STTR Phase I: Solar-driven, thermally responsive membranes for off-grid water purification

STTR第一阶段项目的更广泛影响将是开发一种基于太阳能的水净化解决方案，该解决方案有可能克服安全饮用水获取的持续障碍，这些障碍困扰着8100多万生活在水质问题严重的县的美国人。由于与气候有关的自然灾害频繁发生，饮用水供应普遍受到污染（例如，由于全氟烷基/多氟烷基物质（PFAS，“永久化学品”）的检测增加，迫切需要易于实施的水处理方案以保持获得安全饮用水。该技术提供了一种离网、成本效益高、无能源的方法，适合提供安全的饮用水解决方案，可以在不需要对水基础设施进行大修的情况下进行成本效益高的部署。与依赖能源投入和基础设施投资的现有水处理方法相比，所提出的技术既可持续又可靠，并且具有易于部署所需的灵活性，模块化和可扩展性。考虑到目前寻求水处理解决方案的社区数量，以及随后创造的与安装和维护相关的就业机会，这种颠覆性技术的潜在商业影响很高。该项目的技术创新来自于太阳能吸收凝胶（SAG）膜的开发，该膜利用自然阳光或废热源被动净化水。该系统旨在选择性地在低温下捕获清洁水，并在较高温度下在自然阳光下释放。与其他依赖于高能量蒸发和冷凝过程的被动式太阳能水净化方法相比，该技术不依赖于相变，而是由于微小的温度波动而吸收和释放液态水，并且可以在几分钟内达到水释放的临界温度。该系统有望以可持续的方式实现模块化和固定式水净化。第一阶段项目将重点展示满足饮用水标准的性能能力，提高水收集率，并提高膜的耐用性。这些目标包括：1）调查具有开孔膜结构的SAG膜的性质和性能，其显著提高水净化率; 2）对SAG对有害混合杂质的截留率进行详细调查，并满足国家卫生基金会标准;和3）评估SAG膜的长期可重复使用性，该奖项反映了NSF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。

The broader impact of this STTR Phase I project will be the development of a solar-based water purification solution that has the potential to overcome the persistent barriers to safe drinking water access plaguing the more than 81 million Americans living in counties with elevated water quality issues. As the frequency of climate-related natural disasters and the prevalence of contaminated drinking water supplies (e.g., from detection of per-/poly-fluoroalkyl substances (PFAS) ‘forever chemicals’) increases, there is an urgent need for easily implementable water treatment options to maintain access to safe drinking water. Offering an off-grid, cost effective, energy-free approach, this technology is suited to provide a safe drinking water solution that can be cost-effectively deployed without requiring a water infrastructure overhaul. In contrast to existing water treatment approaches, which rely on energy inputs and infrastructure investment, the proposed technology is both sustainable and reliable, and has the flexibility, modularity, and scalability needed for facile deployment. Potential commercial impact of this disruptive technology is high, considering the number of communities currently seeking water treatment solutions that would be easily met with the technology, and the subsequent jobs created related to installation and maintenance. The technical innovation of this project comes from the development of a solar absorber gel (SAG) membrane that passively purifies water using natural sunlight or a waste heat source. This system is designed to selectively capture clean water at low temperatures and release it under natural sunlight at higher temperatures. Compared to other passive solar water purification methods, which rely on the energy-intense evaporation and condensation processes, this technology does not rely on a phase transformation but instead absorbs and releases liquid water due to minor temperature swings and can achieve the critical temperature for water release within a matter of minutes. This system holds promise for both modular and stationary water purification in a sustainable manner. Phase I project will focus on demonstrating performance capabilities to meet drinking water standards, improving water collection rates, and enhancing the durability of the membranes. The objectives include: 1) investigating the properties and performance of SAG membranes with an open-cell membrane structure that dramatically improves the water purification rate; 2) performing detailed investigation on the SAG rejection rate to harmful mixed impurities and meeting National Sanitation Foundation standards; and 3) assessing the long-term reusability of the SAG membrane, including on accelerated degradation studies.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.