Polymer-Based Capsules of Active Liquids Templated by Non-Aqueous Emulsions

非技术总结：科学家和工程师们不断开发性能更好的新材料，用于电池、水净化、气体吸收等领域。这些新材料为创造影响和改善现代生活几乎方方面面的新技术提供了基础。不幸的是，一些新材料，如离子液体和共晶溶剂，很难单独处理，而且它们需要某种容器，限制了它们在实际系统中的应用。本研究工作通过开发方法来解决这些目前的局限性，该方法将特殊液体的核心包裹在聚合物外壳中。这种方法是通过使用由分散在油中的活性液体液滴组成的无水乳液，再加上聚合技术而实现的。无水乳剂对这种封装系统的发展至关重要，因为它们使专用液体保持纯净和无掺杂。这项工作解决了聚合物外壳的组成如何影响胶囊的性能特性，即机械性能和气体二氧化碳的吸收。这项研究促进了复合材料领域的进步，并在储能和气体分离等关键领域得到了应用。除研究外，本计划还将支持本科生和研究生的培训，以及制作“如何做”视频。这些视频计划公开提供，并向新的研究人员展示如何使用科学仪器来表征聚合物基材料，从而更广泛地支持科学家和工程师的发展和培训。技术概述：计划研究的目标是开发以活性液体（如离子液体和深共晶溶剂）为核心的胶囊和具有不同渗透率、稳定性和机械性能的聚合物复合壳的方法。这将通过利用非水乳液中的界面聚合来实现。采用烷基化氧化石墨烯纳米片作为颗粒表面活性剂稳定皮克林乳状液，以甲苯或辛烷为连续相，以离子液体或深度共晶溶剂为间断相。Aim 1的重点是利用远旋低聚物作为单体，通过开环复分解聚合（ROMP）、可逆加成断裂链转移聚合（RAFT）和自由基端聚合（DEP）制备具有不同渗透性和力学性能的胶囊壳。在目标2中，胶囊壳的稳定性将通过加入动态共价键来调节；这将使胶囊壳能够被摧毁或融合。在Aim 3中，通过使用活性颗粒表面活性剂和硫醇化学，将胶囊壳厚度最小化，核心流体纯度最大化。将建立胶囊的组成、形态、热性能、渗透性和机械性能。与Burcu Gurkan教授的一项未获资助的合作将揭示壳成分与气体CO2渗透率之间的关系。与George farr教授的一项未获资助的合作将支持使用微操作技术对单个胶囊进行评估，产生力-位移剖面。科学研究得到了本科生和研究生研究人员的支持，以及演示用于表征软物质的技术的工作原理和实际考虑因素的教程视频（HTVs）的补充。该奖项反映了美国国家科学基金会的法定使命，并通过使用基金会的智力价值和更广泛的影响审查标准进行评估，被认为值得支持。

NON-TECHNICAL SUMMARY:Scientists and engineers continue to develop new materials with improved performance in applications such as batteries, water purification, gas uptake, and so on. These novel materials provide the foundation used to create new technologies that impact and improve nearly every facet of modern life. Unfortunately, some of the new materials, such as ionic liquids and eutectic solvents, are difficult to handle by themselves, and they require containment of some kind, limiting their use in practical systems. This research work addresses these current limitations by developing methods to prepare capsules with cores of the specialized liquid wrapped in polymer shells. This approach is made possible by the use of a water-free emulsion that is composed of droplets of the active liquid dispersed in an oil, coupled with polymerization techniques. The water-free emulsions are critical to the development of this encapsulation system, as they allow the specialized liquid to remain pure and unadulterated. The work addresses how the composition of the polymer shell impacts performance properties of the capsules, namely mechanical properties and the uptake of gaseous carbon dioxide. This research promotes progress in the areas of composite materials with applications in critical areas such as energy storage and gas separations. In addition to the research, this project will support the training of undergraduate and graduate students and development of How-To Videos. These videos are planned to be publicly available and to show new researchers how to use scientific instruments to characterize polymer-based materials, thereby supporting the development and training of scientists and engineers more broadly. TECHNICAL SUMMARY:The goal of the planned research is to develop methods to prepare capsules with cores of active liquids (e.g., ionic liquids and deep eutectic solvents) and polymer composite shells of varied permeability, stability, and mechanical properties. This will be accomplished by leveraging interfacial polymerizations in non-aqueous emulsions. Alkylated graphene oxide (GO) nanosheets will be used as particle surfactant to stabilizing Pickering emulsions, toluene or octane will be used as the continuous phase, and ionic liquid or deep eutectic solvent as the discontinuous phase. Aim 1 focuses on preparing capsule shells of varied permeability and mechanical properties using telechelic oligomers as monomers, as prepared by ring opening metathesis polymerization (ROMP), reversible-addition fragmentation-chain transfer (RAFT) polymerization, and radical dead-end polymerization (DEP). In Aim 2, the stability of the capsule shell will be tuned by incorporation of dynamic covalent bonds; this will enable destruction or fusion of the capsule shells. In Aim 3, the capsule shell thickness will be minimized and the core fluid purity maximized by using reactive particle surfactants and thiol-ene chemistry. The capsule composition, morphology, thermal properties, permeability, and mechanical properties will be established. An unfunded collaboration with Prof. Burcu Gurkan will reveal the relationship between shell composition and permeability to gaseous CO2. An unfunded collaboration with Prof. George Pharr will support evaluation of individual capsules using micromanipulation techniques, producing force-displacement profiles. The scientific research is complemented by support of undergraduate and graduate researchers, as well as How-To Videos (HTVs) which demonstrate working principles and practical considerations for techniques used to characterize soft matter..This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.