Characterization, transport and sorption properties of poly(thiol ester amide) thin-film composite pervaporation membranes

Hydrophobic nano-silica/polydimethylsiloxane membrane for dimethylcarbonate–methanol separation via pervaporation

“…So it is of great importance to investigate the effect of sorption and diffusion on the PV performance separately [29,30]. In this work, sorption selectivity was measured using the homogeneous membrane instead of the composite membrane which was used in pervaporation.…”

Interfacially polymerized thin-film composite polyamide membrane: positron annihilation spectroscopic study, characterization and pervaporation performance

“…The S parameter value increases by increasing the relative contribution of low momentum electrons to the positron annihilation in the open volume voids. [18][19][24][25] DBES can, therefore, be applied to measure the variation in free volume in a composite membrane. The multilayer structure of a composite membrane can be analyzed from the S parameter variation (free volume variation).…”

“…Studies on interfacially polymerized thin-film composite (TFC) membranes are usually about their application in reverse osmosis [7][8][9][10][11] or nanofiltration, [12][13][14][15][16] but few reports on their application in pervaporation are available. [17][18][19] Therefore, in this study, to improve the pervaporation performance of polyamide membranes, TFC polyamide membranes were prepared through the interfacial polymerization reaction between amines (m-phenylenediamine (MPDA) or 1,3-phenylenediamine-4-sulfonic acid (MPDASA) (sulfonated MPDA)) and acyl chloride (trimesoyl chloride (TMC)) on the surface of a modified asymmetric polyacrylonitrile (mPAN) membrane. These TFC polyamide membranes were then applied in the pervaporation separation of aqueous isopropanol solution at 25 1C The polyamide layer's characteristics such as morphology, surface roughness, hydrophilicity, degree of crosslinking, free volume and thickness were correlated with the pervaporation performance.…”

“…[20][21][22][23] However, there are few studies on polymeric TFC pervaporation membranes investigated with PAS. [18][19][24][25] In this regard, to probe the variation in the free volume in the active polyamide layer, the TFC polyamide membrane was examined by conducting PAS experiments, in which a variable monoenergy slow-positron beam was used.…”

Characterization and pervaporation dehydration of heat-treatment PAN hollow fiber membranes

“…The positron annihilation spectroscopy (PAS) technique is based on an investigation on annihilation phenomena after injecting positrons into the membrane. Recently, PAS becomes a new important method for probing the variation of free volume in the membranes [19][20][21][22][23][24][25][26]. The positron will be annihilated with an electron and emitted with two 511 keV ␥ quanta when the positron is implanted into a condensed matter.…”