			Home About us Contact

Solid Substrates (solid + substrate)

Distribution by Scientific Domains

Polymers and Materials Science	41%
Life Sciences	30%
Chemistry	19%
3 Other Domains	10%

Selected Abstracts

Orthogonal Transformations on Solid Substrates: Efficient Avenues to Surface Modification

ADVANCED MATERIALS, Issue 34 2009
Leena Nebhani
Abstract The performance of solid substrates is not only governed by their molecular constitution, but is also critically influenced by their surface constitution at the solid/gas or solid/liquid interface. In here, we critically review the use of orthogonal chemical transformations (so-called click chemistry) to achieve efficient surface modifications of materials ranging from gold and silica nanoparticles, polymeric films, and microspheres to fullerenes as well as carbon nanotubes. In addition, the functionalization of surfaces via click chemistry with biomolecules is explored. Although a large host of reactions fulfilling the click -criteria exist, pericyclic reactions are most frequently employed for efficient surface modifications. The advent of the click chemistry concept has led,as evident from the current literature,to a paradigm shift in current approaches for materials modification: Away from unspecific and nonselective reactions to highly specific true surface engineering. [source]

Surface Selective Deposition of PMMA on Layered Double Hydroxide Nanocrystals Immobilized on Solid Substrates,

ADVANCED MATERIALS, Issue 5 2009
Jong Hyeon Lee
A novel nanostructured hybrid PMMA/MgAl-LDH thin film enables a strong UV-blocking effect, up to 97% below 300,nm, and excellent visible transparency. The graft density of PMMA films can be controlled by adjusting the area coverage of immobilized LDH monolayer with a highly-orientated structure on oxide, metal, and polymer substrates. [source]

A Simple Method for the Attachment of Polymer Films on Solid Substrates,

ADVANCED MATERIALS, Issue 3 2003
M. Yan
The immobilization of polymer thin films on solid substrates has been achieved using a very simple method, involving spin coating the polymer, followed by UV irradiation. A robust film remains on the substrate surface after solvent extraction. The procedure could be employed to fabricate patterned polymer thin films via photolithography (see Figure). [source]

A Direct, Multiplex Biosensor Platform for Pathogen Detection Based on Cross-linked Polydiacetylene (PDA) Supramolecules

ADVANCED FUNCTIONAL MATERIALS, Issue 23 2009
Cheol Hee Park
Abstract This study focuses on the development of a multiplex pathogen-detection platform based on polydiacetylene (PDA) using a novel immobilization procedure. PDA liposome-based solid sensors have a critical drawback as the PDA liposomes are not stably immobilized onto the solid substrate. Therefore, to overcome this problem, an interlinker, ethylenediamine, is introduced, which acts as a cross-linker between individual PDA liposomes. The quantity of ethylenediamine added was optimized to 1,mM, as measured by the fluorescence signal emitted by the stably immobilized PDA liposomes, a concentration at which the fluorescence signal is 10 times higher than for the resulting PDA chips made without the interlinker. This procedure is used to manufacture PDA liposome-based multiplex biosensor arrays for well-known water and food-borne pathogens. The fabricated biosensor was able to perform the simultaneous and quantitative detection of 6 species of pathogens. As such, the results demonstrated from this research can be exploited for the development of more advanced PDA-based biosensors and diagnostics. [source]

A study on thermal conductivity of a quasi-ordered liquid layer on a solid substrate

HEAT TRANSFER - ASIAN RESEARCH (FORMERLY HEAT TRANSFER-JAPANESE RESEARCH), Issue 7 2007
Xiao-Yan Shi
Abstract In the present paper, a study on thermal conductivity of a quasi-ordered liquid layer on a solid surface was performed by molecular dynamic simulation. Results showed that the motion of the molecules and their radial distribution function in the quasi-ordered liquid layer were similar to those of solid molecules. By using the Green,Kubo formula, the thermal conductivity of the layer was calculated. It was found that it increased with the increase of the parameters of ordering. The size effect and the influence of the boundary condition were also discussed. © 2007 Wiley Periodicals, Inc. Heat Trans Asian Res, 36(7): 429,434, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/htj.20171 [source]

