Effect of silica on the properties of polyvinyl alcohol nanocomposite membranes -

Abstract

The sol–gel process is a promising approach for the preparation of nanocomposite films in the presence of templates. The hybrid nanocomposites formed by the sol–gel technique are an emerging ongoing field of exploration in materials science. These nanocomposites form an interesting approach because they exhibit properties of both the organic and inorganic part of the hybrid mixture such as good permeability, selectivity, mechanical strength and thermal and chemical stability. Polyvinyl alcohol (PVA) are being used as the organic polymer part of the composites due to its various biomedical applications such as joint replacement, and controlled drug-releasing devices. In this presented work, polyvinyl alcohol has been used as the organic part of the synthesized nanocomposites. As for the inorganic part of the nanocomposites, colloidal silica, ethyl trimethoxysilane, isobutyl trimethoxysilane, propyl trimethoxysilane and octyl trimethoxysilane have been employed. Colloidal silica was used as the precursor for silica. All the resultant nanocomposites were optically clear.Scanning electron microscopic analyses proved the existence of silica nanoparticles that were uniformly embedded in the organic matrix. Thermal properties of the hybrid nanocomposites were studied using TGA and DSC, proving that the higher presence of silanes enhanced the Tg, Tm and the decomposition temperature of polyvinyl alcohol.