Mixed micellization behavior of benzyldimethylhexadecylammonium chloride with gemini surfactants and their applications in the synthesis of silver nanoparticles.

Aggregation and adsorption properties of benzyldimethylhexadecylammonium chloride (BDHAC) with three cationic alkanediyl-1,s-bis(tetradecyldimethyl-ammonium bromide) gemini surfactants, viz. butanediyl-1,4-bis(tetradecyldimethylammonium bromide), pentanediyl-1,5-bis(tetradecyldimethylammonium bromide) and hexanediyl-1,6-bis(tetradecyldimethylammonium bromide) respectively referred to as 14-4-14, 14-5-14 and 14-6-14 (in general 14-s-14, where s = 4, 5, 6) have been studied by tensiometric, conductometric, fluorimetric and dynamic light scattering experimental methods at 298.15 K. The studies were conducted at various compositions of the mixed systems ranging between 0 and 1. The parameters determined include different physicochemical and interaction parameters. The negative values of interaction parameters obtained for mixed micelle formation point out the attractive interaction among the components and lead to non-ideality which has been theoretically treated by Clint's and Rubingh's models. The BDHAC + 14-s-14 mixtures in different mole fractions were used in the synthesis of very stable silver nanoparticles (Ag NPs) in aqueous media, which were characterized by UV-visible spectroscopy. Dynamic light scattering measurements revealed that the size of micelles as well as Ag NPs increases with the increase in mole fraction of BDHAC in the mixtures and the size of Ag NPs can be very much controlled by using mixtures of surfactants. [ABSTRACT FROM AUTHOR]