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

密歇根州立大学的Merlin Bruening教授在分析和表面化学项目的支持下，合成和评估超薄聚电解质薄膜的性能，以开发高通量、选择性的膜皮。最初的目的是通过交替吸附聚酰胺酸（PAA）和聚丙烯胺盐酸盐，然后亚酰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毛孔或不明确毛孔的实际支架上的方法。这项工作将涉及合成具有非常大渗透率的高支化聚电解质沟槽层。原子力显微镜图像、输运测量和红外光谱将用于它们的表征。这项工作的第二部分旨在制造高通量膜，这种膜可以快速有选择地从水中去除有机物。这些膜将在膜诱导质谱（MIMS）中进行测试。第三个领域涉及在基质辅助激光解吸/电离质谱（MALDI-MS）分析之前使用衍生化PAA膜预浓缩和过滤蛋白质和DNA。混合物的化学分析通常需要预处理步骤，以简化样品，降低干扰物的浓度。膜在这方面提供了潜力，并可用于快速和敏感的分析含水污染物或化学战剂。这项关于膜的新生长方法和新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分析。

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.