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Poor interfacial bonding between diamond and matrices has limited industrial applications of diamond-containing composites. Herein, continuous and dense nanometer SiC coatings were deposited on both large size (200 μm) and small size (1.0 μm) diamond particles to improve the wettability of diamond and protect it from oxidation and graphitization. Coating procedure consisted of first pretreating diamond particles followed by chemical vapor deposition (CVD) using methyltrichlorosilane (MTS: CH3SiCl3) as a precursor. Effects of deposition temperature, time, and gas flowing rate on microstructures of SiC coatings were all studied. Results showed that diamond surfaces were fully coated by SiC with thicknesses of 30 nm and 20 nm for large and small size diamond particles, respectively. Meanwhile, onset oxidation temperatures of large and small SiC-coated diamond particles increased by 250 and 130 °C, showing greatly enhanced oxidation resistance than that of raw diamond particles. The compressive fracture strength (CFS) of SiC-coated diamond (200 μm) is 226 N, improved by 8.5% compared with that of the raw diamond (201 N). In sum, CVD method is promising for the preparation of homogeneous nanometer SiC coatings on diamond particles for its modification and further application in composites.

Poly(vinyl alcohol-co-ethylene) (PVA-co-PE) nanofibers (flexible and effective bonding together) were combined with stiff and flame-resistant sepiolite nanorods (SEP) to fabricate composite nanofibrous aerogels (NFAs) through a versatile and gelation-free freeze-drying method. The PVA-co-PE nanofibers prepared based on a high-yield Melt-Extrusion-Phase-Separation process could form a continuous fibrous structure, and the fibrous networks and surface wettability of composite NFAs could be tuned by the amount of SEP used. The introduction of an appropriate amount of SEP improved mechanical properties of composite aerogels, while excessive SEP would lead to a decrease in compression strength of them. The mechanical properties of composite NFAs are shown to be governed by a combination of stiffness of SEP and effective bonding of PVA-co-PE nanofibers. More importantly, the presence of SEP can substantially improve flame resistance of aerogels. After a simple thermal chemical vapor deposition treatment with methyltrichlorosilane, the surface of composite NFAs become rougher and siloxane nanoparticles became visible. With this deposition, hydrophilic NFAs became hydrophobic as a significant surface property modification. Furthermore, the maximum stress at 60% strain went up from 15.57 to 19.17 kPa and the resilience of composite aerogels improved. Thermal properties results confirmed silane coating can improve the thermal stability and insulation characteristics of polymeric aerogel. The manufactured NFAs are demonstrated as good thermal insulators (0.0274 W m−1 K−1), excellent refractories, efficient water/oil separators (45–108 g/g, 78.58–91.76%) and reusable absorbers. Consequently, the multifunctional silane-coated PVA-co-PE/SEP composite NFAs could be envisaged for several demanding applications.

A SiC and ZrC composite coating layer on a tristructural-isotropic (TRISO) coated particle was deposited by fluidized bed chemical vapor deposition method. Methyltrichlorosilane (MTS) and ZrCl4 powder were used as the source materials of the SiC coating and the ZrC coating, respectively. Two kinds of the SiC and ZrC composite coating layers were fabricated with other source gas fraction. The composite coating layer, with a similar ratio of SiC and ZrC, which was observed in the SEM microstructure, was fabricated, and each phase was confirmed by XRD, Raman, and TEM analysis. Only the SiC and ZrC phases were co-deposited; the ZrSi and free carbon phases were not. The composite coating layer with very small ZrC particles embedded in a SiC matrix was fabricated by decreasing the ZrCl4 source gas ratio. Nano-sized ZrC particles in the coating layer were confirmed by high resolution TEM and EDS analysis.

Water pollution due to oil spills has become a significant concern in recent times for the marine ecosystem. The use of oleophilic/hydrophobic sorbents for oil–water separation has gained a lot of attention as an economical and environment-friendly solution. Herein, we developed a superhydrophobic/superoleophilic cotton by silica nanoparticles (~ 800 nm) treatment followed by surface functionalization with methyltrichlorosilane (MTCS). X-ray diffraction, field emission scanning electron microscopy, energy-dispersive X-ray spectroscopy, and Fourier-transform infrared spectroscopy studies reveal that the formation of pseudo-amorphous SiO2 NPs and a C–Si–O coverage on cotton fiber render it superhydrophobic with increased surface roughness. The MTCS/SiO2-treated cotton exhibited contact angles of ~ 173 ± 2° and 0° on the water–cotton and oil–cotton interface, respectively. Moreover, the MTCS/SiO2-treated cotton demonstrated superhydrophobicity over the entire pH range, with excellent absorption capacities for various oil–water mixtures ranging from ~ 30 to 40 times its weight.

