The action of alkyl-substituted ammonium chlorides on negative silver iodide sol

Abstract

1. The action of alkyl-substituted ammonium chlorides (secondary-, tertiary- and quaternary-salt) on negative silver iodide sol has been studied. 2. It has been found as a whole that the coagulation values of these electrolytes decrease with the increase of the number of total carbon atoms of alkyl chains contained in a molecule, and that the coagulation values of the electrolytes of the same carbon atom number are put in the following order: primary amine salt >secondary amine salt >tertiary amine salt = quaternary ammonium salt. 3) It has been found that tri- and tetra-n-butylammonium chlorides show the same action in coagulating silver iodide sol as n-alkylammonium chlorides with alkyl chains of more than 12 carbon atoms, that is, the coagulation values of the former electrolytes are coincident with those of the latter electrolytes, and that these values decrease with the decrease of the sol concentration. It has been further found that the coagulum once formed is peptized at much higher concentrations of these electrolytes than in the case of n-alkylammonium chlorides. 4. It is suggested that the coagulating action of the alkyl-substituted ammonium chlorides may be mainly determined by the number of total carbon atoms contained in a molecule, while the peptizing action may be influenced by other structural factors.