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

Abstract Monocationic surfactants cetyltrimethylammonium bromide (CTABr), cetyldimethyl(2-hydroxyethyl)ammonium bromide (CHDABr), and dicationic (gemini) surfactants, alkanediyl-α,ω-bis(dimethyltetradecylammonium 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.