Polyelectrolyte Multilayer-Coated Colloids: Hydration, Internal Properties and Interactions

聚电解质多层涂层胶体：水合、内部性质和相互作用

• 批准号: 5415803
• 负责人: Professorin Dr. Monika Schönhoff
• 金额: --
• 依托单位: Institut de Chimie Séparative de Marcoule (ICSM) - UMR 5257
• 依托单位国家: 德国
• 项目类别: Research Grants
• 财政年份: 2004
• 资助国家: 德国
• 起止时间: 2003-12-31 至 2008-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/5415803?language=en
• 关键词: Polyelectrolyte; Multilayer; Coated; Colloids; Hydration

The hydration water in layered polyelectrolyte complexes will be investigated: Multilayers formed by stepwise self-assembly of polyions of alternating charge will be prepared on colloidal surfaces, using particles as templates (team 1). Employing dispersions of such coated particles, volume techniques can be applied to the study of polyelectrolyte multilayers. Polyelectrolyte multilayers form a 2-dimensionally stratified network structure, comparable to a strongly crosslinked gel. Interesting questions are the influence of the layered arrangement on local properties on a molecular scale: The local heterogeneity is a key parameter for a number of important macroscopic properties, such as permeability for small molecules. NMR spin relaxation experiments deliver information about the average water mobility and structure in coated colloid dispersions. The spin relaxation rate of 2H in deuterated aqueous dispersions will be employed, where previous experiments showed a high sensitivity (team 1). It can be expected that water in the layers exists in different sites, therefore freezing experiments will be performed to investigate the fraction and relaxation rate of the liquid water component at temperatures just below the freezing point. Additional DSC data can confirm the shift of the freezing point, and can further contribute to a separation of water sites. In addition, the hydration of multilayers can be controlled by equilibrating them at defined osmotic pressures (team 2). The equilibrium distance can be determined by structural techniques, and is a function of the internal hydration/ swelling of the multilayers, as well as of the steric arrangement of the terminating polymer layer. The combination of such volume methods studying water in PEMs, such as spin relaxation, osmotic pressure equilibration and DSC measurements is expected to give insight into details of the hydration properties of PEMs.

将研究层状复合物中的水合水：将使用颗粒作为模板，在胶体表面上制备通过交替电荷的聚离子逐步自组装形成的多层膜（第1组）。采用这种涂层颗粒的分散体，体积技术可以应用于多层膜的研究。聚电解质多层膜形成了一个二维分层网络结构，相当于一个强交联凝胶。有趣的问题是分层排列对分子尺度上局部性质的影响：局部不均匀性是许多重要宏观性质的关键参数，例如小分子的渗透性。NMR自旋弛豫实验提供了关于包覆胶体分散体中的平均水流动性和结构的信息。将采用氘代水分散体中2 H的自旋弛豫速率，其中先前的实验显示出高灵敏度（团队1）。可以预期，水在层中存在于不同的位置，因此冻结实验将进行调查的分数和松弛率的液态水成分在温度略低于冰点。额外的DSC数据可以确认凝固点的移动，并可以进一步有助于水位点的分离。此外，可以通过在定义的渗透压下平衡多层膜来控制多层膜的水合作用（团队2）。平衡距离可以通过结构技术来确定，并且是多层的内部水合/溶胀以及终止聚合物层的空间排列的函数。这种体积方法的组合研究水在PEM中，如自旋弛豫，渗透压平衡和DSC测量，预计将深入了解详细的水化性能的PEM。