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Understanding supersaturation‐dependent crystal growth of L‐alanine in aqueous solution
Author(s) -
Tan Wenhui,
Yang Xiangyu,
Duan Xuezhi,
Zhang Xiangyang,
Qian Gang,
Zhou Xinggui
Publication year - 2016
Publication title -
crystal research and technology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.377
H-Index - 64
eISSN - 1521-4079
pISSN - 0232-1300
DOI - 10.1002/crat.201500108
Subject(s) - supersaturation , aqueous solution , chemistry , molecule , crystal (programming language) , crystal growth , crystallography , alanine , surface energy , chemical physics , thermodynamics , organic chemistry , physics , amino acid , computer science , biochemistry , programming language
The dependence of crystal growth rate of L‐alanine on solution supersaturation was investigated by combining experiments and molecular dynamics (MD) simulations. The experimental results show that lower supersaturated solution yields more elongated L‐alanine crystals along the c‐axis, i.e., the aspect ratio ( c / b ) of the crystal decreases with the increase of solution supersaturation, which is due to the higher supersaturation inducing a rise in the relative growth rate between the main side surface (the (120) surface) and the main end surface (the (011) surface). MD simulations on the two surfaces in contact with different supersaturated solutions revealed that the solute molecules tend to be more efficiently attached to the (011) surface than to the (120) surface at both supersaturations studied, as the interaction between the solute molecules and the L‐alanine molecules in the first layer of the (011) surface is stronger than that of the (120) surface. However, higher supersaturation leads to larger relative interaction energy between the (120) and (011) surfaces, suggesting an increase in the relative growth rate of the two surfaces ( R (120) / R (011) ) with supersaturation, which is in agreement with the experimental results.