Surface-modified polysulfone membranes: aqueous phase oxidation via persulfate radical

Peer reviewed: YesNRC publication: Ye

Late Quaternary transgressions and regressions in the Trieste Gulf (northeastern Adriatic Sea)

The integration of high-resolution seismic profiles, core data and radiocarbon plus U-Th datings, allows to document the late Quaternary succession of the Trieste Gulf, which represents the easternmost part of the northern Adriatic Sea. This succession consists of an alternation of shallow marine and continental deposits organized to compose four transgressive-regressive sequences down to ca. 90 m below present sea level. The sequences terminate landwards against a stepped surface bounding the Eocene Trieste Flysch and produced by alternating episodes of wave erosion during transgressions and subaerial exposure during stages of relative sea-level fall and lowstand. Two shallow-marine wedges, in addition to the Holocene one, have been recognized; they are associated with the Marine Isotopic Stage (MIS) 5.5 (Tyrrhenian) and probably at least one of the peaks of MIS 7. The recognized shallow-marine wedges typically prograde just seaward of a buried wave-cut platform lying in front of a receding paleo-coastal cliff. A previously unrecognized stratigraphic hiatus of ca. 25 ka duration, containing the whole Last Glacial Maximum (LGM) phase, was found at the top of palustrine deposits that accumulated on the MIS 5.5 marine sediments until ca. 40 cal ka B.P. and a post-LGM peat bed accumulated during the Younger Dryas stadial. The beginning of the Holocene was characterized by marked fluvial aggradation preceding the marine transgression at ca. 11-10 cal ka B.P. This new evidence is invaluable for better understanding late Quaternary sedimentary and erosional episodes that characterized the easternmost part of the norther Adriatic Sea, in the frame of the well-known glacio-eustatic sea-level changes

Design considerations for plate and frame ultrafiltration modules by computational fluid dynamics analysis

Peer reviewed: YesNRC publication: Ye

Revisiting the experimental and theoretical upper bounds of light pure gas selectivity-permeability for polymeric membranes

Peer reviewed: YesNRC publication: Ye

Polysulfone membranes. IV. Performance evaluation of Radel A/PVP membranes

Peer reviewed: YesNRC publication: Ye

PDMS coatings on asymmetric gas separation membranes: effect on pure gas and mixed gas selectivity

NRC publication: Ye

Polysulfone membranes. V. Poly(phenyl sulfone) (Radel R)-poly(vinyl pyrrolidone) membranes

Peer reviewed: YesNRC publication: Ye

Synthesis and characterization of bis (4-maleimidophenyl) fluorene and its semi interpenetrating network membranes with polyther imide (Ultem 1000)

A semi-interpenetrating network (semi-IPN) of bis (4-maleimidophenyl) fluorene (cardo-BMI) and polyether imide (PEI, Ultem\uae 1000) was prepared. The structure of bis (4-maleimidophenyl) fluorene and the corresponding semi-IPNs was determined by nuclear magnetic resonance and Fourier transform infrared spectroscopy, respectively. The thermal properties of the cardo-BMI and semi-IPNs were evaluated by thermogravimetry and differential scanning calorimetry. The semi-IPNs exhibited thermal stability up to 480 \ub0C. The morphology of the semi-IPNs was evaluated by scanning electron microscopy. Asymmetric membranes were prepared from the semi-IPN material by the wet phase inversion method. The pure gas permeation properties of the PEI and semi-IPN membranes were evaluated for oxygen (O2), nitrogen (N2), carbon dioxide (CO2) and methane (CH4) by the constant pressure and variable volume method at an absolute feed pressure of 0.69 MPa at 22 \ub0C. The CO2/N2 selectivity of 39.2 \ub1 3.0 with a CO2 permeance of 18.3 \ub1 4.0 GPU of semi-IPN membrane was higher than the PEI membranes (selectivity 21.6 \ub1 4.1 and CO2 permeance 0.5 \ub1 0.1 GPU). The highest CO2/CH4 selectivity of the semi-IPN membrane was 49.3 \ub1 3.5 compared to 37 for a PEI dense film. Among the semi-IPN membranes, those with 5 wt% cardo-BMI exhibited better performance than the 1% and 10%.Peer reviewed: YesNRC publication: Ye

Dispersed phase back transport ultrafiltration of cutting oil emulsions with a spinning membrane disc geometry

Peer reviewed: YesNRC publication: Ye

Separation performance of asymmetric membranes based on PEGDa/PEI semi interpenetrating polymer network in pure and binary gas mixtures of CO2, N2 and CH4

Asymmetric membranes of semi-interpenetrating polymer networks (semi-IPN) were prepared with commercial poly (ether imide) (ULTEM\uae) and poly (ethylene glycol) diacrylate (PEGDa) in 1-methyl-2-pyrrolidinone (NMP). The selectivity and permeance of pure and mixed gases using carbon dioxide (CO2) feed concentrations of 10\u201340% in nitrogen (N2) or methane (CH4) were measured by the constant pressure and variable volume method at an absolute feed pressure of 1.35MPa and 22 \u25e6C. The pure gas selectivity matched the mixed gas selectivity values at different feed concentrations, which indicated absence of plasticization. The fugacity based CO2/N2 selectivity of a semi-IPN with 6% PEGDa solids content reached 50\ub14, which is comparable to the pure gas selectivity of a dense PEGDa film (alpha = 54) and is significantly higher than the dense film selectivity of PEI (alpha = 28). The selectivity for CO2/CH4 mixtures is 43\ub110,comparable to the dense film properties of PEI (alpha = 39) and not the dense film selectivity of PEGDa (alpha = 20). The PEGDa/PEI semi-IPN membranes displayed synergistic properties, where the selectivity approached the higher value of the two materials used in making the semi-IPNs.Peer reviewed: YesNRC publication: Ye