The subject of slippery liquid-infused porous surfaces (SLIPS) have attracted many researchers due to their excellent liquid repellent properties and widespread usage in many fields such as anti-wetting, anti-icing, omniphobic, self-cleaning and anti-biofouling surfaces. Choosing an environmentally friendly, durable lubricant and easy-clean preparation method is very important when designing SLIPS. In this work, fluorine-free, transparent, water and oil repellent slippery liquid-infused porous surfaces (SLIPS) were successfully obtained via infusing silicone oil, which is a fluorine free and durable liquid, onto superhydrophobic polysiloxane nanofilament surfaces. Polysiloxane nanofilaments were prepared on activated glass slides by an easy, clean and environmentally friendly gas phase reactions of n-propyltrichlorosilane (n-PTCS) for the first time and also methyltrichlorosilane (MTCS) and the results were compared. Advancing contact angles of the n-PTCS based polysiloxane nanofilament layers were between 143 and 172 degrees and contact angle hysteresis as low as 7 degrees was obtained on these surfaces by altering the relative humidity and reaction time during filament growth. Then, transparent SLIPS were obtained by infusing silicone oil into polysiloxane filament layers of MTCS and n-PTCS. The obtained SLIPS shows excellent liquid repellency, very low contact angle hysteresis for long durations and maintains its water repellency after heating up to 80 degrees C for 6 days and also after exposure to continuous water droplet flow up to 2 h.

Dual-component fibrous materials were produced by co-extrusion and multiplication technology in combination with a water jet procedure. High density polyethylene/poly(vinylidene fluoride) (HDPE/PVDF) and polypropylene/high density polyethylene (PP/HDPE) systems were obtained. Modification of these fibrous materials with multiwall carbon nanotubes imparted electrical conductivity. Methyltrichlorosilane treatment permitted to reach superhydrophobicity reflected in a water contact angle (WCA) ≥ 160°. Both types of modification decreased a pore size of HDPE/PVDF fibrous material and strongly increased its surface area. The material subjected to both treatments possess pore size of 3.1 μm. This electrically conductive and superhydrophobic HDPE/PVDF fibrous material is characterized by WCA of 164° and low surface resistivity of 87.4 Ω/sq. Electrochemical modification using cyclic voltammetry resulted in the formation of silver nanoparticles (Ag°) on surfaces of the fibers, which imparted antibacterial properties against Staphylococcus aureus and Escherichia coli. Keywords: Smart materials, Dual-component fibrous materials, Lotus effect, Multiwall carbon nanotubes, Cyclic voltammetry

Superhydrophobic silk fabrics were prepared using an environmentally friendly enzyme-etching approach, followed by the modification with methyltrichlorosilane (MTCS) via a simple thermal chemical vapor deposition (CVD) process at 70 °C. The effects of the concentration, treatment time and temperature of enzyme on the etched surface properties were discussed. The composite superhydrophobic silk fabrics demonstrated excellent self-cleaning ability, relatively unscathed effecting their intrinsic properties such as the luster, softness, color and style of the fabrics. Furthermore, these treated fabrics demonstrated excellent mechanical durability after silane-treatment as evidenced by the cyclic abrasion and laundering tests. The composite superhydrophobic cotton fabrics have also demonstrated a high efficiency in oil-water separation. The facile technology via enzymatic hydrolysis to etch the substrate possesses extensive potential applications on various other cellulose-based substrates. Accepted version

To reduce the flammability, hydrophobic silica aerogels (SAs) were modified by replacing commonly used trimethylchlorosilane (TMCS) with methyltrichlorosilane (MTCS). It was observed that the MTCS modified SAs (MSA) showed similar physicochemical properties to those TMCS modified SAs (TSA), including the density, thermal conductivity, hydrophobicity, and even thermal stability. However, the flammability of MSA was observed much lower than that of TSA, which was reflected by the significantly decreased gross calorific value (GCV). Furthermore, it was known from the kinetic and thermodynamic analyses that the pyrolysis of MSA became more difficult with the increasing conversion rate (α), which was evidenced by the fact that the apparent activation energy (E) kept rising to about 194 kJ/mol during the whole pyrolysis. Based on the changed E along the time, the pyrolysis process could be divided into two stages, in which α = 0.4 was considered as the turning point. Those main thermodynamic parameters, including pre-exponential factor (A) and the changes of enthalpy (ΔH) and entropy (ΔS), showed a quite consistent tendency with the E, whereas the change of Gibbs free energy (ΔG) almost kept unchanged. The research outcome of this study can provide a deep understanding of the pyrolysis process of SAs and render the public realize the thermal hazard risk of SAs.

The effect of pyrolytic carbon (PyC) thickness on the tensile property of mini T800-carbon fiber reinforced SiC matrix composites (mini-C/SiC) was studied in this work. PyC interphase was prepared by chemical vapor infiltration (CVI) process using C3H6-Ar as gas source, and the PyC thickness was adjusted from 0 to 400 nm, then the SiC matrix was prepared by CVI process using methyltrichlorosilane (MTS)-H2-Ar as precursor and gas source. The results showed that the tensile strength of mini-C/SiC increased first and then decreased with the increase of the PyC thickness. When the thickness of PyC was 100 nm, the average strength reached the maximum value of 393±70 MPa. The Weibull modulus increased from 2.0 to 8.06 with the increase of PyC thickness, the larger the Weibull modulus, the smaller the dispersion, which indicated that the regulation of PyC thickness is conducive to improve tensile properties.

