气体分离

Abstract(#br)Implementation of try and error method for membrane preparation procedures is a time and cost consuming technique. This study tries to present a novel idea to make membrane preparation procedure heuristic. Applying this method, helps researchers to predict performance of a membrane prior to its preparation . At first, a number of membranes are prepared and characterized. Then, their measured separation properties are used for prediction of performance of a membrane before its preparation.

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)Thin film composite (TFC) membranes for CO 2 /N 2 separation were prepared by interfacial polymerization from N-Methyldiethanolamine (MEDA) and Trimesoyl chloride (TMC) on crosslinked polydimethylsiloxane (PDMS) coating polysulfone (PS) support membrane. The structural properties of TFC membrane surfaces were characterized by scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), and X-ray diffractometer (XRD). The relationships among the skin layer formation conditions, skin layer structure, and membrane separation performance were investigated.

Abstract(#br)Supported carbon membranes have been regarded as more competitive than traditional gas separation materials due to the versatile combination of different pyrolyzable polymers and supports which in turn leads to high separation factors and mechanical stability. In order to determine the extent to which supported carbon membranes are more competitive, the transport mechanism of supported carbon membranes was investigated in the range 32–150 °C and 1–2.5 bar.

Abstract(#br)Polydimethylsiloxane (PDMS) composites with different weight amounts of multi-walled carbon nanotubes (MWCNT) were synthesised as membranes to evaluate their gas separation properties. The selectivity of the membranes was investigated for the separation of H 2 from CH 4 gas species. Membranes with MWCNT concentrations of 1% increased the selectivity to H 2 gas by 94.8%. Furthermore, CH 4 permeation was almost totally blocked through membranes with MWCNT concentrations greater than 5%.

Abstract(#br)Poly(fluoropropylmethylsiloxane) (PTFPMS), which had different properties with polydimethylsiloxane (PDMS) due to C\u003cce:glyph name=\"sbnd\"/\u003eF bond. The limitation for PTFPMS membrane to achieve industrial-scale applications was the forms of membrane modules. Thus, PTSPMS/polyetherimide (PEI) hollow fiber composite membranes have been prepared. Effects of PTFPMS concentration, coating method, selective layer thickness, operating pressure and temperature on the separation performance of the composite membranes have been investigated.

Abstract(#br)Thin film composite (TFC) reverse osmosis (RO) membranes are semipermeable membranes that are utilized in water purification or water desalination systems. Discarding these membranes after end-of-life leads to environmental problems. Reusing old TFC-RO membranes is one way to solve this problem. For this reason, in this study, used TFC-RO membranes were coated with polydimethylsiloxane (PDMS) for CO 2 /N 2 gas separation application. Attenuated total reflectance Fourier transform infrared spectroscopy (ATR-FTIR) was utilized to confirm the crosslinking of coated PDMS.

Abstract(#br)A small quantity of high-value, crude, mono-isotopic silane is a prospective gas for a small-scale, high-recovery, ultra-high membrane purification process. This is an unusual application of gas membrane separation for which we provide a comprehensive analysis of a simple purification model. The goal is to develop direct analytic expressions for estimating the feasibility and efficiency of the method, and guide process design; this is only possible for binary mixtures of silane in the dilute limit which is a somewhat realistic case.

Abstract(#br)Transport properties of silica membranes derived from the oxidative thermolysis of crosslinked polydimethylsiloxane (PDMS) were studied between 35–100\u003cce:hsp sp=\"0.25\"/\u003e°C. Changes in pore morphology and transport properties were investigated for varying thermolysis and crosslinking treatments. Permeation and pressure-decay sorption measurements were made for CO 2 , H 2 , He, O 2 , N 2, and CH 4 . Physisorption data for CO 2 and N 2 were also analyzed to characterize the pore size distributions of these materials.

Abstract(#br)In this study, the extended Resistance-Based (RB) model introduced in the preceding paper, was validated for the prediction of the steady state mass transport of species through various mixed matrix membranes (MMMs) used in pervaporation and gas separation applications.