Chem. J. Chinese Universities ›› 2022, Vol. 43 ›› Issue (10): 20220361.doi: 10.7503/cjcu20220361

• Physical Chemistry • Previous Articles     Next Articles

Vacuum Freeze Drying to Prepare Porous Carbon Based Composite Membranes for Efficient Solar Steam Generation

XU Xiaojian, LI Bo(), LIN Mengxiao, ZHAN Shuo   

  1. College of Science,Zhejiang University of Technology,Hangzhou 310023,China
  • Received:2022-05-20 Online:2022-10-10 Published:2022-07-28
  • Contact: LI Bo E-mail:libo@zjut.edu.cn
  • Supported by:
    the Zhejiang Provincial Natural Science Foundation of China(LY14F040003)

Abstract:

Multi walled carbon nanotubes(CNTs) and polyvinylidene fluoride(PVDF) were used as raw materials to form a uniformly blended colloid by phase conversion method. The colloid was solidified by vacuum freeze drying technology, and some solvents volatilized in vacuum to prepare CNTs/PVDF composite membrane with porous structure. The experiments show that the freeze dried CNTs/PVDF composite membrane has excellent light absorption ability and surface hydrophilicity. Under the illumination intensity of 1 kW/m2, the water evaporation rate can reach 1.95 kg·m-2·h-1 and the photothermal conversion efficiency is 92.9%. At the same time, the evaporator equipped with freeze dried CNTs/PVDF composite membrane shows good salt pollution resistance, significant stability and excellent solar evaporation performance when treating simulated seawater and dye wastewater. These results show that freeze dried CNTs/PVDF composite membrane will have a wide application prospect in freshwater acquisition, sewage treatment and other fields in the future.

Key words: Vacuum freeze drying, Solar steam generation, Carbon nanotubes, Microporous structure, Thermal localization

CLC Number: 

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