Oil removal or oil/water separation from the industrial waste water especially under harsh environment such as acid and alkali solutions have now been becoming an urgent task for human being. Here, flexible nanofibrous membrane with super-hydrophobicity/super-oleophilicity was prepared through a facile one-step solution-immersion approach, i.e., the poly(vinylidene fluoride) nanofiber mat modified with methyltrichlorosilane (MTS). The nanostructured polysiloxane with different morphologies including the ultrathin cylindrical wires and particles, were present on the nanofiber surface after MTS hydrolysis and subsequent condensation, which significantly enhanced the surface roughness and hence the hydrophobicity of the membrane. The influence of MTS concentration in the n-hexane solution and the hydrolysis time of MTS on the morphology of polysiloxane decorated nanofiber and hence the super-hydrophobicity was investigated in detail. The super-hydrophobic nanofibrous membrane could repel hot water and corrosive solutions, and the contact angle maintained around 150° with a pH ranging from 1 to 13. It was found that the oil/water separation with a high flux and efficiency was achieved by using the nanofibrous membrane that could not only separate the oil with the pure water and hot water but also the corrosive solution including the salt, acid and alkali solution. The organic/inorganic hybrid nanofibrous membrane may have find its potential applications in oil/water separation under a harsh environment.

With good thermal properties, dielectric property and high-temperature ceramics performance, silicon-containing arylacetylene resin (PSA) has opened an attractive alternative to high performance thermosetting resins in application in the area of aircraft and missile. However, it is difficult to introduce silicon into the main chain of organic arylacetylene. In this paper, branched silicon-containing arylethyleneacetylene (BSA) resin was synthesized by methyltrichlorosilane and diethynylbenzene with zinc powder as catalyst. The advantages lie in simple operation, short reaction period and mild heat release. BSA resin exhibits excellent processability with the processing temperature of 20?C - 150?C and processing window of 130?C. The glass transition temperature of the resin casting is over 500?C. The temperature of 5% weight loss (Td5) is up to 575?C and char yield of thermoset at 800?C (Y800) reaches 91% under nitrogen. Also, the dielectric constant and dielectric loss of casting has no change within 10 - 106 Hz.

Self-cleaning coloured superhydrophobic surfaces can find huge market in decorative applications. Here we present a novel and simplistic approach to prepare self-cleaning yellow superhydrophobic polycarbonates by simple nitric acid treatment to attain yellow colour polycarbonate (PC) and subsequent surface silylation by methyltrichlorosilane (MTCS) for superhydrophobicity. A colour of PC can be controlled from light to dark yellow by simply varying the immersion time in nitric acid. The surface silylation by MTCS provides morphologies from nanofibers to nanospheres depending on reaction times. These morphologies are responsible to achieve superhydrophobicity on yellow coloured PC with water contact angle higher than 155° and sliding angle

PVDF membranes were modified by pulse inductively coupled plasma (PICP) and followed by grafting by chloroalkylsilanes for hydrophobicity enhancement and applied to dye wastewater treatment by ozonation membrane contactor. Two plasma gases (oxygen and argon), two grafting chloroalkylsilanes (methyltrichlorosilane [MTCS] and trimethylchlorosilane [TMCS]), and a range of grafting times (0.5–4 h) were investigated. Hydrophobicity enhancement was influenced by the modification conditions including the type of plasma gas, the applied voltage and pressure, the number of plasma treatment shots, and the grafting agent and duration. The results revealed that oxygen-plasma activation was more effective than argon plasma for functionalizing MTCS for hydrophobicity enhancement. The hydrophobicity increased with MTCS grafting but not with TMCS grafting. Successful membrane modification using MTCS was confirmed by the presence of silicon using FT-IR and EDX analysis. Modifying membranes greatly increased the water contact angle, from 74.7° to 125.3° after activation by 2 shots of oxygen plasma under 10 kV/0.3 mbar followed by grafting with MTCS for 4 h. The duration of the exposure of the membranes to ozone determined the membrane properties. The modified membrane also had a higher and more stable ozone flux than the original membrane. Using the modified membrane, DB 71 decolorization by ozonation with membrane contactor was almost complete after 90 min. COD and TOC removals were 63% and 20%, respectively. This study demonstrates that membrane modification via PICP grafted with MTCS has the potential to improve hydrophobicity and membrane contactor applications.

Self-cleaning polyester fabrics were prepared by a simple gas phase deposition procedure in which a layer of polydimethylsiloxane nanofilaments was grown onto textile fibers. Superhydrophobic and self-cleaning properties, tensile breaking strength, mechanical stability and permeability of polyester fabrics were investigated. The results showed that the fabrics deposited had superhydrophobicity, and the contact angle and sliding angle of the fabric surface were 159° and 1.7°, respectively. The self-cleaning test showed that dust particles adhere to rolling water and shed from the surface of polyester fabric, leaving an extremely clean surface. In addition, the polyester fabric deposited still has excellent breaking strength and permeability. This approach is simple, inexpensive and has little effect on the mechanical properties of the fabric.

