DIFFUSION IN BIMODAL AND POLYDISPERSE POLYMER SYSTEMS .1. BIMODAL SOLUTIONS OF PROTONATED AND DEUTERATED POLYMERS

In the first of two papers studying diffusion in bimodal and polydispe rse polymer solutions, the self-diffusion coefficients of various prot onated polymers in a series of bimodal solutions containing deuterated polymers have been measured. Utilizing the chemical specificity of th e pulsed-field gradient nuclear magnetic resonance (p.f.g.n.m.r.) tech nique, it was possible to study the effects of both molecular weight a nd concentration of each component. A simple friction dependence was s hown to account for the observed trends. The p.f.g.n.m.r. results are contrasted with mutual diffusion coefficient measurements, obtained fr om multi-tau photon correlation spectroscopy on similar bimodal system s.