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Regenerated cellulose packaging materials can alleviate the environmental pollution and carbon emissions caused by conventional plastics and other chemicals. They require regenerated cellulose films with good barrier properties, such as strong water resistance. Herein, using an environmentally friendly solvent at room temperature, a straightforward procedure for synthesizing these regenerated cellulose (RC) films, with excellent barrier properties and doping with nano-SiO2, is presented. After the surface silanization modification, the obtained nanocomposite films exhibited a hydrophobic surface (HRC), in which the nano-SiO2 provided a high mechanical strength, whereas octadecyltrichlorosilane (OTS) provided hydrophobic long-chain alkanes. The contents of the nano-SiO2 and the concentrations of the OTS/n-hexane in regenerated cellulose composite films are crucial, as they define its morphological structure, tensile strength, UV-shielding ability, and the other performance of these composite films. When the nano-SiO2 content was 6%, the tensile stress of the composite film (RC6) increased by 41.2%, the maximum tensile stress was 77.22 MPa, and the strain-at-break was 14%. Meanwhile, the HRC films had more superior multifunctional integrations of tensile strength (73.91 MPa), hydrophobicity (HRC WCA = 143.8°), UV resistance (>95%), and oxygen barrier properties (5.41 × 10−11 mL·cm/m2·s·Pa) than the previously reported regenerated cellulose films in packaging materials. Moreover, the modified regenerated cellulose films could biodegrade entirely in soil. These results provide an experimental basis for preparing regenerated-cellulose-based nanocomposite films that exhibit a high performance in packaging applications. [ABSTRACT FROM AUTHOR]

Herein we report the synthesis and characterization of novel castor oil-based polyurethane (PU) foam functionalized with octadecyltrichlorosilane (C18)-modified diatomaceous earth (DE) particles, exhibiting superior hydrophobicity and oil adsorption, and poor water absorption, for use in effective clean-up of crude oil spillage in water bodies. High-performance and low-cost sorbents have a tremendous attraction in oil spill clean-up applications. Recent studies have focused on the use of castor oil as a significant polyol that can be used as a biodegradable and eco-friendly raw material for the synthesis of PU. However, biobased in-house synthesis of foam modified with C18-DE particles has not yet been reported. This study involves the synthesis of PU using castor oil, further modification of castor oil-based PU using C18 silane, characterization studies and elucidation of oil adsorption capacity. The FTIR analysis confirmed the fusion of C18 silane particles inside the PU skeleton by adding the new functional group, and the XRD study signified the inclusion of crystalline peaks in amorphous pristine PU foam owing to the silane cross-link structure. Thermogravimetric analysis indicated improvement in thermal stability and high residual content after chemical modification with alkyl chain moieties. The SEM and EDX analyses showed the surface's roughness and the incorporation of inorganic and organic elements into pristine PU foam. The contact angle analysis showed increased hydrophobicity of the modified PU foams treated with C18-DE particles. The oil absorption studies showed that the C18-DE-modified PU foam, in comparison with the unmodified one, exhibited a 2.91-fold increase in the oil adsorption capacity and a 3.44-fold decrease in the water absorbing nature. From these studies, it is understood that this novel foam can be considered as a potential candidate for cleaning up oil spillage on water bodies. [ABSTRACT FROM AUTHOR]

