Dense polymer membranes enable a diverse range of separations and clean energy technologies, including gas separation, water treatment, and renewable fuel production or conversion. The transport of small molecular and ionic solutes in the majority of these membranes is described by the same solution-diffusion mechanism, yet a comparison of membrane separation performance across applications is rare. A better understanding of how structure–property relationships and driving forces compare among applications would drive innovation in membrane development by identifying opportunities for cross-disciplinary knowledge transfer. Here, we aim to inspire such cross-pollination by evaluating the selectivity and electrochemical driving forces for 29 separations across nine different applications using a common framework grounded in the physicochemical characteristics of the permeating and rejected solutes. Our analysis shows that highly selective membranes usually exhibit high solute rejection, rather than fast solute permeation, and often exploit contrasts in the size and charge of solutes rather than a nonelectrostatic chemical property, polarizability. We also highlight the power of selective driving forces (e.g., the fact that applied electric potential acts on charged solutes but not on neutral ones) to enable effective separation processes, even when the membrane itself has poor selectivity. We conclude by proposing several research opportunities that are likely to impact multiple areas of membrane science. The high-level perspective of membrane separation across fields presented herein aims to promote cross-pollination and innovation by enabling comparisons of solute transport and driving forces among membrane separation applications.

中文翻译：

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统一对话：能源、水和工业应用中的膜分离性能

致密聚合物膜可实现多种分离和清洁能源技术，包括气体分离、水处理和可再生燃料生产或转化。大多数这些膜中小分子和离子溶质的传输是通过相同的溶液扩散机制来描述的，但跨应用的膜分离性能的比较很少。更好地了解应用之间结构-性能关系和驱动力的比较，将通过识别跨学科知识转移的机会来推动膜开发的创新。在这里，我们的目标是通过使用基于渗透和截留溶质的物理化学特性的通用框架来评估九种不同应用中 29 种分离的选择性和电化学驱动力，从而激发这种异花授粉的灵感。我们的分析表明，高选择性膜通常表现出高溶质截留率，而不是快速溶质渗透，并且经常利用溶质尺寸和电荷的对比，而不是非静电化学性质、极化性。我们还强调了选择性驱动力的力量（例如，施加的电势作用于带电溶质而不是中性溶质）以实现有效的分离过程，即使膜本身的选择性较差。最后，我们提出了几个可能影响膜科学多个领域的研究机会。本文提出的跨领域膜分离的高层次视角旨在通过比较膜分离应用之间的溶质运输和驱动力来促进异花授粉和创新。