Molecular Dynamics Simulations Investigation of Structure and Thermodynamic Properties of Symmetric Poly(styrene‐ block ‐acrylic acid) (PS‐ b ‐PAA) Micelle in Salt‐Free Aqueous Solution

The structure and thermodynamic aspects of symmetric poly(styrene‐ block ‐acrylicacid)(PS‐ b ‐PAA) copolymer micelle in salt‐free aqueous solution as a function of ionization ( f ) of PAA was probed by molecular dynamics simulations. Quantitative comparison of micelle radius shows that the GROMOS parameter set gives the best agreement with experiment. As f increases, Micelle size increases, attains spherical shape, PS surface area increases, and PAA water hydrogen‐bonds increases. Pair correlation functions and solvation enthalpy show that PS interactions are insensitive to f . Density profiles and solvation enthalpy of PAA–Na + , water–Na + pairs confirm the micelle being in the “osmotic regime” experiments.