Hypocalcemia is caused by a sharp decline in blood calcium concentration after dairy cow calving, which can lead to various diseases or even death. It is necessary to develop an inexpensive, easy-to-operate, reliable sensor to diagnose hypocalcemia. The cellulose-paper-based microfluidic field-effect biosensor is promising for point-of-care, but it has poor mechanical strength and a short service life after exposure to an aqueous solution. Octadecyltrichlorosilane (OTS), as a popular organosilane derivative, can improve the hydrophobicity of cellulose paper to overcome the shortage of cellulose paper. In this work, OTS was used to produce the superhydrophobic cellulose paper that enhances the mechanical strength and short service life of MFB, and a microfluidic field-effect biosensor (MFB) with semiconducting single-walled carbon nanotubes (SWNTs) and DNAzyme was then developed for the Ca2+ determination. Pyrene carboxylic acid (PCA) attached to SWNTs through a non-covalent π-π stacking interaction provided a carboxyl group that can bond with an amino group of DNAzyme. Two DNAzymes with different sensitivities were designed by changing the sequence length and cleavage site, which were functionalized with SPFET/SWNTs-PCA to form Dual-MFB, decreasing the interference of impurities in cow blood. After optimizing the detecting parameters, Dual-MFB could determine the Ca2+ concentration in the range of 25 μM to 5 mM, with a detection limit of 10.7 μM. The proposed Dual-MFB was applied to measure Ca2+ concentration in cow blood, which provided a new method to diagnose hypocalcemia after dairy cow calving. [ABSTRACT FROM AUTHOR]

We report here a facile method of modulating the lengthscales of self-organized dewetting of polystyrene thin films by varying the extent of silane grafting on the substrate. The self-assembled monolayers (SAM) of octadecyltrichlorosilane (OTS) were grafted on glass substrates by exposing them to different doses of OTS vapors in a controlled, low pressure environment. Measurement of water contact angles on the modified glass surfaces showed that the contact angles could be continuously increased from 40° to 70° by increasing the time of exposure to the OTS vapors from a few minutes to several hours. Polystyrene (PS) thin films were spin coated on the modified glass substrates and water-solvent mixture induced dewetting of the PS thin films was carried out, where the dewetting kinetics depended on the spreadability of water on the surface. We observed a reduction in the length scales of the dewetting, i.e. the wavelength of instability (λ) and droplet size (d), by increasing the extent of OTS exposure. The λ for a 50 nm thick PS film decreased from 12 to 4 µm while the droplet diameter (d) also decreased, from 2.5 to 1.6 µm. [ABSTRACT FROM AUTHOR]

The performance of a pentacene organic thin film transistor (OTFT) is discussed here where the substrate consists of a self-assembled monolayer (SAM) formed from octadecyltrichlorosilane (OTS) on the gate insulator. By changing the substrate from hydrophilic to hydrophobic interface defects are minimized. OTS SAM was studied for two samples according to OTS density 0.5 wt % and 1.0 wt % based on chloroform solution. The water contact angle was measured to investigate OTS growth and distribution. AFM and SEM were used to give organic thin film topography and morphology. The OTFT with 0.5 wt % OTS has a higher mobility and on/off ratio than the OTFT with 1.0 wt % OTS but has an increased threshold voltage. At the same time, the hysteresis at room temperature almost disappeared due to the OTS SAM processing. [ABSTRACT FROM AUTHOR]

Recently, there has been increasing interest in developing artificial superhydrophobic surfaces, especially in the field of self-cleaning application. However, the poor robustness and high-cost preparation of these surfaces have always been some issues for their industrial development. Herein, we describe an environmentally friendly way to prepare stable, robust, and transparent superhydrophobic coatings through the deposition of a rough substructure of TiO2 film followed by chemical modification using octadecyltrichlorosilane (OTS), a fluorine-free organic silane. The as-prepared coatings exhibited a great superhydrophobic property and ultralow adhesion (with a static water contact angle of 158 ± 2° and sliding angle of 4 ± 1°). It was found that the superhydrophobic coatings can still maintain good performance after UV irradiation, chemical immersion, and physical abrasion. More importantly, the coated surfaces showed an excellent self-cleaning ability against dirt particles after rinsed with water droplets. Highlights: Environmentally friendly and low-cost method to prepare superhydrophobic coatings using TiO2 thin film and monolayer octadecyltrichlorosilane (OTS). High transparency of the as-prepared superhydrophobic coatings. The superhydrophobic coatings exhibited good chemical and mechanical stability. The surface of superhydrophobic glass showed an excellent self-cleaning property. [ABSTRACT FROM AUTHOR]

