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Cotton is widely used in various forms in textile industries, medical appliances, and different commercial materials and appropriate surface modification of cotton can greatly enhance its applicati...

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.

The stability of luminescent materials is a key factor for the practical application in white light-emitting diodes (LEDs). Poor chemical stability of narrow-band green-emitting RbLi(Li3 SiO4 )2 :Eu2+ (RLSO:Eu2+ ) phosphor hinders their further commercialization even if they have excellent stability against thermal quenching. Herein, we propose an efficient protection scheme by combining the surface coating of amorphous Al2 O3 and hydrophobic modification by octadecyltrimethoxysilane (ODTMS) to construct the moisture-resistant dual-shelled RLSO:Eu2+ @Al2 O3 @ODTMS composite. The growth mechanisms of both the Al2 O3 inorganic layer and the silane organic layer on the phosphor surface are investigated. The results remarkably improve the water-stability of this narrow-band green emitter. The evaluation of the white LED by employing this composite as the green component demonstrates that RLSO:Eu2+ @Al2 O3 @ODTMS is a promising candidate for the high-performance display backlights, and this dual-shelled strategy provides an alternative method to improve the moisture-resistant property of humidity-sensitive phosphors.

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.

As a promising insulation material for HVDC cable, polypropylene (PP)-based nanocomposite shows excellent electrical properties under high operating temperature. The coupling agent plays an important role in the nanocomposite and may affect the high-temperature performance. In this paper, octyltrimethoxysilane and octadecyltrimethoxysilane were used to surface-modify MgO nanoparticles respectively. The PP/MgO nanocomposites were prepared and the surface-modification effect on electrical properties under 30 °C and 90 °C were investigated. The results show that deep traps were introduced in the nanocomposites by surface-modified MgO, whose density is proportional to the alkyl length of silane. Both PP/MgO nanocomposites show better electrical properties than pure PP. The nanocomposite with octadecyl-modified MgO shows the highest DC breakdown strength and lowest DC leakage current under 30 °C. Whereas octyl-modified PP/MgO nanocomposite performs better on these electrical properties under 90 °C. The reason of them may be correlated with the chemical stability of silane under high electric field and temperature. The work can be useful for selecting coupling agents in PP-based nanocomposite cable insulation considering high operating temperature.

Herein, light-responsive nanocarriers based on hollow mesoporous silica (HMS) nanoparticles modified with spiropyran-containing light-responsive copolymer (PRMS-FA) were fabricated via a simple self-assembly process. HMS modified with long-chain hydrocarbon octadecyltrimethoxysilane was an ideal base material owing to its good biocompatibility and drug capability. The spiropyran-containing amphiphilic copolymer could shift its hydrophilic–hydrophobic balance to become hydrophilic upon UV (λ = 365 nm) irradiation and then break away from the hydrophobic surface of the HMS core, followed by the uncaging and release of the pre-loaded anticancer drug. Simultaneously, the fluorescence resonance energy transfer (FRET) process based on the structural transformation of PRMS-FA was observed, which could act as a real-time monitor for the light-controlled drug release. Our model experiments in vitro tested and verified that this composite nanocarrier has good biocompatibility, active tumour targeting to the folate receptor over-expressed in tumour cells, is non-toxic to normal cells and that light-controlled drug release with real-time monitoring can be achieved.