Bioinspired Design of a Superoleophobic and Low Adhesive Water/Solid Interface,

ADVANCED MATERIALS, Issue 6 2009
Mingjie Liu
The wetting/antiwetting behavior of liquid droplets on a solid surface is not an apparent or simple contact between two phases, but among three phases. Inspired by the antiwetting behavior of oil droplets on fish scales in water, a superoleophobic and low-adhesive interface is created on a solid substrate with micro/nanohierarchical structures, using oil/water/solid three-phase systems. [source]

L-methioninase production by Aspergillus flavipes under solid-state fermentation

JOURNAL OF BASIC MICROBIOLOGY, Issue 4 2009
Ashraf S. A. El-Sayed
Abstract Solid-state fermentation was carried out for the production of extra-cellular L-methioninase by Aspergillus flavipes (Bain and Sart.) using nine agro-industrial residues, namely wheat bran, rice bran, wheat flour, coconut seeds, cotton seeds, ground nut cake, lentil hulls, soya beans and chicken feathers. Chicken feathers were selected as solid substrate for L-methioninase production by A. flavipes. The maximum L-methioninase productivity (71.0 U/mg protein) and growth (11 mg protein/ml) of A. flavipes was obtained using alkali pretreated chicken feathers of 50% initial moisture content as substrate supplemented with D-glucose (1.0% w/v) and L-methionine (0.2% w/v). External supplementation of the fermentation medium with various vitamin sources has no overinductive effect on L-methioninase biosynthesis. The partially purified A. flavipes L-methioninase preparation showed highest activity (181 U/ml) at pH 8.0 with stability over a pH range (pH 6,8) for 2 h. L-methioninase activity was increased by preincubation of the enzyme for 2 h with Co2+, Mn2+, Cu2+ and Mg2+ and strongly inhibited by the presence of EDTA, NaN3, Li2+, Cd2+, DMSO and 2-mercaptoethanol. The enzyme preparation has a broad substrate spectrum showing a higher affinity to deaminate L-glycine, N -acetylglucosamine and glutamic acid, in addition to their proteolytic activity against bovine serum albumin, casein, gelatin and keratin. The partially purified enzyme was found to be glyco-metalloproteinic in nature as concluded from the analytical and spectroscopic profiles of the enzyme preparation. The demethiolating activity of the enzyme was also visualized chromogenially. (© 2009 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source]

Sample preparation procedures for biological atomic force microscopy

JOURNAL OF MICROSCOPY, Issue 3 2005
K. EL KIRAT
Summary Since the late 1980s, atomic force microscopy (AFM) has been increasingly used in biological sciences and it is now established as a versatile tool to address the structure, properties and functions of biological specimens. AFM is unique in that it provides three-dimensional images of biological structures, including biomolecules, lipid films, 2D protein crystals and cells, under physiological conditions and with unprecedented resolution. A crucial prerequisite for successful, reliable biological AFM is that the samples need to be well attached to a solid substrate using appropriate, nondestructive methods. In this review, we discuss common techniques for immobilizing biological specimens for AFM studies. [source]

Effect of solvent quality on kinetics of tethered layer formation

JOURNAL OF POLYMER SCIENCE (IN TWO SECTIONS), Issue 21 2004
Heqing Huang
Abstract We conducted a study of the effect of solvent quality on the kinetics of formation of a layer of polymer chains tethered to a solid substrate. In these experiments, tethering was accomplished by means of chemical bond formation between reactive sites on the surface and the end-functional groups of the polymer chains in solution. All experimental variables were held constant except for the ,-parameter between the polymer and solvent. Variation in the ,-parameter was achieved by use of a series of nonpolar, organic solvents. The distinct three-regime kinetics, typical of tethering reactions run in a good solvent and in the absence of segmental adsorption, was observed over the range of values for the ,-parameter. As expected, an increase in the ,-parameter (a decrease in solvent quality) did result in increased tethering density, but, contrary to expectation, no increase in tethering rate was observed. © 2004 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 42: 5530,5537, 2004 [source]

