Preparation of Janus nanosheets via reusable cross-linked polymer microspheres template

Abstract

Janus nanosheets have great potential applications in diverse fields to provide improved performance over conventional homogenous nanoparticles. A novel strategy to prepare Janus nanosheets by surface adsorption and the sol–gel process of trialkoxy silanes onto the reusable cross-linked polymer microspheres template is presented in this paper. Polymer microspheres were synthesized by inverse suspension polymerization, and the matched silanes were screened by molecular simulations. After adsorption and sol–gel of silanes onto microspheres surface, the microspheres were covered with silica-based membranes. The silica-based membranes were further selective modified and exfoliated from the microspheres surface to obtain Janus nanosheets. Microspheres could be easily recycled and reused. Two kinds of silica-based Janus nanosheets of carboxyl/alkyl composite and amide/alkyl composite were successfully prepared by the above approach. The synthesized nanosheets exhibited sheet-like morphology, Janus nature, interfacial activity and excellent ability to stabilize emulsions. This study provides a scalable method for the controllable synthesis of Janus nanosheets, which may provide a new avenue for their fundamental studies and practical applications.