Kinetics of dissolution of glass fibre in hot alkaline solution

Abstract

Kinetics of the dissolution of E-glass fibres in alkaline solutions was investigated. To allow an accurate determination of conversion, glass fibres were immersed individually in the corrosive medium and the diameter change was measured with the use of a scanning electron microscope. Few studies have been reported in the literature on the kinetics of E-glass fibre dissolution or the dissolution of individual fibres. Our experimental results fit well in the zero-order and shrinking cylinder models, suggesting either the diffusion of hydroxide ions through the solution or the glass fibre etching itself was rate-limiting step. The rate constant for the reaction of glass fibre with alkaline solution at 95 °C was found to be between 1.3 × 10−4 and 4.3 × 10−4 g/(m2 s). The reaction order (n) was determined as 0.31–0.49 with respect to the alkaline solution, and the activation energy was 58–79 kJ/mol.