| Abstract
| - For simulating hydrophobic−amphiphilic (HA) copolymers, we have developed a “side-chain”HA model in which hydrophilic (P) interaction sites are attached to hydrophobic (H) main chain, therebyforming amphiphilic (A) monomer units, each with dualistic (hydrophobic/hydrophilic) properties. Usingthis coarse-grained model, we performed molecular dynamics simulations of the hydrophobically drivenself-assembly in a selective solvent, for both single-chain and multichain systems. The focus is on theregime in which H and P interaction sites are strongly segregated. Single-chain simulations are performedfor copolymers with the same HA composition but with different distribution of H and A monomer unitsalong the hydrophobic backbone, including regular copolymers comprising H and A units in alternatingsequence, (HA)x, regular multiblock copolymers (HLAL)x composed of H and A blocks of equal lengths L= 3, and quasi-random proteinlike copolymers having quenched primary structure. In a solvent selectivelypoor for H sites, the proteinlike polyamphiphiles can readily adopt spherical-shaped compact conformationswith the hydrophobic chain sections clustered at the globular core and the hydrophilic groups formingthe envelope of this core and buffering it from solvent. Because of the fact that these globules are size-and shape-persistent objects, they maintain their morphological integrity even in rather concentratedsolutions where no large-scale aggregation is observed. Moreover, we find that the population of aggregatesgenerally decreases with worsening solvent quality. The compact conformations of long regular copolymerstend to be strongly elongated in one direction.
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