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Cardiomyocytes, differentiated from induced pluripotent stem cells (iPSCs), have the potential to produce patient- and disease-specific pharmacological and toxicological platforms, in addition to their cardiac cell therapy applications. However, the lack of both a robust and a simple procedure for scalable cell substrate production is one of the major limitations in this area. Mimicking the natural healthy myocardium extracellular matrix (ECM) properties by altering the cell substrate properties, such as stiffness and chemical/biochemical composition, can significantly affect cell substrate interfacial characteristics and potentially influence cellular behavior and differentiation of iPSCs to cardiomyocytes. Here, we propose a systematic and biomimetic approach, based on the preparation of poly(dimethylsiloxane) (PDMS) substrates having the similar stiffness as healthy heart tissue and a well-defined surface chemistry obtained by conventional [(3-aminopropyl)triethoxysilane (APTES) and octadecyltrimethoxysilane (OTS)] and amino acid (histidine and leucine)-conjugated self-assembled monolayers (SAMs). Among a wide range of different concentrations, the 50:1 prepolymer cross-linker ratio of PDMS allowed adaptation of the myocardium stiffness with a Young's modulus of 23.79 +/- 0.61 kPa. Compared with conventional SAM modification, amino acidconjugated SAMs greatly improved iPSC adhesion, viability, and cardiac marker expression by increasing surface biomimetic properties, whereas all SAMs enhanced cell behavior, with respect to native PDMS. Furthermore, leucine-conjugated SAM modification provided the best environment for cardiac differentiation of iPSCs. This optimized approach can be easily adapted for cardiac differentiation of iPSCs in vitro, rendering a very promising tool for microfluidics, drug screening, and organ-on-chip platforms.

BACKGROUND: Novel hybrid absorption coupled with membrane filtration technology is proposed for the recovery of oil from produced water. This study aims at developing a low cost superhydrophobic-superoleophilic kaolin-based hollow fiber ceramic membrane using phase inversion and sintering technique for the recovery of oil from synthetic produced water. The influence of different organosialanes, such as methyltriethoxysilane (MTES), octadecyltrimethoxysilane (OTMS), 1H,1H,2H,2H-perfluorooctyltriethoxysilane (FAS), trichloro(octadecyl)silane, and chlorotrimethylsilane, was investigated for the modification process. RESULTS: Field emission scanning electron microscopy results clearly indicated that membrane morphology was altered with coating of the organosilanes. The surface functionality of the organosilanes on kaolin membranes was also confirmed by X-ray photoelectron spectroscopy and Fourier-transform infrared spectroscopy. From the atomic force microscopy studies, membrane surface roughness was observed to be higher for MTES, FAS, and OTMS coated kaolin membranes. Contact analysis show that the membranes coated with MTES, FAS and OTMS organosilane agents possessed superhydrophobicity of 161.3°, 155.6°, and 150.2° as well as superoleophilicity of 0°, 1.5°, and 2.3°, respectively. CONCLUSION: Crude oil with a concentration of 2 g L−1 displayed a higher oil flux of 80 L m−2h−1 and absorption of 90% for MTES coated kaolin membrane. This study extends the frontier of knowledge in ceramic membrane application for produced water treatment.

Hypothesis: Surfactants are widely used in agri-sprays to improve pesticide efficiency, but the mechanism underlying their interactions with the surface wax film on plants remains poorly understood. To facilitate physical characterisations, we have reconstituted wheat cuticular wax films onto an optically flat silicon substrate with and without octadecyltrimethoxysilane modification to control surface hydrophobicity. Experiments: Imaging techniques including scanning electron microscopy (SEM) unravelled morphological features of the reconstituted wax films similar to those on leaves, showing little impact from the different substrates used. Neutron reflection (NR) established that reconstituted wax films were comprised of an underlying wax film decorated with top surface wax protrusions, a common feature irrespective of substrate hydrophobicity and highly consistent with what was observed from natural wax films. NR measurements, with the help of isotopic H/D substitutions to modify the scattering contributions of the wax and solvent, revealed different wax regimes within the wax films, illustrating the impact of surface hydrophilicity on the nanostructures within the wax films. Findings: It was observed from both spectroscopic ellipsometry and NR measurements that wax films formed on the hydrophobic substrate were more robust and durable against attack by nonionic surfactant C 12E 6 solubilised with pesticide Cyprodinil (CP) than films coated on the bare hydrophilic silica. Thus, the former could be a more feasible model for studying the wax-surfactant-pesticide interactions.

The physical properties of electronic devices made by 2,6-diphenyl anthracene (DPA) are influenced by the microtexture of DPA surfaces. This work focused on the experimental investigation of the 3-D surface microtexture of DPA thin films deposited on OTS (octadecyltrichlorosilane), HMDS (Hexamethyldisilasane), OTMS (octadecyltrimethoxysilane), and Si/SiO2 (300 nm SiO2 thickness) substrates with 5 and 50 nm thicknesses and 5 and 10 μm scan size. The thin film surfaces were recorded using atomic force microscopy (AFM) and their images were stereometrically analyzed to obtain statistical parameters, in accordance with ASME B46.1-2009 and ISO 25178-2: 2012. The results showed the effect of different manufacturing parameters on microtexture values where the granular structure is confirmed in all films. In addition, root mean square is increased by increasing the thickness from 5 to 50 nm for all types of substrates.

Solid wastes, such as polystyrene foam waste and silica gel waste which are ubiquitous products have caused serious environmental issues, such as “white pollution”, threatening the health of humans and animals. As such, the need to recycle and re-use of solid wastes has attracted increasing attention in the last few years. In this work, a self-healing superhydrophobic coating is successfully fabricated by blending polystyrene foam waste with fluorinated silica gel waste (F-silica gel waste), octadecyltrimethoxysilane (OTMS) modified silica particles (OTMS-silica particles), and near-infrared (NIR) light responsive microcapsules. The F-silica gel waste and OTMS-silica nanoparticles act as hydrophobic fillers meanwhile the polystyrene foam waste acts as a coating binder. The NIR-responsive microcapsules are obtained by the electrostatic adsorption of carbon nanoparticles onto the surface of microcapsules loaded with 1H, 1H, 2H, 2H-perfluorooctyltriethoxysilane. The superhydrophobic property of the coating can be healed after 10 minutes of NIR irradiation. Additionally, the as-prepared coating can be coated on several different substrates, similar to commercial coatings, and it is seen that its excellent superhydrophobic property is durable and is maintained even when the coating is subjected to a sand-drop test. The self-healing mechanism of the superhydrophobic coatings is also investigated.

