混合基质膜

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 incorporation of metal-organic frameworks (MOFs) as fillers in polydimethylsiloxane (PDMS) membranes was investigated. Mixed matrix membranes (MMMs) with MOFs [Cu 3 (BTC) 2 ], MIL-47, MIL-53(Al) and ZIF-8 as dispersed phases were synthesized and characterized. The membranes were applied in solvent resistant nanofiltration (SRNF), more in particular in the separation of Rose Bengal (RB) from isopropanol. The membranes showed increased permeance but lower retention compared to unfilled membranes.

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)Gas transport behaviors of oxygen (O 2 ), nitrogen (N 2 ) and propylene (C 3 H 6 ) in polydimethylsiloxane (PDMS) mixed matrix membranes (MMM) containing modified silica (SiO 2 ) nanoparticles are presented. Two surface modified SiO 2 nanoparticles, silica dimethyloctyl silane (Si-DMOS) and silica dimethylphenyl silane (Si-DMPS), were used as fillers. Surface modification was carried out through silanization, which was confirmed via Fourier transform infrared spectroscopy.

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.

Abstract(#br)The diffusion behavior of ethanol solutions in polydimethylsiloxane (PDMS) and zeolite-filled PDMS membranes at 298\u003cce:hsp sp=\"0.25\"/\u003eK was investigated. The partial effective diffusion coefficients of the ethanol and water permeants were determined experimentally using the gravimetric method in conjunction with concentration determination on remaining mixtures. The time-resolved sorption levels of ethanol/water binary mixtures in the membranes were measured and partitioned into individual solvent uptakes.

Abstract(#br)The transport properties of gases in polydimethylsiloxane (PDMS)/zeolite A mixed matrix membranes (MMMs) were determined based on pure gas permeation experiments. MMMs were prepared by incorporating zeolite 4A nanoparticles into a PDMS matrix using a new procedure. The permeation rates of C 3 H 8 , CH 4 , CO 2 , and H 2 were evaluated through a dense homogeneous pure PDMS membrane and PDMS/4A MMMs to assess the viability of these membranes for natural gas sweetening and hydrogen purification. SEM investigations showed good adhesion of the polymer to the zeolite in MMMs.

Abstract(#br)The present study explores the fundamental science of estimating sorption of gases in membranes comprised of inorganic porous fillers within a polymer matrix with a novel semi-empirical correlation. The sorption properties of H 2 , C 3 H 8 , CO 2 and CH 4 were determined in polydimethylsiloxane (PDMS)/zeolite 4A mixed matrix membranes (MMMs) to assess the viability of these membranes for hydrogen purification and natural gas sweetening. Zeolite filling in MMMs results an increase in solubility over neat PDMS membrane.

Abstract(#br)Gas permeability through synthesized polydimethylsiloxane (PDMS)/zeolite 4A mixed matrix membranes (MMMs) were investigated with the aid of artificial neural network (ANN) approach. Kinetic diameter and critical temperature of permeating components (e.g. H 2 , CH 4 , CO 2 and C 3 H 8 ), zeolite content and upstream pressure as input variables and gas permeability as output were inspected. Collected data of the experimental operation was used to ANN training and optimum numbers of hidden layers and neurons were obtained by trial-error method.