For solutions containing rod‐shaped polyelectrolytes and their counterions only, the Poisson‐Boltzmann equation can be solved explicity without the usual assumption of the Deybe‐Hückel theory. At charge densities corresponding to half‐neutralized polyacrylic acid a large proportion of monovalent counterions is located close to the polyion even in solutions as dilute as 1/800 base molar.
Fibers were drawn from polymers of octadecyl acrylate, octadecyl methacrylate, N‐octadecylacrylamide, and a series of N‐substituted acrylamides with a second amide group in the side chain as well as from copolymers of octadecyl and methyl esters of acrylic and methacrylic acid. Wide‐angle and small‐angle x‐ray diffraction patterns were recorded for these materials. The interpretation of the characteristic difference between the behavior of the polycrylates and polymethacrylates, as proposed by Platé and his collaborators, is found to be inconsistent with a number of features of the experimental evidence. In the case of poly(octadecyl methacrylate) the data allow the estimation of two parameters of the electron density distribution in the side‐chain crystallites. With polyacrylamide derivatives, a second amide group in the side chain is found to destabilize the side chain crystallites. The bahavior of the copolymers is very complex and exhibits, in one case, evidence for a long periodicity parallel to the fiber axis.
Nonradiative energy transfer between fluorescent labels attached to polymers has been used to characterize polymer miscibility, the interpenetration of chain molecules in solution, micelle formation in graft copolymers, the unfolding of collapsed chain molecules in polymer melts, and the transfer of energy absorbed by a large number of donor labels to a small number of acceptors by an "antenna effect." The change in the emission spectrum after ionomer solutions with different fluorescent counterions were mixed provided rate constants for counterion interchange. The fluorescence behavior of dispersions of donor-labeled polymers stabilized by a graft copolymer with acceptor fluorophores in the solution phase led to inferences about the morphology of the dispersed particles.
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