Engineering Membrane Platforms Based on Active Transporter Architectures

印度肯塔基州大学目前的膜技术主要基于孔径和化学功能。天然产生的蛋白质通道远远超过任何人造工程毛孔，选择性超过百万分之几，流速快10,000倍。PI建议模仿天然蛋白质通道结构和纳米级电极几何形状来增加流量。如果成功，这可能会为高化学选择性和高处理速度之间的长期权衡提供解决方案，从而可能使膜功能发生革命性变化。两种有前景的材料平台是碳纳米管(CNT)膜和阳极氧化铝(AAO)上的纳米级电极多层膜。碳纳米管(CNT)膜有三个独特的关键属性：1)原子扁平的疏水石墨层，可以诱导出近乎完美的滑动层，从而实现戏剧性的流体流动；2)功能化学必然位于碳纳米管核心的切割入口处，以进行把关活动；3)碳纳米管具有导电性，可以进行电化学转换和施加电场。需要一种方法来在进入碳纳米管孔的入口处产生流体流动(具有化学相互作用或选择性)，并使塞流沿着快速的碳纳米管核心快速地向下传递。电渗泵被发现具有与压力驱动泵相似的流动增强作用，并可以加速推流多肽库中的选择性结合物种，从而允许筛选109个肽组合，找到远远超过简单配位化学实现的高选择性亲和力化学。然而，较强的结合系数导致单层泵浦循环的动力学太慢。PI已经发现，适度的电压足以从高表面积导电的AAO表面释放阳离子结合的稀土离子。多层电极允许泵浦循环，在高孔率的AAO系统中引导强大的电场。这允许一个非常通用的分离系统，其基础是结合目标与孔入口处的特定多肽的快速循环，然后通过膜泵送静电释放。由于多肽亲和库的广泛性，这一概念被广泛应用于能量储存、能量处理、化学传感器、选择性药物分离、药物输送和水净化等领域。这一研究领域的支持将提供许多与新型纳米材料的制造、表征和在分离科学和工程中的应用有关的教育机会。

1403750HindsUniversity of KentuckyCurrent membrane technology is based primarily on pore size and chemical functionality. Naturally occurring protein channels far exceed any man-made engineering pores with selectivities exceeding parts per million and flow rates 10,000 fold faster. The PI proposes to imitate natural protein channel structures and nanometer scale electrode geometries to increase flow. If successful, this could potentially revolutionize membrane function by providing a solution to the long standing trade-off between high chemical selectivity and high processing rate. Two promising material platforms are Carbon Nanotube (CNT) Membranes and nm-scale electrode multilayers on anodized aluminum oxide (AAO). There are three key attributes unique to Carbon Nanotube (CNT) membranes: 1) atomically flat hydrophobic graphitic core that induces a near perfect slip layer for dramatic fluid flow 2) functional chemistry by necessity is at the cut entrances to the CNT cores for gatekeeper activity and 3) CNTs are conductive allowing for electrochemical transformation and application of electric field. Needed is a method to generate fluid flow (with chemical interaction or selectivity) in the entrance to CNT pores and have the plug flow rapidly transfer down the fast CNT core. Electro-osmotic pumping is found to have similar flow enhancements as pressure driven pumping and can accelerate selectively bound species within plug flow Peptide libraries allow the screening of 109 peptide combinations to find highly selective affinity chemistry far beyond what is achieved with simple coordination chemistry. However, strong binding coefficients result in kinetics too slow for monolayer-based pumping cycles. The PIs have found that modest voltages are sufficient to release cationic bound rare-earth ions, from high surface area conductive AAO surface. Multilayer electrodes allow for pumping cycles to direct strong electric fields in a high porosity AAO system. This allows for a very general separation system based on rapid cycles of binding targets to specific peptides at the pore entrances followed by electrostatic release pumping across the membrane. Due to the large breadth of peptide affinity libraries, this concept is applied to a large number of commercially relevant applications in energy storage, energy processing, chemical sensors, selective pharmaceutical separations, drug delivery and water purification. Support of this research area will enable many educational opportunities related to novel nanometer scale materials fabrication, characterization and application into separations science and engineering.