Polyetherimide/polyvinylpyrrolidone vapor permeation membranes. Physical and chemical characterization

Electrokinetic and surface chemical characterizations of an irradiated microfiltration polysulfone membrane: Comparison of two irradiation doses

“…Finally, Fig. 3b shows the N1s core-level spectra for the three membranes, which present an almost symmetrical peak at a binding energy of 400 eV, approximately, and no differences among the samples can be observed; this binding energy might correspond to dimethylformamide (400.4 eV) or polyvinylpyrrolidone (399.9 eV) [31], in agreement with the previous comments. According to the XPS results, we can state the main effect of radiation is the cleaning (elimination of impurities or additives) of the external membrane surface, but it does not seem to cause membrane damage.…”

“…Fig. 2a shows a comparison of the O1s core level for the three membranes, with two differentiated peaks at 533.2 eV (O A : for C-O-C or O=C-O [31,32]) and at 531.6 eV (O B : for O=S=O and/or O=C-N [32]), and Fig. 2b shows the deconvolution of the GRMO-Ir80 spectrum; as can be observed, membrane irradiation increases the relative intensity of the oxygen associated with polysulfone (peak at 531.6 eV), in agreement with the results obtained from the C1s spectra.…”

Optimization of ultrafiltration membrane fabrication using backpropagation neural network and genetic algorithm

“…On the one hand, since it is soluble in water coagulation bath, it is a pore-forming agent [46,47]. On the other hand, the addition of PVP sharply increases the viscosity of the casting solution thereby decreases the inlet velocity of nonsolvent and outlet velocity of solvent and additive and consequently makes a denser skin layer [48][49][50]. The latter is the primary.…”

Teflon AF2400/Ultem composite hollow fiber membranes for alcohol dehydration by high‐temperature vapor permeation

“…Among numerous polymer materials for membranes, polyimides have excellent thermal, chemical and mechanical stabilities, high water selectivity, and less degree of swelling compared with hydrophilic polymers such as polyvinyl alcohol, and thus they have emerged as potential membrane materials for solvent dehydration via both pervaporation 3,4,[16][17][18][19][20] and vapor permeation. 11,21,22 However, similar to other membranes, polyimide membranes also suffer the problem of swelling which severely reduces the separation performance. Thus, modifications of polyimide membranes such as crosslinking treatments are still needed to control the swelling and improve the stability, particularly in harsh environments.…”