BACKGOUND Membrane distillation (MD) is a promising low-cost and efficient desalination process, yet it has not been fully implemented at an industrial scale. Membrane wetting and low porosity are limiting factors leading to low water recovery rates. The current study involved the synthesis of membranes that combined high mechanical stability, porosity and superhydrophobicity, to prevent wetting, with high salt rejection and water flux. RESULTS Silica nanoparticles (SiO(2)NPs) were synthesized by a novel green chemistry procedure, modified with three different silane reagents [octadecyltrimethoxysilane, N-octadecyltrichlorosilane (ODTS) and chlorodimethyl-octadecyl silane] and finally embedded on polyvinylidene fluoride (PVDF) nanofibre membranes using an in-situ electrospinning technique. These modified membranes displayed a Young's modulus of similar to 43 MPa and showed highly porous properties (similar to 80% porosity, 1.24-1.41 mu m pore sizes) and superhydrophobic surfaces (contact angle >150(o)); thus possessing parameters falling within the range of highly recommended values in MD. Remarkably, the concentration of modified SiO(2)NPs used to produce the superhydrophobic PVDF nanofibre membranes was significantly lower (1% w/w) than those reported in the literature (3-4% w/w), clearly indicating the efficiency of these silane reagents. CONCLUSION Membranes embedded with ODTS-modified SiO(2)NPs were the most efficient; rejecting salts at high efficiencies (>99.9%) with water fluxes of approximate to 34.2 LMH at 60 degrees C, thus indicating their capacity as an energy-efficient process to produce high purity water. (c) 2019 Society of Chemical Industry

Secondary reactions of surface coating are of great importance and have drawn great attentions, since it can make the coating as a versatile platform for different uses via tailoring surface properties. A good example is the polydopamine (PDA) coating which has been widely used for preparation of various functional materials owing to its secondary reactions. In our recent study, we have developed hierarchical tannic acid (TA)-aminopropyltriethoxysilane (APTES) coating with distinct layer-nanospheres structure. Herein, the secondary reactions of the TA-APTES coating has been investigated in detail. And for the first time, various (TA-APTES)-based functional materials including superhydrophobic, adsorbent, and catalytic materials have been prepared for oil/water separation, dye adsorption, and 4-nitrophenol reduction, respectively. Significantly, under the same conditions, the performance of the (TA-APTES)-based functional materials is much better than that of the PDA-based materials: (a) The adsorptive capacity of the (TA-APTES)-based adsorbent toward rose bengal, methyl bule, orange G, and amaranthus red is 80.1%, 96.2%, 86.1%, and 98.6% higher than that of the PDA-based adsorbent, respectively; (b) The (TA-APTES)-based catalytic material can reduce about 98% of 4-NP in 10 min, while the PDA-based material can only reduce 60% of 4-NP under the same conditions; (c) After reacting with octadecyltrimethoxysilane, the TA-APTES coating can be directly transformed into superhydrophobic coating for oil/water separation, while the PDA coating is only hydrophobic and cannot separate oil/water mixture. The reasons for the significantly improved performance of the (TA-APTES)-based materials have been revealed. Our findings demonstrate that the TA-APTES coating can act as an outstanding platform for preparation of various functional materials with preferable performance, and the TA-APTES coating will be a promising substitute for PDA coatings.

Patterned arrays of nanoholes and nanorings were prepared using colloidal lithography combined with steps of solution immersion and vapor deposition of organosilanes. Samples prepared with colloidal lithography exhibit millions of reproducible test structures with a periodic arrangement throughout areas of the surface according to the dimensions and spacing of the particle mask. Views of the size and morphology of nanopatterns obtained with atomic force microscopy (AFM) can provide information of progressive steps of chemical reactions as nanostructures are grown within spatially confined areas surrounded by a resist film. A surface mask of colloidal latex or silica spheres was used to protect discrete areas of a Si(111) substrate from the deposition of organosilanes. When the mask was removed, the uncovered areas of the surface revealed regularly-shaped, small sites of uncovered substrate available for further reaction steps to build hierarchical surface structures. Nanostructures of zinc phthalocyanines (ZnPcs) were constructed using amine-terminated nanopatterns as sites for binding. Spatial selectivity was achieved for directing the attachment of ZnPcs to the surface using resist films of 2-methoxy(polyethyleneoxy)propyl]trichlorosilane (PEO-silane) and also with octadecyltrimethoxysilane (OTMS). The molecule chosen as a linker was (3-aminopropyl)triethoxysilane (APTES) which presents an amine group at the interface. In general, phthalocyanine molecules tend to bind in a coplanar orientation by physisorption to the surface and can stack together through pi-pi interactions between adjacent macrocycles. However, the nature of the substituents will also influence whether the molecules assemble on surfaces in a side-on orientation or with the macrocycle oriented in a coplanar arrangement. Hydroxyl and isothiocyanate pendant groups were attached to the macrocycles of ZnPcs chosen for this study, to investigate conformational differences when attached to APTES nanopatterns. The size and morphology of nanostructures was visualized and sensitively measured with tapping-mode AFM. The elastic response of samples patterned with ZnPc was mapped with force modulation AFM. Changes in the height of nanostructures indicate whether the macrocycles are oriented upright or parallel to the surface plane, or if multilayers were formed.

In the present work octadecyltrimethoxysilane (ODTMS) was deposited on mild steel in one and two-step treatments for corrosion resistance against a chloride medium (with and without sulphate reducing bacteria (SRB)). Electrochemical results showed that a hydrolysis of ODTMS for 3 h at pH 4 was sufficient for achieving a considerable enhancement in corrosion protection due to just one-step coating. However, corrosion resistance was found to be significantly superior due to the two-step treatment. The influence of the coating developed upon two-step treatment on the corrosion resistance of mild steel in the chloride solution containing SRB was assessed using comprehensive electrochemical analysis.

Textured growth of ZnO nanorods with no restriction of the substrate material is beneficial to their applications. The approaches to grow ZnO nanorods with texture are based on preparing suitable surface structure on the growth substrate, e.g. using a crystalline substrate with a specific surface structures or pre-depositing seed layers by high-temperature annealing of precursors. In the aqueous nutrient solution of the chemical bath deposition (CBD) process for ZnO growth, the concentration of Zn2+ ions at the extended hydrophobic surface is sufficiently high for forming self-assembly nuclei with a preferred orientation, resulting in the subsequent textured growth of ZnO nanorods. In this research, the hydrophobic surface is prepared by modifying Si surface with a self-assembly octadecyltrimethoxysilane (OTMS) monolayer. The formation mechanism of the nuclei on this hydrophobic surface for the textured growth of ZnO nanorods is investigated. It is shown that the nuclei form at the beginning of the CBD process and later transform into the Wurtzite structure to seed ZnO growth. An alternative approach to prepare seed layers is therefore involved in the aqueous CBD process, which is applicable to a range of hydrophobic substrates for textured growth of ZnO nanorods.