Multianalyte immunoassay based on surface-enhanced Raman spectroscopy

JOURNAL OF RAMAN SPECTROSCOPY, Issue 7 2007
Yan Cui
Abstract In this paper, two immunoassay methods based on SERS are developed for multiplex analysis, both of which stemmed from the concept of forming a sandwich structure ,capture antibody substrate/antigen/Raman-reporter-labeled immuno-nanoparticles'. They are two-molecule labeled one-nanoparticle and one-molecule labeled two-nanoparticle methods. In both the methods, two different antibodies covalently bound to a solid substrate can specifically capture two different antigens from a sample. The captured antigens in turn bind selectively to their corresponding antibodies immobilized on Raman-reporter-labeled nanoparticles. Multianalyte immunoassay is successfully demonstrated by the detection of characteristic Raman bands of the probe molecules only when the antigen and antibody are matched. Copyright © 2007 John Wiley & Sons, Ltd. [source]

An enzyme-linked immunosorbent assay for monitoring of Aspergillus ochraceus growth in coffee powder, chilli powder and poultry feed

LETTERS IN APPLIED MICROBIOLOGY, Issue 1 2006
S. Anand
Abstract Aims:, The work was carried out to develop an immunoassay for estimation of Aspergillus ochraceus biomass on solid substrate. Methods and Results:, An indirect noncompetitive enzyme-linked immunosorbent assay (ELISA) was developed for determination of fungal biomass in food commodities using antibody raised against A. ochraceus mycelial antigen. The sensitivity of the assay was linear in the range of 10,160 ,g fungal biomass per millilitre extract of coffee (R2 = 0·989), poultry feed (R2 = 0·987) and chilli (R2 = 0·989). The growth of A. ochraceus in the food commodities like chilli, coffee beans and poultry feed, under the influence of two levels of moisture (20% and 30%) were monitored by the ELISA. The maximum fungal colonization was observed in poultry feed (9·8 and 11·8 mg g,1) followed by coffee beans (6·8 and 11·3 mg g,1) and chilli (5·1 and 6·3 mg g,1) at 20% and 30% moisture after 20 days of incubation. Similarly the fungus produced maximum ochratoxin A in poultry feed (25 and 120 ,g g,1) followed by coffee beans (8 and 24 ,g g,1) and chilli (0·2 and 0·45 ,g g,1) at 20% and 30% moisture after 20 days of incubation. Conclusions:, The method can be used for quantitative estimation of fungal biomass and comparison of fungal colonization in food substrates varying in composition. Significance and Impact of the Study:, The method can be adapted for studying the fungal colonization in different solid substrates under different culture condition. The method is sensitive to mould colonization of ,0·02% (w/w) and can be used for early detection of specific fungal infestation in food commodities. [source]

Probing of Thin Slipping Films by Persistent External Disturbances

THE CANADIAN JOURNAL OF CHEMICAL ENGINEERING, Issue 5 2007
N. Alleborn
Abstract This paper investigates the propagation of thickness disturbances on the free surface of a thin viscous liquid film on a solid substrate. On the free surface of the film the disturbances are induced by moving local external pressure perturbations acting on the surface. The analysis is performed by the Fourier-Laplace transform applied to the linearized perturbation equations for small amplitudes. The amplitude of the interface deflection caused by the disturbance, is reconstructed by the inverse Fourier-Laplace transform and numerically evaluated in the long time limit in long wave approximation. The proposed technique appears promising for probing the slip length of a thin film by recording its free surface response to a moving perturbation. On étudie dans cet article la propagation des perturbations d'épaisseur à la surface libre d'un film liquide visqueux sur un substrat solide. Sur la surface libre du film, les perturbations sont provoquées en déplaçant des perturbations de pression externes locales agissant sur la surface. L'analyse est effectuée par l'application de la transformée de Fourier-Laplace aux équations de perturbation linéarisées pour des petites amplitudes. L'amplitude de la déviation de surface causée par la perturbation est reconstruite par la transformée de Fourier-Laplace inverse et évaluée numériquement pour un temps très long par l'approximation des ondes longues. La technique proposée apparaît prometteuse pour sonder la longueur de glissement d'un film mince en enregistrant la réponse de sa surface libre à une perturbation mobile. [source]

Harbour seal movements and haul-out patterns: implications for monitoring and management