This study demonstrates a method for patterning paper-based microfluidic devices. An octadecyltrichlorosilane (OTS) solution is used to coat a chromatography paper to make it hydrophobic. A low-temperature (~ 32.9 °C) atmospheric-pressure dielectric-barrier-discharge jet with a shadow mask is then used to pattern hydrophilic stripes on the OTS-coated hydrophobic paper. In this manner, 1-mm-wide hydrophilic stripes are patterned successfully. Liquids are demonstrated to be transported and mixed in the hydrophilic stripes. Water contact angle measurement, X-ray photoelectron spectroscopy, surface profiler, optical emission spectroscopy, and scanning electron microscopy are used to characterize effect of pattering. [ABSTRACT FROM AUTHOR]

The film quality of insulators significantly affects performance of resistive random‐access memories (RRAMs), particularly in current leakage and degradation. In this study, a facile and practical method is employed to achieve the van der Waals epitaxy of bismuth iodide (BiI3) on silicon by using a self‐assembled monolayer of octadecyltrichlorosilane (OTS) as a buffer layer. The BiI3 layer is compact and has high crystallinity, a pinhole‐free, and compact surface; every BiI3 crystal is horizontally aligned with OTS–Si substrate. The RRAMs with the Si++/OTS/BiI3/Au structure exhibit excellent resistive switching properties with a very high on/off ratio of 109, long‐term stability for data retention, high endurance in write–erase cycles, and multistate information storage capacity. The crystal orientation, anisotropic carrier transport, morphology, deposition rate, and roughness considerably influence the resistive switching results. These are thoroughly investigated by analyzing the current–voltage characteristics at various temperatures, scanning electron microscope, atomic force microscope, X‐ray photoemission spectroscopy, and X‐ray diffraction patterns. It is proposed that the resistive switching mechanisms is caused by the iodine ion migration, which changes the valence charge of bismuth. This leaves a partially formed conductive metallic bismuth filament in the BiI3 layer under the electrical field that enables multistate data storage. [ABSTRACT FROM AUTHOR]

Despite being a standard process in fabrication of organic thin‐film transistors (TFTs) to reduce interface trap density and decrease surface energy, self‐assembled monolayer (SAM) treatment of gate dielectrics is rarely used in oxide‐semiconductor‐based TFTs due to possible damage to the SAM during semiconductor deposition. Here, by studying the dependence of plasma damage to SAM on the deposition conditions of InGaZnO (IGZO) semiconductor thin films, the feasibility of enhancing the performance of oxide TFTs using octadecyltrichlorosilane (OTS)‐treated, ultra‐thin AlxOy gate dielectrics is explored. It is discovered that under optimized conditions, the TFTs can be significantly improved, showing a reduction of interface trap density by 50% and an increase of carrier mobility and current on/off ratio by a factor of 2.3 and 76, respectively. The effects on bias stress stability also show substantial improvement after the SAM interface treatment. Finally, such an optimized condition is found to also work for IGZO TFTs gated with OTS‐treated HfOx, showing an increase of mobility from 7.8 to 16 cm2 V−1 s−1 compared with the untreated devices. As a result, this simple and yet effective interface treatment method and the resulting devices may have potential applications in future low‐cost, low‐power electronics. [ABSTRACT FROM AUTHOR]

A facile strategy was developed to fabricate transparent ultrahydrophobic glass. First, TiO2 films were deposited uniformly on untreated glass substrate after heating aqueous peroxotitanate thin films at 120 °C for 1 h followed by octadecyltrichlorosilane (ODTS) modification. The as‐fabricated surfaces were then possessed ultrahydrophobic properties because of the combination of the rough surface topography of TiO2 and low surface energy due to ODTS monolayer. It was found that the water contact angle and sliding angle of the as‐prepared coatings were about 146° and 7°, respectively. Besides, these coatings showed excellent self‐cleaning performance compared to untreated glass in order to remove dirt particles with water droplets. It is believed that the current method could lead as low‐cost and effective way to fabricate a very promising material for commercial and industrial coatings applications. [ABSTRACT FROM AUTHOR]

