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The development of nanofiber sponge materials with three-dimensional structures, high porosities, and large specific surface areas is crucial for the rapid separation of water-in-oil emulsions. In this study, we fabricated Janus mullite nanofiber (MNF) sponges with efficient oil–water separation performance using a novel combination of electrostatic-assisted solution blow spinning (E -SBS) and in situ growth. MNF sponges weighing 0.074 g were subjected to 100 compression cycles, with the stress reducing to 85.6 % of its initial value after impregnation with ZIF-8 nanoparticles and OTS. Consequently, the MNF sponges changed from hydrophilic to hydrophobic, and after 20 separation experiments, they still maintained high separation fluxes for oil–water mixtures and emulsions, achieving 7959 and 1803 L m−2 h−1, respectively. Moreover, the preparation process of the MNF sponges is environmentally friendly, causing no environmental pollution. Therefore, Janus MNF sponges show great potential for applications in oil–water separation. [Display omitted] • Janus MNF sponges exhibit efficient oil–water separation. • Green preparation process offers an eco-friendly solution. • Maintained high separation fluxes after 20 experiments. • Hydrophilic to hydrophobic transition enhances performance. [ABSTRACT FROM AUTHOR]

Highlights • Crosslinking of PVA nanofibrous membranes by heat and chemical treatments. • Water vapour sorption behavior by automated-vapour sorption technique. • Antimicrobial behavior of crosslink and hydrophobic membranes against mould and algae. Abstract Poly(vinyl alcohol) (PVA) is a water-soluble, semi-ionic and biocompatible polymer with excellent chemical and thermal stability. The chemical crosslinking of PVA membrane improve its stability towards humidity and water. In the present work, PVA nanofibrous membranes were fabricated using roller electrospinning techniques. The prepared membranes were crosslinked by heat treatment, glutaraldehyde dipping, and glutaraldehyde vapour. Furthermore, octadecyltrichlorosilane (OTS) treatment was used for hydrophobization of the crosslinked membranes. The prepared crosslinked membranes were analysed by scanning electron microscopy (SEM) and Fourier-transform infrared spectroscopy (FTIR). The hydrophobization of PVA nanofibrous membranes were analysed by employing optical goniometer and auto-dynamic vapour sorption (AVS) techniques. Further, the PVA membranes were tested against algae and mould growth at in-vitro laboratory conditions. The SEM and FTIR results revealed significant differences in the morphology of the PVA nanofibrous membranes and in chemical bond formation due to crosslinking treatments. Water contact angle and AVS data confirmed a hydrophobization of PVA membranes by the treatments. [ABSTRACT FROM AUTHOR]

Graphical abstract The marriage of porous silicon nanowires and OTS provides a barrier to water molecules in gas detection process. Highlights • The interferences of different humidity in gas detection progress were studied for SiNWs-based gas sensors. • OTS was utilized to modify partially insensitive porous SiNWs surface with the Si-O bond for improving humidity resistance. • The ultra-low concentration NO 2 detection and excellent reversibility of the OTS/SiNWs sensor was observed in high humidity. • Possible mechanism for enhanced performance of OTS/SiNWs was analyzed. Abstract Porous silicon nanowires (SiNWs) is considered as one of promising candidates for high-performance NO 2 sensor application in human health and quality life owing to its fast response and stable operation at room temperature. However, the development of SiNWs-based gas sensors for stable detection of ppb-level NO 2 in practical high-humidity environments remains a challenge. In this study, octadecyltrichlorosilane (OTS) was utilized to modify partially insensitive SiNWs surface with the Si-O bond, yielding an immunity to high humidity in gas detection process. The modified OTS provides an umbrella-like barrier blocking water molecules attraction on the nanowire surface which disinhibits the main adsorption sites and sensing channels of the sensor. The OTS-modified porous SiNWs (OTS/SiNWs) sensor exhibited a practical capability to detect 5 ppb NO 2 at humidity of 25%–55% RH and a response of 1.8% to 50 ppb NO 2 at 75% RH at room temperature. Moreover, the fast response/recovery characteristics and good reversibility of the OTS/SiNWs sensor was observed even under high humidity conditions. In addition, the OTS/SiNWs sensor displayed excellent stability to humidity variations. The enhanced gas sensing performance is attributed to a marriage of porous structure of SiNWs and OTS. The simple modification for SiNWs-based gas sensor will broaden new avenues, not only in chemical trace detection, but also in high humidity health monitoring. [ABSTRACT FROM AUTHOR]

