Oct., 1957
SALTSOF POLY-N-VINYLMETHYLIMIDAZOLIUM HYDROXIDE
are generally more completely sequestered by polymers than are ions of low charge. As an aid to making numerical calculations, we shall now write down a relationship between xo and yo as a function of the ionic strength. If c is the molar concentration of electrolyte of the form Cz*A+, and if we assume the dielectric constant of the medium to be that of water, then for 25" we can write xo = 0.3241 X 1 0 8 d c m TO
where TO is expressed is centimeters. Thus, for a 0.02 N solution of sodium chloride, an ion of radius 300 A. will have a value of z0near 10. Let us now examine the effect of temperature upon ion association. First of all, we recognize no explicit dependence of A upon the temperature. However, we do see that xo varies inversely as the square root of the absolute temperature, assuming the dielectric constant to be independent of tem-
1347
perature. Accordingly, moderate changes in temperature will produce only small effects on ZO. This suggests that ion binding should not be a sensitive function of the temperature, a t least as far as electrostatic effects are concerned.16 Of course, if site binding were important, then the effect of temperature should be more pronounced. It is quite possible that precise temperature effects can be used to learn more about the different kinds of ion association. DISCUSSION MAX BENDER.-Experimentauy, in com aring electrophoresis measurements on the polyelectro$tes with diffusion measurements, are differences in the apparent degree of ion binding obvious and to what degree?
F. T. WALL.-Some differences are observed, but they are not large. For most purposes, the differences can be disregarded. (15) This is in agreement with some recent unpubliahed results obtained in our laboratory.
VISCOSITY AND ELECTRICAL CONDUCTIVITY OF SALTS OF POLY-N-VINYLMETHYLIMIDAZOLIUM HYDROXIDE' BY HARRY P. GREGOR AND DANIELH. GOLD Contribution from the Department of Chernistrg of the Polytechnic Institute of Brooklyn, Brooklyn, New York Received February 86, 1067
The viscosity of poly-N-vinylmethylimidazolium salts over the concentration range 0.0001-0.006M (base moles) followed the expression c/vSp = A Bdi; specific viscosities decreased in the series: iodide > trichloroacetate > chloride., The conductance of a series of salts in the same concentration range could be expressed by the equation A0 - A .= dE/(c-k G d c ) . The calculated value of the limiting polycation conductance (per base mole) was 25 for the chlonde, bromde, nitrate, iodide and iodate polysalts, and 60 for the trichloroacetate and p-toluenesulfonate salts. Making uae of counterion concentrations calculated from 01 = A / A ~ ,i t was found that the data fitted the Henderson-Hasselbalch expressipn which contained a term for the ionic strength, p [CCY] = pK - 2 log [( 1 - 0 1 ) / 0 1 J - +d/cLu. Association of the olysalts increased nitrate < trichloroacetate < p-toluenesulfonate < iogde. in the sequence: iodate < chloride < bromide
+
The interactions of polyelectrolytes with their counterions have been studied widely in recent years. The strong polyion-counterion interactions which occur have been manifested by titrat i ~ n , ~viscosity,606 -~ conductance? and transport8r9 measurements. The extent of polyion-counterion association varies with the nature and size of the counterion, as shown by recent work on the titration of polyacids with alkali metal and quaternary ammonium bases. The viscometric and conductometric behavior of polyacids neutralized with (1) Taken in part from the Dissertation of Daniel H. Gold, submitted in partial fulfillment of the requirements for the degree of Doctor of Philosophy in Chemistry at the Polytechnic Institute of Brooklyn, June, 1957. (2) A. Katchalsky and P. Spitnik, J . Polymer Sci., 2 , 432 (1947). (3) H.P. Gregor, L. B. Luttinger and E. M. Loebl, J . Am. Cham. SOC.,76, 5879 (1954). (4) I. Kagswa and K. Katsuura, J . Polymer Sci., 7 , 89 (1951). (5) R.M. Fuoss and W. N. Maclay, ibid., 6, 305 (1951). (6) A. 0 t h and P. Doty, THISJOURNAL, 66, 43 (1952). (7) D. Edelson and R. M. Fuoss, J . A m . Chem. Soc., 7 0 , 2832 (1948). (8)J. R. Huisenga, P. F. Grieger and F. T. Wall, ibid., 72, 2636, 4228 (1950). (9) F. T. Wall, J. J. Ondrejcin and M. Pikramenou, ibid., 73,2821 (1951). (10) H. P. Gregor and M. Frederick, J . Polymer Sci., 28,451 (1957). (11) I. Kagawa and H.P. Gregor,