The complex aerogel generated from nano-polysaccharides, chitin nanocrystals (ChiNC) and TEMPO-oxidized cellulose nanofibers (TCNF), and its derivative cationic guar gum (CGG) is successfully prepared via a facile freeze-drying method with glutaraldehyde (GA) as cross-linkers. The complexation of ChiNC, TCNF, and CGG is shown to be helpful in creating a porous structure in the three-dimensional aerogel, which creates within the aerogel with large pore volume and excellent compressive properties. The ChiNC/TCNF/CGG aerogel is then modified with methyltrichlorosilane (MTCS) to obtain superhydrophobicity/superoleophilicity and used for oil&ndash, water separation. The successful modification is demonstrated through FTIR, XPS, and surface wettability studies. A water contact angle of 155&deg, on the aerogel surface and 150&deg, on the surface of the inside part of aerogel are obtained for the MTCS-modified ChiNC/TCNF/CGG aerogel, resulting in its effective absorption of corn oil and organic solvents (toluene, n-hexane, and trichloromethane) from both beneath and at the surface of water with excellent absorption capacity (i.e., 21.9 g/g for trichloromethane). More importantly, the modified aerogel can be used to continuously separate oil from water with the assistance of a vacuum setup and maintains a high absorption capacity after being used for 10 cycles. The as-prepared superhydrophobic/superoleophilic ChiNC/TCNF/CGG aerogel can be used as a promising absorbent material for the removal of oil from aqueous media.

SiC nanowires wrapped by carbon nanosheet have been synthesized by chemical vapor deposition using methyltrichlorosilane as precursor at standard atmospheric pressure. The morphological and structure of as-received products were characterized. The nanowires consist of a single-crystalline β-SiC core and a carbon nanosheet shell. The diameter of β-SiC core is about 30 nm. The thickness of carbon nanosheet is about several nanometers. The carbon nanosheet is polycrystalline graphite. EELS analysis of different elements in nanowires further prove that the nanowires are carbon nanosheet wrapped SiC nanowires. To verify its toughening effect, SiC coating has been also deposited in the porous carbon nanosheet wrapped SiC nanowires layer by chemical vapor deposition at low pressure. The thermal shock tests showed that the weight loss of SiC nanowires wrapped by carbon nanosheet-toughened SiC coated C/C composites was only 2.38% after 25 times thermal cycling between 1773 K and room temperature. The incorporation of carbon nanosheet wrapped SiC nanowires can effectively improve the toughness and thermal shock resistance of SiC coating on C/C composites via cracks pining and deflection.

In this paper, a facile and green method was presented to prepare flexible, ultralight, and hydrophobic cellulose aerogels (CA) on the chemical cross-linking of cellulose solution, lyophilization and subsequent hydrophobic modification with methyltrichlorosilane (MTCS) by a thermal chemical vapor deposition (CVD) process. The resultant cellulose aerogels had an interconnected and highly porous structure with a varied pore size owing to different starting solution concentrations. And also the cellulose aerogels were ultralight (as low as 0.027 g cm−3), but they exhibited improved mechanical properties with compress stress of 1.10–3.85 MPa. After silanization, the MTCS-modified cellulose aerogels showed durable hydrophobicity with an average water contact angle of 141°, even maintaining 131° after 5 days. Furthermore, the flexible and hydrophobic cellulose aerogels could rapidly collect oils and organic solvents both on the surface and bottom from water, and exhibited excellent adsorption performances (e.g. 59.32 g g−1 of pump oil) as well as good recyclability. Thus, such a flexible and hydrophobic cellulose aerogel is a very promising material for oil spill cleanup and industrial oily wastewater purification.

Superhydrophobic polysiloxane nanofilaments were successfully grown on polymer coatings prepared by conventional emulsion polymerization without the application of any activation step for the first time using methyltrichlorosilane as the silane precursor. Both gas phase reactions under a controlled humidity environment and liquid phase reactions in standard petroleum ether which is open to air were applied during filament growth. Wettability, morphology and transparency of the obtained polysiloxane nanofilaments were characterized by contact angle measurements, scanning electron microscopy and UV-vis transmittance tests respectively. Advancing contact angle values between 166–172° and 157–169° were obtained via the gas phase reactions and the liquid phase reactions, respectively. It was also shown that polysiloxane nanofilaments can be grown on polystyrene coatings prepared by solution polymerization without any pre-activation step via the liquid phase filament growth reaction. It was determined that the presence of hydroxyl groups on a polymer coating is not required for the growth of polysiloxane nanofilaments, and only the formation of a water film having an adequate thickness on the polymeric coating surface is sufficient.

Nonwovens of commercially available polylactide (PLA) were produced by electrospinning using laboratory scale equipment. The nonwovens were subsequently coated with an aqueous dispersion of multiwall carbon nanotubes (MWCNT), using the padding technique. MWCNT formed 3D networks on fiber surfaces making the nonwovens electrically conducting, with surface electrical resistivity of 77 Ω/sq – 680 Ω/sq. Modification of the nonwovens with methyltrichlorosilane made them superhydrophobic, what was reflected in the water contact angles of 160 − 175°. In turn, electrochemical deposition of silver particles (Ag°) on the conductive nonwovens imparted antibacterial activity against Staphylococcus aureus (gram-positive) and Escherichia coli (gram-negative).