AQUATIC CONSERVATION: MARINE AND FRESHWATER ECOSYSTEMS, Issue 4 2009
Louise Cunningham
Abstract 1.Compliance with conservation legislation requires knowledge on the behaviour, abundance and distribution of protected species. Seal life history is characterized by a combination of marine foraging and a requirement to haul out on a solid substrate for reproduction and moulting. Thus understanding the use of haul out sites, where seals are counted, as well as their at-sea movements is crucial for designing effective monitoring and management plans. 2.This study used satellite transmitters deployed on 24 harbour seals in western Scotland to examine movements and haul-out patterns. 3.The proportion of time harbour seals spent hauled out (daily means of between 11 and 27%) varied spatially, temporally and according to sex. The mean haul-out duration was 5,h, with a maximum of over 24,h. 4.Patterns of movement were observed at two geographical scales; while some seals travelled over 100,km, 50% of trips were within 25,km of a haul-out site. These patterns are important for the identification of a marine component to designated protected areas for the species. 5.On average seals returned to the haul-out sites they last used during 40% of trips, indicating a degree of site fidelity, though there was wide variation between different haul-out sites (range 0% to >75%). 6.Low fidelity haul-out sites could form a network of land-based protected areas, while high fidelity sites might form appropriate management units. Copyright © 2008 John Wiley & Sons, Ltd. [source]

Cellulose hydrolysis in evolving substrate morphologies III: Time-scale analysis

BIOTECHNOLOGY & BIOENGINEERING, Issue 2 2010
Wen Zhou
Abstract We present a time-scale analysis for the enzymatic hydrolysis of solid cellulosic substrates, based on our recently developed kinetic model (Zhou et al., 2009a, Biotechnol Bioeng 104:261,274; Zhou et al., 2009b, Biotechnol Bioeng 104:275,289) which incorporates both enzymatic chain fragmentation and hydrolytic time evolution of the solid substrate morphology. Analytical order-of-magnitude estimates of the relevant single-layer chain depolymerization times are first discussed. These time-scale estimates for pure and mixed enzyme systems can be employed to calculate the degree of synergy between endo - and exo -acting enzymes in a mixed enzyme system. By the way of a quasi-steady-state approximation which allows for a greatly simplified analytical solution of the model, we also explain the origin and give order-of-magnitude estimates of the two characteristic hydrolysis time scales which arise in this model when the solid substrate morphology is taken into account. These analytically derived time-scale relations explain how the embedding of cellulose chains in a solid substrate acts as a crucial rate-limiting factor and results in a substantial slowing down of the hydrolytic conversion process, compared to a hypothetical substrate of immediately enzyme-accessible, isolated chains. The analytical time-scale results are verified by numerical simulations and compared to experimental observations. Biotechnol. Bioeng. 2010;107: 224,234. © 2010 Wiley Periodicals, Inc. [source]

A Self-assembly Route for Double Bilayer Lipid Membrane Formation

CHEMPHYSCHEM, Issue 3 2010
Xiaojun Han Dr.
Biomembranes: A new method of forming double bilayer lipid membranes uses NHS/EDC chemistry to link adjacent bilayers, both of which remain fluid. This approach provides a novel platform for the study of biomembranes, in which the components of the upper membrane are shielded from the solid substrate by a second membrane (see figure); and for studying more complex membrane protein systems which span double lipid bilayers. [source]

Amalgam Electrodes for Electroanalysis

ELECTROANALYSIS, Issue 8 2003
Øyvind Mikkelsen
Abstract Liquid mercury is a unique material for the indicator electrode in voltammetry. One reason for this is the high overvoltage for hydrogen formation, thus extending the actual potential window. Diluted amalgams are important reaction products in voltammetric (polarographic) processes, however liquid amalgams are rarely used directly as electrode material for analytical purposes. Because of the fact that voltammetry is very suitable for field and remote monitoring, issues concerning the use of mercury electrodes in environmental analyses have led to considerable research effort aimed at finding alternative tools with acceptable performance. Solid electrodes are such alternatives. Different types of electrodes are reviewed. In particular, solid amalgam electrodes are very promising, with acceptable low toxicity to be used for field measurements. Solid amalgam electrodes are easy and cheap to construct and are stable over a reasonable time up to several weeks. Assessment of the toxicity risk and the long time stability for remote and unattended monitoring is discussed. The differences between solid dental amalgam electrodes, made by using techniques known from dental clinical practice, and mercury film or mercury layer electrodes on solid substrates are reviewed. In particular the dental technique for constructing solid amalgam electrodes gives advantage because it's fast and inexpensive. Also the technique for making dental amalgam has been explored and optimized over years by dentists, giving advantage when the same technique is used for constructing electrodes. Dental amalgam electrodes has been found to act similar to a silver electrodes, but with high overvoltage towards hydrogen. This make it possible to use the dental amalgam electrode for detection of zinc, cobalt and nickel in additions to other metals like lead, copper, thallium, cadmium, bismuth, iron etc. Also the use for reducible organic compounds is expected to be promising. [source]