Cyclopentanone is a promising building block in the conversion of biomass to fuels. It can be readily obtained from furanics derived from biomass and can be converted to intermediate products in the molecular weight range compatible with fuels via C C bond forming reactions. Among them, aldol condensation is a promising route. Conventional MgO catalysts are intrinsically active to catalyze this reaction, but they usually exhibit low surface areas and low stability in the presence of liquid water. The nitrate-citrate combustion method results in high surface area oxides with high condensation activity, but they are still susceptible to water attack. Here, we show that hydrophobic MgO-based catalysts functionalized with octadecyltrichlorosilane (OTS) exhibit remarkable stability in the liquid phase under conditions in which a conventional MgO deactivates in short time. [ABSTRACT FROM AUTHOR]

Self-assembly of nanocrystals yields wide diversified high-order structures and promises new opportunity for various technological applications. Herein, we developed a facile dip-coating process to fabricate desired patterns of silica nanoparticles with neat edge and high regularity. A micro-pattern of self-assembled monolayer of octadecyltriethoxysilane (OTE) was used as a solution mold for nanoparticle deposition. As a result, self-assembled patterning of nanoparticles could be obtained over wafer-scale areas by using this kind of easy way. Moreover, uniformed mono-layer silica assembly with micro-scale area could be deposited on silicon substrate by tuning the withdrawal speed and concentration of nanoparticle solution. A pre-treatment of vacuum ultraviolet (VUV) irradiation benefits for the orderly arrangement of silica assembly with few cracks. After dip-coating process, super-hydrophilic surface of silica films (<1° of water contact angle) could be also obtained by VUV post-treatment. Furthermore, we directly grew flower-like multi-needle titania on the silica assembly to fabricate SiO 2 -TiO 2 composite bilayer films. Their optical and morphological properties were accessed by UV–vis spectroscopy, X-ray diffraction, and scanning electron microscopy. The composite films have the potential application as enhanced light reflector films. [ABSTRACT FROM AUTHOR]

A self-assembled bilayer film of 1,2-bis(triethoxysilyl) ethane–octadecyltrichlorosilane (BTSE–OTS) was prepared on single-crystal silicon substrates by utilizing BTSE as an intermediate layer. The surface morphology of the film was characterized by small round protuberances, with a surface roughness of about 1.82 nm. Moreover, the BTSE–OTS bilayer film displayed comparable hydrophobicity and nano-scale friction behaviors to the OTS monolayer owing to their identical surface composition and similar surface morphology. The investigation of the micro-tribological properties revealed that the BTSE–OTS bilayer film possessed much higher anti-wear durability and load-carrying capacity than the OTS monolayer while maintaining the low friction coefficient (~ 0.05). The BTSE–OTS bilayer film may find expanded applications in the lubrication of micro-/nano-electromechanical systems as compared to the conventional OTS monolayer. [ABSTRACT FROM AUTHOR]

Alkyltrichlorosilane self-assembled monolayer (SAM) was regarded as the most stable SAM on silicon/silica substrate, but it was rarely coated on stainless steel 316L (SS316L) substrate surface due to the serious surface corrosion caused by the hydrochloric acid released during the hydrolysis process of alkyltrichlorosilane molecules. In this paper, a novel technical route aiming at constructing solid octadecyltrichlorosilane (OTS) SAM on SS316L surface was put forward. By prolonging the storage time of OTS--toluene reaction solution and adding a moderate amount of alkali into the reaction solution, a well-ordered and integrated OTS SAM was successfully coated on SS316L surface. The obtained OTS SAM was characterized by contact angle, atomic force microscopy (AFM), scanning electron microscope (SEM) and attenuated total reflectance Fourier transform infrared (ATR-FTIR). The long-term in vitro stability study of OTS SAM on SS316L showed that, even immersed in physiological saline or phosphate buffered saline (PBS) solution at 37 °C for up to 60 days, the sample surface still kept a typical hydrophobicity. [ABSTRACT FROM AUTHOR]

