Surfactant Solubility Research Articles

Continuing the previous work, salt formation between various amino compounds and higher alkylsulfates was observed systematically and physical changes accompanying substitution of gegenions were assumed from measurement of the Krafft point. Salts indicated in Tables I, II, and III were obtained in pure form from sulfanilamides, basic vitamins, antibiotics, and numerous other pharmaceutics. The Krafft point of these substances rose in proportion to the increasing number of carbon atoms in the alkyl chain of alkylsulfates, similarly as was observed in the case of thiamine alkylsulfates. The Krafft point also changed markedly according to the kind of gegenions and there were also numerous salts in which the Krafft point was not measurable due either to the occurrence of the Krafft phenomenon at an extremely low temperature or non-appearance of the Krafft phenomenon even in boiling water. It is consequently concluded that hydrophilic-lipophilic balance is undergoing changes in a rather wider range than the general conception of the solubility of surfactant in water and hydrophilic-lipophilic balance.