Thermogravimetric behavior of mesoporous hydrated silica-alumina trihydrate hybrid powder synthesized by sol-gel/doping method

Abstract

Thermal degradation of mesoporous hydrated silica (MHS), mesoporous silica (MS), and alumina trihydrate (ATH) hybrid systems for flame retardant materials was investigated. The hybrid powders (contains 64 wt% of ATH) were created by doping ATH particles into a silica sol using the typical sol–gel technique with rice husk as a silica precursor. MHS-ATH has 3% more water by weight, three times lower density (0.9 g/cm3), 37 times larger surface area (186.88 m2/g), and enhanced powder flowability as compared to standard ATH. Thermogravimetric analysis (TGA) study reveals that MHS-ATH has higher thermal stability than ATH, with more water released gradually over a wider temperature range, improving the flame retardancy effect. MHS was also compared with its dehydrated form (MS), but TGA studies suggest that MS-ATH has lower thermal stability due to the powder's tendency to absorb moisture.