Preparation of Macroporous Polymers from Microcapsule-Stabilized Pickering High Internal Phase Emulsions

The ability to make stable water-in-oil (W/O) Pickering high internal phase emulsions (HIPEs) is demonstrated using microcapsules as a stabilizer. The microcapsules are prepared with glycidyl methacrylate (GMA) and poly(melamine-formaldehyde) (PMF) as core and wall materials, respectively. Using these GMA-loaded PMF-walled microcapsules as a sole stabilizer of water-in-styrene/divinylbenzene HIPE, the polymerization of this HIPE causes a closed-cell porous polymer. While with the addition of a certain amount of the nonionic surfactant Span80 to the microcapsule-stabilized HIPEs, a series of open-cell porous materials are obtained. The morphologies of the porous materials are tunable with changing the microcapsules content and/or surfactant amount in the HIPE templates. When Raft polymerization is introduced to cure these HIPEs, owing to both the self-healing agent GMA within the microcapsules and the residue of the chain-transfer agent from Raft polymerization of HIPEs, the resulting porous polymers are proved to be self-repairable. This work suggests a new type of Pickering HIPE and provides a novel idea for preparing self-healing porous materials.