Feng, Shasha, et al. Journal of membrane science, 2018, 549, 332-349.
Polytetrafluoroethylene (PTFE) membrane has excellent chemical stability, high heat resistance, strong hydrophobicity and high fracture toughness, so it is widely used in various applications such as waste gas treatment, membrane distillation, osmotic distillation (OD) and oil-water separation. In order to adapt to different applications, a variety of modification technologies have been developed to expand the specific properties of PTFE membrane. These modification technologies include:
· Wet-chemical modification: Wet-chemical modification involves the reaction between chemical solutions and PTFE membranes, including furan base solution, sodium-naphthalene solution, dopamine, strong acid, and strong oxidizing salt.
· Plasma treatment: Plasma-assisted surface activation and grafting are the two main modification modes of PTFE membranes. Membrane surface activation was achieved by a reactive gas-plasma treatment, resulting in hydrophilic surfaces. While, plasma-assisted grafting and surface polymerization on the membrane surface can efficiently change the surface properties of the membrane.
· Irradiation: Irradiation techniques utilize sources such as ultraviolet, laser, gamma rays, ion beam, and electrons for polymer material modification.
· Atomic-layer deposition (ALD): ALD has emerged as an important technique for depositing thin films for a variety of applications. Many kinds of metal oxides can be successfully deposited on materials with a good binding force by ALD. For example, metal oxide (ZnO, ZrO2, and Al2O3) can be deposited on PTFE by ALD.
