渗透蒸发

Abstract(#br)A new membrane is developed, which is composed of highly crosslinked polydimethylsiloxane as the active layer on a support layer containing polyethersulfone and an appropriate additive (polyvinylpyrrolidone or polyethyleneglycol). The effect of porosity of the support layer on the performance of the fabricated membrane for pervaporative removal of toluene as a representative volatile organic compound from water is then studied. The support layer represents high porosity to improve the permeation rate of the composite membrane while it preserves the reasonable enrichment factor.

Abstract(#br)The separation of organic components has become increasingly important as one of the applications of pervaporation membranes. This interest is due to their application in areas that include the recovery of ethanol from a fermentation broth as a lower-energy-cost alternative to classical separation processes such as distillation. The present work seeks to evaluate the separation of ethanol produced from banana waste (unused fruit and pulp) using pervaporation.

Abstract(#br)Preparation of a high flux poly(dimethylsiloxane) (PDMS) membrane for separation of organics from water by pervaporation has been a challenging task. For this, the membrane should be as thin as possible since the productivity flux is inversely proportional to the membrane thickness. In an attempt to understand the relationship between the membrane structure and flux, the membranes of different thickness varying from about 0.2 to 150\u003cce:hsp sp=\"0.25\"/\u003eμm were prepared and studied.

Abstract(#br)Mesoporous MCM-41 silica spheres were synthesized via modified Stöber method and modified by silylation. The MCM-41 pore structures, surface properties and morphological features before and after modification were examined by XRD, SEM, TEM, FT-IR, TGA, 29 Si CP/MAS NMR and nitrogen adsorption–desorption. The results showed that the obtained MCM-41 silica had ordered mesoporous structure and spherical morphology. After silylation, the surface property of MCM-41 silica changed from hydrophilic to hydrophobic, whereas the MCM-41 framework and morphology were retained.

Abstract(#br)A novel organophilic nano-silica (ONS) filled polydimethylsiloxane (PDMS) composite membrane was prepared and characterized for the pervaporation (PV) of ethanol from water. The sorption and diffusion behaviors of ethanol and water in the composite membranes were investigated. The results showed that with increasing ONS concentration from 0\u003cce:hsp sp=\"0.25\"/\u003ewt.% to 10\u003cce:hsp sp=\"0.25\"/\u003ewt.%, the solubility selectivity and the diffusion selectivity increased from 21.87 to 38.85 and from 1.87 to 6.18, respectively.

Abstract(#br)We have developed novel thin film composite (TFC) membranes on ceramic substrates (referred as ceramic TFC membranes thereafter) for pervaporation dehydration of isopropanol (IPA) by using interfacial polymerization (IP) of m-phenylenediamine (MPD) and trymesoylchoride (TMC) to create ultra-thin polyamide films as selective layers. Prior to IP, a gutter layer of polydopamine (PDA) or polyethyleneimine (PEI) was deposited on α-alumina ceramic surfaces to improve the adhesion of polyamide thin films onto the ceramic.

Abstract(#br)Butanol has potential to become an important renewable transportation fuel and feedstock chemical in the future. However, low yield and high separation costs are the main obstacles in feasible industrial scale biobutanol production by the acetone–butanol–ethanol (ABE) fermentation process. Both problems can be overcome by using pervaporation as the product removal technique. The performance of a polydimethylsiloxane (PDMS) membrane with a support layer of polyacrylonitrile (PAN) was studied for the removal of acetone, butanol and ethanol from dilute aqueous model solutions.

Abstract(#br)A poly(vinylidenefluoride) (PVDF) layer was obtained by casting PVDF/ N -methylpyrrolidone solution on a poly(ethylene terephthalate) non-woven sheet using phase inversion. Polydimethylsiloxane (PDMS) and phenyltrimethoxysilane (PhTMS) were cured on PVDF layer surfaces to obtain composite membranes. Multilayer polyphenylsiloxane (PPhS)/PDMS/PVDF composite membranes were prepared for butanol separation in acetone/butanol/ethanol (ABE).

Abstract(#br)In this paper, polydimethylsiloxane (PDMS) composite membranes that were supported using polyvinylidene fluoride (PVDF) microfiltration membrane were developed for the pervaporation (PV) of dimethyl carbonate (DMC) from a methanol solution. Experimental studies on the solubility and the diffusivity of pure DMC and methanol in the membrane were first measured. Higher DMC uptake indicates that the sorption step is the rate-limiting step in the selective transport through the membrane.