• Journal of the Korean Chemical Society
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• v.28 no.2
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• pp.86-94
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• 1984

The single crystal ion-selective electrode,$ {\beta}-Ag_3SI/PVC-THF $membrane electrode has showed a linear potential response to the activities of iodide ion (10-1${\sim}$10-7M). The $ {\beta}-Ag_3SI$ membrane electrode was compared with AgI/PVC-THF membrane and copper metal plate membrane electrodes. In order to measure the selectivity coefficient of the electrodes toward $Cl^-$ and $Br^-$, the separation and mixed solution method were employed. The potential-time curve was obtained by the usual immersion technique and pH effect was also examined. The orders of selectivity for $Br^-$, $Cl^-$ and stability of response time are ${\beta}-Ag_3SI/PVC-THF $membrane > AgI/PVC-THF membrane > copper metal plate membrane. These electrodes could be used as indicating electrodes in the potentiometric titration of a single halide and mixed halides with the standard solution of silver nitrate.

• Proceedings of the Membrane Society of Korea Conference
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• 1998.04a
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• pp.97-98
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• 1998

1. Introduction : Polypropylene(PP) membrane is widely used in the field of microfiltration and ultrafiltration. However, the hydrophobicity of PP causes the adsorption of hydrophobic and amphoteric solutes in the feed. Surface modification techniques of membrane through the treatment of hydrophilizing agents, coating of hydrophilic compounds, UV, plasma and high energy irradiation, etc. can have a great effect on propensities to prevent the protein from staining membranes. Among them, the modification to hydophilize membrane surface using UV is very simple and effective. Recently many studies for more effective surface modification have been conducted. Iwata et al. prepared membranes by grafting polyethylene glycol diacrylate macromer(PEGDA) onto polysulfone with plasma using a glow discharge reactor which prevent the oil from staining the membrane. The primary mechanism contributing to the membranes is preventing the oil from directly contacting the surface of the membrane as the PEGDA chains dissolved into emulsion. To evaluate their feasibility for use as a anti-fouling separation membrane, we prepared hydrophilic membranes by UV irradiation method and investigated their characteristics.

• Korean Chemical Engineering Research
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• v.60 no.2
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• pp.289-294
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• 2022

Oil contained in domestic and industrial wastewater or marine spilled oil gives rise to severe environmental pollution issues such as water pollution and ecosystem destruction. The membrane filtration method as one of representative oil/water separation strategies has technological challenges such as membrane fouling and low separation rate. In this work, we devise a 3D-printed microhydrocyclone for oil/water separation by utilizing a digital lighting processing-based 3D printer. We demonstrate that the 3D-printed microhydrocyclone can effectively separate oil and water phases from oil-in-water emulsion.

• Journal of the Korea Organic Resources Recycling Association
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• v.22 no.3
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• pp.23-32
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• 2014

Recently, it is increase in the processing of organic waste using anaerobic digestion. Therefore, the studies on the processing method for increasing the anaerobic digestion waste water. But it is very difficult to solid-liquid separation, because the characteristics of anaerobic digestion waste water. So this study evaluate solid-liquid separation efficiency of anaerobic digestion sludge using CST(Capillary Suction Time), TTF(Time to Filter). To address this problem, a membrane filter press of the lab scale was produced and the anaerobic digestion wastewater was applied to it. Polymer coagulants were found to be most suitable 7192PLUS and 1T60, It is necessary to minimum injection concentration is 7192PLUS (200 mg/L), 1T60 (100 mg/L). To evaluate dehydration efficiency, it was measured the moisture content of the dehydrated cake and suspended solids of decanted water. As a result, showed that a high removal efficiency of 97.4% when the solid-liquid separation using the membrane filter press. And the moisture content of the dehydrated cake was less than 65%.

• Membrane Journal
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• v.23 no.4
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• pp.278-282
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• 2013

Zeolitic imidazolate frameworks (ZIFs) have been the focus of interest for their physical and chemical properties, especially, for their extraordinary gas separation properties. In this study, a novel and efficient method for the fabrication of continuous ZIF-7 film on ${\alpha}$-alumina substrate has been investigated. The electrospray deposition method was tried for the first time to prepare ZIF films directly without the necessity of prior substrate seeding. It has the advantage of depositing thin ZIF-7 films directly on the ${\alpha}$-alumina substrate by electrospraying the precursor solution. The ZIF-7 films have been characterized through XRD, FE-SEM, and single gas permeation tests.

