Ceramic Coating on the Glass Fiber by Sol-Gel Method

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 make 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 coating 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 coating fiber was 60×103and80×103kgf/cm2, respectively. The tensile stren of glass fiber and alumina precursor coating fiber increased with the concentration of silane coupling agent.