Abstract: In this research, the tetrahedral and octahedral coordination of Ti(IV) in alkyl silica–titania has been successfully controlled by the addition of water in sol–gel process. Octadecyltrichlorosilane (OTS) and tetraethyl orthotitanate (TEOT) were used as precursors. The effect of the addition of water on the local coordination of Ti(IV) was analyzed by using Fourier transform infrared (FTIR) spectrometer, diffuse reflectance ultra-violet visible (DR UV–Vis) spectrometer, field emission scanning electron microscope (FESEM), X-ray diffraction (XRD) spectrometer and transmission electron microscope (TEM). It was demonstrated that water facilitate the formation of Si O Ti bond which is related to the tetrahedral Ti(IV). These materials exhibit the pattern of peak at the small angle of X-ray diffractogram and type IV shape adsorption–desorption isotherms characteristic of mesoporous silica–titania. The mesoporous structure shaped like ‘broom fibers’, arranged by lamellar structure like fibers with diameter size about 3–5nm has been clearly observed by TEM. The catalytic activity of alkyl silica–titania catalysts obtained was tested in polymerization of styrene in the presence of aqueous hydrogen peroxide. It showed that the presence of the tetrahedral Ti(IV) gave a beneficial effect in increasing the activity in this catalytic reaction. [Copyright &y& Elsevier]

Abstract: Profile switching of two-phase flows is often required in microfluidic systems. Manipulation of flow profiles can be realized by control of local surface energy of micro channel through wettability-patterning of channel surface. This article presents a facile approach for wettability-patterning of the micro channels of glass chips. Commercially available octadecyltrichlorosilane (OTS) was used to hydrophobilize the channels via the formation of OTS self-assembly monolayer (SAM), and a UV-source that mainly emits deep UV-light of 254 and 185nm was employed to degrade the in-channel formed OTS-SAM. The architecture of soda-lime glass/quartz glass hybrid chip was designed to facilitate the deep UV-light effective degrading the OTS-SAM. The established approach, together with the side-by-side laminar-flow patterning technique, was applied to prepare various finely patterned channel networks for different tasks of flow profile switching. The micro device capable of conducting the profile switch from W/O droplets to two separated continuous phases was demonstrated to perform on-chip quick liquid–liquid extraction for the determination of partition coefficients of pharmaceuticals. [Copyright &y& Elsevier]

Abstract: The potential of adsorptive removal of organic compounds with a wide range of solubility (S w) from 55 to 75,000mg/L onto octadecyltrichlorosilane (OTS) modified titanate nanotube (TNT) was investigated. The examined organic adsorbates included trichloromethane, benzene, toluene, ethylbenzene, propylbenzene, n-pentanol, m-cresol, and phenol. The adsorbent was prepared via a hydrothermal method to produce TNT that was modified by the OTS. Effects of OTS modified process on the revolution of microstructure and surface chemistry characteristics of TNT were characterized with XRD, nitrogen adsorption–desorption isotherms, and FTIR. It was found that the prepared TNT weakly adsorbed low-S w organic compounds, but exhibited high uptakes for organic compounds with high S w values. The OTS-modified TNT (OTNT) possessed both hydrophilic and hydrophobic surface and it could uptake organic compounds with a wide range of S w values. The isotherms of low-S w organic compounds on the OTNT approached to linearity and the adsorption capacities were inversely proportional to their S w values, implying that the dominating sorption mechanism was partitioning. The isotherms of the high-S w organic compounds were concave downward curves, indicating that the organic compounds were adsorbed on the sites that were not covered by OTS. It was experimentally concluded that the OTNT might be considered to be an excellent adsorbent which could effectively uptake organic compounds with a wide range of solubility due to its amphiphilic characteristics. [Copyright &y& Elsevier]

Abstract: This article investigated the sorption capacities and sorption mechanisms of several organic compounds, benzene, toluene, ethylbenzene, propylbenzene, trichloromethane, n-pentanol, m-cresol, and phenol with different water solubilities (S w, ranging from 55 to 75000mg/L) onto n-octadecyltrichlorosilane (OTS)-modified and unmodified NaY zeolite. The OTS-modified NaY zeolite (OMZ) featured an external hydrophobic surface, but its internal pores retained their hydrophilic surfaces. Several techniques – including Fourier transform infrared (FTIR) spectroscopy, BET analysis, and elemental analysis – were used to demonstrate experimentally that the OMZ was an amphiphilic adsorbent. The unmodified NaY zeolite weakly adsorbed organic compounds with values of low S w, but exhibited high uptakes of those organic compounds that could form hydrogen bonds with the zeolite surface. For the OMZ, however, the low-S w organic compounds partitioned to the OTS on the modified zeolite to increase their sorption dramatically, while the high-S w organic compounds adsorbed on the internal pore surfaces to maintain their high adsorption capacities. The water solubility, molecular size, and chemical structure of the tested organic compounds were all key factors affecting their adsorption capacities. The OMZ could uptake organic compounds effectively over a wide range of water solubilities. [Copyright &y& Elsevier]

