(198e) Impacts of Solvent and Polymer Additive Polyvinylpyrrolidone on the Ethyl Vanillin Crystal Morphology

Authors: 
Zhang, S. - Presenter, Tianjin University
Zhou, L., Tianjin University
Xie, C., Tianjin University
Hou, B., Tianjin University
Yin, Q., Tianjin University
Ethyl vanillin (EVA) is an important synthetic chemical which is widely used in the food additives, spices, cosmetics and pharmaceuticals. However, EVA crystal crystallized from various solvents by cooling crystallization shows thin flake shape which could be crushed during the downstream process. This study investigated the effects of solvents and additives on the morphology of EVA crystal from experiments and molecular dynamic simulation. By adding polymer additive polyvinylpyrrolidone (PVP) into the EVA solution, the morphology of EVA was modified from the thin flake to the thick flake with distinct side facets. In contrast, the morphology of EVA in the presence of the PVP monomer molecule and other similar additives didn’t change. Molecular dynamic simulation revealed that the solvent molecules were trapped in the holes of {010} surface and hindered its growth process significantly resulting the {010} surface dominated the morphology. The strong interaction between PVP and {100} surface accounted for the growth inhibition along the <100> direction giving rise to the appearance of side facets. Furthermore, mean square displacement analysis showed that polymer additive PVP possessed the obvious lower displacement ability compared with other similar additives, besides, distinct mean square displacement difference was found between different crystal surfaces of EVA, these may affect solute approaching process. These simulation results were consistent with the experimental results.
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