Effect of structure of polycyclic aromatic substrates on solubilization capacity and size of cationic monomeric and gemini 14-s-14 surfactant aggregates

Monocationic surfactants cetyltrimethylammonium bromide (CTABr), cetyldimethyl(2-hydroxyethyl) ammonium bromide (CHDABr), and dicationic (gemini) surfactants, alkanediyl-alpha,beta-bis(dimethyltetra-decylammonium bromides) (14-s-14, where s = 2, 4, 6) were studied in the solubilization of polycyclic aromatic compounds (PAC) anthracene, naphthalene, and organic dye alizarin. By means of UV-vis was found that gemini 14-s-14 surfactants demonstrate 2-4 times higher solubilisation capacity compared to the monomer surfactants. Solubilization of anthracene increases in the series 14-2-14: 14-4-14: 14-6-14 whereas naphthalene does not demonstrate remarkable sensitivity to the spacer length. Solubilization profile of Alizarin undergoes a break point causing lower solubilisation capacity at high surfactant concentration. The aggregates size was shown using DLS method to be dependent on solubilizate structure and nature and concentration of surfactant. (C) 2016 Elsevier B.V. All rights reserved.