Polymer, Vol.128, 40-46, 2017
Hierarchically porous silica composites via a colloidal reaction sequence
A new class of polymeric colloids, multiple suspension particles (MSP), with a size of several micrometers consisting of many small polystyrene particles with a diameter below 100 nm grown in a poly (N-iso-propyl acrylamide) precursor scaffold is obtained, as reported in our previous paper. Herein, the unique MSP are applied as template for silica nanocasting and hierarchically organized porous silica with raspberry-like aggregation structure is obtained. The aggregates with a diameter of about 1 mm are composed of thousands of hollow silica particles, which are with a size of about 70 nm originating from polystyrene particles and with mesopores of about 5.8 nm on the shell from PNIPAM chains. The aggregates have high specific surface area and pore volume. With the advantage of high mass transport contributed by macropores and of high specific surface area due to mesopores, the hierarchically organized structure has great potential application in catalysis field. (C) 2017 Elsevier Ltd. All rights reserved.