In this work, a two-stage methodology to design super-hydrophobic surfaces was proposed. The first step consists of creating a rough nano/micro-structure and the second step consists of reducing the surface energy using octadecyltrimethoxysilane. The surface roughening was realized by three different short-term pretreatments: (i) Boiling water, (ii) HNO3/HCl etching, or (iii) HF/HCl etching. Then, the surface energy was reduced by dip-coating in diluted solution of octadecyltrimethoxysilane to allow the formation of self-assembled silane monolayers on a 6082-T6 aluminum alloy surface. Super-hydrophobic aluminum surfaces were investigated by SEM-EDS, FTIR, profilometry, and contact and sliding angles measurements. The resulting surface morphologies by the three approaches were structured by a dual hierarchical nano/micro-roughness. The surface wettability varied with the applied roughening pretreatment. In particular, an extremely high water contact angle (around 180&deg, ) and low sliding angle (0&deg, ) were evidenced for the HF/HCl-etched silanized surface. The results of electrochemical tests demonstrate a remarkable enhancement of the aluminum alloy corrosion resistance through the proposed superhydrophobic surface modifications. Thus, the obtained results evidenced that the anti-wetting behavior of the aluminum surface can be optimized by coupling an appropriate roughening pretreatment with a self-assembled silane monolayer deposition (to reduce surface energy) for anticorrosion application.

The present investigation deals with the surface modification of sub-micrometer boron particles with octadecyltrimethoxysilane (OTMS, a silane compound) to improve the dispersion stability of boron...

International audience; ure continues to inspire scientists to adapt solutions in order to satisfy human needs, mainly in the maritime domain with metallic surface corrosion and its mechanical friction. In this research, the source of innovation comes from the lotus leaf and its well-known super-hydrophobicity. In this study, we have investigated the lotus leaf as a model for a super-hydrophobic maritime surface. The hydrothermal technique, which is considered to be a simple, low-cost, and scalable coating method, is applied to create zinc oxide (ZnO) nanorods (NRs), and an evaporation method is used to apply octadecyltrimethoxysilane (ODS). We apply such eco-green coatings onto commercial epoxy paints. Superhydrophobic surfaces (SHS) are obtained on maritime aluminum substrates. The characterization of SHS indicates improved behavior of water droplets on the treated surface: higher water static contact angles (WCA) from 98° to more than 152° and reduced sliding angles (SA) from 46° to 7°. Sliding speeds (SS) have been largely raised from 54 in the epoxy case to 1300 mm·s-1 after treatment. These results clearly demonstrate the real opportunity to apply ZnO-based nanomaterials onto existing commercial maritime coatings.

A miniaturized solid-phase method was proposed for the extraction of aflatoxin M1 and B1 from milk and jujube samples. Target analytes were identified by ultra high performance liquid chromatography coupled with quadrupole time-of-flight tandem mass spectrometry in positive mode. The main factors that affected the extraction ability and sensitivity of the analytical method were evaluated in detail. In the optimal conditions, 30 mg of silica particles functionalized with octadecyltrimethoxysilane and methanol were used as sorbent and desorption solvent in miniaturized solid-phase extraction, respectively. The calibration curves for aflatoxin B1 and M1 showed good linearity (r2 > 0.9921) within linear ranges. The limit of detection (S/N = 3) were determined to be 0.049 and 0.023 μg/kg for aflatoxin M1 and B1, respectively. In addition, the good spiked recoveries were obtained ranging from 88.24 to 105.35%. The results demonstrated that the proposed method had significant advantages including simple, inexpensive, rapid, and accurate, which considered as a suitable method for the trace analysis of aflatoxins.

[EN] Herein, a novel drug photorelease system based on gold nanostars (AuNSts), coated with a mesoporous silica shell and capped with paraffin as thermosensitive molecular gate, is reported. Direct measurements of the surface temperature of a single gold nanostar irradiated using a tightly focused laser beam are performed via a heat sensitive biological matrix. The surface temperature of a AuNSt increases by hundreds of degrees (degrees C) even at low laser powers. AuNSts coated with a mesoporous silica shell using a surfactant-templated synthesis are used as chemotherapeutic nanocarriers. Synthetic parameters are optimized to d avoid AuNSt reshaping, and thus to obtain nanoparticles with suitable and stable plasmonic properties for near-infrared (NIR) laser-triggered cargo delivery. The mesoporous silica-coated nanostars are loaded with doxorubicin (Dox) and coated with octadecyltrimethoxysilane and the paraffin heneicosane. The paraffin molecules formed a hydrophobic layer that blocks the pores, impeding the release of the cargo. This hybrid nanosystem exhibits a well-defined photodelivery profile using NIR radiation, even at low power density, whereas the nonirradiated sample shows a negligible payload release. Dox-loaded nanoparticles displayed no cytotoxicity toward HeLa cells, until they are irradiated with 808 nm laser, provoking paraffin melting and drug release. Hence, these novel, functional, and biocompatible nanoparticles display adequate plasmonic properties for NIR-triggered drug photorelease applications., The authors gratefully acknowledge financial support from the Spanish Government (Projects AGL2015-70235-C2-2-R and MAT2015-64139-C4-1-R), the Generalitat Valenciana (Project PROMETEOII/2014/047), and European Union (Programme European Union Action 2 Erasmus Mundus Partnerships, Grant-2014-0870/001-001). A. Samadi and L. B. Oddershede acknowledge financial support from the Novo Nordisk Foundation (NNF14OC0011361) and from the Danish National Research Foundation (DNRF116). A. H. Montoto thanks Erasmus Mundus Programme for his PhD scholarship at EurolnkaNet project. The authors thank UPV electron microscopy and CIPF confocal and electron microscopy services for technical support.

A superhydrophobic CeO2-modified kapok fiber (SCMKF) was fabricated using CeO2 and octadecyltrimethoxysilane (OTMS) by a simple chemical deposition method. Scanning electron microscopy, Fo...

A simple and effective approach for vertical alignment of liquid crystals (LCs) over a functionalized transparent flexible substrate is described. Surface characterization of this commercially available plastic substrate through X-ray photoelectron spectroscopy (XPS) and attenuated total reflection infrared spectroscopy (ATR-IR) indicated that cellulose acetate is main component of the transparent substrate. This substrate was chemically functionalized with a suitable LC compound. A trimethoxysilane terminated new rod-shaped mesogen is synthesized and covalently attached to the pre-treated film through silane condensation reaction. LC functionalization of the polymer film is confirmed through contact angle (CA), atomic force microscopy (AFM), XPS and ATR-IR spectroscopy studies. Versatility of the LC modified flexible substrates for the alignment of bulk LC sample at substrate-LC interface was assessed for nematic (N) and smectic A (SmA) phases. Remarkably, LC functionalized cellulose acetate films were found to be highly efficient in assisting a perfect homeotropic alignment of LCs (for both, a room temperature N and a high temperature SmA phase) over the entire area of the LC sample under observation indicating their superior aligning ability in comparison to their unmodified and octadecyltrimethoxysilane (OTS) modified counterparts. The demonstrated method of surface modification of flexible polymer film is easy, surface modified substrates are stable for several months, retained their aligning ability intact and more importantly they are reusable with maximum delivery.

