Micellar characteristics of an amphiphilic star-block copolymer in DES-water mixture

Deep eutectic solvents (DES) have revealed the ability to promote the aggregation of amphiphiles in solution. With a brief overview on the self-assembly of amphiphilic substances in protic/aprotic, polar/non-polar solvents, ionic liquids (ILs), and deep eutectic solvents, we herein report the aggregation behavior of a star block (4-arm) ethylene oxide (EO)-propylene oxide (PO) block copolymer (5 %w/v) tetronic T1304 in the presence of different DESs [ChCl: urea, ChCl: ethylene glycol (EG), ChCl: glycerol (Gly), ChCl: malonic acid (MA), ChCl: glutaric acid (GA), and ChCl: oxalic acid (OA)] in varying aqueous molar ratio solution. From high-sensitivity differential scanning calorimetry (HSDSC), surface tension (S.T.), small-angle neutron scattering (SANS), and dynamic light scattering (DLS), we present for the first time the self-aggregation and size distribution profile of amphiphilic tetronic T1304 in DES-water mixture system. The solubility of poorly water-soluble drug, quercetin (QN), was also checked in 5 %w/v copolymeric micelles and in presence of different DESs using UV-Visible spectroscopy. The presence of various DESs alter the micellization and micellar characteristics and such observed behavior are due to the favorable interactions that support the self-assembly in DES-water solvent mixture which is further elucidated by the molecular simulation study using the Gauss View 5.0.9.