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. Graphical abstract Schematic illustration portraying the favorable physicochemical characterization leading to the micellization and depicting enhanced drug solubilization efficiency of optimized T1304-DES mixture.