Template-Free Formation of Monodisperse Doughnut-Shaped Silica Microparticles by Droplet-Based Microfluidics

摘要

Silica materials have been extensively investigated because of their applications in a wide variety of areas, such as large-molecule catalysis, biomolecule separations, and development of sensors and devices. Since the early 1990s, mesoporous silica has drawn much attention because of its extraordinary functionalities (mesoporosity, chirality, surface functionalities, etc.)- To control their pore size and morphology, soft matters, such as amphiphilic surfactants, block polymers, and biomacromole-cules, have been successfully used as templates for the synthesis of hollow silica spheres. The unique properties of these mesoporous silica particles, such as their high surface area, large pore volume, tunable pore size with a narrow distribution, and good chemical and thermal stability, render them suitable candidates for various controlled release applications. However, their poly-dispersity, either in size or shape, presents a major challenge in understanding and controlling the mass-transport properties. Additionally, nonspherical silica particles, such as disklike ones, will inspire new research in the fields of nanomedicine.