Research on the Application of Phenyltrimethoxysilane

Introduction

Phenyltrimethoxysilane (Figure 1) ,also known as trimethoxyphenylsilane, is a widely used organic siloxane in industry, which is the main raw material for silicone resin, phenyl silicone oil, etc. Its chemical properties are quite active, and it can generate organic silicon derivatives with unique structures and good physicochemical properties through a series of reactions such as ester exchange and substitution. The polymer molecules generated from phenyltrimethoxysilane contain rigid hydrophobic groups such as benzene rings and permeable silicon oxygen chains, which have surface activity and durability. They can be used as additives in the coating industry. The introduction of phenyl siloxane chains can significantly improve the thermal elasticity, mechanical properties, and adhesion of resins. Therefore, phenyltrimethoxysilane is widely used as high-temperature resistant electrical insulation paints, high-temperature resistant coatings, high-temperature resistant molding and packaging materials, etc.[1]

Structural and dynamic properties of liquid phenyltrimethoxysilane

Herein, researchers present a combined experimental and computational study of liquid phenyltrimethoxysilane. A femtosecond time-resolved optical Kerr effect experiment has been performed to study the rotational diffusion of the molecule. A new all-atoms molecular model of the compound, based on the OPLS force field, has been developed to reproduce the rotational diffusion time constant and other physical and dynamic properties available in the literature. The density obtained from the simulations is1074±4kg/m³ , which is within 1% of the experimental value of 1062 kg/m³. The viscosity from the simulations is1.6±0.1mPa·s while the experimental value is 2.1mPa·s. The average bulk dipole moment of 1.8±0.5Debye obtained from the simulation matches the experimental value of 1.77Debye. The average relative dielectric constant from the simulations is 3.86±0.04, which is within 13% of the experimental value (4.4). The rotational diffusion time of the dipole moment obtained from the simulations is 20.39±0.06ps, which is in excellent agreement with the experimental value of 20±1ps obtained from our measurements. The new model has also been used to calculate structural and dynamic properties of the molecule not yet determined experimentally.[2]

Amine-phenyl multi-component gradient stationary phases

Continuous multi-component gradients in amine and phenyl groups were fabricated using controlled rate infusion (CRI). Solutions prepared from either 3-aminopropyltriethoxysilane (APTEOS) or phenyltrimethoxysilane (PTMOS) were infused, in a sequential fashion, at a controlled rate into an empty graduated cylinder housing a vertically aligned thin layer chromatography (TLC) plate. The hydrolyzed precursors reacted with an abundance of silanol (Si-OH) groups on the TLC plates, covalently attaching the functionalized silane to its surface. The extent of modification by phenyl and amine was determined by the kinetics of each reaction and the exposure time at each point along the TLC plate. The local concentrations of phenyl and amine were measured using diffuse reflectance spectroscopy and X-ray photoelectron spectroscopy, respectively. The profile of the multi-component gradients strongly depended on the order of infusion, the direction of the gradient and the presence of available surface silanol groups. A slightly higher amount of phenyl can be deposited on the TLC plate by first modifying its surface with amine groups as they serve as a catalyst, enhancing condensation. Separation of water- and fat-soluble vitamins and the control of retention factors were demonstrated on the multi-component gradient TLC plates.Uniformly modified and single-component TLC plates gave different separations compared to the multi-component gradient plates. The retention factors of the individual vitamins depended on the order of surface modification, the spotting end, and whether the multi-component gradients align or oppose each other.[3]

Phenyltrimethoxysilane used as silane precursors

Mesoporous silica SBA-15 has been synthesized and functionalized by one-step synthesis method to widen their various application possibilities. In this study, phenyltrimethoxysilane (PTMS), 3-mercaptopropyltrimethoxysilane (MPTMS) and trimethoxypropylsilane (TMPS) were used as silane precursors for the functionalization, and after treated with HCl solution, their catalytic activities were evaluated in the lactic acid–methanol esterification. The presence of anchoring of functional groups on SBA-15 was proved by XRD, FT-IR, BET surface area and pore size distributions. Good catalytic activity was observed especially for SBA-15–SO₃H–MPTMS, and the catalytic activity order was determined as follows: SBA-15–SO₃H–MPTMS>SBA-15–TMPS>SBA-15–PTMS, which is directly associated with the surface area, pore size and pore volume. As compared with homogeneous catalyst, SBA-15–SO₃H–MPTMS heterogeneous catalyst shows remarkable performance, such as separation, recovery and reusability.[4]

Alumina Nanoparticles Modified by Phenyltrimethoxysilane

Recently, it was reported that silica nanoparticles with surface carbonized by pyrolysis of phenylmethoxy groups exhibit strong visible photoluminescence (PL) under ultraviolet excitation. Materials that demonstrate effective broad band visible PL at room temperature without heavy metal activators are of great interest as a potential alternative to expansive rare earth-doped ceramic phosphors for artificial white light sources on the base of compact gas-discharge lamps and light-emitting diodes. Though similar SiO₂:C materials have been reported previously to demonstrate broadband visible PL, origin of light emission centers is unclear until now. One of the basic hypothesis associates emission centers in SiO2:C with carbon nanoclusters. In frameof this model, SiO₂ nanopowder can be considered as morphological template with high specific surface area that provides high concentration of carbon-related emission centers located on the silica surface. Procedure of surface carbonization was similar to that used for carbonization of fumed silica in, i.e., successive procedure of chemical grafting of phenylmethoxy groups (treated by phenyltrimethoxysilane) to the surface of nanoparticles followed by thermal calcinations in chemically inert ambient.

Al₂O₃:SiOC nanocomposites were synthesized using thermal treatment of fumed alumina nanopowder modified by phenyltrimethoxysilane. Hydroxyl groups on the surfaceof alumina nanoparticles were replaced with phenylsiloxane groups followed by annealing in temperature range 400–600°C. It is demonstrated that increase of annealing temperature results in pyrolysis of phenyl groups and formation of silica precipitates. No carbon precipitation was detected after pyrolysis of organosilicon groups. It is suggested that development of photoluminescence after thermal treatment is due to formation of carbonized silica on the surface of alumina particles.[5]

References

[1] Wu JC,Zhu JW,Zhang Q,et al.Study on Synthesis of Phenyltrimethoxysilane by Halide Lithium Exchange,2023,37(01):14-19+37.

[2] Karki K, Materny A, Roccatano D. Study of structural and dynamic properties of liquid phenyltrimethoxysilane. Phys Chem Chem Phys. 2011;13(25):11864-11871. doi:10.1039/c1cp20349e

[3] Dewoolkar VC, Kannan B, Ashraf KM, Higgins DA, Collinson MM. Amine-phenyl multi-component gradient stationary phases. J Chromatogr A. 2015;1410:190-199. doi:10.1016/j.chroma.2015.07.089

[4] C?tak A, Erdem B, Erdem S, Oksüzo?lu RM. Synthesis, characterization and catalytic behavior of functionalized mesoporous SBA-15 with various organo-silanes. J Colloid Interface Sci. 2012;369(1):160-163. doi:10.1016/j.jcis.2011.11.070

[5] Kysil DV, Vasin AV, Sevostianov SV, et al. Formation and Luminescent Properties of Al2O3:SiOC Nanocomposites on the Base of Alumina Nanoparticles Modified by Phenyltrimethoxysilane. Nanoscale Res Lett. 2017;12(1):477. doi:10.1186/s11671-017-2245-z