Abstract: Simultaneous measurement of growth morphology and electronic energy level alignment for pentacene layers on silicon oxide before and after the octadecyltrichlorosilane (OTS) self-assembled monolayer treatment has been carried out by photoemission electron microscopy (PEEM) and ultraviolet photoelectron spectroscopy (UPS). On the bare silicon oxide, the change of the highest occupied molecular orbital (HOMO) position with the pentacene thickness is marginal because of relatively strong interaction between the substrate and pentacene from the beginning. On the OTS-covered surface, due to the weak interaction between the substrate and pentacene, the diffusion of pentacene is enhanced and domain size gradually grows, leading to more or less standing-up orientation of the pentacene molecules. This comparison explains well the substrate-dependent growth morphology and interfacial dipole change of pentacene thin films. [Copyright &y& Elsevier]

Abstract: Surfaces with superhydrophobicity are important in a number of biological and industrial processes. Hierarchical film based on polydimethylsiloxane (PDMS) and SiO2 with a water contact angle of 155° and sliding angle of 6° was prepared by a facile drop-coating method. Surface modification of SiO2 spheres was found to improve particle dispersion and increase their compatibility with PDMS, which eventually affected the stability of the hierarchical structure. Different curing temperatures were studied for enhancing the hydrophobicity of the hierarchical structure. We examined the mechanical robustness of the superhydrophobic surface by using a shear test, and found that the hierarchical PDMS-based SiO2 films retained superhydrophobicity after 48KPa mechanical shears. [Copyright &y& Elsevier]

Abstract: A MVD silica layer that consists of a highly hydrated surface favorable for organosilane surface reaction is investigated. The MVD silica layer lacks free surface silanol groups while supporting a more extensive adsorbed water layer as compared to oxidized Si(100). Octadecyltrichlorosilane monolayers (OTS) deposited on the MVD silica layer are found to follow the same mechanisms of growth and exhibit properties comparable to those formed on oxidized Si(100) surfaces. The growth process of octadecylsiloxane films is investigated as a function of immersion time and temperature by utilizing ATR-FTIR, ellipsometry, contact angle analysis, and AFM. The MVD silica layer is shown to support an ordered interfacial water structure that is more tightly bound due to a higher degree of hydrogen bonding associated with the hydroxylated surface. The importance of interfacial water on the OTS film formation process is highlighted and the role of free OH groups on the adsorption mechanism is diminished. It is shown that OTS films can be formed on a highly hydrated surface comparable to those formed on oxidized Si(100) surfaces. [Copyright &y& Elsevier]

Abstract: Potassium titanate whiskers (PTWs) were modified with n-octadecyltrichlorosilane (OTS) by self-assembled method and polytetrafluoroethylene (PTFE)/polyetheretherketone (PEEK) composites were fabricated with either pristine PTW or OTS modified PTW. Tribological and mechanical properties of PTFE/PEEK composites with both fillers were comparatively studied. Results show that OTS was successfully self-assembled on the surface of PTW, which introduces a dramatic increase of water contact angle from 5.5° to 141°. The dispersion of PTW and interfacial compatibility between PTW and PTFE/PEEK matrix were improved owing to the reduction of surface energy of PTW with OTS surface modification, which are the main reasons for the improvements of mechanical and tribological properties of PTW(OTS)/PTFE/PEEK composites. The best wear resistance of PEEK composites was achieved with the addition of 10wt.% OTS treated PTW, which is 150% higher than the unfilled ones. Water contact angle, Fourier transform infrared spectroscopy, scanning electron microscopy, energy dispersive spectrometry and differential scanning calorimetry were used in this work for better understanding of the reinforcing mechanisms in both mechanical and tribological properties. [Copyright &y& Elsevier]