Hollow mesoporous silica nanoparticles (HMSNs) with different dispersities, mesoporous structures and particle sizes have been systematically synthesized by simply changing the octadecyltrimethoxysilane (C18TMS, mesopore-forming agent) percentage of the total silica sources over a wide range. The effects of the C18TMS percentage on the dispersity, mesoporous structure and particle size of HMSNs have been discussed in detail based on elaborate structure characterization. In addition, the volume of the core-etching agent and etching time have been adjusted carefully to further modulate the mesoporous structure of HMSNs. Encouragingly, the obtained HMSNs show excellent performance in removing organic pollutants with short equilibrium adsorption time, high adsorption capacity and outstanding recyclability. It is believed that these prepared HMSNs with different dispersities, mesoporous structures and particle sizes possess the potential to be used in many fields.

Superhydrophobic membranes are essential for improved seawater desalination. This study presents the successful casting of a three-layered membrane composed of a top superhydrophobic coating onto a polypropylene (PP) mat through simple sol-gel processing of octadecyltrimethoxysilane (OTMS), and the bottom layer was casted with hydrophilic poly(vinyl alcohol) (PVA) by using a knife casting technique; this membrane represents a novel class of improved-performance membranes consisting of a top superhydrophobic coating onto a hydrophobic PP mat and a hydrophilic layer (PVA) at the bottom. OTMSs are well known low-surface-energy materials that enhance superhydrophobicity, and they were observed to be the ideal chemical group for increasing the hydrophobicity of the PP mat. The PVA layer acted as base layer absorbing the condensed vapor and thus enhancing the vapor flux across the membrane. The hybrid three-layered membrane exhibited superhydrophobicity, with an average contact angle of more than 160°, and demonstrated high performance in terms of rejection and water flux. This study also examined the pore size distribution, surface roughness, surface area, tensile strength, water flux, and salt rejection of the fabricated membrane. The salt rejection level was calculated to be 99.7%, and a high permeate flux of approximately 6.7 LMH was maintained for 16 h.

With unique and efficient narrow-band red emission and broadband blue light absorption characteristics, Mn4+-activated fluoride red phosphors have gained increasing attention in warm white LEDs (WLEDs) and liquid crystal display (LCD) backlighting applications, whereas the intrinsic hygroscopic nature of these phosphors have inevitably limited their practical applications. Herein, a waterproof narrow-band fluoride phosphor K2TiF6:Mn4+ (KTF) has been demonstrated via a facile superhydrophobic surface-modification strategy. With the use of superhydrophobic surface modification with octadecyltrimethoxysilane (ODTMS) on KTF surfaces, the moisture-resistance performance and thermal stability of the phosphor KTF can be significantly improved. Meanwhile, the absorption, and quantum efficiency did not show obvious changes. The surface-modification processes and mechanism, as well as moisture-resistance performances and luminescence properties, of the phosphors have been carefully investigated. It was found that the luminous efficiency (LE) of the modified KTF was maintained at 83.9% or 84.3% after being dispersed in water for 2 h or aged at high temperature (85 °C) and high humidity (85%) atmosphere (HTHH) for 240 h, respectively. The WLEDs fabricated with modified KTF phosphor showed excellent color rendition with lower color temperature (2736 K), higher color rendering index (CRI, Ra = 87.3, R9 = 80.6), and high luminous efficiency (LE = 100.6 lm/W) at 300 mA. These results indicate that hydrophobic silane coupling agent (SCA) surface modification was a promising strategy for enhancing moisture resistance of humidity-sensitive phosphors, exhibiting great potential for practical applications.

Three-dimensional porous sponge has been demonstrated as an outstanding candidate in oil/water separation due to its hydrophobicity and oleophilicity that originates from the synergistic effect of rough structure and low surface energy, but the separation process has not been illuminated clearly. This paper presents the study of the synthesis of oil/water separation sponge, mechanism of separation process and establishment of kinetic model, via the combination among dopamine chemistry, covalent modification, theoretical analysis, experimental results and mathematical model. Results show that both the dopamine deposition time and the octadecyltrimethoxysilane hydrolysis system significantly affect the hydrophobicity of the modified-melamine sponge and that the oil/water separation process is composed of six scenarios with different physical state. Furthermore, with the experimental results, established iso-potential separation model and the height-quantized model, we conclude that the time-dependent separation patterns and kinetics are subjected to the modulation of the viscosity of the separated substance and the immersion depth of the sponge.

Nanoscience and nanotechnology present ubiquitous possibilities in almost any scientific field because of property enhancement occurring in nanoparticles with unique size and shape. The physicochemical characteristics of nanoparticles play an imperative role in their prospective applications. This article reports an in-depth study on the variance of the physicochemical characteristics, the methane decomposition activity, and the sustainability of nano-NiO/SiO 2 ( n- NiO/SiO 2 ) catalysts with different preparation parameters. The influence of nickel/silicate ratio, octadecyltrimethoxysilane (C18TMS)/tetraethylorthosilicate (TEOS) ratio, and of different solvents was investigated. The characteristic features of the prepared catalysts were inspected using N 2 adsorption–desorption measurements, X-ray diffraction, hydrogen temperature-programmed reduction, field-emission scanning electron microscopy, energy-dispersive X-ray spectroscopy, transmission electron microscopy, and methane cracking catalytic activity in a fixed bed reactor. Methane decomposition activity was evaluated by measuring the instantaneous hydrogen production (vol %) and carbon yield (%) at the end of the examination. The results showed that C18TMS has extensively improved the microporosity of the material, hence resulting in the improvement of the catalytic performance. The microporosity of the n- NiO/SiO 2 catalyst has increased from 10.7% to 26.8% when the quantity of C18TMS was increased from 0 to 1.2 mL in the synthesis mixture. Catalysts prepared with a maximum quantity of C18TMS and a minimum quantity of tetraethylorthosilicate exhibited a minimum activity loss of 17.46%.

Hybrid sodalite zeolites were produced by grinding, homogenizing and heating the reactants, including different organosilanes, without the addition of solvent (water). Hybrid sodalite zeolites were produced in the presence of triethoxy(octyl)silane (C8Si), 3-chloropropyltrimethoxysilane, triethoxymethylsilane, hexamethyldisiloxane, octadecyltrimethoxysilane (ODS) and chlorotrimethylsilane. The resulting hybrid zeolites were characterized by Fourier transform infrared spectroscopy, scanning electron microscopy, X-ray diffraction, water contact angle, small-angle X-ray scattering and thermogravimetric analysis. The presence of 6 wt.-% of organosilane introduced in the reaction medium caused no disturbance to the crystal growth. All materials exhibited dense, spherical and uniform particles, with slightly rough surfaces according to SAXS measurements. In the case of octadecylsilane, it appears that the alkyl chains are well packaged and organized, while for octylsilane, a more disordered structure seems to be present. Only organosilanes with longer alkyl chains (C8Si and ODS) show hydrophobic properties. The solvent-free method proved to be effective in synthesizing samples with good crystallinity and hydrophobic characteristics. This synthesis method was shown to be efficient, fast, economical and environmentally friendly.

