| 초록 |
There are non-classical pathways of crystallization via colloidal intermediates and subsequent mesoscale transformation in crystallization processes. With polymeric additives, self-organization can be stopped at an intermediary step -a mesocrystal- in which the primary units can still be identified. The influence of polymers on crystal formation is attributed to their selective adsorption onto crystal faces, similar to that seen with ionic compounds, which inhibits the growth of faces. Polymer-surface interactions increase colloidal stability, thereby influencing the size and shape of the primary clusters. To understand the effects and parameters for the formation of mesocrystals, the crystallization of charged molecules with oppositely charged polymeric additives was performed. Chitosan and polyethylene glycol were used as the oppositely charged polymers for a negatively charged molecule. The results indicate that the mesocrystals are formed by a polymer-induced structuring process. |
