Dynamic Microcapsules with Rapid and Reversible Permeability Switching
Dynamic Microcapsules with Rapid and Reversible Permeability Switching
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DOI：
10.1002/adfm.201803385
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发表时间：
2018-08
影响因子：
19
通讯作者：
J. Werner;B. Deveney;S. Nawar;D. Weitz
中科院分区：
文献类型：
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作者：
J. Werner;B. Deveney;S. Nawar;D. Weitz
据报道，动态微胶囊表现出壳膜，其响应于外部刺激而具有快速和可逆的渗透性变化。疏水性酸酐单体在硫醇-烯聚合中用作含酸壳的伪装前体;这使得能够使用水包油包水双重乳液滴的微流体制造将水性货物直接包封在液体核心中。聚（酸酐）壳在其水性环境中水解而无需进一步化学处理，产生交联的聚（酸）微胶囊，其表现出触发响应和可逆的性质变化。由于硫醇-烯网络的特殊机械性能，微胶囊壳可以在不可渗透和可渗透之间主动地切换多次，所述特殊机械性能防止膜的破裂或失效，允许其承受在动态性能变化期间施加在胶囊上的机械应力。微胶囊的渗透性和截留分子量可以用诸如pH和离子环境的触发器动态地控制。壳的渗透性的可逆触发变化表现出秒级的响应时间，从而能够主动调节释放曲线，以及按需捕获、捕获和释放具有分子选择性和快速开关速率的货物分子。
Dynamic microcapsules are reported that exhibit shell membranes with fast and reversible changes in permeability in response to external stimuli. A hydrophobic anhydride monomer is employed in the thiol–ene polymerization as a disguised precursor for the acid‐containing shells; this enables the direct encapsulation of aqueous cargo in the liquid core using microfluidic fabrication of water‐in‐oil‐in‐water double emulsion drops. The poly(anhydride) shells hydrolyze in their aqueous environment without further chemical treatment, yielding cross‐linked poly(acid) microcapsules that exhibit trigger‐responsive and reversible property changes. The microcapsule shell can actively be switched numerous times between impermeable and permeable due to the exceptional mechanical properties of the thiol–ene network that prevent rupture or failure of the membrane, allowing it to withstand the mechanical stresses imposed on the capsule during the dynamic property changes. The permeability and molecular weight cutoff of the microcapsules can dynamically be controlled with triggers such as pH and ionic environment. The reversibly triggered changes in permeability of the shell exhibit a response time of seconds, enabling actively adjustable release profiles, as well as on‐demand capture, trapping, and release of cargo molecules with molecular selectivity and fast on‐off rates.