UV-Spectrophotometric Determination of 3-Glycidoxypropyltrimethoxysilane (GPTMS) and Epoxy Groups on GPTMS Modified Nanosilica

Abstract

A UV-spectrophotometric method has been developed for quantitative determination of 3-glycidoxypropyltrimethoxysilane (GPTMS) and epoxy groups on GPTMS modified nanosilica (GPTMS-SiO₂). The procedure is based on the quantitative reaction of dihydroxyl of hydrated epoxy groups with potassium periodate to form iodate, which can be detected by UV-spectrophotometry, after being coloured using excessive iodide anion. The analysis of GPTMS and epoxy groups on GPTMSSiO₂ yields results with favourable accuracy and reproducibility. Linearity has been obtained over the GPTMS (or epoxy groups) concentration range of 2.2 × 10^-6-2.7 × 10^-5 mol L^-1 with r value of 0.9999. Influences of hydrolysis, oxidation and colouring conditions have also been investigated.