The oil industry is plagued with regular incidences of spills into the environment, causing environmental damage to flora and fauna, especially in marine environments where spills easily travel long distances from their sources. This study was carried out to investigate a simple two-step process for the conversion of waste cigarette filters into a superhydrophobic and oleophilic sorbent for application in oil/water separation and spill clean-up. Ultrasonically cleaned filters were surface modified by chemical vapour deposition using methyltrichlorosilane. The results show that the functionalised waste filters achieved superhydrophobic properties with a water contact angle of 154 &plusmn, 3.5&deg, adsorbing 16 to 26 times their weights in various oils, which is a better oil sorption performance than those of commercially available non-woven polypropylene adsorbents. Also, the sorption capacity did not significantly deteriorate after 20 cycles of reuse, with up to 75% sorption capacity retained. The surface modified filters demonstrated excellent water repellency, oil sorption, and recyclability showing their potential application for full scale oil spill clean-up.

Organosilicon material is widely used because of its dual structure. Dimethyldichlorosilane is the largest and most versatile of organic silicon monomer. In this article, MP2/6-311 $$++\hbox {G}$$ (3df, 2pd) basis set has been used to calculate the reaction mechanism of disproportionation for producing dimethyldichlorosilane by catalysts $$\hbox {AlCl}_{3}/\hbox {ZSM-5}$$ (3T, 4T, 6T). The results show that the activation energies (3T, 4T, 6T) of the rate-determining step of the main reaction are: 100.3, 110.6 and $$113.1~\hbox {kJ}~\hbox {mol}^{-1}$$ , respectively. The structure analysis, activation energy analysis and LOL analysis for different catalysts all show that the catalytic effect of 4T cluster $$\hbox {AlCl}_{3}/\hbox {ZSM-5}$$ is the best. SYNOPSIS The disproportionation of methyltrichlorosilane and trimethylchlorosilane, catalyzed by 3T cluster $$\hbox {AlCl}_{3}$$ /ZSM-5 (Cat.4T and Cat.6T are same as Cat.3T). It has been studied theoretically. The results suggest that the catalytic effect of 4T cluster $$\hbox {AlCl}_{3}/\hbox {ZSM-5}$$ is the best. PICTOGRAM

A systematic silylation approach using mono-, di-, and trichlorosilanes with different alkyl chain lengths was employed to enhance the hydrothermal stability of zeolite Y. DRIFT spectra of the silylated zeolites indicate that the attachment of the silanes takes place at surface silanol groups. Regarding hydrothermal stability under aqueous-phase processing (APP) conditions, i.e., pH ≈ 2, 473 K and autogenous pressure, the selective silylation of the zeolite surface using monochlorosilanes has no considerable influence. By using trichlorosilanes, the hydrothermal stability of zeolite Y can be improved significantly as proven by a stability test in an aqueous solution of 0.2 M levulinic acid (LA) and 0.6 M formic acid (FA) at 473 K. However, the silylation with trichlorosilanes results in a significant loss of total specific pore volume and total specific surface area, e.g., 0.35 cm3 g−1 and 507 m2 g−1 for the silylated zeolite Y functionalized with n-octadecyltrichlorosilane compared to 0.51 cm3 g−1 and 788 m2 g−1 for the parent zeolite Y. The hydrogenation of LA to γ-valerolactone (GVL) was conducted over 3 wt.-% Pt on zeolite Y (3PtY) silylated with either n-octadecyltrichlorosilane or methyltrichlorosilane using different reducing agents, e.g., FA or H2. While in the stability test an enhanced hydrothermal stability was found for zeolite Y silylated with n-octadecyltrichlorosilane, its stability in the hydrogenation of LA was far less pronounced. Only by applying an excess amount of methyltrichlorosilane, i.e., 10 mmol per 1 g of zeolite Y, presumably resulting in a high degree of polymerization among the silanes, a recognizable improvement of the stability of the 3 PtY catalyst could be achieved. Nonetheless, the pore blockage found for zeolite Y silylated with an excess amount of methyltrichlorosilane was reflected in a drastically lower GVL yield at 493 K using FA as reducing agent, i.e., 12 vs. 34% for 3PtY after 24 h.

