Search results for "Hydrophobic silica"
showing 2 items of 2 documents
The effect of silica nanoparticles on the morphology, mechanical properties and thermal degradation kinetics of polycarbonate
2012
Abstract Polycarbonate/silica nanocomposites with different silica quantities were prepared by a melt compounding method. The effect of silica amount, in the range 1–5 wt.%, on the morphology, mechanical properties and thermal degradation kinetics of polycarbonate (PC) was investigated. Clusters of silica nanoparticles were well dispersed in the polycarbonate whose structure remained amorphous. NMR results showed intermolecular interactions involving the carbonyl groups of different polymeric chains which did not affect the intramolecular rotational motions. The presence of the lowest silica content showed a decrease in the storage and loss moduli below the glass transition temperature, pro…
Performance of porous silica layers in open-tubular columns for liquid chromatography
1989
Abstract Progress has been made in the preparation of porous silica layers in fused-silica capillaries for open-tubular liquid chromatography. The porous silica layer is prepared by (i) static coating of the silica precursor, polyethoxysiloxane (PES), followed by (ii) converting the PES film into a porous silica layer with ammonia solution. The porous silica layer can be easily modified by silane reagents commonly used in packed column high-performance liquid chromatography. The performance of the silica layer with the different phase systems was tested with polyaromatic hydrocarbons and derivatized amino acids as samples.