Collaborative Research: Electrospray Additive Manufacturing of Thin Low Resistance Polyamide-Based Ion Exchange Membranes for Water Treatment

该基金支持研究开发有关电喷涂增材制造工艺的新知识，以促进科学进步，并通过促进材料的制造来解决水净化挑战和清洁水短缺问题，从而促进国家的繁荣和福祉。电喷雾增材制造是一种将有机单体沉积在表面上形成薄聚合物薄膜或膜的工艺。这个过程仔细地控制了这些分子在表面上的放置方式，并且可以快速适应制造一系列不同的膜材料。从这个意义上说，电喷涂工艺比传统的薄膜涂层或铸造工艺具有显著的优点。这种方法的一个好处是，制造商可以快速调整工艺，以制造定制的水处理膜，以应对新出现的污染物或水中的污染物。这项研究的结果使美国经济和社会受益，使高效膜的生产成为可能，从而更好地获得清洁的水。这项研究涉及先进制造、材料科学、化学工程和电化学等多个学科。多学科方法的使用扩大了代表性不足的群体在研究中的参与，并加强了对未来工程劳动力的工程教育和培训。电喷雾增材制造工艺克服了传统制造固有的基本限制，这些限制阻碍了具有可调性能的超薄聚酰胺离子交换膜的可靠和可控制备。本研究解决了与使用电喷涂增材制造相关的知识空白，以使一系列共单体结合到最终膜中。该组合物范围允许制造以前无法通过传统制造（如刀型或槽型压铸）获得的材料。研究小组制备并表征了膜，以确定电喷雾增材制造是否可以用来克服传统界面聚合制造相关的传质、溶解度和反应动力学限制。此外，该团队使用新工艺将固定离子基团结合到聚酰胺膜中，通过控制固定离子基团浓度和交联密度来精确地设计其性能。此外，研究小组证明，电喷涂增材制造工艺可用于在一系列不同的基板上制造膜，并且电阻串联模型可用于选择支撑基板。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知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

This grant supports research to develop new knowledge about an electrospray additive manufacturing process to promote the progress of science and to advance national prosperity and well-being by facilitating the manufacture of materials to address water purification challenges and clean water shortages. Electrospray additive manufacturing is a process where organic monomers are deposited onto a surface to form a thin polymer film or membrane. This process carefully controls the way by which these molecules are placed on the surface and can be quickly adapted to manufacture a range of different membrane materials. The electrospray process, in this sense, has significant advantages over conventional film coating or casting processes. An example of one benefit of this approach would be that manufacturers could quickly adapt the process to make tailored water treatment membranes in response to emerging contaminants or pollutants in water. Results from this research benefit the U.S. economy and society by enabling the manufacture of very efficient membranes that provide better access to clean water. This research involves several disciplines including advanced manufacturing, materials science, chemical engineering, and electrochemistry. The use of a multi-disciplinary approach broadens participation of underrepresented groups in research and enhances engineering education and training for the future engineering workforce.The electrospray additive manufacturing process overcomes fundamental limitations, inherent to conventional manufacturing, that prevent reliable and controlled preparation of very thin polyamide ion exchange membranes with tunable properties. This research addresses knowledge gaps related to the use of electrospray additive manufacturing to enable incorporation of a range of co-monomers into the final membrane. This range of compositions allow the manufacture of materials not previously accessible via conventional manufacturing such as doctor-blade or slot-die casting. The research team prepares and characterizes the membranes to determine if electrospray additive manufacturing can be used to overcome mass transfer, solubility, and reaction kinetics limitations associated with conventional interfacial polymerization manufacturing. Additionally, the team uses the new process to incorporate fixed ionic groups into polyamide membranes to precisely engineer their properties via control of fixed ionic group concentration and cross-link density. Furthermore, the research team demonstrates that the electrospray additive manufacturing process can be used to manufacture membranes on a range of different substrates and that a resistances-in-series model can be used to inform the selection of support substrates.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.