Abstract: Hydrophobic micro/nano-engineered surfaces (MNESs) with good adhesion and frictional performances were fabricated by the combination of aluminum-induced crystallization (AIC) of amorphous silicon (a-Si) and octadecyltrichlorosilane (OTS) coating. The AIC of a-Si technique was used to produce silicon micro/nano-textured surfaces, while an OTS self-assembled monolayer was used to lower the surface energies of the textured surfaces. The wetting properties of the MNESs were studied using a video-based contact angle measurement system. The adhesion and friction properties of the MNESs were investigated using a TriboIndenter. This study shows that the adhesion and frictional performances of all MNESs are significantly improved compared to untreated silicon substrate surfaces, and the adhesion and frictional performances of the OTS-modified textured surfaces strongly correlate to their surface wetting property, i.e., the larger the water contact angle, the better the adhesion and frictional performances of the OTS-modified textured surfaces. [Copyright &y& Elsevier]

Abstract: The treatment of hydrophilic porous ceramics to render them hydrophobic and wetting to non-aqueous phase liquids (NAPLs) is frequently needed in multiphase flow experiments to control the flow or to measure the pressure of the NAPL. In addition, research dealing with soil wettability implies a need for hydrophobic or NAPL-wet soils. The traditional procedure, which has been widely used in literature, to render hydrophilic porous ceramics and soils hydrophobic is achieved by placing the hydrophilic solid in a 5% (by volume) octadecyltrichlorosilane (OTS) solution in ethanol followed by rinsing in ethanol. This research assesses the use of this procedure as it was found that this treatment procedure resulted in excess OTS on the surface of treated hydrophobic solids which can dissolve in an organic phase and in turn alter the wettability condition of adjacent hydrophilic soils. A modified procedure, which results in hydrophobic solids free of excess OTS, is presented. [Copyright &y& Elsevier]

Abstract: Selective-area atomic layer deposition (ALD) was studied using microcontact printed self-assembled monolayers (SAM) as growth preventing mask layers. Patterned self-assembled octadecyltrichlorosilane (OTS, H3C(CH2)17SiCl3) monolayers were prepared on the silicon (100) surface by an elastomeric stamp which had 1.5 µm wide parallel print lines with 1.5 µm wide spaces in between. Passivation properties of the monolayers against ALD growth were verified by ALD processes of iridium and TiO2. Iridium was grown at 225 °C and TiO2 at 250 °C. The quality of SAM was controlled by water contact angle measurements. Patterned iridium and TiO2 films were studied with field emission scanning electron microscope and energy dispersive X-ray spectrometer. [Copyright &y& Elsevier]

Abstract: The coating processes involving octadecyltrichlorosilane (OTS) self-assembled monolayers are known to be highly irreproducible due to the bulk hydrolysis reaction with the release of Cl, forming aggregates of siloxane (Si–O–Si) bonded networks. Factors known to affect deposition include temperature, solvent and most importantly water content of the coating solvents. Bulk silanization reaction of octadecyltrichlorosilane in cyclohexane was investigated at varying relative humidities. In situ FTIR transmission was used to determine OTS converting from silane to silanol along with water content and ion chromatography analysis from the release of Cl gas as a function of extended period of times. Silane to silanol conversion did not occur at less than 18% relative humidity over an 11 days test whereas all silanes converted to silanols after 2 days at a relative humidity of 83%. Based on these results, one may conclude that there is a finite lifetime for silane molecules during coating before converting into silanols. [Copyright &y& Elsevier]

Abstract: The tools of surface science have enabled a thorough understanding of the ordering of liquid crystalline materials in contact with the surfaces of solids. This report moves beyond these past studies of solid–liquid crystal interfaces by describing the emergence of a set of experimental observations that revolve around the ordering of liquid crystals at interfaces to immiscible aqueous phases. The self-assembly of surfactants, lipids, proteins and synthetic polymers at these interfaces has recently been shown to lead to a rich but poorly understood spectrum of orientational ordering behaviors of liquid crystalline materials. It is also evident that the ordering of the liquid crystals influences the organization of the molecules that assemble at these interfaces. In particular, recent experiments have revealed the influence of the molecular structure and interfacial organization of adsorbed surfactants on the ordering of the liquid crystals. The time-dependent behaviors of liquid crystals, which can reorganize on time scales of tens of milliseconds, have been used to follow dynamic phenomena at these interfaces, including the adsorption, desorption and spatial reorganization of surfactants. At these same aqueous–liquid crystal interfaces, phospholipids have been shown to assemble into monolayers that mimic dynamic properties of biological membranes. Specific protein binding events and enzyme-catalyzed reactions at phospholipid-decorated interfaces of liquid crystals lead to changes in the organization of the phospholipids that are reported as ordering transitions in the liquid crystals. Larger amphiphilic molecules, including polymers and proteins, have also been shown to assemble at aqueous–liquid crystal interfaces and to couple to the ordering of the liquid crystal. For example, functional amphiphilic polymers impart a means to reversibly control the ordering of liquid crystals in response to changes in solution conditions (e.g., pH). These observations, when combined, suggest that interfaces formed between liquid crystals and aqueous phases represent a fundamentally interesting and technologically promising class of interfaces for chemical and biological sensing, active control of interfacial assemblies and realization of stimuli-responsive materials. These interfaces define a rich set of scientific challenges that warrant the attention of the surface science community. [Copyright &y& Elsevier]

