Study Of Induced-crystallization For Methylparaben

Regulation of crystal nucleation and crystal growth is the research focus ofcrystallization. However, complexities of the influencing factors and mechanism of thecrystallization process limit understanding and regulating the crystallization process, furtherstudy is highly required. Recently, molecular dynamics simulation is used to construct crystalstructure, simulate and predict polymorphs and crystal habits, analysis the influencing factorsand mechanism of the crystallization process. In this paper, research method, which based onmolecular dynamics simulation combined with modern experimental and characterizingtechniques, was established to study the effect of additives on the MP crystal nucleation andcrystal growth.MP crystals growthed with different concentrations of additives(APAP, PMAA andACET) were characterizatied by HPLC and XRD. The results show those MP crystal are thesame polymorphs with different crystal habit. Diffraction results show MP crystals unit cellparameters: space group as CC, monoclinic, cell parameters: α=90°, β=120.7°, γ=90°, a=13.568, b=16.958, c=11.021. Adsorbed energy between the crystal surface andadditives were calculated by DFT functional theory and the electrostatic field analysis, theresults showed that APAP, PMAA and ACET would selectively adsorb on the growth surfaceof the crystal surface, which induced the change of MP crystal habit. Furthermore, numberand size distribution of crystals were monitored by FBRM during the MP coolingcrystallization. The results show additives would change the metastable zone width,nucleation time and size distribution.This study would provide useful guidance for analyzing the impact of additives oncrystallization.