pH sensors based on rubbery ormosils preparation and their spectrum studies

Abstract

A new type of methyl substitued ormosils as a matrix for bromophenol blue (BPhB) and bromocresol green (BCG) is described. The new ormosils combine features of classical TEOS sol-gel material such as solvbility in organic solvent and those of sol-gel glasses such as transparent and a porous structure, the ormosils also make a good mechanical stability. The influene of the conditions during the polymerisation process on the photochemical properties of BPhB and BCG has been studied. This sol-gel material was wed to immobilize pH-sensitive absorption dyes, bromothymol blue and bromocresol green, to prepare pH sensing films. The several aspects of the sensing films, including the leaching of the dye from gel, response time to different pH buffer solution, absorption spcetra and the improvement of the immobilization of the dyes to filmo, were also discussed.