SCI和EI收录∣中国化工学会会刊

›› 2014, Vol. 22 ›› Issue (10): 1092-1097.DOI: 10.1016/j.cjche.2014.09.014

• SEPARATION SCIENCE AND ENGINEERING • Previous Articles     Next Articles

Analysis of pH-dependent Structure and Mass Transfer Characteristics of Polydopamine Membranes by Molecular Dynamics Simulation

Fusheng Pan1,2, Ruisi Xing1,2, Zhongyi Jiang1,2   

  1. 1 Key Laboratory for Green Chemical Technology of Ministry of Education, School of Chemical Engineering and Technology, Tianjin University, Tianjin 300072, China;
    2 Collaborative Innovation Center of Chemical Science and Engineering (Tianjin), Tianjin 300072, China
  • Received:2013-12-14 Revised:2014-04-09 Online:2014-12-01 Published:2014-10-28
  • Supported by:
    Supported by the National Science Fund for Distinguished Young Scholars (21125627), the National Natural Science Foundation of China (21306131), Specialized Research Fund for the Doctoral Program of Higher Education (20120032120009), Seed Foundation of Tianjin University, and the Programme of Introducing Talents of Discipline to Universities (B06006).

Analysis of pH-dependent Structure and Mass Transfer Characteristics of Polydopamine Membranes by Molecular Dynamics Simulation

Fusheng Pan1,2, Ruisi Xing1,2, Zhongyi Jiang1,2   

  1. 1 Key Laboratory for Green Chemical Technology of Ministry of Education, School of Chemical Engineering and Technology, Tianjin University, Tianjin 300072, China;
    2 Collaborative Innovation Center of Chemical Science and Engineering (Tianjin), Tianjin 300072, China
  • 通讯作者: Zhongyi Jiang
  • 基金资助:
    Supported by the National Science Fund for Distinguished Young Scholars (21125627), the National Natural Science Foundation of China (21306131), Specialized Research Fund for the Doctoral Program of Higher Education (20120032120009), Seed Foundation of Tianjin University, and the Programme of Introducing Talents of Discipline to Universities (B06006).

Abstract: Detailed atomistic structures are constructed for polydopamine membranes containing different amounts of catechol and quinone groups to investigate the effect of pH value in themembrane casting solution on sorption and diffusion of small gas molecules (water and propylene) in the membranes. Interactions between dopamine oligomers are calculated, and it is found that the interactions decrease from -2356.52 kJ·mol-1 in DOP-1 to -1586.69 kJ·mol-1 in DOP-3 when all of the catechol groups are converted to quinone groups. The mobility of polymer segments and free volume properties of polydopamine membranes are analyzed. The sorption quantities of water and propylene in the membrane are calculated using Grand Canonical Monte Carlo method. The sorption results show that water adsorbed in DOP-1, DOP-2 and DOP-3 are 17.3, 18.6 and 20.0 mg water per gram polymer, respectively, and no propylene molecule can be adsorbed. The diffusion behavior of water molecules in the membrane is investigated by molecular dynamics simulation. The diffusion coefficients of water molecules in DOP-1, DOP-2 and DOP-3 membranes are (1.80 ± 0.52) × 10-11, (3.40 ± 0.64) × 10-11 and (4.50 ± 0.92) × 10-11 m2·s-1, respectively. The predicted sorption quantities and diffusion coefficients of water and propylene in the membrane present the same trends as those from experimental results.

Key words: Membranes, Polydopamine, Molecular dynamics simulation, Free volume, Diffusion

摘要: Detailed atomistic structures are constructed for polydopamine membranes containing different amounts of catechol and quinone groups to investigate the effect of pH value in themembrane casting solution on sorption and diffusion of small gas molecules (water and propylene) in the membranes. Interactions between dopamine oligomers are calculated, and it is found that the interactions decrease from -2356.52 kJ·mol-1 in DOP-1 to -1586.69 kJ·mol-1 in DOP-3 when all of the catechol groups are converted to quinone groups. The mobility of polymer segments and free volume properties of polydopamine membranes are analyzed. The sorption quantities of water and propylene in the membrane are calculated using Grand Canonical Monte Carlo method. The sorption results show that water adsorbed in DOP-1, DOP-2 and DOP-3 are 17.3, 18.6 and 20.0 mg water per gram polymer, respectively, and no propylene molecule can be adsorbed. The diffusion behavior of water molecules in the membrane is investigated by molecular dynamics simulation. The diffusion coefficients of water molecules in DOP-1, DOP-2 and DOP-3 membranes are (1.80 ± 0.52) × 10-11, (3.40 ± 0.64) × 10-11 and (4.50 ± 0.92) × 10-11 m2·s-1, respectively. The predicted sorption quantities and diffusion coefficients of water and propylene in the membrane present the same trends as those from experimental results.

关键词: Membranes, Polydopamine, Molecular dynamics simulation, Free volume, Diffusion