In this paper, octadecyltrichlorosilane (OTS) self-assembled multilayer (SAM) films are fabricated on Pyrex glass by dipping method. The hydrophobicity, constituent and surface morphology of OTS SAM at various dipping times in solutions of 1, 2 and 5mM concentrations are investigated. Characteristic absorption peaks around 2850 and 2920cm−1 are observed by FTIR and island-like structures on samples are detected by AFM. After 15min dipping time for solution of 5mM, water contact angle of the sample reaches the maximum value of 116.4∘ with relatively low surface root mean square (Rms) roughness of 0.152nm. The critical surface tension (γc) of the analyzed sample is 18.2dyne/cm. The optimum dipping time in the solution of 5mM for a complete SAM film is about 30min. The study of the optimal conditions for the formation of integrated OTS SAM has significant scientific and practical values in modification of solid surfaces. [ABSTRACT FROM AUTHOR]

Surface defects cause the measured tensile strength of alkali glass fibers to be significantly lower than their theoretical values. Coatings can be used to “heal” surface flaws and to modify surface properties. In the present work, the nanocoating on alkali-resistant glass (ARG) fiber rovings was carried out by self-assembled monolayers (SAMs) of octadecyltrichlorosilane (OTS). The ARG roving was dipped into OTS nanosol, which deposited the organic–inorganic SAMs of OTS on the ARG surface. The assessment of changes in the fiber surfaces was characterized by scanning electron microscopy (SEM) and fluorescence microscopy, while the chemical changes were characterized by X-ray photoelectron spectroscopy (XPS). Furthermore, the influence of nanocoating on the tensile properties of ARG and OTS-treated ARG with and without an epoxy matrix was also studied. The SEM analysis revealed the formation of nanoscale layers on the ARG surfaces and the XPS confirmed the deposition of organic–inorganic monolayers. The tensile strength of ARG rovings with and without the epoxy matrix was improved significantly. The OTS treatment almost created a superhydrophobic nanocoating on ARG, which was confirmed by the sessile drop water contact angle, and the water absorption by the ARG/epoxy composites reduced. [ABSTRACT FROM AUTHOR]

Poly(vinyl) alcohol (PVA)/nanosilica (SiO2) based electrospun nanofibers has been deposited on wood substrate by means of the roll electrospinning process. The nanofibrous coating was hydrophobized by self-assembled monolayers of octadecyltrichlorosilane (OTS) via a solgel dipping process. The PVA/SiO2 nanofiber coating and OTS hydrophobized coating were characterized by Fourier transform infrared (FTIR) spectroscopy, scanning electron microscopy (SEM), and energy dispersive X-ray analysis (EDXA). All methods confirmed the formation of OTS monolayers on hybrid coatings. The adhesive strength and resistance to scratch of nanofibers coating was also evaluated. [ABSTRACT FROM AUTHOR]

A hydrophobic layer was formed on smooth surfaces of Calotropis gigantea fiber (CGF) and kapok fiber (KF) by adsorption of octadecyltrichlorosilane (OTS) from a toluene solution and then a comparative study was carried out on the basis of various characterizations and oil-absorbing performances for the two natural plant fibers. The resulting OTS-CGF and OTS-KF exhibit outstanding hydrophobic-oleophilic property and an enhancement in the oil-absorbing capacity for engine oil, soybean oil and kerosene. Moreover, the fibers can be utilized for rapid and selective removal of oil spills on the water surface. Compared to KF, CGF seems to be acid-resistant during the hydrolysis process of OTS, with the result that the oil-absorbing capacity exhibits no significant decrease after ten cycles. Eventually, CGF-based material can be further developed for oil-water separation, demonstrating its potential as a promising alternative for treatment of oil-containing wastewaters. [ABSTRACT FROM AUTHOR]

