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Synthesis of Temperature/pH Dual-Stimuli-Response Multicompartmental Microcapsules via Pickering Emulsion for Preprogrammable Payload Release
journal contribution
posted on 2020-01-14, 13:10 authored by Yaxin Chen, Wei Wei, Ye Zhu, Jing Luo, Ren Liu, Xiaoya LiuStimuli-responsive
microcapsules, which can release the encapsulated
payload under various environmental stimuli, have attracted great
interests of the food, pharmaceutical, cosmetics, and agricultural
fields in recent years. However, most reported responsive microcapsules
normally have a single storage area and thus load/release only one
type of payload under one stimulus. In this work, we fabricated a
novel kind of multicompartmental intelligent microcapsule with two
storage areas and independently controlled (preprogrammable) releasing
behavior under different stimuli via rapid photopolymerization of
Pickering emulsions. In our strategy, a temperature-sensitive polymeric
(N-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.