Abstract: Thin organic films of octadecyltrichlorosilane (OTS) and aminopropyltriethoxysilane (APTES) were deposited on oxidized Si(111) substrates and characterised using atomic force microscopy (AFM) and nanoindentation methods. Films derived from a novel alkylsilane, 4-[N,N-(2-pyridyl)aniline]triethoxysilane (NDTS), which has properties similar to related electroluminescent and fluorescent compounds, were also examined. This latter compound could be used to directly couple a fluorescent or electroluminescent centre to a semiconductor surface, with applications in microfluidics or other microelectronic-based sensors. AFM images showed that when OTS or APTES was deposited from ethanol solution onto the oxidized Si surface, an inhomogeneous film was formed, containing both smooth regions and polymerised particles of the alkylsilanes up to 200nm in diameter. Nanoindentation force/displacement curves could clearly distinguish these two regions of the film, and they showed quite different mechanical properties. When deposited from a solution of ethanol and CH2Cl2, OTS films were smooth and completely covered the surface. Discontinuities in the force/displacement curves, corresponding to a breakthrough by the indentor through the film into the substrate showed that these films were some 2nm in thickness. When OTS, APTES or NDTS were deposited from CH2Cl2 solution, similar discontinuities could be observed, and showed that the film thickness increased, and roughness decreased, as the concentration of alkylsilane in solution was decreased. The results are discussed in the context of using nanoindentation methods as a means of characterising organic thin films. [Copyright &y& Elsevier]

Abstract: It has been well known that plasma pretreatment can stabilize the hydrocarbon silane monolayer self-assembled on a mica surface. However, the extent of this improvement is not well known. To explore this issue, n-octadecyltrichlorosilane (OTS) monolayers were self-assembled on both untreated and plasma-treated mica surfaces, and their interfacial properties were investigated and compared at various physical conditions (temperature, relative humidity, contact time, high stress, and contact repetition) through the use of surface force measurements. This study revealed that in highly humid conditions (>90% relative humidity) there is a substantial difference of stability between untreated and plasma-treated surfaces, the OTS monolayer on plasma-treated mica surface being much more stable. In particular, protrusion behavior in the monolayer was always observed in untreated samples, but never in plasma-treated samples during contact repetition experiments. This directly demonstrates that the significantly improved stability directly comes from extensive chemical bonds between OTS molecules and the plasma-treated mica surface. [Copyright &y& Elsevier]

Abstract: A simple procedure for the fabrication of submicron-sized functional organic templates is demonstrated. Native silicon samples are partially coated in millimolar octadecyltrichlorosilane (OTS) solutions. After coating, atomic force microscopy (AFM) reveals islands with diameters ranging from 0.6 to 1μm. The hydrocarbon chains of the self-assembled silane entities within these islands subsequently are chemically functionalized following a robust preparation scheme. X-ray photoelectron spectroscopy (XPS) and water contact angle measurements were used for characterization. After functionalization, alkylsiloxane islands provide a versatile means to direct the deposition of nanoscopic components. In particular, citrate-stabilized gold nanoparticles (d =16±2nm) are shown to selectively adsorb onto aminated islands, whereas adsorption on areas between these islands is negligible. [Copyright &y& Elsevier]

