Plasma Modification and Synthesis of Membrane Materials—A Mechanistic Review

Abstract

Although commercial membranes are well established materials for water desalination and wastewater treatment, modification on commercial membranes is still necessary to deliver high-performance with enhanced flux and/or selectivity and fouling resistance. A modification method with plasma techniques has been extensively applied for high-performance membrane production. The paper presents a mechanistic review on the impact of plasma gas and polymerization, at either low pressure or atmospheric pressure on the material properties and performance of the modified membranes. At first, plasma conditions at low-pressure such as plasma power, gas or monomer flow rate, reactor pressure, and treatment duration which affect the chemical structure, surface hydrophilicity, morphology, as well as performance of the membranes have been discussed. The underlying mechanisms of plasma gas and polymerization have been highlighted. Thereafter, the recent research in plasma techniques toward membrane modification at atmospheric environment has been critically evaluated. The research focuses of future plasma-related membrane modification, and fabrication studies have been predicted to closely relate with the implementation of the atmospheric-pressure processes at the large-scale.

Nanoporous metal–polymer composite membranes for organics separations and catalysis

“…These results are further supported by contact angle measurements, which show a contact angle of 72.6 ± 2.4°f or the unmodified UF PSf, and an angle of 20.7 ± 3.5°for the membrane after plasma treatment. This is in line with the results of other researchers [43,44,45], who have noted that Ar plasma treatment alters O/C ratio at the membrane surface and increases surface energy. These effects serve to improve the bonding of the deposited film to the substrate material, resulting in an enhanced composite.…”

Chemical Degradation of PSF-PUR Blend Hollow Fiber Membranes—Assessment of Changes in Properties and Morphology after Hydrolysis

“…Furthermore, helpful methods to eliminate fouling can be, for example, heat and plasma treatment [ 4 , 34 , 35 , 36 , 37 ], coating or grafting of hydrophilic polymers onto membranes’ surfaces [ 33 , 35 , 38 , 39 , 40 , 41 , 42 , 43 ], or through the addition of hydrophilic pore precursors to a polymer solution or other admixture like nanoparticles [ 6 , 19 , 25 , 44 , 45 , 46 , 47 , 48 ]. The modification could be influenced by an increase of the hydraulic permeability and/or the hydrophilicity of membranes.…”

Plasma and Polymers: Recent Progress and Trends

“…Plasma treatment can be used to modify the topmost layer of the membrane (via functionalization or deposition of an ultra-thin layer) to render it highly selective, while leaving the strong porous substrate virtually unchanged [ 76 , 77 , 78 ]. In a very similar manner, membranes used for energy applications, water purification, and separation of liquid mixtures can be modified and their performance enhanced using plasma treatment [ 79 ].…”