ABSTRACT The various aspects of molecular structure, kinetics, and thermodynamics of symmetric polystyrene-b-poly(methacrylic acid) (PS-b-PMA) block copolymer micelle in salt-free aqueous solution as a function of degree-of-ionisation (f) of PMA (corona) block was investigated by explicit molecular dynamics (MD) simulations. Micelle size increases linearly with f in a qualitative agreement with simulation results in the literature. With increase in charge density of the corona-forming PMA chain block, the micelle becomes more spherical, and there is a decrease in the surface area of micelle core and an increase in the favourable interactions among the PS chains. The structure of the micelle changes with f. The behaviour of the RDF’s of core and corona PMA atoms and the enthalpy of solvation show that the interactions among the segments of the core PS blocks are insensitive to variation in f. The atom density profiles, solvation enthalpy, and coordination number of PMA-Na+ and Water-Na+ pairs reveal the existence of the micelle in the ‘osmotic regime’ in agreement with results from experiments and mean-field theory in literature. The significance of electrostatic interactions on the kinetics of formation, structural aspects, and thermodynamics of micellisation is shown. The characteristics of PMA-b-PS micelle are compared with those of PAA-b-PS.
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