Key Laboratory of Synthetic and Biological Colloids, Ministry of Education, School of Chemical and Material Engineering, Jiangnan University, Wuxi, Jiangsu 214122, P. R. China.
ACS Appl Mater Interfaces. 2021 Mar 31;13(12):14518-14529. doi: 10.1021/acsami.0c20276. Epub 2021 Mar 19.
Dye-filled microcapsules are an attractive way to identify microscopic damage of materials by the naked eye. However, there are many disadvantages in traditional microcapsule-based self-reporting materials, such as a poor self-reporting effect. A new concept for the design of self-reporting microcapsules is presented here. Our work develops a novel kind of dual-compartmental microcapsule via Pickering emulsion photopolymerization, which can encapsulate two interacting species ("pro-dye" and "developer") separately in a single microcapsule. In our strategy, SiO microspheres encapsulating polyetheramine (PEA, developer) were first prepared and employed as a Pickering emulsifier to stabilize oil-in-water emulsions, in which the oil phase consisted of 2',7'-dichlorofluorescein (DCF, pro-dye) and a monomer. After the monomer polymerization, a dual-compartment microcapsule, which encapsulated the pro-dye in the core and the developer in the shell, was obtained. Upon the rupture of the microcapsule, the pro-dye and the developer were released simultaneously and reacted to yield a pronounced chromogenic response. Compared with traditional double-microcapsule systems, this dual-compartment microcapsule system demonstrated a more efficient and pronounced self-reporting effect. This is the first time that a double-encapsulation scheme involving the compartmentalized release of two interacting species within a single microcapsule has been demonstrated for self-reporting, which overcomes the tough problems of the uneven distribution of the traditional double-microcapsule systems.
染色微胶囊是一种通过肉眼识别材料微观损伤的有吸引力的方法。然而，传统的基于微胶囊的自报告材料存在许多缺点，例如自报告效果差。这里提出了一种设计自报告微胶囊的新概念。我们的工作通过 Pickering 乳液光聚合开发了一种新型的双隔室微胶囊，可以将两种相互作用的物质（“前染料”和“显色剂”）分别封装在单个微胶囊中。在我们的策略中，首先制备了封装聚醚胺（PEA，显色剂）的 SiO2 微球，并将其用作 Pickering 乳化剂来稳定油包水乳液，其中油相由 2'，7'-二氯荧光素（DCF，前染料）和单体组成。单体聚合后，得到了一种双隔室微胶囊，其中前染料封装在核内，显色剂封装在壳内。微胶囊破裂后，前染料和显色剂同时释放并反应，产生明显的显色响应。与传统的双微胶囊体系相比，这种双隔室微胶囊体系表现出更高效和更明显的自报告效果。这是首次在单个微胶囊内实现涉及两种相互作用物质的隔室释放的双封装方案，克服了传统双微胶囊体系分布不均匀的难题。