A new multifunctional nanovehicle for tumor therapy and cell imaging was fabricated by coating NIR light-responsive polymers (HAMAFA-b-DDACMM) onto the surface of octadecyltrimethoxysilane (C18)-modified hollow mesoporous silica nanoparticles (HMS@C18) via self-assembly. First, the targeting NIR light-responsive block copolymer was synthesized by the RAFT living polymerization of [7-(didodecylamino) coumarin-4-yl] methyl methacrylate with hydroxyethylacrylate and N-(3-aminopropyl) methacrylamide hydrochloride and then grafted with folic acid (FA). The copolymers could be disrupted by excitation by a femtosecond NIR light laser (800 nm) via a two-photon absorption process due to the high two-photon absorption cross-section of the coumarin moiety. In order to enhance the drug loading capacity and biological stability of the nanovehicle, HMS nanoparticles modified by hydrophobic octadecyl chains were selected as the “core”, which had a considerable drug loading efficiency of more than 70%. Then the core–shell nanocomposites (HMS@C18@HAMAFA-b-DDACMM) were obtained by coating the amphiphilic copolymers onto the core via self-assembly. Under excitation by NIR light at 800 nm, the pre-loaded drugs could be released from the nanocomposites due to the degradation of the light-responsive copolymers and the release efficiency was correlated with the irradiation time and light power. The in vitro experiments indicated that the nanocomposites were easily targeted into the tumor cells that over-expressed folic acid receptor (FR(+)) such as KB cells by endocytosis. Furthermore, the copolymer itself had strong fluorescence, which could be used to track the process of drug delivery.

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.

ZSM-5-TiO2 composites are usually used as adsorbents as well as photocatalyst in waste treatment. However, these composites are less effective insoluble waste treatment, so it needs to modify by adding organic substances that can react with the waste. In this study, Octadecyltrimethoxysilane (OTMS) was added to the surface of the ZSM-5-TiO2 composite. The effect of addition OTMS on morphology ZSM-5-TiO2 composite was studied. ZSM-5-TiO2-OTMS composite was characterized by X-Ray Diffraction (XRD), Fourier Transformation Infrared Spectroscopy (FTIR), and Energy Dispersive X-ray Scanning Electron Microscopy (SEM-EDX). ZSM-5-TiO2-OTMS shows a carbon-related peak at 2900 and 1470 cm−1 that can be ascribed as C-H stretching and C-O stretching vibration respectively from FTIR spectra. ZSM-5-TiO2-OTMS composite retains the hexagonal shape surrounded by round-shaped. The addition of OTMS affects the morphology of the ZSM-5-TiO2 composite. The more OTMS is added, the morphology of the ZSM-5-TiO2-OTMS composite to be more irregular than composite ZSM-5-TiO2. It also affects the amount of carbon content that is distributed on the surface of the ZSM-5-TiO2 composite. This provides information material that can be used in synthesize catalysts in the insoluble waste treatment.

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.

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.

[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.

A novel superhydrophobic octadecyltrimethoxysilane (OTMS)-modified composite membrane was fabricated by incorporating recycled carbon black (CB) into a polyvinylidene fluoride (PVDF) membrane. Waste tires have been treated with extraction and high-temperature calcination to obtain recycled CB. After incorporating CB into the PVDF solution, a steep increase of 18–20% was observed in the loss and storage moduli. CB was observed to be an ideal filler for doping the PVDF solution to enhance the mechanical properties of the material. OTMSs are known for their low surface energy, which improves hydrophobicity. Moreover, OTMSs were found to be ideal agents for enhancing the superhydrophobicity of PVDF membranes. The results of surface treatment with OTMS, CB loading, particle size, and membrane properties and their effect on desalination performance were thoroughly studied. The composite membrane was observed to be superhydrophobic with a contact angle of 160° and exhibited high desalination performance in terms of permeate water flux and salt rejection. The fabricated membrane has been reused after physical cleaning in order to analyse the anti-wetting and long-term performance.

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.

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

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.

Effects of different silane coupling agents on the mechanical strength, tribological properties, thermal behaviors, swelling properties and rheological properties of bentonite (Bent)/nitrile butadiene rubber (NBR) nanocomposites were explored. The nanocomposites were fabricated with an innovative green method in NBR latex. The composition of the nanocomposites was determined by Fourier transform infrared spectroscopy (FT-IR). The intercalated/exfoliated structure and the dispersion of Bent in rubber matrix were characterized with X-ray diffraction (XRD) and field emission-scanning electron microscopy (FE-SEM). It is revealed that different functional groups from the silanes were effective to the properties of the nanocomposites mainly because of their different interactions with the rubber matrix. Mercaptopropyltrimethoxysilane (MPTMS) showed attractive effects on mechanical modulus, tribological properties and swelling properties. Incorporation of bis-[3-(triethoxysilyl)propyl]tetrasulfide (TESPT) resulted in the highest elongation at break. With octadecyltrimethoxysilane (OTMS), the degradation temperature of the nanocomposite was noticeably elevated due to its “barrier effect”.

