Phase behaviour and characterization of micelles of graft copolymer Soluplus® and non-ionic surfactant Solutol® HS15: A detailed comparison in the presence of additives

Abstract The present study deals with the self-assembly of a pure graft copolymer: Soluplus® and a non-ionic surfactant: Solutol® HS15 and focuses on their clouding behaviour [expressed as cloud point (CP)] in the presence of different additives viz. inorganic salts (NaF, NaCl, NaBr, NaI, NaNO3, KCl, KBr, KI), bile salts (sodium cholate-NaC, sodium taurocholate-NaTC, sodium deoxycholate-NaDC), denaturants (urea, methylurea, dimethylurea), amino acids (alanine, glycine, lysine, valine, cysteine hydrochloride), sugars (glucose, fructose, mannitol, sucrose, maltose, lactose), cationic surfactants (cetyltrimethylammonium bromide-CTAB, tetradecyltrimethylammonium bromide-TTAB, dodecyltrimethylammonium bromide-DTAB) and alcohols (methanol, ethanol, propanol, 1-butanol, ethanediol, 1,3-propanediol, 1,4-butanediol). The aqueous solutions of these amphiphiles show a complex phase behaviour and have revealed the occurrences of spherical micelles using dynamic light scattering (DLS) and small-angle neutron scattering (SANS) techniques. Herein, we report the variation of amphiphilic CP in the presence of different kinds of additives that show the influence of the water structure and its hydrophobicity, making this study important for pharmaceutical/ biomedical applications.