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Ionizable copolymers assembly in solutions is driven by the formation of ionic clusters. Fast clustering of the ionizable blocks often leads to the formation of far-from equilibrium assemblies that ultimately impact the structure of polymer membranes and affect their many applications. Using large-scale atomistic molecular dynamics simulations, we probe the effects of electrostatics on the formation of ionizable copolymer micelles that dominate their solution structure, with the overarching goal of defining the factors that control the assembly of structured ionizable copolymers. A symmetric pentablock ionizable copolymer, with a randomly sulfonated polystyrene center tethered to polyethylene-r-propylene block, terminated by poly(t-butyl styrene), in solvents of varying dielectric constants from 2 to 20, serves as the model system. We find that independent of the solvents, this polymer forms a core–shell micelle with the ionizable segment segregating to the center of the assembly. The specific block conformation, however, strongly depends on the sulfonation levels and the dielectric constant and the polarity of the solvents. 

ABSTRACT Sustainable alternatives to petroleum‐based plastics are needed urgently, but biodegradable materials from renewable sources often suffer from inadequate mechanical properties. Here, we demonstrate a bio‐inspired strategy to enhance soy protein isolate (SPI) nanocomposites through surface modification of cellulose nanocrystal (CNC) reinforcing filler particles with a polydopamine (polyDOPA) coating via dopamine polymerization under alkaline conditions. This modification creates multifunctional interfaces at filler surfaces that enhance nanocomposite mechanical properties likely by simultaneously altering filler dispersion and filler–matrix interactions. PolyDOPA‐modified CNCs increase the tensile strength and elastic modulus of SPI films (plasticized with 50% glycerol) by more than threefold compared to unreinforced controls. Transmission electron microscopy, spectroscopic techniques, and thermal analysis reveal that polyDOPA coatings influenced nanocomposite structure across multiple length scales, tripling the effective diameter of the CNC inclusions, reducing the tendency of CNC nanocrystals to aggregate, and increasing the glass transition temperature. The increase in glass transition temperature suggests reduced SPI molecular mobility, which, along with micromechanical modeling, indicates the potential for improved interfacial interactions. Results reveal how polyDOPA‐modified CNCs influence the interphase behavior and filler dispersion of SPI‐glycerol nanocomposites, providing a pathway to further improve their performance for various applications, including packaging, membranes, and coatings.