The effect of alkyl chain length on the wetting properties of alkyltrichlorosilane coated cellulose-based paper is reported for four different reagents: methyltrichlorosilane (MTCS; -CH), butyltrichlorosilane (BTCS; -CH), dodecyltrichlorosilane (DTCS; -CH) and octadecyltrichlorosilane (OTCS; -CH). SEM analysis reveals that by systematically varying alkyl chain length, films with different surface morphologies can be generated on flat silicon wafer control samples and on cellulose-based paper samples. The variation in surface morphology leads to different wetting behavior, as determined by measuring static water and oil contact angles. Due to the nano- and micron- scale roughness on MTCS coated substrates, paper samples coated with MTCS display superhydrophobicity with a water contact angle of 152.2°, which is the highest water contact angle among these four alkyltrichlorosilanes. However, additional nano-scale roughness from MTCS coating reduces the oil resistance of coated paper samples, while paper samples coated with long-chain alkyltrichlorosilanes have lower surface energy and also lack nano-scale roughness. As a result, paper samples coated with OTCS display the highest resistance against oils (ethylene glycol contact angle 125.5°; diiodomethane contact angle 101.3°). The intrinsic porosity of paper is largely retained after coating, as indicated by the fact that low surface tension fluids like methanol can easily penetrate coated paper samples. [ABSTRACT FROM AUTHOR]

A general and convenient strategy is proposed for enhancing photovoltaic performance of aqueous dye-sensitized solar cells (DSCs) through the surface modification of titania using an organic alkyl silane. Introduction of octadecyltrichlorosilane on the surface of dyed titania photoanode as an organic barrier layer leads to the efficient suppression of electron recombination with oxidized cobalt species by restricting access of the cobalt redox couple to the titania surface. The champion ODTS-treated aqueous DSCs (0.25 m M ODTS in hexane for 5 min) exhibit a Voc of 821±4 mV and Jsc of 10.17±0.21 mA cm−2, yielding a record PCE of 5.64±0.10 %. This surface treatment thus serves as a promising post-dye strategy for improving the photovoltaic performance of other aqueous DSCs. [ABSTRACT FROM AUTHOR]

A novel C18 functionalized graphene oxide ( GO) coated solid-phase microextraction fiber was prepared by a novel protocol. Based on the strong van der Waals interaction present in GO and abundant oxygenous groups in GO sheets, a simple layer-by-layer self-assembly method was used in the preparation process and then C18 was successfully self-assembled on GO via C-O-Si bonding. Coupled with gas chromatography, extraction performance of the fiber was tested with polycyclic aromatic hydrocarbons ( PAHs) as model analytes. The fiber not only exhibited excellent extraction efficiency and selectivity, but also showed many advantages including high rigidity, long service life and well stability toward organic solvent, acidic and alkali solutions, and high temperature. The relative standard deviations for single-fiber repeatability and fiber-to-fiber reproducibility were less than 7.26 and 17.25%, respectively. The detection limits to the PAHs were less than 0.08 μg L−1 and the calibration curves were linear in a wide range for all analytes. The as-established Solid-phase microextraction GC method was also successfully used for determination of PAHs in two real water samples. [ABSTRACT FROM AUTHOR]

NaA type zeolites were surface modified with octadecyltrichlorosilane (OTS) and then added in polyamide layer of thin film composite (TFC) membranes to prepare surface-modified zeolite-polyamide thin film nanocomposite (TFN) membranes for desalination. The zeolites were characterized by Fourier transform infrared spectroscopy (FT-IR) and X-ray diffraction (XRD). The properties of membranes were characterized by scanning electron microscopy (SEM), contact angle measurement, and the permeation experiment, respectively. The results showed that zeolites were successfully surface-modified with OTS without changing of its structure. The SEM images depicted that the membrane morphology was more homogeneous and the zeolites aggregation in membranes was ameliorated after the zeolites were surface modified. The results of contact angle measurement indicated that the hydrophilic property of membranes was not changed after the zeolites were modified with the long alkyl chain organosilane. The RO performance results verified that the flux of the modified-zeolite TFN membranes was all higher than that of the original-zeolite TFN membranes under the same conditions whereas the salt rejection was improved slightly. The flux of the TFN membranes with 0.05% (w/v) zeolite loading was increased from 28.5 to 40.9 l/m²h, while the salt rejection was increased from 97.8% to 98.5% after the zeolite modification. The experimental results revealed that the modification of zeolites made the molecular sieve zeolite nanocrystals well dispersed in the polyamide thin film layer, and hence improved the water permeation while maintaining high solute rejection. [ABSTRACT FROM AUTHOR]

