• Membrane Journal
• /
• v.25 no.5
• /
• pp.398-405
• /
• 2015

Facilitated transport is considered to be a possible solution to simultaneously improve permeability and selectivity, which is challenging in normal polymeric membranes based on solution-diffusion transport only. We investigated the effect of adding mesoporous $TiO_2$ ($m-TiO_2$) upon the separation performance of facilitated olefin transport membranes comprising poly(vinyl pyrrolidone), Ag nanoparticles, and 7,7,8,8-tetracyanoquinodimethane as the polymer matrix, olefin carrier, and electron acceptor, respectively. In particular, $m-TiO_2$ was prepared by means of a facile, mass-producible method using poly(vinyl chloride)-g-poly(oxyethylene methacrylate) graft copolymer as the template. The crystal phase of $m-TiO_2$ consisted of an anatase/rutile mixture, of crystallite size approximately 16 nm as determined by X-ray diffraction. The introduction of $m-TiO_2$ increased the membrane diffusivity, thereby increasing the mixed-gas permeance from 1.6 to 16.0 GPU ($1GPU=10^{-6}cm^3$(STP)/($s{\times}cm^2{\times}cmHg$), and slightly decreased the propylene/propane selectivity from 45 to 37. However, both the mixed-gas permeance and selectivity of the membrane containing $m-TiO_2$ rapidly decreased over time, whereas the membrane without $m-TiO_2$ had more stable long-term performance. This difference might be attributed to specific chemical interactions between $TiO_2$ and Ag nanoparticles, causing Ag to lose activity as an olefin carrier.

• Proceedings of the Membrane Society of Korea Conference
• /
• 2002.05a
• /
• pp.106-109
• /
• 2002

No Abstract, See Full-text

• Proceedings of the Korean Nuclear Society Conference
• /
• 2002.10a
• /
• pp.344.3-344
• /
• 2002

• Membrane Journal
• /
• v.26 no.1
• /
• pp.32-37
• /
• 2016

The poly(vinyl alcohol) $(PVA)/AgCF_3SO_3/Al(NO_3)_3$ electrolyte membrane was fabricated to prepare for highly permeable facilitated olefin transport membrane, compared with poly(vinylpyrrolidone) $(PVP)/AgCF_3SO_3/Al(NO_3)_3$ complex. In order to examine the characteristics of $PVA/AgCF_3SO_3/Al(NO_3)_3$ membrane, we used the analytical methods such as SEM, FT-IR, and FT-Raman. The best separation performance was observed at the mole ratio of 1 : 1 : 0.01 $PVA/AgCF_3SO_3/Al(NO_3)_3$ among various $Al(NO_3)_3$ concentration. As a result, the selectivity was 12 and mixed-gas permeability was 3.5 Barrer. Furthermore, the selectivity and permeability remained constant for up to 115 h.

• Membrane Journal
• /
• v.25 no.1
• /
• pp.1-6
• /
• 2015

It was known that the polarlized surface of silver nanoparticles could be interacted revesibly with olefin molecules for facilitated olefin transport. However, it was thought that it can be regenerated by interaction between oxide surface of AgNPs and olefin molecules because the surface of the silver nanoparticles is easily oxidized in the air. In order to investigate the effect of the silver oxide, 5 wt% AgO or $Ag_2O$ was dispersed in polymer PVP solutions and 0.005~0.02% electron acceptor as TCNQ or p-BQ were added to fabricate the separation membrane. After the addition of the electron acceptor, it was expected to improve the polarity on the surface of the silver oxide and the degree of dispersion. The characteristics of the separation membrane were identified by the gas permeance, XPS and TEM.

