STRUCTURAL CHARACTERIZATION OF ACID AND BASE-CATALYZED SILICA XEROGELS

Authors : Eda KELEŞ GÜNER, Abdulkadir ÖZER

Pages : 1199-1206

View : 45 | Download : 6

Publication Date : 2019-12-01

Article Type : Research Paper

Abstract :In this study, silica xerogels were synthesized by the sol gel method using TEOS insert ignore into journalissuearticles values(tetraethyl orthosilicate);, ethanol, water and sulfuric acid as acidic catalyst and ammonia as basic catalyst. The structural characterizations of the synthesized acid-catalyzed silica xerogels insert ignore into journalissuearticles values(ACXs); and base-catalyzed silica xerogels insert ignore into journalissuearticles values(BCXs); were investigated by thermal gravimetric analysis insert ignore into journalissuearticles values(TGA);, scanning electron microscopy insert ignore into journalissuearticles values(SEM); and N2 adsorption and desorption techniques. It was seen from TGA analyzes that the thermal decomposition process of silica xerogels consists of two steps. The SEM images show that the solid skeletal phase of ACXs has a globular morphology with primary particles that are joined together to form agglomerates. In contrast, SEM images of the BCXs indicate a hierarchical morphology with the clusters of these agglomerates organized into larger spherical particles. The pore size distributions insert ignore into journalissuearticles values(PSD); of ACXs and BCXs samples show a main peak in the micropore and micro-mesopore regions, respectively.
Keywords : Silica xerogels, sol gel method, microporous materials, pore structure

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