Synthesis of Temperature/pH Dual-Stimuli-Response Multicompartmental Microcapsules via Pickering Emulsion for Preprogrammable Payload Release

-isopropyl acrylamide, pNIPAM) particle was prepared and loaded with Nile Red (NR), which was then employed as a Pickering emulsifier to stabilize oil-in-water droplets. The oil was composed of pH-responsive monomers and oil-soluble fluorescent green (OG). Upon exposure to photoirradiation, pH-responsive monomers were polymerized along the interior of the droplets and converted into microcapsules. With NR in the temperature-sensitive pNIPAM@NR particles and OG in the interior of the microcapsules, the as-prepared microcapsules possess dual-carrier capability with two payloads encapsulated dependently in two different compartments. In addition, the microcapsules could respond to two different external stimuli (temperature and pH) and realize the selective and independent release of encapsulated molecules (NR and OG) from the shell and core without any mutual interference. More importantly, the release of NR and OG can be programmed by preprogramming the order of the stimulus responses, which can be altered. Our work develops a simple and effective strategy to fabricate responsive multicompartment microcapsules with preprogrammable release of different molecules.