• Clean Technology
• /
• v.13 no.1 s.36
• /
• pp.79-84
• /
• 2007

Separation of ethylene from ethane and propylene from propane have been conducted using facilitated olefin transport membrane with SPEEK-Ag (Ag substituted sulfonated poly(ether ether ketone)). SPEEK was prepared by the sulfonation of PEEK using cone. $H_2SO_4$ and the reaction time affected the degree of sulfonation (DS) of the resulting SPEEK. SPEEK-Ag composite membrane was formed by soaking SPEEK in the polyester support into the Ag salt solution. With increasing the concentration of SPEEK in MeOH, the thickness of SPEEK on the polyester increased. The selectivity and the flux of SPEEK-Ag membrane for the separation of ethylene/ethane and propylene/propane were changed by the thickness of SPEEK layer on the top of polyester support. The anion of silver salt also affects the membrane performance.

• Membrane Journal
• /
• v.24 no.6
• /
• pp.417-422
• /
• 2014

The poly(ethylene oxide) (PEO)/Ag Nanoparticles (NPs)/7,7,8,8-Tetracyanoquinodimethane (TCNQ) membrane was fabricated to obtain highly permeable facilitated olefin transport nanocomposite membrane, compared with PEO/Ag NPs/p-Benzoquinone (p-BQ) membrane. Polymer matrix, PEO and silver nanoparticle precursor $AgBF_4$ were fixed at 1 : 0.4 mole ratio and electron acceptor TCNQ content was controlled variously. And the best olefin separation performance was obtained at 1/0.4/0.004 mole ratio, and long-term separation performance was measured at this ratio. As a result, mixed-gas permeance decreased from 23 to 6 GPU, and selectivity decreased from 6 to 2 (propylene/propane) after 32 hours.

• Korean Chemical Engineering Research
• /
• v.46 no.1
• /
• pp.164-169
• /
• 2008

In this study, the facilitated transport membranes, poly (ether ether)ketone (SPEEK)-Ag salts layers on top of polycarbonate supports membrane, were prepared and tested for the separation of propylene/propane. SPEEK was synthesised using PEEK and $H_2SO_4$. Experiments were porformed at room temperature and feed pressures up to 30 psig. The SPEEK-Ag salt membranes showed good selectivity for propane over propylene. With increasing the concentration of SPEEK in MeOH, 5~20 wt%, the thickness of SPEEK membrane on the polycarbonate increased. The selectivity and permeance of SPEKK-Ag membrane for propylene/propane were changed by membrane thickness and concentration of Ag salts.

• Clean Technology
• /
• v.10 no.3
• /
• pp.169-176
• /
• 2004

Sulfonated ionomer membranes, sulfonated poly(ether ether)ketone (SPEEK)-$AgNO_3$, were prepared and tested for separation of the isoprene/n-pentane mixtures. The facilitated transport membranes showed good selectivity and permeance of isoprene over n-pentane and long-term stability. Depending on various reaction conditions, the degree of sulfonation (DS) of SPEEK was measured by 1H NMR spectroscopy and the performance of the membranes was affected by the DS of SPEEK as a whole. As the DS of SPEEK was increased, the selectivity of isoprene over n-pentane increased and eventually reached a maximum selectivity of 850 ~ 900 and the stability of that was continued more than 100 h.

• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
• /
• v.20 no.4
• /
• pp.455-468
• /
• 2022

Colloid Formation and Migration (CFM) project is being carried out within the Grimsel Test Site (GTS) Phase Ⅵ. Since 2008, the Korea Atomic Energy Research Institute (KAERI) has joined CFM to investigate the behavior of colloid-facilitated radionuclide transport in a generic Underground Research Laboratory (URL). The CFM project includes a long-term in-situ test (LIT) and an in-rock bentonite erosion test (i-BET) to assess the in-situ colloid-facilitated radionuclide transport through the bentonite erosion in the natural flow field. In the LIT experiment, radionuclide-containing compacted bentonite was equipped with a triple-packer system and then positioned at the borehole in the shear zone. It was observed that colloid transport was limited owing to the low swelling pressure and low hydraulic conductivity. Therefore, a postmortem analysis is being conducted to estimate the partial migration and diffusion of radionuclides. The i-BET experiment, that focuses more on bentonite erosion, was newly designed to assess colloid formation in another flow field. The i-BET experiment started with the placement of compacted bentonite rings in the double-packer system, and the hydraulic parameters and bentonite erosion have been monitored since December 2018.