Mesoporous silica nanoparticles (MSN) with tunable pore size have been proved to be excellent potential in molecular-related applications. Herein, in this study, we designed to synthesize MSN with tunable pore size by varying the n -octadecyltrimethoxysilane (C 18 TMS)/tetraethylorthosilicate (TEOS) molar ratio or the ethanol (EtOH)/H 2 O volume ratio in a water-ethanol-ammonia system, where C 18 TMS acted as structure-directing agent, TEOS as silica source, ammonia as catalyst, EtOH and H 2 O as solvents. The as-obtained MSN were characterized by the scanning electron microscopy (SEM), transmission electron microscopy (TEM) and N 2 adsorption-desorption analysis. The results showed that the as-synthesized MSN possessed spherical morphology with diameter ranging from 100 to 200 nm, and the pore size of MSN could be easily tailored from 2.4 to 6.5 nm simply by varying the C 18 TMS/TEOS molar ratio from 0.32 to 0.74 and the EtOH/H 2 O volume ratio from 3.6 to 7.5. Meanwhile, the pore volume also could be adjusted from 0.6 to 1.0 cm 3 /g by this strategy. These results suggested that our strategy could effectively enlarge and adjust the mesopores of the MSN. We supposed our approach may provide a platform of nanotechnology for preparation of porous silica materials with adjustable mesopores which would be great potential in practical applications where different sizes of molecules were involved.

The dependence of performance on the dielectric-semiconductor interface in pentacene-based organic field-effect transistors (OFETs) was investigated by modification of the substrate with octadecylsilane (OTS) compared with octadecyltrimethoxysilane (OTMS). The hole mobility of OFETs was enhanced from 0.43 cm2/V s to 0.72 cm2/V s when treating the substrate with OTMS versus OTS. However, the subsequent ammonia vapor did not lead to enhanced FET performance, which might be closely related to its negative influence on the pentacene growth. According to atomic force microscopy (AFM) and X-ray diffraction (XRD) measurements, flat pentacene domains with larger grain sizes and less crystal boundaries were observed for the OTS treated surface, demonstrating higher crystallinity, which may play a positive role for the charge transport and thus accounts for the improved mobility.

Phospholipid monolayers at oil-water interfaces are often obtained via vesicle adsorption. However, the interaction mechanisms of vesicles with these oil-water interfaces remain unclear. Herein, we studied the adsorption of giant unilamellar vesicles (GUVs) of approximately 2-5 μm diameter onto silicone oil-water interfaces and glass surfaces modified with hexamethyldisilazane (HMDS) and octadecyltrimethoxysilane (ODTMS) using fluorescence microscopy. The GUVs exhibited various modes of interaction, adsorbing on the silanized glass surfaces without sizable deformation, whereas GUVs bound to the silicone oil-water interface exhibited large deformation. After adsorption, GUV rupture occurred within 350, 110, and 3 ms on HMDS-modified glass, ODTMS-modified glass, and silicone oil-water interface, respectively. On glass surfaces, GUV rupture was often initiated and proceeded with pore formation near the surface. The monolayer patches formed by GUV rupture on HMDS-modified glass remained for at least 1 h over an area approximately twice of that estimated from the original GUV. On the ODTMS-modified glass and silicone oil surfaces, the monolayer patch structures disappeared in milliseconds owing to lipid diffusion across the interface. When adsorbed on the oil-water interface, the GUVs spontaneously underwent dynamic shape changes, internal vesicle formation, and desorption without rupture. Thus, it can be concluded that these different pathways arose from different lipid-surface affinities.

The possibility and conditions for the formation of nano- or submicrocapsules loaded with hydrophobic active ingredients (alkoxysilanes) into the matrix of coatings with self-lubricating effect are considered. The optimal composition of the alkoxysilane submicrocapsules, and their physicochemical properties were determined. The longer the radical chain length is, the lower is the rate of hydrolysis, and, accordingly, the more stable is the formed emulsion. The methods of laser correlation spectroscopy in measuring the size and zeta potentials of the submicrocapsules with different loads of the active agent allowed to determine the optimal ratios of the active ingredients. The optimal concentration of the active agent is between 4 and 9%. Based on contact angle studies, octadecyltrimethoxysilane was selected as optimum compound. The introduction of 4 wt% of octadecyltrimethoxysilane reduces the friction coefficient of coatings by 20–30% under vibrating motion and by 15–20% under continuous motion. The data obtained can also be useful for the encapsulation of other hydrophobic active agents and for various other purposes, for example, for the introduction of biocidal agents.

In recent years, various slippery liquid-infused porous surfaces (SLIPSs) have been reported in protection of various materials. However, these SLIPSs are restricted to specific substrates, complicated fabrication process and poor durability. Herein, natural attapulgite (APT) with existing micro-nano porous structure was selected as raw material, avoiding complex hole making process involved in the traditional SLIPSs preparation. Subsequently, a robust superhydrophobic surface (SHS) was successfully fabricated by one-step process via manipulation of both the surface roughness and surface energy through spraying suspension containing attapulgite (APT) and octadecyltrimethoxysilane (OTMS) on desired substrates. Besides, inorganic aluminum phosphate (AP) binder was selected as a building block to improve the adhesive strength between the APT and the substrates. Finally, the SLIPSs were fabricated successfully after infused the SHSs with silicone oil, which showed superior liquid repellency, anti-corrosion, anti-icing performance with intensified durability compared with the original SHSs. This facile method can be applied to protect various materials without the restriction of specific substrates, which is essential to guide the manufacture of SLIPS and expand potential applications in engineering.

In this work, novel mesoporous SiO 2 yolk-shell confined core-satellite Ag nanoparticles (Ag@mSiO 2 ) synthesized with a simple route were reported. Firstly, the core/shell Ag@C nanospheres whose carbon shells were doped with Ag nanoparticles, were facilely prepared by using a simple hydrothermal method. After coating with a uniform layer of hybrid SiO 2 in the presence of octadecyltrimethoxysilane (C 18 TMS), the Ag@C@h-SiO 2 composite nanospheres were obtained. The final calcination removed all the carbon and organic compound and left the yolk shell Ag@mSiO 2 nanosphere, in which an individually large Ag core and many tiny Ag nanoparticles were encapsulated within the mesoporous silica shell. The core-satellite like Ag nanoparticles exhibited excellent catalytic activity in RhB reduction. Benefited from the m -SiO 2 shell with a uniform pore size of 3.5 nm, the bi-mode Ag nanoparticles were very stable, thus the activity of Ag@mSiO 2 could keep as high as 92% after five cycles.

