Heat treatment is a standard method to increase the hardness of silica in various applications. Here, we tested the effect of high temperature annealing on the mechanical properties of silica microcapsules by force spectroscopy under point loads applied to the particle shell. The Young's modulus of the shells moderately increases after annealing at temperatures above 500 °C. Temperatures over 8...

Title of Dissertation: DEVELOPMENT OF ARYL SILOXANE CROSSCOUPLING TECHNOLOGY AND ITS APPLICATION TO THE SYNTHESIS OF COLCHICINE AND ALLOCOLCHICINE DERIVATIVES William Michael Seganish, Doctor of Philosophy, 2005 Dissertation directed by: Professor Philip DeShong Department of Chemistry and Biochemistry One of the most versatile methods for the formation of aryl-aryl bonds is the palladium-catal...

Create three-dimensional network of siloxane polymer in the epoxy resin is an appropriate mechanical properties .Dispersion of nanoclay in these coating was prepared by ultrasonication method. Mechanical properties of nanocomposit coatings such as abrasion, hardness and adhesion was increased by addition of nanoclay montmorillonite. Different percentages of nanoclay in coating showed that even ...

New biodegradable network polymers containing siloxane-linked polymeric prodrugs of 5-ammino-2-hydroxybenzoic acid (5-ASA) in the main chain were prepared by ter polymerization of methacrylic acid (MA), 2-hydroxyethylmethacrylate (HEMA), and bis (trimethylsilyloxy) methylsilane (VBM) in the presence of some new cross-linking agents.The monomers and polymers were characterized by FT-IR and 1H-NM...

A new decomposition method for structural analysis of polysiloxanes (silicones) was developed using methyl orthoformate. The siloxane bonds in samples with vinyl and/or methyl side groups decomposed under relatively mild acidic conditions up to around 70°C and were followed by methoxylation at the cleaved linkages with few side reactions. The product yields with respect to the siloxane monomer ...

Optimization of performance of holographic gratings was investigated by changing the chemical structures of photopolymerizable monomers, the LC content, and recording beam intensity, which strongly related to the control of kinetics of polymerization and phase separation of LCs. High diffraction efficiency was obtained using 3-acryloxypropyltrimethoxysilane (APTMS) and 2-[(3,4-epoxycyclohexyl)e...

Soreanu, G., M. Béland, P. Falletta, K. Edmonson, L. Svoboda, M. Al-Jamal and P. Seto. 2011. Approaches concerning siloxane removal from biogas * A review. Canadian Biosystems Engineering/Le génie des biosystèmes au Canada. 53: 8.1 8.18. One of the major barriers to the use of biogas as an alternative renewable energy source is the presence of siloxanes. At combustion temperatures, siloxanes ar...

Water purification is of extreme importance worldwide. p-Nitrophenol was used as a test chemical to design and test an organoclay for the removal of p-nitrophenol from an aqueous solution. Synthesis of the organoclay with methyltrioctadecylammonium bromide [CH(3)(CH(2))(17)](3)NBr(CH(3)) labeled as MTOAB results in multiple expansions of the montmorillonite clay from 1.24 nm to a maximum of 5.2...

PURPOSE To evaluate the dimensional accuracy of the resultant (duplicative) casts made from two different impression materials (polyvinyl siloxane and polyether) in parallel and angulated implants. MATERIALS AND METHODS Three definitive master casts (control groups) were fabricated in dental stone with three implants, placed at equi-distance. In first group (control), all three implants were ...