Carbon Fiber Reinforcement of Silica Gels

We investigated the processing and properties of silica gels reinforced with carbon fibers to prevent cracking during drying and handling. Commercial carbon (graphitic, 10microns diameter and 1 mm long) fibers were homogenized with silica sols and the mixture was then gelled chemically by organic additives. Mechanical bending tests showed that the carbon fiber reinforced gels exhibited a significant strain-softening; and the modulus of rupture and the fracture energy were increased 80% and 400% respectively by 10 wt% carbon fiber addition.