SCI和EI收录∣中国化工学会会刊

中国化学工程学报 ›› 2020, Vol. 28 ›› Issue (12): 3152-3158.DOI: 10.1016/j.cjche.2020.08.026

• Materials and Product Engineering • 上一篇    下一篇

High permeability poly(vinylidene fluoride) ultrafiltration membrane doped with polydopamine modified TiO2 nanoparticles

Qi Zhang1,2, Zhaoliang Cui1,2, Weixing Li1,2   

  1. 1 State Key Laboratory of Materials-Oriented Chemical Engineering, College of Chemical Engineering, Nanjing Tech University, Nanjing 210009, China;
    2 National Engineering Research Center for Special Separation Membrane, Nanjing Tech University, Nanjing 210009, China
  • 收稿日期:2020-04-08 修回日期:2020-08-04 出版日期:2020-12-28 发布日期:2021-01-11
  • 通讯作者: Zhaoliang Cui, Weixing Li
  • 基金资助:
    The authors wish to acknowledge the financial support from National Key R&D Program of China (2017YFD0400402), National Natural Science Foundation of China (No. 21576132).

High permeability poly(vinylidene fluoride) ultrafiltration membrane doped with polydopamine modified TiO2 nanoparticles

Qi Zhang1,2, Zhaoliang Cui1,2, Weixing Li1,2   

  1. 1 State Key Laboratory of Materials-Oriented Chemical Engineering, College of Chemical Engineering, Nanjing Tech University, Nanjing 210009, China;
    2 National Engineering Research Center for Special Separation Membrane, Nanjing Tech University, Nanjing 210009, China
  • Received:2020-04-08 Revised:2020-08-04 Online:2020-12-28 Published:2021-01-11
  • Contact: Zhaoliang Cui, Weixing Li
  • Supported by:
    The authors wish to acknowledge the financial support from National Key R&D Program of China (2017YFD0400402), National Natural Science Foundation of China (No. 21576132).

摘要: In order to improve the water permeability of poly(vinylidene fluoride) (PVDF) ultrafiltration (UF) membranes with low molecular weight cut-off (MWCO), polydopamine (PDA) was employed in the membrane preparation process. Owing to its merits of material-independent adhesion, PDA was coated on inorganic particles or added in coagulation bath to tailor the final membrane structure and property. The introduction of PDA broke through the permeability/selectivity trade-off of the PVDF membrane. By adding the PDA coated titanium dioxide (PDA/TiO2) nanoparticles, water flux increased by 287% while MWCO kept similar with the pristine PVDF membrane. Thermodynamics and Kinetics of the PVDF/additives/non-solvent were analyzed and shown that nanoparticles reduced the thermodynamic stability and increased the phase separation speed, and the speed can be adjusted using different nanoparticles. Additionally, X-ray diffraction (XRD) test indicated that PVDF crystalline form changed from α phase to β phase after adding different nanoparticles. Permeability/selectivity trade-off was broken through by DA addition in coagulation bath. Compared with the original PVDF membrane, when the DA concentration of the coagulation bath was 2.0 g·L-1, water flux increased by 312%, and MWCO of the PVDF membrane ranged in 10,000 to 20,000 Da as well as contact angle decreased from 81.4° to 45°.

关键词: Poly(vinylidene fluoride) membrane, Polydopamine, Permeability/selectivity trade-off

Abstract: In order to improve the water permeability of poly(vinylidene fluoride) (PVDF) ultrafiltration (UF) membranes with low molecular weight cut-off (MWCO), polydopamine (PDA) was employed in the membrane preparation process. Owing to its merits of material-independent adhesion, PDA was coated on inorganic particles or added in coagulation bath to tailor the final membrane structure and property. The introduction of PDA broke through the permeability/selectivity trade-off of the PVDF membrane. By adding the PDA coated titanium dioxide (PDA/TiO2) nanoparticles, water flux increased by 287% while MWCO kept similar with the pristine PVDF membrane. Thermodynamics and Kinetics of the PVDF/additives/non-solvent were analyzed and shown that nanoparticles reduced the thermodynamic stability and increased the phase separation speed, and the speed can be adjusted using different nanoparticles. Additionally, X-ray diffraction (XRD) test indicated that PVDF crystalline form changed from α phase to β phase after adding different nanoparticles. Permeability/selectivity trade-off was broken through by DA addition in coagulation bath. Compared with the original PVDF membrane, when the DA concentration of the coagulation bath was 2.0 g·L-1, water flux increased by 312%, and MWCO of the PVDF membrane ranged in 10,000 to 20,000 Da as well as contact angle decreased from 81.4° to 45°.

Key words: Poly(vinylidene fluoride) membrane, Polydopamine, Permeability/selectivity trade-off