in the area of bioinspired directional surfaces with precisely tuned physicochemical surface properties are summarized. These surfaces, characterized by asymmetric features, can transport droplets, provide directional wet and dry adhesion, and exhibit directional friction.
Lijuan Zhang, Chunlei Wang, Renzhong Tai, Jun Hu, Haiping Fang
The Morphology and Stability of Nanoscopic Gas States at Water/Solid Interfaces [Minireview]
Forever blowing (nano)bubbles! Gas states observed at the nanometer scale include nanobubbles, micropancakes, multiple gas layers, and their coexistence (see picture). Molecular dynamic simulations showed that nanoscale gas bubbles may have a high inner density, which could be one reason why nanobubbles are stable at water/solid interfaces.
James R. T. Seddon, Detlef Lohse, William A. Ducker, Vincent S. J. Craig
A Deliberation on Nanobubbles at Surfaces and in Bulk [Minireview]
On the bubble: Surface and bulk nanobubbles (see picture) are two types of nanoscopic gaseous domain that occur in interfacial physics. The common and disparate features of both bubble types are described, and their possible stabilising mechanisms and potential applications are examined.
Erin E. Bedford, Jolanda Spadavecchia, Claire-Marie Pradier, Frank X. Gu
Surface Plasmon Resonance Biosensors Incorporating Gold Nanoparticles [Review]
The incorporation of gold nanoparticles in surface plasmon resonance biosensing can be used to improve device sensitivity. A number of formats have been used in which gold nanoparticles enhance the signal for detecting a variety of biomolecules, including both label-free and labeled methods. These methods as well as device fabrication and the results of incorporation are reviewed.
Ronghui Que, Qi Shao, Qinliang Li, Mingwang Shao, Shiduan Cai, Suidong Wang, Shuit-Tong Lee
Flexible Nanogenerators Based on Graphene Oxide Films for Acoustic Energy Harvesting [Communication]
Graphene oxide films were fabricated as low-cost and flexible nanogenerators to convert acoustic energy into electricity with a conversion efficiency of 12.1 % (see picture). The generated current sensitively depended on the pH value of the suspensions for graphene oxide (GO) film production.
Stanley C. S. Lai, Anisha N. Patel, Kim McKelvey, Patrick R. Unwin
Definitive Evidence for Fast Electron Transfer at Pristine Basal Plane Graphite from High-Resolution Electrochemical Imaging [Communication]
After all, it's active: High-resolution scanning electrochemical cell microscopy (SECCM) demonstrates that electron transfer at the basal plane of highly oriented pyrolytic graphite (HOPG) is fast. This finding requires radical revision of the current textbook model for HOPG electrochemistry.
Eda Yilmaz, Hikmet Sezen, Sefik Suzer
Probing the Charge Build-Up and Dissipation on Thin PMMA Film Surfaces at the Molecular Level by XPS [Communication]
What's the charge? X-ray photoelectron spectroscopy was used to determine the charge state and dynamics of charge build-up and decay on a thin poly(methyl methacrylate) film. The film is initially negatively charged to around −2 V and becomes progressively positively charged during the course of the XPS analysis.
Elena Bellido, Neus Domingo, Isaac Ojea-Jiménez, Daniel Ruiz-Molina
Structuration and Integration of Magnetic Nanoparticles on Surfaces and Devices [Review]
A detailed review of the experimental approaches followed for the structuration of magnetic nanoparticles on surfaces is presented. Special attention is given to understand the parameters that control self-assembly, including the use of biological templates. Finally, the implementation of all the knowledge previously gained is translated to the integration and implementation on sensors and devices.
Long Fu, Yanyan Chen, Hongwei Ma
Solidified Liquid Layer Model Expands the Application Fields of Quartz Crystal Microbalance [Feature Article]
The swelling behaviour of surface- tethered weak polyelectrolytes in salt solutions is studied by both ellipsometry and quartz crystal microbalance (QCM). Ellipsometry studies support the proposed solidified liquid layer (SLL) model. QCM experiments designed according to the SLL model are highly sensitive: a 0.18 nm thickness change of the SLL will lead to a 1 Hz frequency change.
Peter Licence
In Situ XPS Monitoring of Bulk Ionic Liquid Reactions: Shedding Light on Organic Reaction Mechanisms [Highlight]
In the swim: Until now, X-ray photoelectron spectroscopy (XPS) has been predominantly applied to the investigation of near-surface regions. Recent work has now brought XPS into a new domain with the direct monitoring of bulk reactions in the liquid phase. In the monitored reaction, the cation of an ionic liquid (IL) reacts with the anion of another IL (see scheme).
