The conductance of the deionized colloidal dispersions

The conductance of deionized and protonated styrene‐styrenesulfonate copolymer dispersions of various particle sizes and charge numbers were measured, and the conductometric coefficient ( f ) was defined as the ratio of the practical conductance to the one calculated simply from the total concentration of protons. The experimental values were compared with the theoretical ones obtained by modifying the formulation in the Ohshima‐Healy‐White theory, which was originally established for salt‐added systems. Although the theoretical values turned to be slightly smaller than the experimental data, they reproduced the experimental tendency to a certain extent. Furthermore the added [HC1] and [NaCl] dependence of the conductance was also evaluated for deionized and protonated samples, and additivity of conductivity was discussed.