White-rot fungi combined with lignite granules and lignitic xylite to decolorize textile industry wastewater

ENGINEERING IN LIFE SCIENCES (ELECTRONIC), Issue 1 2010
Ulrike Böhmer
Abstract The feasibility of using immobilized fungi to decolorize textile industry wastewater containing dyes was examined in experiments with: two species of white-rot fungi (a Marasmius species from Indonesia, which produces copious biomass, and Trametes hirsuta, which produces high levels of laccase); two types of lignite products as adsorbents and solid substrates (lignitic xylite and lignite granules); and four simulated wastewaters, each containing a different kinds of reactive textile azo dye. The growth, extracellular enzyme production, dye degradation and dye absorption parameters afforded by each permutation of fungus, substrate and dye were then measured. Both fungal species grew poorly on xylite, but much better on lignite granules. Marasmius sp. produced up to 67,U/L laccase on lignite granules, but just 10,U/L on xylite, and no other detectable extracellular enzymes. T. hirsuta produced 1343,U/L laccase and up to 12,U/L unspecific peroxidase when immobilized on lignite granules, and 898,U/L laccase with 14,U/L unspecific peroxidase when immobilized on xylite. The amount of color lost from the dye solutions depended on both the type of dye and the enzyme levels in the fermenter. [source]

Cationic Polyelectrolyte Amplified Bead Array for DNA Detection with Zeptomole Sensitivity and Single Nucleotide Polymorphism Selectivity

ADVANCED FUNCTIONAL MATERIALS, Issue 16 2010
Chun Wang
Abstract A highly sensitive strand specific DNA assay, which consists of a peptide nucleic acid (PNA) probe, a cationic conjugated polymer (PFVP), and self-assembled polystyrene beads in microwell arrays on silicon chip, is reported. PFVP, as an efficient signal amplifier and signal reporter, has been specially designed and synthesized to be compatible with commercial confocal microscopes for sensing on solid substrates. The assay operates on the net increase in negative charge at the PNA surface that occurs upon single-stranded DNA hybridization, which subsequently allows complex formation with the positively charged PFVP to favor energy transfer between the polymer and Cy5-labeled target. With maximized surface contact provided by bead arrays and signal amplification provided by PFVP, this assay allows detection of ,300 copies of Cy5-labeled DNA using a commercial confocal microscope. In addition, the same strategy is also extended for label-free DNA detection with a detection sensitivity of 150 attomole. Excellent discrimination against single nucleotide polymorphism (SNP) is also demonstrated for both Cy5-labeled and label-free target detection. This study indicates that cationic conjugated polymers have great potential to be incorporated into the widely used microarray technology for simplified process with improved detection sensitivity. [source]

Aspergillus oryzae in solid-state and submerged fermentations

FEMS YEAST RESEARCH, Issue 2 2002
Progress report on a multi-disciplinary project
Abstract We report the progress of a multi-disciplinary research project on solid-state fermentation (SSF) of the filamentous fungus Aspergillus oryzae. The molecular and physiological aspects of the fungus in submerged fermentation (SmF) and SSF are compared and we observe a number of differences correlated with the different growth conditions. First, the aerial hyphae which occur only in SSFs are mainly responsible for oxygen uptake. Second, SSF is characterised by gradients in temperature, water activity and nutrient concentration, and inside the hyphae different polyols are accumulating. Third, pelleted growth in SmF and mycelial growth in SSF show different gene expression and protein secretion patterns. With this approach we aim to expand our knowledge of mechanisms of fungal growth on solid substrates and to exploit the biotechnological applications. [source]

