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https://www.ias.ac.in/article/fulltext/jcsc/118/03/0281-0285

Surface activity; cetyl trimethylammonium bromide; sodium dodecyl sulfate; temperature; oxidation

The γ_cmc values of CTAB-SDS decrease from 63.67 mN/m at 10‡C to 36.38 mN/m at 90‡C, slightly lower than those of either CTAB or SDS. Correspondingly, the CMC of CTAB-SDS decreases almost by half. The increase of surface activity of CTAB-SDS can be attributed to the relatively weak electrostatic interaction at high temperature, which is supported by the increase of solubility of CTAB-SDS with rise in temperature. Catalytic effect on oxidation of toluene derivatives with potassium permanganate follows the order CTAB-SDS > SDS > CTAB. This is not caused by the dissociative effect of CTAB-SDS with low surface activity at low temperature, as seen from the fact that almost all oxidative products can be retrieved for different toluene derivatives and surfactants by mimicking the conditions of reaction. In the emulsifications of toluene derivatives at 90‡C, the time that turbid water layers of surfactant solutions take to become clear is the same as that of the catalytic effect on oxidation of toluene derivatives. Thus, it can be inferred that surfactants can improve the oxidation yields of toluene derivatives by increasing the contact between two reacting phases.

Yu Tang¹ Biying Du¹ Jun Yang¹ Yuanming Zhang¹

1. Chemistry Department, Jinan University, Guangdong Guangzhou - 510632, People’s Republic of China

Published

May 2006

Manuscript received

9 September 2005

Manuscript revised

11 November 2005