The results of conductance and transference measurements on dilute, salt-free aqueous solutions of poly(4-vinyl-N-n-butyl pyridinium bromide) and poly(vinylbenzy1 trimethyl ammonium chloride) are recorded. From conductance and transference data the charge fraction of the polyions is found to remain essentially constant with dilution down to concentrations of less than 10-4 equiv/l. The principles of the methods used and the experimental details are critically discussed and the results compared with recent theories of ion binding in polyelectrolyte solutions. The effects of the dielectric constant of the solvent and of the temperature have been briefly studied and factors influencing the electrochemical properties of polyelectrolyte solutions are discussed.
The main decomposition products formed from triforine by hydrolysis in solution and by photolysis were isolated and identified. In aqueous solution at 21°, hydrolysis proceeds rapidly by formation of chloride ions and, through several intermediates, 1‐(dihydroxyacetyl)piperazine and piperazine. Photolysis by ultraviolet light in the absence of water leads preferentially to the removal of one side chain, the second side chain being attacked more slowly. In aqueous solution, triforine is rapidly destroyed by ultraviolet light. N‐(2,2‐Dichlorovinyl)formamide was isolated as an intermediate photodecomposition product.
synopsisThe concentration dependence of the reduced viscosity has been studied for several polyelectrolyka in conductivity water. It is shown that the viscosity maximum previously reported for polyelectrolyte solutions without added; electrolyte can be explained either by the presence of ionic impurities in the solvent or by the contamination of t-he solutions. It is concluded that the folding chain theory of plyelectrolyte solutions requires amendment to account for the experimental results on counterion association.A suggestad amendment th the theory implies that the application of the Huggins equation to the concentration dependence of polyelectrolyte solutions in the presence of added electrolyte may not lead to information concerning the interactions between the polyiona in solution.The ionization of a flexible, linear polyelectrolyte markedly increases the viscosity of its salt-free aqueous solution, often by several orders of magnitude. This increase in viscosity has been explained'J in terms of an unfolding of the polymer coil due to the mutual repulsion between the increasing number of like charges attached to the coil aa ionization proceeds. Similaxly, the increase of the reduced viscosity on dilution of a salt-free polyelectrolyte solution has been attributed to the decreased screening of the fixed charges by the counterions and the consequent coil expansion.
A light‐scattering phtometer for measurements on solutions in the angular range 6–170° is described. Its use is illustrated by the determination of the average molecular weights Mw and Mn, as well as the gyration radii 〈r2〉z1/2 and 〈r2〉n1/2, on a polystryene fraction.
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