The elastic modulus, modulus of rupture (MOR), and viscosity of wet silica gels were measured as functions of age of the gels, using a beam-bending method. The gels were prepared by acid-catalyzed hydrolysis of tetraethyl orthosilicate (TEOS) with a water/TEOS ratio of 16/1. The gels were aged and their properties were measured while immersed in the pore liquid. The modulus increased by about two decades and the MOR and viscosity increased by about one decade over a two-week period. Measurements of stress relaxation showed a strong dependence on sample size that is attributed to the flow of pore liquid out of the samples. The gels were found to be linearly viscoelastic.
All Science Journal Classification (ASJC) codes
- Electronic, Optical and Magnetic Materials
- Ceramics and Composites
- Condensed Matter Physics
- Materials Chemistry