渗透蒸发

Abstract(#br)Mixed matrix membranes were prepared by incorporating ZSM-5 zeolite particles into polydimethylsiloxane. A uniform dispersion of the zeolite in the membrane was obtained. The membranes were characterized with scanning electron microscopy, and the effects of zeolite loading on membrane performance were evaluated. It was found that 80\u003cce:hsp sp=\"0.25\"/\u003ewt.% ZSM-5 loading was optimal for selectivity.

Abstract(#br)The objective of this work was to apply dense polymeric membranes for pervaporation of tetrachloroethene from aqueous solution. Three membranes were evaluated: polydimethylsiloxane (PDMS-PV1 and PDMS-PV2) membranes, and a PDMS with ZSM-5 zeolite filled (PERVAP-1070) membrane. The effect of feed composition on flux and selectivity was also investigated.(#br)Tested membranes showed good properties in the separation of tetrachloroethylene, although better selectivity and enrichment of the permeate was achieved for both PDMS-PV1 and PDMS-PV2 membranes.

Abstract(#br)Crosslinked polydimethylsiloxane (PDMS)/ceramic composite membranes were prepared and employed for desulfurization of model gasoline composed of n-octane and thiophene. The structural morphology and thermal stability of the composite membranes were characterized by scanning electron microscope (SEM) and thermogravimetric analysis (TGA). The pervaporation performances of the membranes under various crosslinking agent amounts, feed sulfur content, feed temperature, permeate pressure and feed flow rate were investigated.

ABSTRACT(#br)Pervaporation is an alternative to distillation for recovering ethanol produced by fermentation of grains and biomass. Ethanol-selective mixed matrix membranes of the hydrophobic zeolite ZSM-5 in polydimethylsiloxane (PDMS) have superior performance compared to pure PDMS membranes in pervaporation of clean ethanol/water solutions, but are susceptible to performance reduction when pervaporating fermentation broths. The effects of pervaporating a variety of solutions with 60\u003cce:hsp sp=\"0.25\"/\u003ewt% ZSM-5/PDMS membranes were studied.

Abstract(#br)To improve the affinity between silicalite-1 and polydimethylsiloxane (PDMS), the silicalite-1 particles were modified by a silane coupling agent vinyltriethoxysilane (VTES) and incorporated into polydimethylsiloxane (PDMS) matrix for the preparation of silicalite-1/PDMS hybrid membranes. The modified silicalite-1 particles were examined by XRD, FT-IR and TGA, and the results showed that the silane coupling agent was bonded to the surface of silicalite-1 particles through chemical bonds and the modification did not influence the framework of silicalite-1 crystals.

Abstract(#br)A novel tri-layer composite membrane consisting of the active layer polydimethylsiloxane (PDMS, Sylgard ® 184) and dual support layers of high porosity polyethylene (PE) and high mechanical stiffness perforated metal was investigated for the separation of 1-butanol from aqueous solution by means of pervaporation. The experimental data show that total flux and separation factor are both increased by placing a layer of hydrophobic PE between the PDMS and the metal support. The enhancement is especially obvious at low temperatures.

Abstract(#br)We report characterization of polydimethylsiloxane (PDMS) pervaporation membranes prepared from various conditions using the small-angle neutron scattering (SANS). The PDMS membranes were prepared by cross-linking reactions between hydroxyl terminated polydimethylsiloxane (HPDMS) and polymethylhydrosiloxane with pendant hydride (PHMS). The radius of gyration ( R g ) of HPDMS and PHMS polymer chains determined from the SANS data analysis is found to be similar with the size of about 12\u003cce:hsp sp=\"0.25\"/\u003eÅ.

Abstract(#br)The objective of this work was to investigate the effect of polydimethylsiloxane (PDMS) molecular weights on the pervaporation performance and the confinement behavior of PDMS/ceramic composite membranes for the separation of ethanol from aqueous solutions by pervaporation. PDMS with three different molecular weights was used to prepare PDMS/ceramic composite membranes.

Abstract(#br)The PDMS mixed matrix membranes containing 10-μm sized zeolite were prepared, characterized, and tested on the pervaporation (PV) performance for ethanol–water solutions. We found that the membrane with the zeolite mixed after the PDMS cross-linker addition (“post-addition”) was more effective at removing ethanol from the aqueous mixtures than the pristine PDMS and the PDMS–zeolite membrane made with the zeolite addition prior to the PDMS cross-linker addition.

Abstract(#br)We report a thin-film composite (TFC) membrane fabrication method based on transfer of a pre-formed, cured active layer onto a microporous support. The active layer is cast on a polyvinyl alcohol (PVA) water-soluble film and cured, then the active side of the bilayer is placed against the skin side of the microporous support and the water soluble layer is dissolved. This method can be used with supports of relatively high pore size and porosity, thus reducing mass transfer resistance from the support.