Zhi Wei Seh, Shuhua Liu, Michelle Low, Shuang-Yuan Zhang, Zhaolin Liu, Adnen Mlayah, Ming-Yong Han
Janus Au-TiO2 Photocatalysts with Strong Localization of Plasmonic Near-Fields for Efficient Visible-Light Hydrogen Generation [Communication]
The first use of non-centrosymmetric Janus Au-TiO2 photocatalysts in efficient, plasmon-enhanced visible-light hydrogen generation is demonstrated. The intense localization of plasmonic near-fields close to the Au-TiO2 interface, coupled with optical transitions involving localized electronic states in amorphous TiO2 brings about enhanced optical absorption and the generation of electron-hole pairs for photocatalysis.
Yihan Zhu, Qingxiao Wang, Lan Zhao, Yu Han
Direct Observation of Surface Reconstruction and Termination on a Complex Metal Oxide Catalyst by Electron Microscopy [Communication]
On the surface: The surface reconstruction of an MoVTeO complex metal oxide catalyst was observed directly by various electron microscopic techniques and the results explain the puzzling catalytic behavior.
Rene Jørgensen, Lena Lisbeth Grimm, Nora Sindhuwinata, Thomas Peters, Monica M. Palcic
A Glycosyltransferase Inhibitor from a Molecular Fragment Library Simultaneously Interferes with Metal Ion and Substrate Binding [Communication]
A fragmented approach: 3-Phenyl-5-piperazino-1,2,4-thiadiazole (designated “compound 382” in the Ro5 Maybridge Fragment Library, see scheme) is demonstrated to be an effective inhibitor of human blood group glycosyltransferase B. The compound interferes with both acceptor and donor binding and also displaces the Mn2+ ion in the binding pocket.
Li Chen, Gao Yang, Shutao Wang
Air-Grid Surface Patterning Provided by Superhydrophobic Surfaces [Concepts]
With a little air, one can make a huge impact! Surface patterning is one of the most fundamental techniques in modern times. Recently air was employed as the separating barrier for surface patterning using superhydrophobic surfaces. This new concept has promising potential for flexible, high-throughput, and high-resolution micropatterning, and it is expected to further expand the applications of superhydrophobic surfaces.
Manabu Kiguchi, Satoshi Kaneko
Electron Transport through Single π-Conjugated Molecules Bridging between Metal Electrodes [Review]
One and all: Electron transport through a single molecule between metal electrodes is a topic of great interest in the development of nanoscale molecular electronic devices. π-Conjugated molecules have attracted attention due to their unique properties. The fabrication and electron-transport properties of the single π-conjugated molecule junction (see picture) are discussed.
Sameh Tawfick, Michael De Volder, Davor Copic, Sei Jin Park, C. Ryan Oliver, Erik S. Polsen, Megan J. Roberts, A. John Hart
Engineering of Micro- and Nanostructured Surfaces with Anisotropic Geometries and Properties [Review]
Approaches to fabricate arrays of asymmetric 2D and 3D surface features, in polymers, metals, and ceramics are reviewed. These combinations of geometries and materials can impart unique anisotropy in surface properties including wetting, adhesion, thermal and/or electrical conductivity, optical activity, and capability to direct cell growth, and are of interest for applications including energy conversion, microelectronics, chemical and biological sensing, and bioengineering.
Zhuang Xie, Xuechang Zhou, Xiaoming Tao, Zijian Zheng
Polymer Nanostructures Made by Scanning Probe Lithography: Recent Progress in Material Applications [Feature Article]
The latest developments in the fabrication of polymer nanostructures using scanning probe lithography (SPL) are highlighted, with special categorization by different material applications into polymer resists, polymeric carriers for functional materials, electronically active polymers and polymer brushes. The attributes of SPL in patterning polymer nanostructures are also summarized.
Dario Natali, Mario Caironi
Charge Injection in Solution-Processed Organic Field-Effect Transistors: Physics, Models and Characterization Methods [Review]
A comprehensive overview on the subject of current injection in organic thin-film transistors is given: physical principles concerning energy level (mis)alignment at interfaces, models describing charge injection, technologies for interface tuning, and techniques for characterizing devices. Finally, a survey of the most recent accomplishments in the field is given.
Ronald G. Larson
Re-Shaping the Coffee Ring [Highlight]
Not your cup of tea? “Coffee rings” of spherical colloidal particles are left behind after water droplets resting on surfaces have dried out. This controlled evaporation of colloidal solutions can be exploited to deposit material in regular patterns (see picture). It is now shown that if spherical colloids are replaced by slightly elongated ones, the coffee ring is not formed and is replaced by an even more uniform deposition.
