SCI和EI收录∣中国化工学会会刊

Chinese Journal of Chemical Engineering ›› 2013, Vol. 21 ›› Issue (3): 301-309.DOI: 10.1016/S1004-9541(13)60472-7

• 化工热力学 • 上一篇    下一篇

Molecular Simulation of Oxygen Sorption and Diffusion in the Poly (lactic acid)

孙德林, 周健   

  1. School of Chemistry and Chemical Engineering, Guangdong Provincial Key Lab for Green Chemical Product Technology, South China University of Technology, Guangzhou 510640, China
  • 收稿日期:2011-11-10 修回日期:2012-04-20 出版日期:2013-03-28 发布日期:2013-04-01
  • 通讯作者: ZHOU Jian
  • 基金资助:

    Supported by Program of New Century Excellent Talents in University (NCET-07-0313), the National Natural Science Foundation of China (20706019, 20876052), Guangdong Science Foundation (S2011010002078).

Molecular Simulation of Oxygen Sorption and Diffusion in the Poly (lactic acid)

SUN Delin, ZHOU Jian   

  1. School of Chemistry and Chemical Engineering, Guangdong Provincial Key Lab for Green Chemical Product Technology, South China University of Technology, Guangzhou 510640, China
  • Received:2011-11-10 Revised:2012-04-20 Online:2013-03-28 Published:2013-04-01
  • Supported by:

    Supported by Program of New Century Excellent Talents in University (NCET-07-0313), the National Natural Science Foundation of China (20706019, 20876052), Guangdong Science Foundation (S2011010002078).

摘要: Grand canonical Monte Carlo and molecular dynamics simulation methods are used to simulate oxygen sorption and diffusion in amorphous poly(lactic acid) (PLA). The simulated solubility coefficient of oxygen is close to experimental data obtained from the quartz crystal microbalance but much higher than those from the time-lag method. This discrepancy is explained by using the dual-mode sorption model. It is found that oxygen sorption in PLA is predominantly Langmuir type controlled, em.e., through the process of filling holes. The time-lag method only takes into account oxygen molecules that participate the diffusion process whereas a large proportion of oxygen molecules trapped in the void have little chance to execute hopping due to the glassy nature of PLA at room temperature. The simulated diffusion coefficient of oxygen is reasonably close to the data obtained from the time-lag method. The solubility coefficient of oxygen decreases linearly with increasing relative humidity while its diffusion coefficient firstly decreases and then increases as a function of relative humidity.

关键词: polymer, sorption, gas diffusion, molecular simulation, molecular dynamics

Abstract: Grand canonical Monte Carlo and molecular dynamics simulation methods are used to simulate oxygen sorption and diffusion in amorphous poly(lactic acid) (PLA). The simulated solubility coefficient of oxygen is close to experimental data obtained from the quartz crystal microbalance but much higher than those from the time-lag method. This discrepancy is explained by using the dual-mode sorption model. It is found that oxygen sorption in PLA is predominantly Langmuir type controlled, em.e., through the process of filling holes. The time-lag method only takes into account oxygen molecules that participate the diffusion process whereas a large proportion of oxygen molecules trapped in the void have little chance to execute hopping due to the glassy nature of PLA at room temperature. The simulated diffusion coefficient of oxygen is reasonably close to the data obtained from the time-lag method. The solubility coefficient of oxygen decreases linearly with increasing relative humidity while its diffusion coefficient firstly decreases and then increases as a function of relative humidity.

Key words: polymer, sorption, gas diffusion, molecular simulation, molecular dynamics