• Korean Chemical Engineering Research
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• v.43 no.1
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• pp.16-20
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• 2005

Porous polypropylene membranes were prepared by a thermally induced phase separation method in super-critical $CO_2$, where polypropylene and Camphene were used as raw materials. The porosity of polypropylene membranes with 10 wt% polypropylene concentration was 78, 80, 73% by using methanol, ethanol, and n-buthanol as an analytical solvent, respectively. The tensile strength increased with an increasing polypropylene concentration, where it was $0.17kg_f/mm^2$ at 10 wt% polypropylene concentration. The extraction rate for Camphene increased with time and Camphene was removed 94% in 5 min. It increased with an increasing temperature and was 99% at $45^{\circ}C$, however, decreased with an increasing temperature at higher than $45^{\circ}C$. The extraction rate increased with an increasing pressue up to 150 bar, however, decreased slightly with an increasing pressure over 150 bar. The extraction rate had a relation with the solubility of Camphene in supercritical $CO_2$.

• Membrane Journal
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• v.26 no.6
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• pp.449-457
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• 2016

In this study, polyvinylidene fluoride (PVDF) membrane with excellent mechanical properties and chemical resistance was prepared and characterized for the application of water treatment. Dibutyl-phthalate (DBP) was used as a diluent for making a membranes through temperature induced phase separation (TIPS) method, and the crystallization temperature, melting point, cloud point and SEM image were observed with different ratio of diluent in polymer/diluent mixture. The crystallization temperature and melting point increased proportionally with the content of polymer, while the cloud point temperature decreased. Finally, it was confirmed that stable membrane could be manufactured at a polymer content of 62 wt% and a temperature $125^{\circ}C$ using the phase diagram of PVDF/DBP mixtures with temperatures.

• Membrane Journal
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• v.13 no.3
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• pp.200-209
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• 2003

Polymer-metal complexed membranes were prepared by solvent evaporation method using ethylcellulose, platinum(II)acetylacetonate, and rhodium(III)acetylacetonate. The various composition of metal salt(0.3-4.0 wt%) were employed to obtain the optimum performance of final membrane. EC-metal complexed membranes were characterized by FTIR and scanning electron microscopy(SEM) to observe the morphology and the performance of oxygen, nitrogen, carbon dioxide, and methane gases was tested. It was shown that the metal salts enhanced the permeability of all gases without decrease of selectivity. However, it was found that Pt had more effects on the permeability of oxygen and nitrogen gases while Rh had more effects on the permeability of carbon dioxide and methane gases. EC-Pt complexed membrane(Pt 1.0 wt%) even showed the enhanced selectivity of oxygen/nitrogen(37%) due to the affinity characteristic of Pt to oxygen.

• Membrane Journal
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• v.16 no.4
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• pp.252-258
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• 2006

A numerical analysis was performed for a separation process of carbon dioxide from a flue gas stream using polyethersulfone hollow fiber membranes. Countercurrent flow governing equations were regarded to be two point boundary-value problem and the nonlinear ordinary differential equation were simultaneously solved using the finite- difference method. A computer program was developed using the Compaq Visual Fortran 6.6 software. The carbon dioxide permeate driving force and the fred gas residence time at the inside of membrane were found to be very important factors affecting the permeation characteristics of carbon dioxide. The carbon dioxide concentration in the permeate and the flow rate of the permeate were found to be slightly larger by a few percent with a countercurrent flow analysis than those with a cocurrent flow analysis.

• Membrane Journal
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• v.31 no.3
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• pp.161-169
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• 2021

As clean water continues to be a demand in this global water crisis, development of separation membrane technology for water purification becomes a necessity. The effectiveness of separation membranes is hindered in the water crisis due to fouling of membranes. To address this problem, the application of patterns on flat membranes via various methods have been recently studied and experimented. Patterned membranes have shown to not only reduce the fouling effects of membranes, but also increase the fluxes depending on the method and materials used. Each application has shown benefits that include, but not limited to, enhanced surface area, higher pure-water permeability, and increased number of filtration cycles. In this review, the effects of patterned membranes against antifouling is summarized and discussed.