Anke Krueger, Daniel Lang
Functionality is Key: Recent Progress in the Surface Modification of Nanodiamond [Feature Article]
Surface chemistry on nanodiamond has developed into a field in its own right in recent years. The large variety of possible functionalization reactions on the surface of this purportedly inert material is presented. These modifications enable the application of nanodiamond in areas such as bioimaging, composites, or quantum engineering.
Peter A. Bobbert, Abhinav Sharma, Simon G. J. Mathijssen, Martijn Kemerink, Dago M. de Leeuw
Operational Stability of Organic Field-Effect Transistors [Progress Report]
In an organic field-effect transistor redox reactions at the surface of the gate dielectric involving water can lead to conversion of holes in the accumulation layer into protons. The protons diffuse into the gate dielectric and cause a shift of the threshold voltage of the transistor.
Rajeswari Ravichandran, Subramanian Sundarrajan, Jayarama Reddy Venugopal, Shayanti Mukherjee, Seeram Ramakrishna
Advances in Polymeric Systems for Tissue Engineering and Biomedical Applications [Special Article Series - Review]
Smart stimuli-responsive polymeric systems with smart surfaces are used for engineering a biological construct embedded with cells and biomolecules/drugs. Upon response to suitable stimuli like pH in vivo, the polymer unwinds and becomes hydrophobic thereby delivering cells and biomolecules to the target organ in the human body.
Liqiang Li, Michael H. Köpf, Svetlana V. Gurevich, Rudolf Friedrich, Lifeng Chi
Structure Formation by Dynamic Self-Assembly [Review]
The recent experimental and theoretical work on the fabrication of well-ordered mesoscopic structural surfaces over large areas is reviewed. Methods such as the Langmuir–Blodgett (LB) technique are described. Furthermore, the patterning of materials with LB transfer or other dynamic processes such as dip-coating is summarized.
Huaping Xu, Monika Schönhoff, Xi Zhang
Unconventional Layer-by-Layer Assembly: Surface Molecular Imprinting and Its Applications [Concepts]
Preassembling singly charged, uncharged, or water-repellent building blocks in an unconventional layer-by-layer fashion enhances the ability for advanced functionality, in particular, surface molecular imprinting, of the resulting multilayer film.
Lin Jiang, Yinghui Sun, Xiaodong Chen
Chemical Reaction on a Solid Surface with Nanoconfined Geometry [Highlight]
Linear alkane polymerization is achieved on the Au(110) surface with 1D constrained nanochannels, which play a key role in the selective C–H activation and C–C bond coupling.
Alexander Hinderhofer, Frank Schreiber
Organic–Organic Heterostructures: Concepts and Applications [Review]
Less is more: Basic concepts, examples and applications of organic–organic heterostructures are reviewed (see picture). Heterostructures in the monolayer regime, including nanostructuring concepts and systems involving self-assembled monolayers, as well as various other architectures, including superlattices, are discussed.
Jürgen Hüpkes, Jorj I. Owen, Sascha E. Pust, Eerke Bunte
Chemical Etching of Zinc Oxide for Thin-Film Silicon Solar Cells [Minireview]
Chemical etching is widely applied to texture the surface of sputter-deposited zinc oxide for light scattering in thin-film silicon solar cells. Based on experimental findings from the literature and our own results we propose a model that explains the etching behavior of ZnO depending on the structural material properties and the etching agent (see picture).
Takeo Minari, Chuan Liu, Masataka Kano, Kazuhito Tsukagoshi
Controlled Self-Assembly of Organic Semiconductors for Solution-Based Fabrication of Organic Field-Effect Transistors [Research News]
Bottom-up fabrication methods based on self assembly of molecules are developed for solution-processed production of organic semiconductor devices. Our methods enable area selective crystallization of molecules and direct formation of organic single crystals from solution. Since these methods can be processed under ambient condition at room temperature, they are fully compatible with printable electronics technology.
Jens S. Hummelshøj, Frank Abild-Pedersen, Felix Studt, Thomas Bligaard, Jens K. Nørskov
CatApp: A Web Application for Surface Chemistry and Heterogeneous Catalysis [And Finally]
A rich source: Calculated reaction and activation energies for elementary coupling reactions occurring on metal surfaces can be found by using a web application. This tool provides access to data for reactions of molecules with up to three C, N, or O atoms on a number of different transition-metal surfaces. The underlying dataset is generated from a consistent set of DFT calculations and extrapolations based on linear scaling relations.
© Wiley-VCH 2011.
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