Fabrication of silicon carbide fibres reinforced silicon carbide composite (SiC/SiC) by chemical vapour infiltration (CVI) process was investigated in this research with the help of both simulation and experimental set-up. CVI of silicon carbide preform was carried out through the pyrolysis of methyltrichlorosilane (MTS) over a broad temperature range at atmospheric pressure. The overall aim was the morphological description of the matrix (co-deposition of Si, SiC and C) during pyrolysis of MTS by CVI process and its state-of-the-art numerical calculation. Phase-field model was developed and deployed to predict the evolution of the microstructures and to describe the influence of the infiltration conditions on the properties of the composite during CVI process in conjunction with the implication of finite element method. Both mass transport and fluid motion in gas phase were considered. Experimental results exhibit three deposition regimes at different temperature ranges as predicted by the numerical simulation results. This also implies different deposition kinetics involved as investigated in the present research. The great difference of the steady-state deposition rate exceeding three orders of magnitude was explained in terms of a multiple steady-state surface reaction model of co-deposition of SiC, Si and C. Corresponding gas-phase compositions, over the temperature region covered in the present experiments, were calculated with a detailed pyrolysis reaction mechanism of MTS. (Less)

A microwave plasma process operating at atmospheric pressure was developed for the synthesis of SiC nanoparticles. The process utilizes methyltrichlorosilane (MTS) as precursor, acting as both carbon and silicon source, along with an additional hydrogen feed to ensure a fully reducing reaction environment. In addition, argon served as carrier gas.. The parameters studied were the H2:MTS molar ratio and the total enthalpy, in the range 0 to 10 and 70 to 220 MJ/kg respectively. The particles size distribution ranged from 15 to 140 nm as determined by SEM and TEM micrographs. It was found that an increase in enthalpy and a higher H2:MTS ratio resulted in smaller SiC particle sizes. The adhesion of particles was a common ocuurence during the process, resulting in larger agglomerate sizes.

A simple and time-saving approach for preparing self-cleaning superhydrophobic silica coatings using a dip-coating technique is reported in this study. Commercially available silica particles were modified with methyl groups using methyltrichlorosilane as a modifying agent. By adopting a multi-layer deposition process, a superhydrophobic silica coating with a water contact angle of 153°±2° and roll-off angle of 8°±1° was obtained. The prepared silica coating exhibited excellent self-cleaning performance; moreover, it was able to maintain superhydrophobicity under the impact of a water jet. This method could be an effective strategy for fabricating self-cleaning superhydrophobic surfaces for promising industrial applications.

To improve the ablation resistance of PIP-C/SiC composites, SiC/Zr–Si–C multilayer coating was prepared by chemical vapor deposition (CVD) using methyltrichlorosilane (MTS) and hydrogen as the precursors and molten salt reaction using KCl–NaCl, sponge Zr and K2ZrF6, then the ablation capability of the coated composites was tested under oxyacetylene torch flame. The linear and mass ablation rates were much lower than those of uncoated samples. The linear and mass ablation rates of the three coating coated samples reached 0.0452 mm/s and 0.031 g/s, decreased by 27.3% and 27.1%, respectively. Moreover, the linear and mass ablation rates of the five coating coated samples reached 0.0255 mm/s and 0.0274 g/s, decreased by 59.0% and 35.5%. The gases released during ablation could take away a lot of heat, which was also helpful to the protection of the composites.

Porous thin-film polymethylsiloxane microparticles have been prepared successfully from octyltrichlorosilane and methyltrichlorosilane in (water/oil) W/O emulsion systems by using several oil phases and changing the amount of the silanes or of the surfactant Span 60. Hollow microspheres of various shell thicknesses (120-180 nm) and high surface area were prepared by using four types of nonpolar solvents as the oil phase of the W/O emulsion system. The diameter of the spheres can also be controlled (1-1.6 mu m) by using different oil phases. The results of thermal analysis, nitrogen adsorption isotherm, infrared spectra and X-ray diffraction data showed that hollow microspheres of amorphous polymethylsiloxane with high surface area (360-385 m(2)g(-1)) can be obtained by heating the spheres in air at 673 K; the polymethylsiloxane microspheres become nonporous silica particles after calcination at 873 K for 3 h. Cup-shape microparticles of polymethylsiloxane with nano-order thickness (20-120 nm) were prepared by reducing the amount of silanes in the mixture. Small hollow particles were prepared by replacing a portion of the octyltrichlorosilane with Span 60., Article, POLYMER JOURNAL. 47(6): 449-455 (2015)

Off-the-shelf laboratory filter paper of different pore-sizes and thicknesses can be modified with fluorine-free organosilanes to be superhydrophobic, patternable, and ready for quantitative assay applications. In particular, we have demonstrated that cellulose filter paper treated with a binary hexane solution of short (methyltrichlorosilane, MTS) and long (octadecyltrichlorosilane, OTS) organosilanes, exhibits remarkably high water contact angles (> 150 °) and low wetting hysteresis (~10 °). Beyond the optimized ratio between the two organosilanes, we have discovered that the thickness rather than the pore size dictates the resulting superhydrophobicity. Scanning electron microscope (SEM) images showed that silianization does not damage the cellulose microfibers; instead they are coated with uniform, particulate nanostructures, which should contribute to the observed surface properties. The modified filter paper is chemically stable and mechanically durable; it can be readily patterned with UV/ozone treatment to create hydrophilic regions to prepare chemical assays for colorimetric pH and nitrite detections.

