Electro-Optic Study of the Conformational Changes Induced in Partially Charged Poly-4-Vinylpyridine by Ions of Heavy Metals
We first studied, in aqueous solution, the effect of the degree of charge on the electro-optical parameters and on the conformation of poly-4-vinylpyridine partially quaternized by ethylbromide. We then investigated the influence of CaBr2 and CuBr2, showing that the former salt only acts through the increased ionic strength. On the contrary, the coordination of Cu++ ions on the uncharged pyridine units produces, with increasing ion concentration, an increase of the electric polarizability and a much more pronounced decrease of the optical anisotropy. Birefringence relaxation time and reduced viscosity data display for Ca++ and Cu++ ions a sharp decrease of the extension of the polyelectrolyte. The influence of the degree of charge and of the Cu++ ions attached to the uncharged pyridine units on the electric and optical parameters is tentatively explained on the basis of a segmental chain model and of the polarization of the counterionic atmosphere along rigid subunits.
KeywordsInfinite Dilution Electric Polarizability Optical Anisotropy Induce Dipole Moment Polymeric Ligand
Unable to display preview. Download preview PDF.
- 3.Nishikawa H and Tsuchida E, J. Phys. Chem. 79 (1975) 2072.Google Scholar
- 4.Nishide H and Tsuchida E, Makrom. Chem. 177 (1976) 2295.Google Scholar
- 7.Fredericq E and Houssier C, “Electric Dichroism and Electric Birefringence”, Oxford University Press, London (1973).Google Scholar
- 8.Tricot M and Houssier C, in “Polyelectrolytes”, 43–90, Technomic Publ., Westport (1976).Google Scholar
- 9.Tricot M, Houssier C, Desreux V and Van der Touw F, Biophys. Chem. 8 (1978) in press.Google Scholar