CAREER: Fundamental Investigation of Thin-Film Evaporation Using Crystalline Porous Inverse Opals

从现代电子设备到发电厂冷却，通过相变过程（例如蒸发）散发极端热量是一项艰巨的挑战。为此，纳米结构由于其大表面积和将工作流体输送到蒸发表面的能力而引起了极大的兴趣。然而，迄今为止，由于纳米结构的复杂结构，确定其在相变过程中的作用一直具有挑战性。为了解决这个问题，这个CAREER项目将采用非常规则的多孔介质来研究薄膜蒸发物理。这种多孔介质的结构规律将允许在材料的形式和蒸发传热之间发展新的关系。该项目的研究成果将纳入教育和推广活动，以促进公众对热输运现象的兴趣，并培养下一代研究人员。综合教育和推广计划将通过新的感官学习教育工具，研究和指导计划，以及纳米级相变传热主题的新研究生课程来解决。本CAREER项目的科学目标是利用新型有序多孔介质在与结构相关的蒸发相变物理中找到新的发现。该项目的具体任务包括(1)证明具有理想输运性质的亲水反蛋白石；(2)在孔隙水平上研究薄膜的局部蒸发（旨在了解此类孔隙的球形凹形对薄膜蒸发的作用）；(3)检查装置的传热性能。通过表面工程、多尺度计算模型和高保真度测量来验证对蒸发性能的理解，研究蛋白石模板的自组装和金属化可以完成这些任务。关于多孔介质输运物理的新发现将为利用新兴多孔材料的微流控通道、柔性冷却器和热管等下一代热管理器件的设计提供一大步。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。

Dissipating extreme heat through phase change processes (e.g. evaporation) is a daunting challenge for various applications ranging from modern electronic devices to power plant cooling. For this purpose, nanoscale structures have drawn significant interest due to their large surface area and ability to deliver working fluid to evaporating surfaces. However, to date it has been challenging to identify the role of the nanostructures in phase change processes owing to their complex structures. To address this problem, this CAREER project will employ extremely regular porous media to investigate thin-film evaporation physics. The structural regularity of such porous media will allow new relationships to be developed between the form of the material and the evaporation heat transfer. The research outcomes from this project will be integrated into educational and outreach activities to promote public interest in thermal transport phenomena and train the next generation of researchers. The integrated educational and outreach plan will be addressed through new sensory learning educational tools, research and mentoring programs, and a new graduate course on nanoscale phase change heat transfer topics. The scientific objective of this CAREER project is to find new discoveries in structure-related evaporation phase change physics utilizing new classes of well-ordered porous media. The specific tasks of this project include (1) demonstrating hydrophilic inverse opals with desired transport properties; (2) studying local thin-film evaporation at the pore-level (with the aim of understanding the role of the spherical concave shape of such pores on thin-film evaporation); and (3) examining heat transfer performance in the devices. The tasks can be accomplished by studying the self-assembly and metallization of the opal template with surface engineering, multiscale computational models, and high-fidelity measurements to validate understanding of evaporation performance. The new discoveries about the transport physics through porous media will provide a big step forward for the design of next-generation thermal management devices such as microfluidic channels, flexible coolers, and heat pipes that leverage emerging porous materials.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.