This article presents the findings concerning the preparation and properties of cotton woven fabrics with a conductive network made of multiwall carbon nanotubes deposited on the fiber surface by the padding method. The next stage of treatment consisted of imparting superhydrophobic properties to the fabrics in solution with methyltrichlorosilane (MTCS) in a waterless medium. The tests performed show that the state of surface and water content in cotton fibers exerts a significant influence on the hydrophobic properties of the analyzed samples. In order to explain the differences in hydrophobic properties, the morphology of the cotton fabric surface was examined using samples with various water contents. The formation mechanism of MTCS coatings on cotton fabric has been proposed.

The preparation and application of new intercalation compounds of graphite oxide are reviewed. Graphite oxide was silylated with different silylating reagents such as alkyltrichlorosilane and 3-aminopropylethoxysilanes. After they were bidentately or monodentately attached to layers of graphite oxide, Si–OH groups which are available for further functionalization were introduced. When highly silylated graphite oxide was heated under vacuum, microporous or mesoporous pillared carbons in which adjacent carbon layers are connected with siloxane or silsesquioxane pillars were obtained. Organic molecules were size-selectively intercalated into the pillared carbon obtained from graphite oxide silyated 3 times with methyltrichlorosilane. The excess hydrogen adsorption of pillared carbons at ambient temperature reached 0.6 wt% at 20 MPa. Pillared carbon thin films were prepared and they showed a selective electrical resistance change response to electron donating and smaller organic molecules. [TANSO 2014 (No. 263) 109–13.]

We report in situ growth of amorphous silicon/carbon (Si/C) layers on graphitized carbon black (GCB) particles in porous microspheres (PMs) for formation of novel GCB@Si/C PMs as high performance anode materials. The preparation included spray drying, KOH activation and chemical vapor deposition at 900 °C, and used methyltrichlorosilane as both the Si and C precursor, which is a cheap byproduct in the organosilane industry. The obtained samples were characterized by X-ray diffraction, thermogravimetric analysis, nitrogen adsorption, transmission electron microscopy, and scanning electron microscopy. Compared with the bare GCB PMs, the GCB@Si/C PMs showed a significantly enhanced electrochemical performance with high lithium storage capacity and excellent cycling stability (the discharge capacity of GCB@Si/C-3 PMs and GCB@Si/C-6 PMs is maintained at 587.2 and 729.7 mA h g−1 after 200 cycles at a current density of 100 mA g−1), because the unique interconnected porous structure within the microspheres could absorb a large portion of Si volume change during Li insertion and extraction reactions, promote the diffusion of Li-ion and electrolyte solution, hinder the cracking or crumbling of the electrode, and additionally, the GCB and amorphous C provide high conductive electron pathway. This work opens a new way for fabrication of Si/C nanocomposites as anode materials for Li-ion batteries.

Polyoxometalates were grafted covalently on SBA-15 by a two-step procedure. The dehydroxylated mesoporous silica was first modified by reaction with methyltrichlorosilane in presence of triethylamine. The resulting solid was fully characterized and contained a mixture of mono- and digrafted species . These surface Si–Cl bonds can react with lacunary polyoxometalates as in solution, yielding to a ≡Si–O–POM linkage. However, solid state MAS NMR shows that only the digrafted species react with the polyoxometalate. This new grafting method opens the way to the synthesis of a new class of catalysts which could operate in solution without leaching.

The oxidation resistive properties of bare, dense SiC and nanostructured SiC coated carbon fibers were examined in different oxidative environments from room temperature to 1350 °C. Chemical vapor deposition process was used for the preparation of dense and nanostructured silicon carbide (SiC) coating on carbon fiber using methyltrichlorosilane. SEM, TEM and XRD analysis inferred dense and nanostructured β SiC coatings. The dense and nanostructured SiC coated carbon fibers have shown much improved oxidation property in oxygen as well as in static air environment. Possible mechanism of oxidation behavior of dense and nanostructured SiC coated carbon fibers and role of SiO 2 have been discussed.

A procedure is developed for the gas chromatographic determination of admixtures of permanent gases, CO, CO2, and hydrocarbons in methylsilane with detection limits of 0.02–0.8 ppm. The procedure was applied to the analysis of methylsilane obtained by reducing methyltrichlorosilane with sodium tetrahydrob-orate in an organic solvent. Admixtures of permanent gases and C1–C5 hydrocarbons the in synthesized methylsilane were detected.

The multiphase field model for chemical vapor infiltration (CVI) of SiC/SiC composites is developed in this study, thereby to reproduce the microstructure evolution during CVI process and to achieve better understanding of the effect of process parameters (e.g., temperature, pressure, etc.) on the final product. In order to incorporate the thermodynamics of methyltrichlorosilane (MTS) pyrolysis into phase field model framework, the reduced chemical reaction mechanism is adopted. The model consists of a set of nonlinear partial differential equations by coupling Ginzburg-Landau type phase field equations with mass balance equations (e.g., convection-diffusion equation) and the modified Navier-Stokes equations which accounts for the fluid motion. The microstructure of preferential codeposition of Si, SiC under high ratio of H2to MTS is simulated and the potential risk of blockage of the premature pores during isothermal CVI process is predicted. The competitive growth mechanism of SiC grains is discussed and the formation process of potential premature pore blockage is reproduced.

