Structure, Dynamics and Transport in Self-Assembled Ionomeric Systems

9625451施利克这项建议旨在研究全氟化离聚体和质子化离聚体在体相和溶液中的自组装，作为溶剂、离子含量和中和度的函数。计划进行以下实验。(A)将在乙醇、水、甲酰胺和N-甲基甲酰胺中测量全氟离聚体的F-核磁共振光谱，这些溶剂的介电常数范围从24到182。线型将被分析，并与全氟聚合物和短链全氟表面活性剂的结果进行比较，以推断在低浓度下存在的最小单元，以及聚集度。(B)将通过ESR成像测量中性、阳离子和阴离子示踪剂在全氟离聚体中的扩散系数，并将其与聚合物链的自组装程度和类型相关联。(C)为了了解主链对自组装的贡献，将用自旋探针ESR方法和ESR成像研究聚合物(EMAA)离聚体在溶液中以及在干燥和溶胀状态下随离子单体(MAA)浓度的变化，以推断聚集体的动力学和聚合物-溶剂界面的曲率。(D)将在三个主要领域进一步发展电子自旋共振成像。将通过傅里叶变换图像重建方法减少数据采集所需的时间，以扩大可推导的扩散系数的范围；将组装二维空间-空间成像所需的硬件和软件；并将制备旨在提高空间分辨率的新型自旋探测器。提出的研究和收集自组装离聚体系统数据的方法被认为对研究药物输送系统、眼和人工晶状体中的传输过程、制备包括催化剂在内的新材料以及涉及细胞膜传输的生物系统具有重要意义。***

9625451 Schlick This proposal is directed to the study of self-assembling of perfluorinated and protiated ionomers in the bulk and in solution, as a function of the solvent, the ion content, and the degree of neutralization. The following experiments are planned. (a) F-NMR spectra of perfluorinated ionomers as a function of concentration will be measured in ethanol, water, formamide and N-methyl formamide, solvents that span a range of dielectric constants from 24 to 182. The lineshapes will be analyzed and compared with results for perfluorinated polymers and short-chain perfluorinated surfactants, to deduce the smallest unit that exists at low concentrations, and the degree of aggregation. (b) The diffusion coefficients of neutral, cationic and anionic tracers in perfluorinated ionomers will be measured by ESR imaging and correlated with the degree and type of self- assembling of the polymer chains. (c) In an attempt to understand the contribution of the backbone to self- assembling, poly(ethylene-co-methacrylic acid) (EMAA) ionomers in solution, and in the dry and solvent-swollen state, will be studied by the spin probe ESR method and ESR imaging as a function of the concentration of the ionic monomer (MAA), to deduce the dynamics of the aggregates and the curvature of the polymer-solvent interface. (d) ESR imaging will be further developed in three main areas. The time required for data acquisition will be reduced by a Fourier transform method for image reconstruction so as to increase the range of diffusion coefficients that can be deduced; the hardware and software necessary for 2D spatial- spatial imaging will be assembled; and novel spin probes designed to enhance the spatial resolution will be prepared. %%% The methods proposed for the study of, and collection of data on, self-assembled ionomer systems are considered important for the study of transport processes in drug delivery systems; in ocular and intraocular lenses; in preparation of new materials, including catalysts; and in biological systems that involve transport through cell membranes. ***