Isotactic polypropylene (iPP) fibers containing silica nanocapsules (described as SNCs) were prepared with twin-screw extruder. Modification of silica nanocapsules was hydrolyzed with octadecyltrimethoxysilane in order to improve the interaction between capsules and the hydrophobic PP matrix. Characterization of iPP/SNCs blends were performed by transmission electron microscopy, field-emission scanning electron microscopy (FE-SEM), differential scanning calorimetry, thermogravimetric analysis, X-ray diffraction, and tensile strength tests. Dispersion quality of silica nanocapsules was examined using FE-SEM. As a result, the modified silica nanocapsules with octadecyltrimethoxysilane (SNCs-C18) could be well dispersed into iPP matrix because of the hydrophobic surface of modified capsules. The incorporation of all the SNCs samples showed little influence on the crystallization behavior, thermal stability of iPP and mechanical properties. By contrast, the presence of unmodified SNCs in iPP showed a negative effect on mechanical properties due to the poor interface interaction between the inorganic and organic phases. This study presented a successful potential applied for encapsulation. POLYM. COMPOS., 2016. © 2016 Society of Plastics Engineers

We have demonstrated a novel way to form thickness-controllable polyelectrolyte-film/nanoparticle patterns by using a plasma etching technique to form, first, a patterned self-assembled monolayer surface, followed by layer-by-layer assembly of polyelectrolyte-films/nanoparticles. Octadecyltrimethoxysilane (ODS) and (3-aminopropyl)triethoxysilane (APTES) self-assembled monolayers (SAMs) were used for polyelectrolyte-film and nanoparticle patterning, respectively. The resolution of the proposed patterning method can easily reach approximately 2.5 μm. The height of the groove structure was tunable from approximately 2.5 to 150 nm. The suspended lipid membrane across the grooves was fabricated by incubating the patterned polyelectrolyte groove arrays in solutions of 1,2-dioleoyl-sn-glycero-3-phosphocholine (DOPC) giant unilamellar vesicles (GUVs). The method demonstrated here reveals a new path to create patterned 2D or 3D structures.

The formation mechanism of a self-assembled monolayer (SAM) of octadecyltrimethoxysilane on a silicon oxide surface in reaction is studied in situ by using a high-speed atomic force microscope that has a time resolution of 2 s per frame. The SAM formation of a silane coupling reagent on silicon is known to comprise three development stages of nucleation, growth, and coalescence. In the present study, the first nucleation stage is found to have dynamical processes: a molecular cluster attached to the substrate works as a reaction base, on which additional reactive molecules are in a bind/unbind equilibrium. In this time period, the cluster needs a long time to develop in diameter. Once a domain of ca. 30 nm in diameter is formed, the reaction rate is changed, which is dominated by the rim length of the domain. This implies that the weakly adsorbing limit approximation on the substrate surface can be employed. Another important point is that the molecular domains generate a SAM like an occupied sheet of tiles, and each tile is connected to the substrate by a few feet. In fact, a molecular tile can easily be removed by applying soft air plasma leaving the rest of the tiles of highly packed molecules, which is confirmed by infrared p-polarized external reflection spectroscopy.

Vapor-phase covalently bound siloxane thin films of various functionalities on a variety of surfaces, including glass, aluminum, and polyester, were demonstrated in a one-step process. Siloxane films a few nanometers thick were deposited on surfaces from the vapor phase using different inert polydimethylsiloxanes (PDMSs) without the use of solvent, initiator, or a crosslinking agent. Functional PDMSs fluoro-polysiloxane (F-PDMS) and amino-polysiloxane (A-PDMS) were also coated on glass substrates, providing functional surfaces for patterned array of microlenses (MLs) for near-field imaging applications. We call our siloxane film deposition method SOLVED which refers to Siloxane-bound Layers through Vapor-Enhanced Deposition. Our ellipsometry data on the PDMS SOLVED surfaces indicated the film thickness was 6.5 ± 0.3 nm. The siloxane–surface binding was a thermally activated reaction with an apparent activation energy of ∼11 kcal mol−1. Our optical spectroscopic X-ray photoelectron spectroscopy (XPS), Fourier-transform infrared spectroscopy (FTIR) and mass-spectrometry analysis data provided strong evidence that the SOLVED films retained the chemical nature of the polymers used for the coatings. The redox diffusion coefficients of Fe(CN)64−/3− species on SOLVED films using cyclic voltammetry (CV) studies were comparable with that of highly packed C18-silane self-assembled monolayers (SAMs) on ITO surfaces – implying high quality pinhole-defect-free SOLVED coatings on the surfaces. Further, both the CV and water contact angle (CA) measurements indicated that the photostability of SOLVED and octadecyltrimethoxysilane (OTMS) SAM films on the ITO substrates was comparable. Unlike bulk PDMS, our ultra-thin SOLVED films did not exhibit any significant changes in the water CA over two weeks. A reproducible and stable hydrophobicity with tunable water CAs between 30° and 97° was obtained through plasma treatment. By selectively removing the SOLVED films thru oxygen plasma treatment, we demonstrated the fabrication of self-assembled aqueous ZnCl2 ML array. Near-field imaging using MLs yielded much higher spatial resolution than can be obtained using diffraction-limited wide-field imaging.

Inorganic membranes are becoming increasingly interesting for CO2 gas separation processes considering their potential in CO2 capture and storage for mitigating global warming. Porous alumina filters with the ability of CO2 gas separation were prepared by modifying four types of silane coupling agents: 3-Aminopropyltriethoxysilane (APTES), 3-Ureidopropyltriethoxysilane (Ureido), Octadecyltrimethoxysilane (ODS), and Heptadecafluorodecyltrimethoxysilane (FAS17). CO2/N2 gas selectivity was less than 1.0 for all the filters, meaning that less CO2 gas could permeate the filter, compared with N2 gas. The difference of gas selectivity among the prepared filters was ascribed to two main factors. The first was the relative electric charges of the atoms in both the gas molecules and the functional groups of the silane coupling agents. Oppositely charged atoms result in a physical interaction between CO2 molecule and the silane coupling agent at the surface of porous alumina structure. The second factor was the configuration of the CO2 molecule. It could be considered that the oxygen atoms at the exterior of the CO2 molecule have a stronger physical interaction with other charged species than the carbon atoms located at the center of the molecule.

