Exploration of Polyelectrolyte Film Properties Relevant to Membrane-based Separations and Sample Introduction

密歇根州立大学的梅林·布鲁宁教授在分析和表面化学计划的支持下，合成和评估超薄聚电解质膜的性能，以开发高通量、选择性的膜皮肤。最初的目标是通过交替吸附聚酰胺酸(PAA)和聚烯丙基胺盐酸盐以及随后的亚胺化来制备聚酰亚胺薄膜。目的是确定聚酰亚胺薄膜仍能表现出选择性和渗透性的最小厚度。第二个目标是开发将这些皮肤吸附到含有大孔或定义不清的孔的实际载体上的方法。这项工作将涉及合成具有非常大渗透率的高度支化的聚电解质沟层。将使用原子力显微镜图像、传输测量和红外光谱来表征它们。这项工作的第二部分旨在创造能够快速、选择性地从水中去除有机物的高通量膜。这种膜将在膜感应质谱仪(MIMS)中进行测试。第三个领域涉及使用衍生的PAA膜对蛋白质和DNA进行预浓缩和过滤，然后再进行基质辅助激光解吸/电离质谱仪(MALDI-MS)分析。混合物的化学分析通常需要一个前处理步骤，以简化样品，降低干扰物的浓度。膜在这方面具有潜力，可用于对含水污染物或化学战剂进行快速和灵敏的分析。对新的膜生长方法和新的膜材料的研究将促进我们对这种潜在的廉价和环境清洁的方法的理解，以加快化学分析。该项目的另一个应用是蛋白质组的质谱学。

Professor Merlin Bruening of Michigan State University is supported by the Analytical and Surface Chemistry Program to synthesize and evaluate the performance of ultrathin polyelectrolyte films in order to develop high-flux, selective membrane skins. The initial objective is to make polyimide films by alternating adsorption of poly(amic acids) (PAA) and poly(allylamine hydrochloride) and subsequent imidization. An aim is to determine the minimal thickness at which the polyimide film can still exhibit selectivity and permeability. The second goal is to develop methods of adsorption of these skins onto practical supports that contain large or ill-defined pores. The work will involve synthesis of highly branched polyelectrolyte gutter layers that have very large permeabilities. AFM images, transport measurements and infrared spectra will be used in their characterization. A second section of the work aims at creating high-flux membranes that quickly and selectively remove organics from water. Such membranes will be tested in membrane induction mass spectrometry (MIMS). A third area deals with using derivitized PAA films to preconcentrate and filter proteins and DNA prior to analysis by matrix-assisted laser-desorption/ionization mass spectrometry (MALDI-MS).Chemical analysis of mixtures often requires a pre-treatment step in order to simplify the sample, lowering concentrations of interferents. Membranes offer potential in this regard, and could be used for rapid and sensitive analysis of aqueous pollutants or chemical warfare agents. This research on new growth methods of membranes and new membrane materials will advance our understanding of this potentially inexpensive and environmentally clean way to expedite chemical analysis. Another application of the project is in mass spectrometry of the proteome.