Isolating the effects of gate layer permeability and sorbent density on the performance of solute-selective polymeric ion pumps
Isolating the effects of gate layer permeability and sorbent density on the performance of solute-selective polymeric ion pumps
复制标题
DOI：
10.1039/d3me00073g
复制
发表时间：
2023-07-19
影响因子：
3.6
通讯作者：
Phillip，William A.
中科院分区：
文献类型：
--
作者：
Ouimet，Jonathan Aubuchon;Dowling，Alexander W.;Phillip，William A.
对溶质选择性分离的需求不断增长，需要开发能够分离具有相似电荷和尺寸的物质的材料和工艺。聚合物离子泵是由位于吸附剂层顶部的门层组成的复合膜，有可能解决这个问题。门层和吸附剂层被设计为分别响应外部刺激而发生渗透性和亲和力的变化。随后，刺激的循环变化促进目标溶质的选择性转运。在这项研究中，开发了数学模型和数值求解器来研究栅极层电阻对聚合物离子泵性能的影响。值得注意的是，不完善的门层会导致溶质扩散回进料溶液中，从而降低但不会不可挽回地阻碍膜性能。在高吸附剂密度的限制下，扩散到接收溶液中的溶质分数由门层和吸附剂层的相对阻力决定，而目标溶质的总通量与吸附剂密度成比例增加。分析强调，当前材料拥有制造性能超越传统膜系统的聚合物离子泵所需的特性。提高聚合物离子泵的性能将依赖于识别对快速变化的刺激做出一致响应的材料组合。
The growing demand for solute selective separations necessitates the development of materials and processes capable of separating species of similar charge and size. Polymeric ion pumps, which are composite membranes composed of a gate layer situated on top of a sorbent layer, have the potential to address this opportunity. The gate and sorbent layers are designed to undergo changes in permeability and affinity, respectively, in response to an external stimulus. Subsequently, cyclic changes in the stimulus promote the selective transport of a target solute. Within this study, a mathematical model and numerical solver were developed to investigate the effect of the gate layer resistance on the performance of polymeric ion pumps. Notably, imperfect gate layers lead to solute diffusing back into the feed solution, reducing but not irrevocably hindering membrane performance. In the limit of high sorbent densities, the fraction of solute diffusing into the receiving solution is determined by the relative resistances of the gate and sorbent layers while the total flux of the target solute increases in proportion to the sorbent density. The analysis highlights that current materials possess the necessary properties to fabricate polymeric ions pumps with performances that exceed conventional membrane systems. Enhancing the performance of polymeric ion pumps will rely on identifying material combinations that respond coherently to rapidly changing stimuli.