While membrane distillation (MD) is considered a promising cost-effective and efficient desalination process, it remains severely affected by membrane fouling that compromises the quantity and quality of water recovered. In this study, superhydrophobic PVDF membranes modified with organically-functionalised silica (f-SiO2) nanoparticles (NPs) were synthesized. Silica nanoparticles (SiO2NPs) were functionalised with three different silane reagents, namely: octadecyltrimethoxysilane (OTMS), N-octadecyltrichlorosilane (ODTS), and chlorodimethyl-octadecyl silane (Cl-DMOS), and finally embedded on polyvinylidene fluoride (PVDF) nanofibre membranes using an in-situ electrospinning technique. The resulting superhydrophobic membranes were coated with a thin layer containing carboxylated multiwalled carbon nanotubes (f-MWCNTs) and silver nanoparticles (AgNPs) to reduce membrane fouling. Fouling tests were conducted using sodium alginate, colloidal silica, and thermophilic bacteria effluent as model organic, inorganic, and bio-foulants, respectively, in direct contact membrane distillation (DCMD). The uncoated membranes were characterized by flux decays ranging from 30 to 90% and salt rejection decays of 1.4–6.1 %. Membrane coating reduced the flux and salt rejection decays to 10–24 % and 0.07–0.75 %, respectively. The hydrophilic coating layer of the nanofibre membrane induced a decrease in the initial water flux (i.e., from 36-42 LMH to 16–17 LMH). However, this coating layer also proved to be efficient in maintaining high salt rejection and resistance to flux decline. This approach is a suitable one-step solution for fouling mitigation in DCMD

We report the assembly of an asymmetric membrane consisting of octadecyltrimethoxysilane (ODTMS) Langmuir film covalently attached to a sol-gel based sublayer, supported by a mesoporous membrane. The ODTMS Langmuir film was compressed at the interface of a subphase containing tetramethoxysilane (TMOS), formamide and polyethylenimine. Exposure of the Langmuir film to NH3 vapours increased the pH at the interface (pHinterface) and catalysed the condensation of TMOS. The assembly of the layers was of a self-healing nature, due to the π-pressure set-up of the Langmuir film and the faster diffusion of the NH3 through the defects. The resulting asymmetric film was transferred onto polysulfone ultrafiltration membranes to form a thin film composite (TFC) structure composed of a Langmuir organic skin, the sol-gel blend sublayer and the support. The asymmetry of the film was confirmed by various methods and a gradual transition from mesoporous support to dense ceramic-polymeric film was seen. A preliminary study demonstrated that the modification of the polysulfone membrane improved its selectivity from ultra to nanofiltration range. The obtained fluxes were significantly higher as compared to commercial membranes of similar selectivity. This generic approach is applicable for assembling large-area selective TFC membranes with ultrathin skin layers and high fluxes of effluents.

The extensive increase of application of surface-modified halloysite nanotubes in industry and biomedicine suggests that their biocompatibility and cellular uptake should be thoroughly investigated. Here we report the fabrication and cytocompatibility study of hydrophobic halloysite nanotubes coated with octadecyltrimethoxysilane (ODTMS). The interaction of ODTMS-modified halloysite nanotubes with human lung carcinoma alveolar epithelial cell A549 was investigated using dark field and atomic force microscopies, colorimetric viability tests and flow cytometry. Halloysite with different degrees of hydrophobicity penetrates into the human lung cells without membrane damage promising for efficient drug delivery. This formulation did not have an apoptosis-inducing effect on the cells, did not increase the activity of NO-synthase and can be employed for intracellular delivery of drugs, proteins and DNA without any toxic side effects.

The structure control during the formation of films from nanoparticles is investigated. The particles are synthesized by miniemulsion polymerization with different ratios of methyl methacrylate and butyl methacrylate in the presence of silica nanoparticles. The structure of the hybrid particles is controlled by changing the surface properties of the silica through functionalization with 3-methacryloxypropyltrimethoxysilane (MPS) and octadecyltrimethoxysilane (ODTMS). Fixation of the MPS-silica due to polymerizable groups leads to a homogeneous distribution inside the polymer, while the inert alkyl chains of ODTMS result in segregation of the silica and the polymer. This difference in the structure is preserved during film formation and aggregation in films can be prevented effectively.

BACKGROUND Remediation of oil spillage accidents requires efficient and low cost floating absorbents to remove small amounts of contaminant oil. In this work, a highly hydrophobic floating magnetic macroporous structure based on silica encapsulated Fe nanoparticles was prepared and used for oil absorption from water. RESULTS The magnetic macroporous materials were prepared by silica encapsulation of iron oxide/hydroxide nanoparticles followed by a thermal treatment with H2. Mossbauer, XRD, SEM/TEM, CHN, IR, TG/DTA and contact angle analyses showed that the Fe oxides nanoparticles are reduced by H2 to form Feo cores protected by silica which sinters to form a macroporous network. The surface reaction with octadecyltrimethoxysilane (Si(CH3O)3C18H37) was used to produce highly hydrophobic materials. CONCLUSIONS The materials obtained showed very high oil absorption capacities for different model contaminants, i.e. petroleum, soy bean oil, diesel, gasoline and xylene removal. The results are discussed in terms of a macroporous structure with strong capillarity combined with a very hydrophobic surface. © 2015 Society of Chemical Industry

Surface wettability is of importance for electrochemical reactions. Herein, its role in electrochemical hydrogen evolution reactions is investigated using light-sensitive nanotubular TiO2 supported Pt as hydrogen evolution electrodes (HEEs). The HEEs are fabricated by photocatalytic deposition of Pt particles on TiO2 nanotubes followed by hydrophobization with vaporized octadecyltrimethoxysilane (OTS) molecules. The surface wettability of HEEs is subsequently regulated in situ from hydrophobicity to hydrophilicity by photocatalytic decomposition of OTS molecules using ultraviolet light. It is found that hydrophilic HEEs demonstrate a larger electrochemical active area of Pt and a lower adhesion force to a gas bubble when compared with hydrophobic ones. The former allows more protons to react on the electrode surface at small overpotential so that a larger current is produced. The latter leads to a quick release of hydrogen gas bubbles from the electrode surface at large overpotential, which ensures the contact between catalysts and electrolyte. These two characteristics make hydrophilic HEEs generate a much high current density for HERs. Our results imply that the optimization of surface wettability is of significance for improving the electrocatalytic activity of HEEs.

Achieving structurally well-defined catalytic species requires a fundamental understanding of surface chemistry. Detailed structural characterization of the catalyst binding sites in situ, such as single site catalysts on silica supports, is technically challenging or even unattainable. Octadecyltrioxysilane (OTOS) monolayers formed from octadecyltrimethoxysilane (OTMS) at the air-liquid interface after hydrolysis and condensation at low pH were chosen as a model system of surface binding sites in silica-supported Zn(2+) catalysts. We characterize the system by grazing incidence X-ray diffraction, X-ray reflectivity (XR), and X-ray fluorescence spectroscopy (XFS). Previous X-ray and infrared surface studies of OTMS/OTOS films at the air-liquid interface proposed the formation of polymer OTOS structures. According to our analysis, polymer formation is inconsistent with the X-ray observations and structural properties of siloxanes; it is energetically unfavorable and thus highly unlikely. We suggest an alternative mechanism of hydrolysis/condensation in OTMS leading to the formation of structurally allowed cyclic trimers with the six-membered siloxane rings, which explain well both the X-ray and infrared results. XR and XFS consistently demonstrate that tetrahedral [Zn(NH3)4](2+) ions bind to hydroxyl groups of the film at a stoichiometric ratio of OTOS:Zn ∼ 2:1. The high binding affinity of zinc ions to OTOS trimers suggests that the six-membered siloxane rings are binding locations for single site Zn/SiO2 catalysts. Our results show that OTOS monolayers may serve as a platform for studying silica surface chemistry or hydroxyl-mediated reactions.