Abstract: Sapphire is one of the most promising materials for the development of implantable biomedical devices due to its exceptional chemical, mechanical, electrical, thermal and optical properties. Silicon has also been widely used to manufacture neuroprosthetic devices in the past. However, both of these materials have been found to cause the most severe tissue reactions while implanted in vivo in the rat brain, compared with other biomaterials. In order to enhance the biocompatibility of sapphire and silicon, their surfaces were modified by depositing a self-assembled monolayer (SAM) of octadecyltrichlorosilane (OTS), followed by the photo-immobilization of heparin. To comprehensively evaluate the short- and long-term neural biocompatibility, sapphire and silicon wafers (2.5 mm dia×0.25 mm thick) with and without heparin coating were implanted on the surface of adult rat''s cortex for 10, 28 and 90 days. Specific evaluations of the cell types that contribute to an inflammatory response were performed. The histological results indicate that the biocompatibility of sapphire is dramatically improved by heparin immobilization, while this dramatic improvement is not observed on heparin coated silicon. The failure to improve the biocompatibility of silicon by heparin immobilization can be attributed to the corrosion of the silicon surface in vivo, which was confirmed by atomic force microscopy (AFM). Meanwhile, no corrosion was observed on heparin coated sapphire surfaces and a very thin layer of proteins or extracellular matrix was deposited on the surfaces. [Copyright &y& Elsevier]

Abstract: CO2-plasma is used to introduce functional groups on the uppermost surface of an alkoxysilane self-assembled monolayer (SAM). The structural and chemical modifications of the material surface were monitored by X-ray reflectometry, atomic force microscopy, X-ray photoelectrons spectroscopy and water contact angle measurements. Optimization of the plasma parameters is performed in order to achieve a maximum functionalization and to prevent degradation of the SAM. Finally, the ability of grafting organic compounds onto the plasma modified SAMS was demonstrated by the formation of an alkoxysilane bilayer. [Copyright &y& Elsevier]

Abstract: Surface modification of mesoporous, inorganic substrates by organo-silanes to enhance the gas separation properties was studied with an emphasis on understanding the influence of the silane layer structure. Dimethyloctadecylchlorosilane (OCS) was used to create a polymer brush on the surface of mesoporous Vycor glass and octadecyltrichlorosilane (ODS) was used to create a polymerized silane layer. The membranes were characterized by gas permeation as well as indirectly by NMR spectroscopy on silica gel that had undergone same silane treatment as that of the membranes. All the modified membranes were selective for n-butane over nitrogen at 295K. A variety of reaction and pretreatment conditions were studied to optimize the loading of monochlorosilanes. The effect of varying the silanization reaction temperature was minimal on the selectivity; however, the pure gas selectivity increased by a factor of three by varying the pretreatment conditions. For a typical OCS modified membrane, the pure n-butane/nitrogen selectivity was 7.8 as compared to the mixed gas selectivity of 72.9 for a 50% mixture of n-butane in nitrogen. This difference was probably due to the pore blocking effects of n-butane. In comparison to the OCS membrane, the ODS membrane was seven times more selective for n-butane over nitrogen in the pure gas experiments. However, in the mixed gas experiments, higher n-butane/nitrogen separation factors were observed for the membrane modified with OCS as compared to the ODS-modified membrane. [Copyright &y& Elsevier]

Abstract: A slab optical waveguide (SOWG) has been used for study of adsorption of both methylene blue (MB) and new methylene blue (NMB) in liquid–solid interface. Adsorption characteristics of MB and NMB on both bare SOWG and silanized SOWG by octadecyltrichlorosilane (ODS) were compared. Effect of pH on adsorption on MB and NMB was investigated. Binding rate constant analysis showed that both MB and NMB on bare SOWG demonstrates larger association constants than those on ODS-SOWG. Interactions of MB and NMB on bare SOWG and ODS-SOWG were analyzed by molecular mechanics calculation method. The binding energy change was in the following order: E NMB–bare > E MB–bare > E NMB–ODS > E MB–ODS. [Copyright &y& Elsevier]

We have performed in situ X-ray reflectivity studies of the growth of octadecyltrichlorosilane (OTS) monolayers on oxidized Si(111) from solutions in heptane. We find that for all concentrations, the film grows through the formation of islands of vertical molecules. The coverage follows a simple Langmuir form as a function of time, except for very low concentration solutions at early times, where a time offset is required to fit the curve. We have also examined films removed from solution, and we find that rinsing removes molecules and causes the remaining molecules to tilt. Thus, samples studied using the ‘interrupted growth’ technique are not representative of the actual growth process. [Copyright &y& Elsevier]

