Manipulating poly(lactic acid) surface morphology by solvent-induced crystallization

Here, we report some unique crystalline morphologies of poly(lactic acid) (PLA) via organic solvent-induced crystallization. It was revealed that the surface morphology of PLA can be fine tuned by simply varying the volume ratio of a mixed solvent (acetone/ethanol). By increasing the ethanol content in the mixed solvent, we observed a morphological evolution of PLA surface from spherulite to shish-kebab and bamboo-cage-like structure. It was also interesting to find that the initial surface structure of PLA plays an important role to determine the final solvent-induced crystalline morphology. This work provides a new method for manipulating PLA crystal morphology through a simple solvent-induced crystallization.

Highlights► PLA crystal morphologies can be tuned by adjusting acetone/ethanol ratio. ► Beautiful PLA shish-kebab crystals can be easily observed using SEM. ► Fractured surface is important for the morphological evolution of PLA surface.