• Applied Chemistry for Engineering
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• v.26 no.3
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• pp.326-330
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• 2015

Polymeric membranes have been used in various applications and generally applied to the systems prevented from exterior exposure. However, polymer membranes for outdoor usages such as, an air quality monitoring and membrane reservoirs for the selective recovery of useful metals from seawater, have been newly developed. Thus it is required to investigate the properties of the membrane for the outdoor use and also studies of the accelerated UV exposure onto the polymeric membranes are essential to estimate their weatherability. Herein, we report on the thermal and mechanical properties, morphology changes, and color differences of the polysulfone anisotropic membranes and non-woven type polypropylene membranes with the accelerated UV exposure. Results showed that the effect of UV exposure on the membrane depend not only on the polymer used but also on the form of the membrane. This work can provide some of key informations of the membrane for outdoor use.

• Membrane Journal
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• v.21 no.2
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• pp.141-147
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• 2011

The cation exchange membrane using TPA (tungstophosphoric acid) and the block co-polymer of polysulfone and polyphenylenesulfidesulfone was prepared for a separator of all-vanadium redox flow battery. The membrane resistance of the prepared cation exchange membrane in 1mol/L $H_2SO_4$ aqueous solution was measured. The membrane resistance of the prepared Psf-PPSS and Psf-TPA-PPSS cation exchange membrane was about $0.94{\Omega}{\cdot}cm^2$. Electrochemical property of all-vanadium redox flow battery using the prepared cation exchange membrane was measured. The measured charge-discharge cell resistance of V-RFB at 4 A decreased in the order; Nafion117 < Psf-TPA-PPSS < Psf-PPSS. The durability of membrane was earried out by soaking it in $VO_2{^+}$ solution and evaluated by measuring the charge-discharge cell resistance of V-RFB with an increase of soaking time. The prepared Psf-PPSS cation exchange membrane had high durability and Psf-TPA-PPSS cation exchange membrane had almost same durability compared with Nafion117.

• Membrane Journal
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• v.27 no.5
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• pp.449-457
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• 2017

In this study, the 10 stages stacked module was designed by increasing the number of unit cells in the membrane capacitive deionization(MCDI) process. The aminated polysulfone and sulfonated poly(ether ether ketone) were synthesized and coated on porous carbon electrode by casting method. The salt removal efficiency was measured for the 10 stage stacked module under the operation conditions of adsorption voltage and time, desorption voltage and time, flow rate and concentration of feed water, and di-valent solutions including $CaSO_4$, $MgCl_2$ and tap water. Typically, when 100 mg/L of NaCl as the feed was used, the salt removal efficiency was 98.3% at a flow rate of 100 mL/min, the adsorption condition of 1.2 V/3 min and desorption condition of -0.5 V/5 min.

• Membrane Journal
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• v.15 no.3
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• pp.198-205
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• 2005

Double-layered polymer films to assay the radioactive contamination were formulated using polysulfone (PSF) and cerium activated yttrium silicate (CAYS), consisting of a dense support layer and a CAYS-holding top layer prepared via the diffusion-induced phase inversion. As the vapor exposure process was omitted, the CAYS-holding layer showed a typical asymmetric structure, with CAYS being transfixed into the polymer network spread with large macropores. With the increase in vapor exposure time before immersion, morphology of the films transformed from asymmetric to sponge-like structures, with CAYS being localized in cellular structure. The border structure between the two layers reflects the phase inversion behavior of a cast solution during the coagulation. In the radioactive detection, the polymer phase in a film holding a sponge-like structure is so dense that the radionuclides, deposited on the film, could not filter through the phase, consequently resulting in the loss in the detection efficiency of the film.

• Membrane Journal
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• v.2 no.1
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• pp.67-73
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• 1992

The effects of after-treatment condition on the permeability of polysulfone hollow fiber membranes were investigated. It was well known that the permeability of and the rejection of hollow fiber membranes prepared by dry-wet spinning technique was highly affected by spinning conditions such as composition of spinning solution, inner and outer coagulant and spinning height. But these are also governed by after-treatment condition such as drying, hot water treatment and glycerine treatment. Since it was difficult to remove DMAc and NMP in membranes by washing with in cold water and even traces of such solvent affected the reproducibility of the membrane characteristics, the hot water-treatment should be required.