Mixed self-assembled monolayers of octadecyltrichlorosilane (OTS) and methyltrichlorosilane (MTS) were deposited via simple silanization procedure on a mechanically polished titanium surface. The monolayers act as molecular anchors for mixed hybrid bilayer lipid membranes (mhBLM) which were accomplished via vesicle fusion. A variation of the MTS concentration in silanization solutions significantly affects properties of mhBLMs composed of a 1,2-dioleoyl-sn-glycero-3-phosphocholine (DOPC) and cholesterol (Chol). The bilayers become less insulating following an increase of the MTS content. On the other hand, an increase of the MTS concentration provides flexibility of the mhBLM membranes necessary for the functional reconstitution of membrane proteins. The optimal molar ratio of MTS in silanization solution is 40% providing anchors for intact mhBLMs as confirmed by their specific capacitance of 0.86 μF cm−2. We found that the bilayers containing 40% (mol) of cholesterol bind cholesterol dependent pneumolysin (PLY). However, we did not observe functional reconstitution of PLY. While α-hemolysin almost fully disrupts mhBLMs assembled from 100% diphytanoyl. An important advantage of the titanium/OTS/MTS molecular anchor systems is their ability of repetitive regeneration of phospholipid bilayers without losing functional properties as demonstrated in the current study. This creates a possibility for the multiple-use phospholipid membrane biosensors which have a potential of decreasing the cost of such electrochemical/electroanalytical devices. Unlabelled Image • Mixed self-assembled silane monolayers form on metallurgical titanium surface. • Mixed hybrid bilayer lipid membranes are obtained by vesicle fusion. • Membrane damaging proteins interact with mixed hybrid bilayers. • Repetitive formation of hybrid bilayers can be accomplished. [ABSTRACT FROM AUTHOR]

• OTS/SiO 2 composite sol was prepared by one-pot synthesis. • OTS/SiO 2 composite films were textured by OTS modified SiO 2 nanoparticles. • The films had excellent anti-wear property. • Anti-wear mechanism of the films was investigated. In order to improve the service life of Si devices applied in micro-electro-mechanical systems (MEMS), anti-wear octadecyltrichlorosilane/silica nanoparticles (OTS/SiO 2) composite films were prepared on silicon by sol-gel and self-assembly techniques. The structure, morphology, chemical composition, wettability, anti-adhesion and tribological properties of the films were characterized. The prepared OTS/SiO 2 composite films were hydrophobic with water contact angle of 119.0 ± 0.5° and textured by OTS modified SiO 2 nanoparticles with long chain structures. Compared with Si substrate and OTS self-assembled monolayer (SAM), OTS/SiO 2 composite films could not only reduce adhesive force to 17.7 ± 0.5 nN but also reduce friction coefficient to 0.18 ± 0.02 under a load of 1 N. The anti-wear lifetime was prolonged to 40,897 s, while OTS SAM was gradually worn out in 104 s under the same friction conditions. The synergistic effect of the transferring of OTS SAM as lubrication films and the repairing of abrasive areas by SiO 2 nanoparticles accounted for the preeminent wear resistance. OTS/SiO 2 composite films are expected to be effectively used in MEMS as high-performance lubrication films. [ABSTRACT FROM AUTHOR]

• Fuorine doped tin oxide (FTO) glass slide was used as substrate for the modification. • Self-assembled monolayer (SAM) from octadeciltrichlorosilane (OTS) was formed over FTO surface. • Scanning electrochemical microscopy (SECM) was used for the investigation of OTS/FTO structure. • Formation of heterogeneous OTS-monolayer on FTO surface has been confirmed by SECM investigations. Recently, self-assembled monolayers (SAMs) are gaining a lot of interest due to their simplicity of preparation and wide applicability in the development of model systems used in pharmaceutical and biomedical analysis. The most efficient methods used for the investigation of SAM-based structures usually include cyclic voltammetry and electrochemical impedance spectroscopy. Scanning electrochemical microscopy (SECM) could be also used as an alternative method for SAM investigations, because this method enables to map modified surface. In this work, the surface of fluorine doped tin oxide (FTO) was modified with octadeciltrichlorosilane (OTS) based SAM and investigated using SECM. Measurements, which were carried out by SECM, lead to conclusion that highly heterogeneous and distributed monolayer has been formed on FTO surface. [ABSTRACT FROM AUTHOR]