Engineering Membrane Platforms Based on Active Transporter Architectures

1403750 HindsUniversity of Champagne目前的膜技术主要基于孔径和化学功能。天然存在的蛋白质通道远远超过任何人造工程孔，其选择性超过百万分之一，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以增加流量。如果成功的话，这可能会通过为高化学选择性和高处理速率之间的长期平衡提供解决方案来彻底改变膜功能。两个有前途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）原子级平坦的疏水石墨芯，其诱导用于剧烈流体流动的近乎完美的滑动层; 2）功能化学必需在CNT芯的切割入口处用于看门人活性;以及3）CNT是导电的，允许电化学转化和电场的施加。需要一种在CNT孔的入口处产生流体流（具有化学相互作用或选择性）并使活塞流快速向下转移到快速CNT芯的方法。发现电渗透泵送具有与压力驱动泵送类似的流动增强，并且可以加速活塞流内的选择性结合物质。肽文库允许筛选109种肽组合，以发现远远超过用简单配位化学实现的高度选择性亲和化学。然而，强结合系数导致动力学对于基于单层的泵送循环太慢。PI已经发现，适度的电压足以从高表面积导电AAO表面释放阳离子结合的稀土离子。多层电极允许泵送循环以在高孔隙度AAO系统中引导强电场。这允许非常通用的分离系统，其基于在孔入口处将靶结合到特定肽的快速循环，随后通过膜的静电释放泵送。由于肽亲和文库的广泛性，该概念被应用于能量储存、能量处理、化学传感器、选择性药物分离、药物递送和水净化中的大量商业相关应用。对这一研究领域的支持将使许多教育机会与新型纳米材料的制造，表征和应用到分离科学和工程。

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.