Reversibly Light-Switchable Wettability of Hybrid Organic/Inorganic Surfaces With Dual Micro-/Nanoscale Roughness

ADVANCED FUNCTIONAL MATERIALS, Issue 8 2009
Gianvito Caputo
Abstract Here, an approach to realize "smart" solid substrates that can convert their wetting behavior between extreme states under selective light irradiation conditions is described. Hybrid organic/inorganic surfaces are engineered by exploiting photolithographically tailored SU-8 polymer patterns as templates for accommodating closely packed arrays of colloidal anatase TiO2 nanorods, which are able to respond to UV light by reversibly changing their surface chemistry. The TiO2 -covered SU-8 substrates are characterized by a dual micro-/nanoscale roughness, arising from the overlapping of surfactant-capped inorganic nanorods onto micrometer-sized polymer pillars. Such combined architectural and chemical surface design enables the achievement of UV-driven reversible transitions from a highly hydrophobic to a highly hydrophilic condition, with excursions in water contact angle values larger than 100°. The influence of the geometric and compositional parameters of the hybrid surfaces on their wettability behavior is examined and discussed within the frame of the available theoretical models. [source]

Nucleation-Governed Reversible Self-Assembly of an Organic Semiconductor at Surfaces: Long-Range Mass Transport Forming Giant Functional Fibers,

ADVANCED FUNCTIONAL MATERIALS, Issue 18 2007
G. De, Luca
Abstract The use of solvent-vapor annealing (SVA) to form millimeter-long crystalline fibers, having a sub-micrometer cross section, on various solid substrates is described. Thin films of a perylene-bis(dicarboximide) (PDI) derivative, with branched alkyl chains, prepared from solution exhibit hundreds of nanometer-sized PDI needles. Upon exposure to the vapors of a chosen solvent, tetrahydrofuran (THF), the needles re-organize into long fibers that have a remarkably high aspect ratio, exceeding 103. Time- and space-resolved mapping with optical microscopy allows the self-assembly mechanism to be unravelled; the mechanism is found to be a nucleation-governed growth, which complies with an Avrami-type of mechanism. SVA is found to lead to self-assembly featuring i),long-range order (up to the millimeter scale), ii),reversible characteristics, as demonstrated through a series of assembly and disassembly steps, obtained by cycling between THF and CHCl3 as solvents, iii),remarkably high mass transport because the PDI molecular motion is found to occur at least over hundreds of micrometers. Such a detailed understanding of the growth process is fundamental to control the formation of self-assembled architectures with pre-programmed structures and physical properties. The versatility of the SVA approach is proved by its successful application using different substrates and solvents. Kelvin probe force microscopy reveals that the highly regular and thermodynamically stable fibers of PDI obtained by SVA exhibit a greater electron-accepting character than the smaller needles of the drop-cast films. The giant fibers can be grown in,situ in the gap between microscopic electrodes supported on SiOx, paving the way towards the application of SVA in micro- and nanoelectronics. [source]

Poly(9,9-dioctylfluorene)-Based Conjugated Polyelectrolyte: Extended ,-Electron Conjugation Induced by Complexation with a Surfactant Zwitterion

ADVANCED MATERIALS, Issue 18 2010
Giuseppina Pace
We report on a conjugated polyelectrolyte (CPE) based on fluorene repeat units, which forms a supramolecular complex with a zwitterion surfactant. The complex self-assembles into multilamellar structures on solid substrates. The luminescence efficiency, low in the uncomplexed polymer, is strongly increased after complexation. This originates from the phase segregation between the aromatic backbone and ionic sides, reducing conformational defects and ionic dipole-induced quenching. [source]

Orthogonal Transformations on Solid Substrates: Efficient Avenues to Surface Modification

