Exploring Ionic Liquids for Low Temperature and Low Emission Water Desalination

清洁水的可获得性已成为21世纪社会和全球经济面临的最关键问题之一。海洋覆盖了地球的71%，储存了大约97%的水。因此，未来的水资源短缺可以通过开发和部署更有效、更具成本效益的海水淡化技术来缓解。目前的商业化海水淡化技术是能源密集型的，其运行需要高品质的电力。最近的研究表明，基于溶剂的海水淡化过程，称为定向溶剂萃取，可以利用现成的热源(例如太阳能、废热等)从高盐度水源中提取和释放清洁水。这一研究项目的目的是更好地了解定向溶剂萃取过程背后的基本物理和化学原理。研究人员将把最先进的计算模型与新材料的合成、表征和实验室评估相结合，以设计和开发下一代方法。该项目的成功成果将通过高效和具有成本效益的海水淡化技术造福社会。学生教育和培训将进一步造福社会，包括指导两名博士生。目前的热力和膜法海水淡化技术是能源密集型和昂贵的。相反，定向溶剂萃取过程可以在温度低至40˚C的情况下使用热源进行操作，并且不需要膜。然而，具有适当性质的溶剂的可获得性仍然是这项技术发展和实施的主要障碍。离子液体相对较低的挥发性、最小的毒性和结构的多变性使其成为用于定向溶剂萃取法海水淡化的潜在溶剂。这项研究的目的是为了更好地了解离子液体在高盐度水溶液中的溶剂化和相行为。通过将分子模拟与材料合成和表征以及实验室规模的海水淡化实验相结合，研究人员将确定控制离子液体与水和天然盐离子竞争溶解度的关键结构-性质关系。最终，调查人员将利用这一新知识开发更节能、更环保的定向溶剂提取工艺。这一奖项反映了NSF的法定使命，并通过使用基金会的智力优势和更广泛的影响审查标准进行评估，被认为值得支持。

The availability of clean water has become one of the most critical problems facing society and the global economy in the 21st century. Oceans cover 71% of the planet and store approximately 97% of its water. Therefore, future water shortages could be alleviated through the development and deployment of more efficient and cost-effective technologies to desalinate seawater. Current commercial seawater desalination technologies are energy intensive and their operations require high-grade electricity. Recent studies have shown that a solvent-based desalination process, referred to as directional solvent extraction, can extract and release clean water from high salinity source waters using readily available sources of heat (e.g., solar energy, waste heat, etc.). The goal of this research project is to gain a better understanding of the underlying physical and chemical principles behind the directional solvent extraction process. The investigators will combine state-of-the-art computational modeling with the synthesis, characterization, and bench scale lab evaluation of new materials for the design and development of next-generation methods. Successful outcomes of this project will benefit society through efficient and cost-effective technologies to desalinate seawater. Further benefits to society will be achieved through student education and training including the mentoring of two doctoral students.Current thermal and membrane-based seawater desalination technologies are energy intensive and costly. In contrast, a directional solvent extraction process could be operated using heat sources at temperatures as low 40 ˚C and without the need for a membrane. However, the availability of solvents with the right properties has remained a major impediment to the development and implementation of this technology. The comparatively low volatility, minimal toxicity, and architectural variability of ionic liquids have made them attractive as potential solvents for use in directional solvent extraction-based desalination. The goal of this research project is to better understand the solvation and phase behavior of ionic liquids in high salinity aqueous solutions. By combining molecular simulations with materials synthesis and characterization and bench scale desalination experiments, the investigators will identify the key structure-property relationships that govern the competing solubilities of ionic liquids with water and natural salt ions. Ultimately, the investigators will leverage this new knowledge in developing more energy-efficient and environmentally benign directional solvent extraction processes.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.