Diverse pore ordering in porous silica: synthesis and quantitative structural insights based on combining scattering and imaging techniques

Mesoporous silica exhibits a diverse range of applications owing to its pore structure and inter-pore correlation. Consequently, quantitative characterization of its mesoscopic structure is extremely crucial to reciprocate its potential applications. In this work, we utilized the chemical and aerosol routes to successfully synthesize granular, porous silica with an average pore size in the range of ∼5-10 nm and different degrees of structural correlation among its pores. To delve into their structural morphology, we employed complementary characterization techniques, including X-ray scattering, electron microscopy, and gas adsorption. Small-angle X-ray scattering (SAXS) was used to obtain statistically averaged quantitative information about their porous network. Field-emission scanning electron microscopy (FESEM) and high-resolution transmission electron microscopy (HRTEM) were used to identify their morphology and positional ordering. The information from these three different techniques was indeed complementary in nature. Thus, combining the comparative results from the detailed analyses using scattering, imaging and gas adsorption techniques is effective in providing an overall quantitative understanding about the morphology and pore correlations in this type of porous material with diverse pore structures.