Photodegradative surfactants: photolyses of p-alkylbenzyltrimethylammonium and alkylbenzyldimethylammonium halides in aqueous solution

Abstract

A series of benzyl-containing ammonium salts, p-alkylbenzyltrimethylammonium halides (C_nBA: 1a–c) and alkylbenzyldimethylammonium halides (C_nAB: 2a–d), have been prepared and their photodegradabilities in aqueous solutions have been compared. The photolytic decomposition proceeded by heterolytic and homolytic cleavages of the benzyl–nitrogen bond. The conversion yields were almost the same for all surfactants, whereas the product yields were slightly dependent on the alkyl-chain length. After irradiation, C₈BA (1b) and C₁₂BA (1c) were converted to non-surfactants, whereas C₁₂AB (2c) and C₁₆AB (2d) still remained surface-active. Their solution properties were concomitantly changed.