3C-SiC layers were deposited on Si substrates by using a low temperature buffer layer and the addition of methyltrichlorosilane (MTS) to the gas phase during the high temperature thick film growth. Several samples were grown by varying the deposition temperature and the MTS content in order to study how these parameters affect the layer quality and the lattice defects. All of the grown layers are single crystalline and epitaxial to the substrate. The formation of empty voids at the SiC/Si interface was successfully avoided. The surface of the layers grown with MTS addition was smoother and contained less residual strain. A 15 mu m thick 3C-SiC sample was grown using an optimized process in order to evaluate its residual strain and bow.

The overall growth kinetics of silicon carbide films deposited from the mixture of methyltrichlorosilane (MTS) and hydrogen were determined by a magnetic suspension microbalance. The results show that three regions are distinguishable in the studied temperature range. In low temperatures (

The microstructure evolution of the isothermal chemical vapor infiltration (ICVI) of silicon carbide (SiC) from methyltrichlorosilane (MTS) is simulated by a phase-field model which is implemented numerically using the discontinuous Galerkin method. The model consists of a phase-field equation describing the diffusive interface kinetics and a species transport equation describing the mass balance. For the diffusive interface kinetics, a new form of the free energy density related to the ICVI process is adopted to ensure two stable states of gas phase and solid phase, and the Gibbs free energy changing between these two phases is taken as driving force. For the mass balance, two process intensities depending on the phase-field parameter are introduced to account for the homogeneous gas reaction and the heterogeneous surface reaction including the influence of the by-product hydrogen chloride (HCl). Finally, a discontinuous Galerkin formulation is derived for the nonlinear phase-field model and a priori error analysis is used for the semi-discontinuous formulations based on the proof of the uniqueness of the solution of the discontinuous approximation. Two numerical examples are presented to demonstrate the validity of the discontinuous Galerkin method and to investigate the effect of geometric parameters on microstructure evolution.

HTGR using a TRISO coated particles as nuclear raw fuel material can be used to produce clean hydrogen gas and process heat for a next-generation energy source. For these purposes, a TRISO coated particle was prepared with 3 pyro-carbon (buffer, IPyC, and OPyC) layers and 1 silicone carbide (SiC) layer using a CVD technique on a spherical UO₂ kernel surface as a fissile material. In this study, a spherical UO₂ particle was prepared using a modified sol-gel method with a vibrating nozzle system, and TRISO coating fabrication was carried out using a fluidized bed reactor with coating gases, such as acetylene, propylene, and methyltrichlorosilane (MTS). As the results of this study, a spherical UO₂ kernel with a sphericity of 1+0.06 was obtained, and the main process parameters in the UO₂ kernel preparation were the well-formed nature of the spherical ADU liquid droplets and the suitable temperature control in the thermal treatment of intermediate compounds in the ADU, UO₃, and UO₂ conversions. Also, the important parameters for the TRISO coating procedure were the coating temperature and feed rate of the feeding gas in the PyC layer coating, the coating temperature, and the volume fraction of the reactant and inert gases in the SiC deposition.

Rice hull ash (RHA) was converted to amorphous silica gel using a modified version of published literature procedures. The gels were characterized by a comparison of their Cross Polarization Magic Angle Spinning 29Si NMR and scanning electron microscopy images with commercial silica gels. The resulting gels were silanized with a 7.5:1 mixture of methyltrichlorosilane and chloropropyltrichlorosilane and then reacted with poly(allylamine) (PAA) to produce the silica polyamine composite (SPC) BP-1. The BP-1 was then further modified with pyridine-2-carboxaldehyde to form the copper-selective SPC, CuSelect. This procedure follows that used to produce the commercialized version of these composite materials from commercially available amorphous silica gels. The composites were characterized by solid-state NMR techniques, elemental analysis, SEM, porosimetry and metal ion capacity and selectivity. The overall goal of the project was to determine the feasibility of using RHA to make SPC. The observed strengths and weaknesses of this approach are discussed. Copyright © 2011 John Wiley & Sons, Ltd.

The rate constants for the gas-phase reactions in the silicon carbide chemical vapor deposition of methyltrichlorosilane (Ge, Y. B.; Gordon, M. S.; Battaglia, F.; Fox, R. O. J. Phys. Chem. A 2007, 111, 1462.) were calculated. Transition state theory was applied to the reactions with a well-defined transition state; canonical variational transition state theory was applied to the barrierless reactions by finding the generalized transition state with the maximum Gibbs free energy along the reaction path. Geometry optimizations were carried out with second-order perturbation theory (MP2) and the cc-pVDZ basis set. The partition functions were calculated within the harmonic oscillator and rigid rotor approximations. The final potential energy surfaces were obtained using the left-eigenstate coupled-cluster theory, CR-CC(2,3) with the cc-pVTZ basis set. The high-pressure approximation was applied to the unimolecular reactions. The predicted rate constants for more than 50 reactions were compared with the experimental ones at various temperatures and pressures; the deviations are generally less than 1 order of magnitude. Theory is found to be in reasonable agreement with the experiments.