10.1021/acs.jpcb.5b01206.s001 Edit Fegyver Edit Fegyver Róbert Mészáros Róbert Mészáros Complexation between Sodium Poly(styrenesulfonate) and Alkyltrimethylammonium Bromides in the Presence of Dodecyl Maltoside American Chemical Society 2015 CTAB surfactant amphiphile PSS cationic alkyl chain length C 12G concentration binding dodecyl maltoside DTAB 2015-04-23 00:00:00 Journal contribution https://acs.figshare.com/articles/journal_contribution/Complexation_between_Sodium_Poly_styrenesulfonate_and_Alkyltrimethylammonium_Bromides_in_the_Presence_of_Dodecyl_Maltoside/2173819 In the present paper, the impact of dodecyl maltoside (C<sub>12</sub>G<sub>2</sub>) on the association of sodium poly­(styrenesulfonate) (PSS) with dodecyl- and hexadecyltrimethylammonium bromides (DTAB and CTAB) was studied. A low amount of nonionic surfactant enhances the binding of the investigated cationic amphiphiles on PSS, reducing the cationic surfactant-to-polyanion ratio needed for charge neutralization and precipitation. This effect is more pronounced for DTAB than for CTAB due to the considerably higher free surfactant concentration of the former cationic amphiphile. The synergistic surfactant binding also affects the nonequilibrium features of PSS/CTAB association via enhancing the kinetically stable concentration range of overcharged polyion/surfactant nanoparticle dispersions. With increasing C<sub>12</sub>G<sub>2</sub> concentration, however, an opposite effect of the uncharged additive dominates. Namely, the CTAB molecules are solubilized excessively into mixed surfactant micelles, which reduces the surface charge of the PSS/CTAB/C<sub>12</sub>G<sub>2</sub> nanoparticles and thus destabilizes their dispersion. At appropriately large nonionic surfactant concentrations, the binding of CTAB is largely reduced, resulting in the redissolution of the precipitate. In contrast, neither the destabilization nor the resolubilization effects of the added dodecyl maltoside were observed for the PSS/DTAB system due to the much lower driving force of DTAB binding compared to CTAB. Our results clearly demonstrate that the alkyl chain length of the ionic amphiphile has a pronounced effect on both the equilibrium and nonequilibrium aspects of polyion/mixed surfactant complexation which might be further exploited in various next generation applications.