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 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.

Painting is a cost-effective technique to delay the onset of corrosion in metals. However, the protection is only temporary, as corrosion begins once the coating becomes scratched. Thus, an increasingly common practice is to add microencapsulated chemical agents to paint in order to confer self-healing capabilities. The additive's ability to protect the exposed surface from corrosion depends upon (i) how long the chemical agent takes to spread across the exposed metal; (ii) how long the agent takes to form an effective barrier layer; and (iii) what happens to the metal surface before the first two steps are complete. To understand this process, we first synthesized 23 ± 10 μm polyurea microcapsules filled with octadecyltrimethoxysilane (OTS), a liquid self-healing agent, and added them to a primer rich in zinc, a cathodic protection agent. In response to coating damage, the microcapsules release OTS into the scratch and initiate the self-healing process. By combining electrochemical impedance spectroscopy, chronoamperometry, and linear polarization techniques, we monitored the progress of self-healing. The results demonstrate how on-demand chemical passivation works synergistically with the cathodic protection: zinc preserves the surface long enough for self-healing by OTS to reach completion, and OTS prolongs the lifetime of cathodic protection.

We demonstrated a method to fabricate functional hybrid film patches that were used to form Pickering emulsions (PEs). The hybrid patches were made of carbon nanotubes, Fe3O4 nanoparticles, octadecyltrimethoxysilane, and poly(diallyldimethylammonium chloride). The aqueous phase of the hybrid-patch stabilized PEs can be easily separated by applying a magnetic field. The hybrid-film-patch stabilized PEs are extremely stable and lasted for eight months at room temperature. Furthermore, they are easily ruptured by adding ethanol, and regenerated by vortexing the patches in aqueous/oil mixtures, enabling the inner hydrophilic side of the patches to be easily modified with metal nanoparticles. As an example, palladium nanoparticles were embedded into the surface of the hybrid patches using an in situ reduction method. The Pd functionalized patch formed PEs showed an excellent catalytic performance for the hydrogenation of acetone with a yield of 99.5%. The same batch of Pd functionalized patches was recycled 13 times without loss of the catalytic activity. The hybrid-patch formed PEs have a great potential in the catalytic field.

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

This work analyzes the anti-icing performance of flat aluminum surfaces coated with widely used alkyl-group based layers of octadecyltrimethoxysilane, fluorinated alkylsilane and stearic acid as they are subjected to repeated icing/deicing cycles. The wetting properties of the samples upon long-term immersion in water are also evaluated. The results demonstrate that smooth aluminum surfaces grafted with alkyl groups are prone to gradual degradation of their hydrophobic and icephobic properties, which is caused by interactions and reactions with both ice and liquid water. This implies that alkyl-group based monolayers on aluminum surfaces are not likely to be durable icephobic coatings unless their durability in contact with ice and/or water is significantly improved.

A novel planar π-conjugated small molecule, benzothienoisoindigo (BTII), in which additional benzene rings are fused with the thieoisoindigo (TII) unit, has been designed and synthesized. We report the impact of the planar π-framework and π-conjugation length on the carrier transport properties using three sets of molecules, BTII, isoindigo (II) and TII, bearing the same hexyl-side chain. The absorption spectra are remarkably red-shifted in the order of II < TII < BTII along with the enhanced molar extinction coefficient in the low-energy region, leading to the reduced bandgap. The single-crystal structure analyses revealed that all molecules have a planar backbone, and II and BTII are packed into a slipped columnar structure showing highly one-dimensional π–π interactions, while TII did not form, any noticeable intermolecular overlaps. The carrier transport properties were investigated in field-effect transistors (FETs). All molecules exhibited typical ambipolar properties. Among them, BTII showed the highest FET p-dominant ambipolar performance with the hole mobility of 0.095 cm2 V−1 s−1 and electron mobility of 5.8 × 10−3 cm2 V−1 s−1 on the tetratetracontane (TTC)-modified substrate and p-type performance with the hole mobility of 0.18 cm2 V−1 s−1 on the octadecyltrimethoxysilane (OTMS)-modified substrate. The microstructure of thin films was characterized by X-ray diffraction (XRD) and atomic force microscopy (AFM) measurements. These results indicated that smooth and densely packed nanorod-like crystalline grains are formed by extension of the π-conjugation in BTII. Due to the π-extension of planar organic semiconductors, the novel BTII unit can be extended for the rational design of high performance FET materials.

