SCI和EI收录∣中国化工学会会刊

Chinese Journal of Chemical Engineering ›› 2019, Vol. 27 ›› Issue (4): 759-764.DOI: 10.1016/j.cjche.2018.09.009

• Fluid Dynamics and Transport Phenomena • Previous Articles     Next Articles

Understanding self-accelerated water diffusion within poly-lactic acid via molecular dynamics simulation

Xiaohui Wang1, Jiachen Li2, Li Zhang2   

  1. 1 School of Economics and Management, Tianjin University of Technology and Education, Tianjin 300222, China;
    2 Department of Chemistry, Zhejiang Sci-Tech University, XiaSha Higher Education Zone, Hangzhou 310018, China
  • Received:2018-07-15 Revised:2018-08-28 Online:2019-06-14 Published:2019-04-28
  • Contact: Li Zhang
  • Supported by:
    Supported by the Scientific Developing Foundation of Tianjin Municipal Education Commission (2017SK055), and the Project Grants 521 Talents Cultivation of Zhejiang Sci-Tech University.

Understanding self-accelerated water diffusion within poly-lactic acid via molecular dynamics simulation

Xiaohui Wang1, Jiachen Li2, Li Zhang2   

  1. 1 School of Economics and Management, Tianjin University of Technology and Education, Tianjin 300222, China;
    2 Department of Chemistry, Zhejiang Sci-Tech University, XiaSha Higher Education Zone, Hangzhou 310018, China
  • 通讯作者: Li Zhang
  • 基金资助:
    Supported by the Scientific Developing Foundation of Tianjin Municipal Education Commission (2017SK055), and the Project Grants 521 Talents Cultivation of Zhejiang Sci-Tech University.

Abstract: Poly-lactic acid (PLA) is widely used as a controlled drug release material and the diffusion property of water within the polymer matrix is closely related to the drug release profile. This paper studies the water diffusion in PLA by molecular dynamic simulations. Free volume analysis indicates that water molecules are expected to fill in the free volumes of the polymer matrix forming water clusters at low water content. Along with the increase of the water concentration, the polymer starts to swell and the density of the system starts to drop. Due to the high mobility of water within water cluster, the calculated diffusion coefficient dramatically increases along with the incensement of water content. Thus, we conclude that the diffusion of water is a self-accelerate process, with higher mobility of water in the case where more water exists.

Key words: Water diffusion coefficient, Controlled release, Molecular dynamic simulation

摘要: Poly-lactic acid (PLA) is widely used as a controlled drug release material and the diffusion property of water within the polymer matrix is closely related to the drug release profile. This paper studies the water diffusion in PLA by molecular dynamic simulations. Free volume analysis indicates that water molecules are expected to fill in the free volumes of the polymer matrix forming water clusters at low water content. Along with the increase of the water concentration, the polymer starts to swell and the density of the system starts to drop. Due to the high mobility of water within water cluster, the calculated diffusion coefficient dramatically increases along with the incensement of water content. Thus, we conclude that the diffusion of water is a self-accelerate process, with higher mobility of water in the case where more water exists.

关键词: Water diffusion coefficient, Controlled release, Molecular dynamic simulation