Zha Liyun, Hu Wenbing
Department of Polymer Science and Engineering, State Key Laboratory of Coordination Chemistry, School of Chemistry and Chemical Engineering, Nanjing University, 210093, Nanjing, China.
J Phys Chem B. 2007 Oct 4;111(39):11373-8. doi: 10.1021/jp068431c. Epub 2007 Sep 13.
We report dynamic Monte Carlo simulations of polymer crystal nucleation initiated by prior spinodal decomposition in polymer solutions. We observed that the kinetic phase diagrams of homogeneous crystal nucleation appear horizontal in the concentration region below their crossovers with the theoretical liquid-liquid spinodal. When the solution was quenched into the temperature beneath this horizontal boundary, the time evolution of structure factors demonstrated the spinodal decomposition at the early stage of crystal nucleation. In comparison with the case without a prior liquid-liquid demixing, we found that the prior spinodal decomposition can regulate the nanoscale small polymer crystallites toward a larger population, more uniform sizes, and a better spatial homogeneity, whereas chain folding in the crystallites seems little affected.
我们报道了聚合物溶液中由先前的旋节线分解引发的聚合物晶体成核的动态蒙特卡罗模拟。我们观察到，在低于其与理论液 - 液旋节线交叉点的浓度区域中，均相晶体成核的动力学相图呈水平状。当溶液被淬火到该水平边界以下的温度时，结构因子的时间演化表明在晶体成核的早期阶段存在旋节线分解。与没有先前液 - 液分层的情况相比，我们发现先前的旋节线分解可以使纳米级小聚合物微晶数量增加、尺寸更均匀且空间均匀性更好，而微晶中的链折叠似乎受影响较小。
