CAREER: Programmable Negative Water Adsorption of Bioinspired Hygroscopic Materials

职业：仿生吸湿材料的可编程负吸水

• 批准号: 2238129
• 负责人: Xi Chen
• 金额: $ 53.86万
• 依托单位: Research Foundation CUNY - Advanced Science Research Center
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2023
• 资助国家: 美国
• 起止时间: 2023-08-01 至 2028-07-31
• 项目状态: 未结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2238129&HistoricalAwards=false
• 关键词: CAREER; Programmable; Negative; Water; Adsorption

Hygroscopic materials typically absorb water and swell when the local relative humidity (RH) increases and then release water and shrink when the RH decreases. A counterintuitive phenomenon has been observed in trees, where they store water when the local environment is dry and deplete water when it is humid. Inspired by this natural phenomenon, the investigator will develop a new class of materials with negative water adsorption capabilities, such that water is released when the RH increases. This project will explore the opportunities for designing hygroscopic materials with programmable negative water adsorption properties. The research is expected to elucidate the underlying mechanisms of the counterintuitive phenomenon of negative water/gas adsorption. This knowledge will lead to breakthroughs related to dynamically regulating material properties and responsive soft condensed matter and reveal how nature designs different micro/nanofluidic systems to harness water evaporation as an energy source. The research will also enable the development of new low-cost water harvesting devices that autonomously collect water in a dry environment without using electrical energy. Educational activities are integrated with the research to promote K-12 students’ interest in STEM and increase the public’s understanding of scientific concepts. The educational activities include developing visible and touchable learning kits and competitions, allowing local students and New Yorkers to interact with state-of-the-art science engagingly. The negative water adsorption phenomenon is achieved when domains of materials with distinctive water-responsive actuation and cavitation characteristics are carefully integrated. A range of hygroscopic materials will be fabricated such that the confined water cavitation behaviors and material water responsiveness are systematically varied through changes to the confining geometry and surface chemistry. Using these materials/structures, the confining geometry and surface chemistry will be correlated with the confined water cavitation behavior. Additionally, the research will program hygroscopic material water-responsive actuation by tuning the properties of confined water. Negative water adsorption materials will be developed by integrating the domains of materials with distinct water-responsive and water cavitation properties. The overarching educational goal is to communicate the concepts and importance of natural water evaporation to students and the public. The City University of New York (CUNY) students will be taught through hands-on learning activities. The investigator will host an annual “Evaporation Energy Challenge” for local high school students and teachers and communicate evaporation science in public venues. The investigator will also redesign an interdisciplinary graduate-level course. The desired educational outcome is to ignite the students’ and the public’s excitement about the potential of natural evaporation as an energy source and attract talented and motivated students to pursue STEM careers.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.

吸湿材料通常在局部相对湿度（RH）增加时吸收水并膨胀，然后在RH降低时释放水并收缩。在树木中观察到一种违反直觉的现象，当当地环境干燥时，树木储存水分，当环境潮湿时，树木消耗水分。受这一自然现象的启发，研究人员将开发出一类具有负吸水能力的新材料，当相对湿度增加时，水就会释放出来。本项目将探索设计具有可编程负吸水性能的吸湿材料的机会。该研究有望阐明负水/气吸附的反直觉现象的潜在机制。这些知识将导致与动态调节材料特性和响应性软凝聚物质相关的突破，并揭示大自然如何设计不同的微/纳流体系统来利用水蒸发作为能源。该研究还将有助于开发新的低成本集水设备，这些设备可以在干燥的环境中自动收集水，而无需使用电能。教育活动与研究相结合，以促进K-12学生对STEM的兴趣，并增加公众对科学概念的理解。教育活动包括开发可视和可触摸的学习工具包和竞赛，让当地学生和纽约人与最先进的科学进行互动。当具有独特的水响应驱动和空化特性的材料域被仔细整合时，可以实现负水吸附现象。将制造一系列吸湿材料，以便通过改变限制几何形状和表面化学，系统地改变受限水空化行为和材料水响应性。使用这些材料/结构，封闭的几何形状和表面化学将与承压水空化行为相关。此外，研究将通过调整承压水的特性来编程吸湿材料水响应驱动。负水吸附材料将通过整合具有不同水响应和水空化特性的材料领域来开发。总体教育目标是向学生和公众传达自然水蒸发的概念和重要性。纽约（CUNY）的学生将通过动手学习活动进行教学。该研究员将为当地高中学生和教师举办一年一度的“蒸发能源挑战赛”，并在公共场所传播蒸发科学。调查员还将重新设计一门跨学科的研究生课程。理想的教育成果是激发学生和公众对自然蒸发作为能源的潜力的兴奋，吸引有才华和有动力的学生追求STEM职业。该奖项反映了NSF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。