Gas permeability and permselectivity of plasma‐treated polypropylene membranes

Abstract

The effects of NH 3 -plasma and N 2 -plasma treatment on rubbery polypropylene (PP) membrane upon permeation behavior for CO 2 , O 2 , and N 2 were investigated from their permeability measurements. The NH 3 -plasma and N 2 -plasma treatment on PP membranes could increase both the permeability coefficient for CO 2 and the ideal separation factor for CO 2 relative to N 2 . For O 2 transport, both the permeability coefficient for O 2 and the ideal separation factor for O 2 relative to N 2 also increased. NH 3 -plasma and N 2 -plasma treatment on PP membranes possibly brings about an augmentation of permeability for CO 2 and permselectivity of CO 2 relative to N 2 simultaneously, but unfortunately the plasma-treated PP membrane does not reach the level of CO 2 separation membrane.

Effect of low‐frequency oxygen plasma on polysulfone membranes for CO2/CH4 Separation

“…The O 2 plasma treatment increased both the CO 2 permeability and CO 2 /CH 4 permselectivity of the six PSf membranes (samples A, B, C, F, H, and I) simultaneously. This favorable phenomenon has been previously observed by Kumazawa and coworkers27–29 after the N 2 and NH 3 plasma treatment of different glassy and rubbery polymer membranes.…”

The gas permeability properties of poly(vinyltrimethylsilane) treated by low‐temperature plasma

“…29 In the case of modification of membranes with a nonporous layer or dense polymeric films, for example, PDMS, 17 Lestosil (a PDMSbased polymer), 30 PIM, 30 and Matrimid 5218, 20 the lowtemperature plasma treatment, in addition to changing the hydrophilicity, leads to an uneven decrease in the permeability of various gases as a result of changes in the chemical structure of the surface and near-surface layers. The effect of modification on gas permeability allows increased gas selectivity, for example, for such pairs as CO 2 /CH 4 18 , O 2 /N 2 , 7,16 He/CH 4 , 30 He/N 2 , 31 and CO 2 /N 2 , 19 and the combination of plasma treatment with UV irradiation allowed an increase not only in the selectivity of PIM membranes for such gas pairs as H 2 /CH 4 , N 2 /CH 4 , but for a number of lower hydrocarbons as well. 32 It should be remembered that one of the serious problems of postprocessing of membrane materials is the stability of the effects achieved; both gas permeability and selectivity may change over time.…”

“…[1][2][3][4][5][6][7][8][9][10][11] At the same time, at present, the most environmentally friendly approaches are based on solution-free technologies, for example, the treatment of the membrane surface using a low-temperature plasma method, which is increasingly used to modify various polymers and polymer membranes. 12,13 Either inert gases, for example, Ar, or reagent gases such as N 2 , O 2 , NH 3 , CF 4 , and CO 2 , are used for low-temperature plasma modification, 12,[14][15][16][17][18][19][20] and it has been shown that the choice of gas significantly affects the results of the surface treatment. 18,20 As a rule, the processing of polymers by a low-temperature plasma method is carried out in order to change the surface properties, for example, the hydrophilicity of polymer films.…”