Aerogel-prepared magnesium oxide (A-MgO) was modified by attachment of gold particles. Subsequent modification of its surface with alkylsilylation of n-octadecyltrichlorosilane and chlorotrimethylsilane exhibits a high catalytic activity for oxidation of styrene with tert-butyl hydroperoxide in liquid phase. Catalytic results show that the introduction of gold on the surface of A-MgO gives a higher catalytic activity in styrene oxidation compared to titanium dioxide. The effect of surface modification of A-MgO was studied with XRD, UV–Vis DR, FTIR and nitrogen adsorption analysis. [ABSTRACT FROM AUTHOR]

A novel way of producing superhydrophobic surfaces by applying a self-assembled monolayer (SAM) to silicon micro/nano-textured surfaces is presented in this paper. The micro/nano-textured surfaces on silicon substrates were generated by the aluminum-induced crystallization (AIC) of amorphous silicon (a-Si) technique. Octadecyltrichlorosilane (OTS) SAMs were then applied to the textured surfaces by dip coating. The topography and wetting properties of the resulting surfaces were characterized using scanning electron microscopy (SEM) and a video-based contact angle measurement system. The results show that by introducing OTS SAMs on the silicon micro/nano-textured surfaces, superhydrophobic surfaces with water contact angles (WCAs) of 155° were obtained, as compared to the WCAs of OTS-modified smooth silicon surfaces of about 112°. Surface topography was found to directly influence the WCA as predicted by the Cassie-Baxter model. [ABSTRACT FROM AUTHOR]

Soft lithography is a method for the manufacture of micro/nano size patterns and structures by using organic materials without the use of high energy. In particular, microcontact printing (muCP) is a very convenient and nonphotolithographic technique that can generate patterned features of self-assembled monolayers (SAMs). In this study, we carried out the selective deposition of HfO2 nano-thin films on Si(100) substrates by combination of muCP using octadecyltrichlorosilane (OTS) and metal-organic chemical vapor deposition (MOCVD). Single molecular precursor of Hf(OtBu) 4 was used for the growth of HfO2 nano-films, and the deposition was carried out between 150degC and 400degC at a pressure of 3times10-2 torr. The as-grown films were characterized by x-ray diffraction (XRD), optical microscopy (OM), scanning electron microscopy (SEM), energy dispersive x-ray (EDX), x-ray photoelectron spectroscopy (XPS), and capacitance-voltage (C-V) and current-voltage (I-V) measurement. It is expected that the combination of muCP of SAM and MOCVD is a better method for fabricating the HfO 2 thin films between micro and nano sizes [ABSTRACT FROM PUBLISHER]

Surface condition and corrosion resistance are major concerns when metallic materials are going to be utilized for applications. In this study, FeCoNiCr medium-entropy alloy (MEA) is first treated with a nitrogen atmospheric-pressure plasma jet (APPJ) and then coated with octadecyltrichlorosilane (OTS) for the surface modification. The hydrophobicity of the FeCoNiCr MEA was effectively improved by OTS-coating treatment, APPJ treatment, or the combination of both treatments (OTS-coated APPJ-treated), which increased the water contact angle from 54.49° of the bare MEA to 70.56°, 93.94°, and 88.42°, respectively. Potentiodynamic polarization and electrochemical impedance spectroscopy tests demonstrate that the APPJ-treated FeCoNiCr MEA exhibits the best anti-corrosion properties. X-ray photoelectron spectroscopy reveals that APPJ treatment at 700 °C oxidizes all the alloying elements in the FeCoNiCr MEA, which demonstrates that a short APPJ treatment of two-minute is effective in forming a metal oxide layer on the surface to improve the corrosion resistance of FeCoNiCr MEA. These results provide a convenient and rapid method for improving surface properties of FeCoNiCr MEA. [ABSTRACT FROM AUTHOR]