EAGER: The First Steps toward Crosslinked Membranes with Non-Collapsible, Uniform Pores of Sub-nanometer Size: Synthesis of Building Blocks and Alignment of Nanotubular Assemblies

这项为期一年的EAGER奖项旨在解决纳米孔膜的早期制造，该膜含有均匀的亚纳米尺寸的不可变形孔。所得膜将用于水净化和海水淡化，以及其他大小和性质相关的分子分离。主要的焦点将是使用一种高效的，一锅合成方法来制备大量的大环构建块，然后用于工程膜。构建单元是大环，它们共享一个刚性的环状骨架，其中包含一个约5-6埃的不可折叠的亲水腔。最近的研究表明，这类大环具有高倾向于结合成一维管状组件。根据初步结果，带有极性末端基团的侧链的类似大环应该自组装成纳米孔膜。一维管状组件在阳极氧化铝膜毛细管孔中的排列将被探索。计算机模拟将研究不同外部压力下纳米孔内水的传输（纳米流体）行为，并评估膜对溶剂中各种离子的渗透性作为纳米孔大小的函数。优化设计的膜有望过滤大多数小分子和离子，并将被评估为用于海水淡化的纳滤膜。拟议的研究是高度跨学科的。不同背景的研究生和本科生将获得涉及化学，材料科学以及相应分子和器件工程的多个领域的技能。具体来说，这项联合研究的教育影响包括：(1)为研究生的培养提供了将分子、超分子和纳米结构的计算机辅助设计、合成和表征与相应材料和器件的工程相结合的独特机会。(2)该项目将招收本科生，特别是那些传统上在科学领域未被充分代表的群体和学生，他们接触和获得相应领域最新发展的机会有限。(3)研究成果不仅将发表在高知名度的期刊上，广泛传播到整个科学界，更重要的是，将导致许多实际应用。从纳米级构建模块的构建和对其1D组装的评估中获得的见解反过来将有助于解决化学和生物分离领域的其他问题的概念的发展。

This one-year EAGER award addresses the early stage fabrication of nanoporous membranes containing non-deformable pores with a uniform, subnanometer size. The resultant membranes will be used for water purification and desalination, as well as other size- and property-dependent molecular separations. The primary focus will be the use of a highly efficient, one-pot synthetic method for preparing large amount of macrocyclic building blocks that will then be used for engineering the membranes. The building blocks are macrocycles sharing a rigidified, cyclic backbone that contain a non-collapsible hydrophilic cavity of ~5-6 angstroms. Recent studies indicate that this class of macrocycles have a high propensity to associate into 1D tubular assemblies. Based on preliminary results, analogous macrocycles with side chains carrying polar terminal groups should self-assemble into nanoporous membranes. The alignment of the 1D tubular assemblies in the capillary pores of anodic alumina membranes will be probed. Computer simulation will be performed to investigate transport (nanofluidic) behavior of water within the nanopore under different external pressures and to evaluate the permeability of the membrane to various ionic species in a solvent as a function of size of nanopores. Optimally designed membranes are expected to reject most small molecules and ions and will be assessed as nanofiltration membranes for water desalination. The proposed research is highly interdisciplinary. Graduate and undergraduate students of various backgrounds will gain skills in multiple fields involving chemistry, materials science and the engineering of corresponding molecules and devices. Specifically, the educational impacts of this joint research include: (1) The unique opportunity to combine computer-aided design, synthesis, and characterization of molecular, supramolecular, and nanosized structures with the engineering of the corresponding materials and devices in the training of graduate students. (2) The program will involve undergraduate students, particularly those from groups traditionally underrepresented in sciences and students, who have limited exposure and access to the latest developments in the corresponding fields. (3) The research results will not only be published in highly visible journals to broadly disseminate this work to scientific society at large, but more importantly, will lead to many practical applications. Insights obtained from the construction of nanosized building blocks and the assessment of their 1D assembly will in turn will help the development of concepts generally useful for addressing other problems in the field of chemical and biological separation.