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. ***