• Journal of the Korea institute for structural maintenance and inspection
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• v.15 no.1
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• pp.263-270
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• 2011

In this study, the performance of Poly-Naphthalene Sulfonate (PNS) type-admixture used widely in South Korea and Polycarboxilic type-admixture(i.e., WF2000) developed in the J company of the domestic, for precast concrete products produced in the factories, was evaluated. With the 20% reduced usage of WF2000 compared to PNS type-admixture, workability was considerably improved due to high water-reducing ratio, accelerating effect of concrete setting and accelerant dispersant action, which the product has, under the high temperature. In addition, the development of initial and long-term strengths of PHC plies was predominant. For WF2000, it is also possible to correspond with the change of original materials and environmental conditions since the control of water-reducing and supporting forces is feasible. Accordingly, it was noted that WF2000 is superior for deterioration of production & workability and bad casting problems in summer and the solution of initial strength reduction problem due to the delay of setting in winter.

• Membrane Journal
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• v.11 no.4
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• pp.179-189
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• 2001

Effect of ozonation on permeate flux was studied by using polysulfone ultrafiltration membrane. The filtration was first carried out by permeating phenol solutions under 3$kg_{f}$/$cm^2$ until steady-state flux was obtained. Then, the ozone of concentration range between 10 and 45 mg/1.min was ozonated in water for reducing the fouling on the UF membrane. Treatment of chemical wastewater by combined ozone and membrane filtration methods was also investigated for the final purpose. The Fenton method assisted by chemical coagulation was employed as a prtreatment method and found to be highly efficient in removing a large amount of organic compounds. And it was found that the ozonation made the permeate flux enhance in the phenol solution and phenolic-chemical wastewaster by 10% and oxidation by ozone and hydrogen peroxide was more effective. Evidence was presented that TMP decreased in more ozone concentrated water and it was found that the ozone-mediated membrane would have a limited role to prevent the membrane fouling rather than to eliminate fully.

• Membrane Journal
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• v.19 no.2
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• pp.129-135
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• 2009

The cation exchange membrane using the block co-polymer of polysulfone and polyphenylenesulfidesulfone was prepared for a separator of all-vanadium redox flow battery. The membrane property of the prepared cation exchange membrane was measured. The thermal stability of the prepared cation exchange analyzed by TG showed a more stable than that of Nafion117. The lowest measured membrane resistance, equilibrated in 1mol/L $H_2SO_4$ aqueous solution, $0.96{\cdot}cm^2$ at 3 cc of CSA (chlorosulfuricacid) which was introduction agent of ion exchange group. Electrochemical property of all-vanadium redox flow battery using the prepared cation exchange membrane was measured. Electromotive force in 100% of state of charge was 1.4 V which was that of all-vanadium redox flow battery, and cell resistance in charge and discharge at each state of charge had a low value compared with that of all-vanadium redox flow battery using Nafion117.

• Membrane Journal
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• v.31 no.4
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• pp.241-252
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• 2021

Rapid industrialization with growing population leads to environmental water pollution. Demand in generation of clean water from waste water is ever increasing by scarcity of rain water due to change in weather pattern. Colorimetric detection of heavy metal present in clean water is very simple and effective technique. In this review membrane based colorimetric detection of mercury (II) ions are discussed in details. Membrane such as cellulose, polycaprolactone, chitosan, polysulfone etc., are used as support for metal ion detection. Nanofiber based materials have wide range of applications in energy, environment and biomedical research. Membranes made up of nanofiber consist up plenty of functional groups available in the polymer along with large surface area and high porosity. As a result, it is easy for surface modification and grafting of ligand on the fiber surface enhanced nanoparticles attachment.

• Membrane Journal
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• v.32 no.1
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• pp.13-22
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• 2022

Ever increasing global energy demand gives rise to uncontrollable environmental pollution. Demand on fossil fuel and consequent carbon emission leads to global warming and climate change. Nuclear energy is an alternative source to generate clean energy but mining of nuclear fuel is associated with harmful chemicals. Mining of valuable minerals from sea water by membrane separation process is a cost effective along with environmental friendly process. Separation and adsorption based mining of valuable minerals from sea water are another efficient process. Recovery of actinides from rare earth elements are very challenging and expensive process. Pressure driven membrane separation process is economically more viable along with environmental process. In this review membrane separation process are based on polyether sulfone, polyamide, polyimide, polyamidoxine and hybrid membranes. In case of adsorption process, mainly amidoxime kind of adsorbent are discussed.