Layer-by-Layer Hydrogen-Bonded Polymer Films: From Fundamentals to Applications

ADVANCED MATERIALS, Issue 30 2009
Eugenia Kharlampieva
Abstract Recent years have seen increasing interest in the construction of nanoscopically layered materials involving aqueous-based sequential assembly of polymers on solid substrates. In the booming research area of layer-by-layer (LbL) assembly of oppositely charged polymers, self-assembly driven by hydrogen bond formation emerges as a powerful technique. Hydrogen-bonded (HB) LbL materials open new opportunities for LbL films, which are more difficult to produce than their electrostatically assembled counterparts. Specifically, the new properties associated with HB assembly include: 1) the ease of producing films responsive to environmental pH at mild pH values, 2) numerous possibilities for converting HB films into single- or two-component ultrathin hydrogel materials, and 3) the inclusion of polymers with low glass transition temperatures (e.g., poly(ethylene oxide)) within ultrathin films. These properties can lead to new applications for HB LbL films, such as pH- and/or temperature-responsive drug delivery systems, materials with tunable mechanical properties, release films dissolvable under physiological conditions, and proton-exchange membranes for fuel cells. In this report, we discuss the recent developments in the synthesis of LbL materials based on HB assembly, the study of their structure,property relationships, and the prospective applications of HB LbL constructs in biotechnology and biomedicine. [source]

Multicolor Emission on Prepatterned Substrates Using a Single Dye Species,

ADVANCED MATERIALS, Issue 16 2007
W. Hu
A new strategy for realizing patterned surfaces with different emission colors is demonstrated. This approach relies on the gas-phase deposition of dye molecules onto solid substrates that are prepatterned by nanoimprint lithography (see figure). Only a single molecular species is involved. Thus, the observed color change and corresponding spectral shift in the emission properties depends on the substrate used and can be tuned by surface engineering. [source]

Large-Scale "Surface-Programmed Assembly" of Pristine Vanadium Oxide Nanowire-Based Devices,

ADVANCED MATERIALS, Issue 19 2005
S. Myung
"Surface-programmed assembly" is presented as a technique (see Figure) to achieve high-precision assembly and alignment of a large number of pristine V2O5 nanowires on solid substrates. Positively charged surface molecular patterns guide the assembly and alignment of negatively charged V2O5 nanowires on solid substrates. Large-scale assembly of V2O5 nanowire-based transistors is demonstrated and their gating effects are confirmed. [source]

A Simple Method for the Attachment of Polymer Films on Solid Substrates,

Behavioral patterns of drop impingement onto rigid substrates with a wide range of wettability and different surface temperatures

AICHE JOURNAL, Issue 8 2009
Xiying Li
Abstract This article concerns behavioral patterns of droplet impingement onto solid substrates covering a wide range of wettability from hydrophilic to superhydrophobic surfaces heated at different temperatures. For droplet impingement onto partial hydrophobic surfaces (mirror-polished Cu substrate), the maximum heights of receding droplet undergoing a consecutive increment with surface temperature can be explained taking account of Marangoni flow. Also, the relation to predict the increment of droplet heights with surface temperature was manifested in the light of lubrication approximation combined with energy conservation. However, this relation is only valid for droplet impacts onto partial hydrophobic surface, because the recoiling droplet height was observed to be independent of surface temperature for both hydrophilic and superhydrophobic targets. This phenomenon was attributed to inherent wettability accompanying larger contact angle hysteresis for the hydrophilic substrate and to the presence of an adiabatic gas layer between the composite surface and impacting droplet, for the superhydrophobic target. © 2009 American Institute of Chemical Engineers AIChE J, 2009 [source]

Temporally-resolved inkjet drop impaction on surfaces

AICHE JOURNAL, Issue 10 2007
Hongming Dong
Abstract Impaction on smooth solid substrates of drops formed by the drop-on-demand (DOD) method was investigated over a wide range of impaction speeds (U0 = 2.21,12.2 m/s), surface contact angles (, = 6,107°), and drop diameters (D0 = 40.8,50.5 ,m). The experimental results were compared with several existing equations for predicting maximum spreading. The dimensionless time to reach maximum spreading ratio, scaled by D0/U0, ranged from 0.6 to 2.99, depending on Weber number and contact angle. Micron and millimeter drop impactions were compared, and the results indicate that scaling based on three dimensionless numbers (We, Re or Oh, and cos ,) is valid, but spreading ratios of millimeter drops are usually slightly larger during the whole process. The difference is ascribed mainly to the effect of gravity. © 2007 American Institute of Chemical Engineers AIChE J, 2007 [source]