Engineered Osmosis for Sustainable Production of Water and Energy: Development of High Performance Micromolded Membranes

1236619 Elimelech工程渗透系统具有通过正向渗透从海水或废水中可持续地生产淡水或通过压力延迟渗透从盐度梯度中发电的潜力。这些基于膜的方法利用在不同浓度的溶液之间形成的渗透梯度，所述溶液由半透膜分离，以实现更有效的分离或可持续地发电。然而，尽管这些技术具有解决全球水和能源挑战的潜力，但生物驱动的膜工艺尚未在概念化之外取得重大进展。推进这些技术的主要障碍是缺乏足够的膜，因为当前膜的性能受到内部浓差极化现象的显著阻碍。 通过引入传质的对流成分，在其他过程中类似的扩散控制现象得到了改善。因此，这项工作将从微流体领域获得灵感，其中在微米长度上混合流体是至关重要的，并制造具有静态混合器样特征的螺旋驱动膜过程的膜，以最大限度地减少内部浓差极化的有害影响。 为了实现这一目标，相分离微成型技术将被用来制造高性能的膜，用于气动驱动的膜过程。该研究还将对混合器几何形状如何影响整体传质和膜性能有基本的了解，以优化膜结构。 该研究解决了我们这个时代的两个主要全球挑战：水资源短缺和清洁能源。完成这项研究将提供科学基础和方法来制造坚固的膜，可以在各种过程中找到应用，包括海水和苦咸水淡化，废水回收和再利用，以及通过压力延迟渗透的可再生发电。 这项工作也是第一个直接将静态混合器的功能到结构的不对称盐排斥膜，在广泛的分离过程中的潜在应用。

1236619ElimelechEngineered osmosis systems have the potential to sustainably produce fresh water from seawater or wastewater by forward osmosis or to generate power from salinity gradients by pressure retarded osmosis. These membrane-based processes utilize the osmotic gradient that develops between solutions of differing concentrations, which are separated by a semi-permeable membrane, to effect a more efficient separation or to sustainably generate power. However, despite the potential of these technologies to address the global water and energy challenges, osmotically-driven membrane processes have yet to progress significantly beyond conceptualization. The major impediment to advancing these technologies is the lack of an adequate membrane, because the performance of current membranes is significantly hampered by the phenomenon of internal concentration polarization. Similar diffusion-controlled phenomena in other processes have been improved by introducing a convective component of mass transfer. Therefore, this work will take inspiration from the field of microfluidics, where mixing fluids on the micrometer length is of utmost importance, and fabricate membranes for osmotically-driven membrane processes with static mixer-like features to minimize the deleterious effects of internal concentration polarization. To achieve this goal, a phase separation micromolding technique will be used to fabricate high-performance membranes for osmotically-driven membrane processes. The research will also develop a fundamental understanding of how the mixer geometry impacts the overall mass transfer and membrane performance in order to optimize the membrane structure. The research addresses two of the major global challenges of our time: water scarcity and clean energy. Accomplishing this research will provide the scientific base and methodology to fabricate robust membranes that can find application in a variety of processes, including seawater and brackish water desalination, wastewater reclamation and reuse, and renewable power generation by pressure retarded osmosis. This work is also the first to directly incorporate static mixer-like features into the structure of asymmetric salt-rejecting membranes, with potential applications in a broad range of separation processes.