Piana Stefano, Gale Julian D
Nanochemistry Research Institute, Department of Applied Chemistry, Curtin University of Technology, P.O. Box U1987, Perth 6845, Western Australia.
J Am Chem Soc. 2005 Feb 16;127(6):1975-82. doi: 10.1021/ja043395l.
Both the dissolution and growth of a molecular crystalline material, urea, has been studied using dynamical atomistic simulation. The kinetic steps of dissolution and growth are clearly identified, and the activation energies for each possible step are calculated. Our molecular dynamics simulations indicate that crystal growth on the [001] face is characterized by a nucleation and growth mechanism. Nucleation on the [001] urea crystal face is predicted to occur at a very high rate, followed by rapid propagation of the steps. The rate-limiting step for crystallization is actually found to be the removal of surface defects, rather than the initial formation of the next surface layer. Through kinetic Monte Carlo modeling of the surface growth, it is found that this crystal face evolves via a rough surface topography, rather than a clean layer-by-layer mechanism.
利用动态原子模拟研究了分子晶体材料尿素的溶解和生长过程。明确确定了溶解和生长的动力学步骤，并计算了每个可能步骤的活化能。我们的分子动力学模拟表明，[001]面上的晶体生长具有成核和生长机制。预计[001]尿素晶体面上的成核速率非常高，随后台阶迅速扩展。实际上发现结晶的限速步骤是表面缺陷的去除，而不是下一个表面层的初始形成。通过对表面生长的动力学蒙特卡罗建模发现，该晶面是通过粗糙的表面形貌演化的，而不是通过干净的逐层机制。
