Ceramic Coating on the Glass Fiber by Sol-Gel Method

Abstract

Alumina ceramics precursor was coated on the glass fibers by sol-gel method using metal alkoxide solution. The optimum coating condition for the concentration of metal alkoxide and silane coupling agent was investigated. Silane coupling agent makes it possible to uniformly coat alumina precursor film on the glass fiber. The organic contents in alumina precursor on the glass fiber increased with the concentration of metal alkoxide. The addition of silane coupling agent led adhesive force between glass fiber and ceramics precursor films to be higher. The alkali-resistance, heat-resistance and tensile strength of ceramics precursor coated glass fibers were superior to original glass fiber. The surface of glass fiber was eroded by curing in NaOH aqueous solution at 40°C. However, the morphology of fiber coated by alumina precursor was retained in NaOH aqueous solution. The crack on the surface of glass fiber was formed by heating at 800°C, but the crack was not observed in the glass fiber coated by alumina precursor. The tensile strength of glass fiber and alumina precursor coated fiber was 60×10³ and 80×10³kgf/cm², respectively. The tensile strength of glass fiber and alumina precursor coated fiber increased with the concentration of silane coupling agent.