Unravelling the structural hierarchy in microemulsion droplet templated dendritic fibrous nano silica

Abstract

Microemulsion-templated dendritic fibrous nanosilica (DFNS) has attracted considerable attention owing to their unique accessible pore structure and high-surface-area but their complex structural hierarchy is still intriguing. In this work, a correlative quantification of the hierarchical structure of such nanospheres has been presented based upon three complementary techniques; small-angle scattering, gas sorption, and electron microscopy. Analysis of scattering data over a wide range of wave-vector transfer using polydisperse Teubner Strey model reveals three distinct levels of correlated bicontinuous morphology and the pore-size distribution from N₂ gas sorption resembles well with the results obtained from scattering analysis. The formation mechanism of such hierarchical pore morphology in these nanospheres is elucidated and it is observed that a relative variation in periodicity, sheet thickness, and their correlation significantly affects the specific surface area and pore structure, which is strongly influenced by hydrolysis rate and reaction time.