Department of Colloid Chemistry, Max Planck Institute of Colloids and Interfaces, Am Mühlenberg 1, 14476 Potsdam, Germany.
School of Chemistry, University of Glasgow, G128QQ Glasgow, United Kingdom.
J Colloid Interface Sci. 2020 Sep 1;575:88-95. doi: 10.1016/j.jcis.2020.04.067. Epub 2020 Apr 22.
Complex aqueous emulsions represent a promising material platform for the encapsulation of cells, pharmaceuticals, or nutrients, for the fabrication of structured particles, as well as for mimicking the barrier-free compartmentalization of biomolecules found in living cells. Herein, we report a novel, simple, and scalable method of creating multicomponent aqueous droplets with highly uniform internal droplet morphologies that can be controllably altered after emulsification by making use of a thermal phase separation approach. Specifically, temperature-induced phase separation inside as-formed emulsion droplets comprising aqueous mixtures of two or more hydrophilic polymers allows for the generation of Janus and Cerberus emulsion droplets with adjustable internal morphologies that are solely controlled by a balance of interfacial tensions. We demonstrate our approach by applying both, microfluidic and scalable batch production, and present a detailed model study with predictive capabilities that enables fine-tuning and dynamically altering the droplet morphology as a function of types, molecular weights, and hydrophilicities of the polymers as well as the surfactant hydrophilic-lipophilic balance. The ability to rationally design complex aqueous emulsion droplets with previously unattainable dynamic control over their morphologies after emulsification entails the potential to design new responsive soft materials with implications for a variety of applications beyond encapsulation, including the design of complex adaptive and self-regulating materials, e.g. for chemical and biological sensing applications.
复杂的水包水乳状液是一种很有前途的材料平台，可用于封装细胞、药物或营养物质，用于制造结构颗粒，以及模拟生物分子在活细胞中无阻碍的分隔化。在此，我们报告了一种新颖、简单且可扩展的方法，可通过利用热相分离方法来创建具有高度均匀内部液滴形态的多组分水包水乳状液。具体而言，在由两种或更多种亲水性聚合物的水混合物形成的乳液液滴内的温度诱导相分离允许生成具有可调节内部形态的 Janus 和 Cerberus 乳液液滴，其仅由界面张力的平衡来控制。我们通过应用微流控和可扩展的批量生产来证明我们的方法，并提出了具有预测能力的详细模型研究，该研究可实现对液滴形态的微调，并可根据聚合物的类型、分子量和亲水性以及表面活性剂的亲水-亲油平衡来动态改变液滴形态。这种对复杂水包水乳状液进行合理设计的能力，以及对其在乳化后形态进行前所未有的动态控制的能力，为设计具有各种应用前景的新型响应性软材料奠定了基础，这些应用不仅限于封装，还包括复杂自适应和自调节材料的设计，例如用于化学和生物传感应用。
