Temperature and Particle-size Effects on the Formation of Silica Gels from Silica Sols

Abstract Silica nanoparticles (silica sols) based gels have increasingly been used as alternative grouting material for sealing the small fractures in tunnel walls. Gelling of silica at room temperature has investigated thoroughly but gelling different temperatures scarcely investigated. At same time is one major factor which can affect long-term stability grouted silica. In this work we three types sols (Levasil CS40-213, Levasil CS40-222, and CS30-236) having particle sizes, 0.28 M NaCl 10, 20 30 °C. Aggregation process, starting from addition salt to point, was monitored by measuring dependent size distribution. Electrospray scanning mobility sizer (ES-SMPS) measure aggregating. These measurements were complemented rheological order get a relationship between changes aggregate structure viscosity suspension. Data gel calculate activation energy. temperature, with smallest average showed shortest times whereas largest longest time. However, increasing shorter seen all sols. Temperature similar trends i.e., increased leads quicker increase sharp near point. Our calculations fractal dimensions that network there are still many free particles continuously incorporated into network. Apparent energies calculated CS30-236 13.40, 23.36 41.45 kJ/mol, respectively. values lower than reported literature. Moreover, zeta potential show less negative increase. The above mentioned odd what literature provided plausible explanation these results.