Influence of reactant catalyst type and Drying Control Chemical Additives (DCCA) on optical and structural properties of silica aerogel prepared via ambient pressure drying

Abstract

We have studied the synthesis environment of ambient pressure silica aerogels influence on their resulting morphological and optical properties. Transparent nanoporous silica aerogel was synthesized at ambient pressure using tetraethylorthosilicate precursor via a sol-gel process. Effect of drying control chemical additives and catalyst on physical properties was investigated. Trimethylchlorolsilane was employed as a hydrophobic reagent in the surface modification process. All aerogel samples were prepared utilizing a subcritical procedure under reactant pH fixed at 8.3, using just ammonium hydroxide or together with ammonium fluoride as catalyst. The effects catalyst types as well as drying control chemical additives on the physical properties of the nanoporous silica aerogels (particle size, surface area, percentage of shrinkage, contact angle, and density) were investigated.