Monolayer and multilayer arrangements (consisting of disorder, parallel alignment and perpendicular superlattice) of hydrophobic gold nanorods have been prepared on silicon substrates via the evaporation-based self-assembly and the heat treatment methods, and the substrates were provided for the surface-enhanced Raman spectroscopic (SERS) examination. The perpendicular superlattice assembly of gold nanorods maximally enhanced intensities of Raman bands in comparison with parallel and disorder assemblies. Moreover, multilayer films of gold nanorods were more effective on SERS than monolayer films. The motive force of the Raman enhancement should be the adequate resonance coupling of localized surface plasmon waves at the reasonable density of spaces between neighboring rods. Moreover, the adsorption ability of analytes on the hydrophobic peripheral octadecyltrimethoxysilane groups will also improve the detection limit and develop the detection scope from aqueous to organic solutions.

In this study, we investigated the effect of doping zinc oxide (ZnO) microrods on fluorine-doped tin oxide (FTO) conductive glass without seed layer and its characteristics at the photo electrode of dye-sensitized solar cell (DSSC). Octadecyltrimethoxysilane (ODS; CH 3 (CH 2 ) 17 Si(OCH 3 ) 3 ) deposited on the substrate form a self-assembled monolayer by to enhance the following growth of ZnO microrods. 0.03M of zinc nitrate hexahydrate (Zn(NO 3 ) 2 ·6H 2 O) and 0.03 M hexamethylene tetramine (C 6 H 12 N 4 , HMT) were the main reaction materials in the hydrothermal method. In this experiment, the ZnO mircorods was doped with gallium, using the gallium nitrate (Ga(NO 3 ) 3 ) of 0.15 to 0.60 mM. The ZnO microrods applied for DSSCs analyzed by FE-SEM, UV-Vis spectra and I–V curves.

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.

Hydrophilic silica particles need to be hydrophobized to be encapsulated in a polymeric environment, which can be achieved by different methods. We report on the relationship between different hydrophobization techniques of silica and the final structure of poly(methyl methacrylate)/silica hybrid nanoparticles obtained by miniemulsion polymerization. Hydrophobization by cetyltrimethylammonium chloride (CTMA-Cl) uses the ionic interaction between the positively charged ammonium salt and the negatively charged silica surface, as shown by isothermal titration calorimetry. In this case, the interaction between polymer and silica surface needs to be enhanced, so 4-vinylpyridine (4-VP) was used as a co-monomer. Alternatively, the condensation reactions of 3-methacryloxypropyltrimethoxysilane (MPS) and octadecyltrimethoxysilane (ODTMS) were used to provide a covalent bond to the silica surface. The condensation reaction of the trimethoxysilane groups onto the silica surface was proven by Fourier transform infrared spectroscopy and thermogravimetric analysis. Hybrid nanoparticles were successfully formed with silica particles functionalized with the different functionalization agents. However, the structure of the resulting hybrid particles (i.e., the distribution of the silica particles within the polymer matrix) depends on the agent. The MPS-functionalized silica particles copolymerize with poly(methyl methacrylate), leading to a fixation of the silica particles inside the polymer and to a homogeneous distribution. The CTMA-Cl- and ODTMS-functionalized silica particles cannot copolymerize, but aggregate at the interface, leading to a Janus-like structure.