Phospholipid single bilayers supported on a hydrophilic solid substrate are extensively used in the study of the interaction between model membranes and proteins or polypeptides. In this article, the formation of a single dimyristoylphosphatidylcholine (DMPC) bilayer under an octadecyltrimethoxysilane (OTMS) polymerized Langmuir monolayer at the air-water interface is followed by Brewster angle microscopy (BAM) and polarization-modulated infrared reflection absorption spectroscopy (PM-IRRAS). The formation of the bilayer is initiated by injection of dimyristoylphosphatidylcholine small unilamellar vesicles into the aqueous subphase. Brewster angle microscopy allows visualization of the kinetics of formation and the homogeneity of the bilayer. Spectral simulations of the polarization-modulated infrared reflection absorption spectroscopy spectra reveal that the bilayer thickness is 39±5Å. This system constitutes the first example of a phospholipid bilayer on a “nanoscopic” support and opens the way to studies involving supported bilayers using powerful experimental techniques such as x-ray reflectivity, vibrational spectroscopies, or Brewster angle microscopy.

We provide a detailed in situ investigation of the two-dimensional polymerization of n-octadecyltrimethoxysilane Langmuir monolayers by PM-IRRAS (polarization-modulated infrared reflection absorption spectroscopy). The formation of the siloxane bonds at the headgroup level is unequivocally assessed by the appearance of a characteristic Si−O−Si band in the 1000−1150 cm-1 region. The aliphatic chains are shown to tilt toward the normal to the interface during polymerization. The process is sterically controlled and can be totally suppressed by replacing the hydrocarbon chain by its fluorocarbon homologous. The chain cross section is then too large to allow the reticulation of the silanol groups between neighboring molecules.

We report a novel hybrid charge sensor realized by the deposition of phospholipid monolayers on highly doped n-GaN electrodes. To detect the binding of recombinant proteins with histidine-tags, lipid vesicles containing chelator lipids were deposited on GaN electrodes pre-coated with octadecyltrimethoxysilane monolayers. Owing to its optical transparency, GaN allows the confirmation of the fluidity of supported membranes by fluorescence recovery after photo-bleaching (FRAP). The electrolyte-(organic) insulator-semiconductor (EIS) setup enables one to transduce variations in the surface charge density ΔQ into a change in the interface capacitance ΔC p and, thus, the flat-band potential ΔU FB. The obtained results demonstrate that the membrane-based charge sensor can reach a high sensitivity to detect reversible changes in the surface charge density on the membranes by the formation of chelator complexes, docking of eGFP with histidine tags, and cancellation by EDTA. The achievable resolution of ΔQ ≥ 0.1 μC/cm2 is better than that obtained for membrane-functionalized p-GaAs, 0.9 μC/cm2, and for ITO coated with a polymer supported lipid monolayer, 2.2 μC/cm2. Moreover, we examined the potential application of optically active InGaN/GaN quantum dot structures, for the detection of changes in the surface potential from the photoluminescence signals measured at room temperature.

International audience; ZnO nanorods were grown on microfibers of Polyethylene terephthalate (PET) fabric by seeding method to develop hierarchical roughness structure. XRD and XPS analysis show the presence of crystalline ZnO and chemical Zn species at the fiber surface at each stage of the process. Five series of samples with different seed concentrations have been realized, and their surface morphology and topography were characterized by AFM and SEM. Increasing seed concentrations lead to samples with superhydrophilic properties. Not only the water contact angle at fabric surface tends to zero but also the water capillary diffusion inside fabric is faster. Nanostructuration affects the structure inside the fabric, and further experiments with decane liquid have been made to get a better understanding of this effect. To study the superhydrophobicity, nanorods treated samples were modified with octadecyltrimethoxysilane (ODS) by two method; solution deposition and vapor deposition. The superhydrophobicity was characterized by measuring the water contact angle and water sliding angle with 5 μl water droplet. The samples modified with ODS by vapor deposition showed higher water contact angles and low water sliding angle than the ones modified with solution method. The lotus effect has been well correlated with the surface morphology of the nanorods structured fibers. The application of the Cassie–Baxter equation is discussed.

The present study describes for the first time the synthesis of silica nanoparticles starting from sodium silicate and oleic acid (OLA). The interactions between OLA and sodium silicate require an optimal OLA/OLANa molar ratio able to generate vesicles that can stabilize silica particles obtained by the sol-gel process of sodium silicate. The optimal molar ratio of OLA/OLANa can be ensured by a proper selection of OLA and respectively of sodium silicate concentration. The titration of sodium silicate with OLA revealed a stabilization phenomenon of silica/OLA vesicles and the dependence between their average size and reagent’s molar ratio. Dynamic light scattering (DLS) and scanning electron microscopy (SEM) measurements emphasized the successful synthesis of silica nanoparticles starting from renewable materials, in mild condition of green chemistry. By grafting octadecyltrimethoxysilane on the initial silica particles, an increased interaction between silica particles and the OLA/OLANa complex was achieved. This interaction between the oleyl and octadecyl chains resulted in the formation of stable gel-like aqueous systems. Subsequently, olive oil and an oleophylic red dye were solubilized in these stable aqueous systems. This great dispersing capacity of oleosoluble compounds opens new perspectives for future green chemistry applications. After the removal of water and of the organic chains by thermal treatment, mesoporous silica was obtained.

Ordered mesoporous materials exhibit potential features to be used as controlled drug delivery systems, including their wide range of chemical compositions and their outstanding textural and structural properties. Therefore, it is possible to control the drug release kinetics by tailoring such parameters. In this paper, mesoporous materials such as MCM-48 and SBA-15, which present different pore sizes (3.7 and 8.8 nm) and structural characteristics (3D-bicontinuous cubic and 2D-hexagonal, respectively) have been synthesized to evaluate their application as drug delivery system and to determine their influence on release kinetic of ibuprofen. Moreover, a chemical modification of the SBA-15 mesoporous material with octadecyltrimethoxysilane has also been performed to study its influence on the release rate of ibuprofen. The structural characteristics (3D cubic and 2D hexagonal pore system) do not affect the release kinetic profiles of ibuprofen. On the contrary, the pore size affects highly to the release kinetic profiles from first-order kinetic to zero-order kinetic for MCM-48 and SBA-15, respectively. Moreover, the importance of surface functionalization was demonstrate through the very fast delivery of ibuprofen from SBA-15 mesoporous materials functionalized with octadecyl chains.