Спектр высокого разрешения полос ν-=SUB=-2-=/SUB=-+ν-=SUB=-4-=/SUB=- (F-=SUB=-1-=/SUB=-,F-=SUB=-2-=/SUB=-) и 2ν-=SUB=-4-=/SUB=- (F-=SUB=-2-=/SUB=-) дейтерированного силана -=SUP=-28-=/SUP=-SiD-=SUB=-4-=/SUB=-

A study of the fine rotational structure of the silane molecule absorption spectrum was carried out for the first time. The high-resolution spectrum of 28SiD4 was recorded in the 1260-1480 cm-1 spectral range the vibrational ν2+ν4 (F1,F2) and 2ν4 (F2) bands were theoretically analyzed. Rotational, centrifugal distortion, tetrahedral splitting and resonance interaction parameters of the upper vibrational states were obtained from the weighted least square fit method. The set parameters obtained reproduces the initial vibrational-rotational structure of the ν2 + ν4 (F1, F2) and 2ν4 (F2) bands with an accuracy of drms = 3.9 · 10-4 cm-1.

Amino Functionalized Micro-Mesoporous Hybrid Particles for the Sustained Release of the Antiretroviral Drug Tenofovir

The sustained release of an antiretroviral agent to women mucosa has been proved as an excellent strategy to reduce the sexual transmission of HIV. Hybrid micro-mesoporous particles have been synthesized and functionalized with a silane coupling agent followed by loading the antiretroviral tenofovir. It has been observed that the disposition of the silane molecule on the surface of the particles determines the interaction mechanism with the antiretroviral molecule loaded independently on the surface area of the particles. In this sense, available and free amino groups are required to achieve a smart pH-responsive material, a condition that is only achieved in those materials containing a silane chemisorbed monolayer. Moreover, the modulation of the release kinetics attributed to the presence of the silane monolayer covering the mesopores has been confirmed by fitting the releasing curves to the first order and Weibull models. The developed micro-mesoporous particles have been demonstrated to be excellent smart-release vehicles for antiviral agents and can be safely used in polymer mucoadhesive vaginal gels.

Converting detrimental HF in electrolytes into a highly fluorinated interphase on cathodes

A silane molecule with an unsaturated functionality effectively scavenges harmful hydrogen fluoride from the electrolyte and forms a complex, which experiences preferential oxidation and eventually delivers the fluorine species to the interphase that protects cathodes of high energy density batteries.

Property Enhancement of Silica-Filled Natural Rubber Compatibilized with Epoxidized Low Molecular Weight Rubber by Extra Sulfur

The properties of both compounds and vulcanizates of silica-filled natural rubber (NR) compatibilized with epoxidized low molecular weight natural rubbers (ELMWNRs) consisting of 12 and 28 mol% epoxide are investigated. The ELMWNRs with a molecular weight range of 50,000 to 60,000 g/mol are produced by depolymerization of epoxidized natural rubber (ENR) latex using periodic acid, and then used as compatibilizer in a range of 0 to 15 phr in virgin NR. The compounds with LMWNR without epoxide groups, and with bis-(triethoxysilylpropyl) tetrasulfide (TESPT) coupling agent are also prepared for comparison purpose. Incorporation of ELMWNRs lowers Mooney viscosity and Payne effect to the level closed to that of silica/TESPT compound, and clearly enhances the modulus and tensile strength of vulcanizates compared to the compounds with no compatibilizer and LMWNR. The higher epoxide groups content results in the better tensile properties but somewhat less than the compound with TESPT. Addition of extra sulfur into the compounds with LMWNR and ELMWNRs to compensate for the sulfur released from silane molecule in the silica/TESPT system shows small influence on Mooney viscosity, but remarkably enhances 300% modulus, tensile strength and loss tangent at 60°C as a result of the better network formation.

Hybrid Coatings Based on Conducting Polymers and Polysiloxane Chains for Corrosion Protection of Al Alloys

It was previously demonstrated that the use of a pyrrole-based silane (PySi) for surface treatment of Al alloys provides both active and barrier protection due to the deposition of a hybrid coating, containing polypyrrole and polysiloxane chains. To further explore these features, a wider range of Al substrates and different silane-based formulations in terms of silane molecule, solvent nature, water amount and pH, were investigated. Also, some tests were carried out by using aniline-based silane (AniSi). Structural/morphological characterization of the coatings, as well as the investigation of PySi solutions by diverse spectroscopic techniques, in addition to corrosion tests in NaCl, strongly support the very promising protection performance of the hybrid film. This is indicated as well from the preliminary results obtained with the AniSi-based approach. Thus, typical silane-based treatments with principally barrier action can gain in active properties if the silane compound contains monomers of conducting polymers as a funtional group.

A Study on Film Precursors in SiH4 Thermal CVD by use of Trench Coverage Measurements

ABSTRACTThe precursors of Si film in SiH4 low pressure thermal CVD are studied by use of the trench coverage analysis. The cross sectional profile of the film deposited in a trench is simulated by a direct Monte-Carlo method using the composition of the precursors and their sticking probabilities as adjustable parameters. A comparison with the experimental results[1] shows that the trench coverage profiles are well reproduced by the model where two kinds of precursors deposit independently with respective sticking probabilities of almost zero and unity. The former is silane molecule, and the latter is radicals produced by gas phase reactions. The deposition rate due to radicals can be estimated from the comparison. Considering the sticking probability and the SiH4 pyrolysis reactions, it is concluded that H3SiSiH is one of ate dominant film precursors in gas phase reaction products.