A single polymer folding and thickening from different dilute solution

•Single chain crystallization from three distinct solutions is compared.•In good solution thicker crystalline stems are formed.•In poor solvent nucleation is fast and a dense crystal forms.•In critical solution crystal counter contracting and lamellar thickening are well coupled.•We suggest a new route to get perfect single-chain crystal.

The primary nucleation and crystal growth of a single chain from different dilute solution are studied by Monte Carlo simulations. The interplay of crystallization and demixing/collapse is conveniently investigated in chain folding. We find the solvent qualities affect the nucleation mechanism, crystal morphology and the thickening process. In good solution the swollen coil allows the stems more extended and facilitates to form thicker crystalline stems. The poor solvent condition is helpful to perform fast nucleation and produce a dense crystal. But to get more reorganization the critical athermal solution is the best choice, where the longitudinal thickening and width contraction of the folded stem is well coupled. Our results may complement the kinetic mechanism of crystal growth beyond the point of lamellar thickening.