• 한국신재생에너지학회:학술대회논문집
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• 2010.06a
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• pp.129.2-129.2
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• 2010

AEM which were used for solid alkaline fuel cell(SAFC) were prepared by photo polymerization in method pore-filling with various quaternary ammonium cationic monomers and crosslinkers without an amination process. Their specific thermal and chemical properties were characterized through various analyses and the physico-chemical properties of the prepared electrolyte membranes such as swelling behavior, ion exchange capacity and ionic conductivity were also investigated in correlation with the electrolyte composition. The polymer electrolyte membranes prepared in this study have a very wide hydroxyl ion conductivity range of 0.01 - 0.45S/cm depending on the composition ratio of the electrolyte monomer and crosslinking agent used for polymerization. However, the hydroxyl ion conductivity of the membranes was relatively higher at the whole cases than those of commercial products such as A201 membrane of Tokuyama. These pore-filling membranes have also excellent properties such as smaller dimensional affects when swollen in solvents, higher mechanical strength, lowest electrolyte crossover through the membranes, and easier preparation process compared of traditional cast membranes. The prepared membranes were then applied to solid alkaline fuel cell and it was found comparable fuel cell performance to A201 membrane of Tokuyama.

• Membrane Journal
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• v.14 no.1
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• pp.53-56
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• 2004

Direct Methanol Fuel Cell (DMFC) is considered as a candidate technology for applications in stationary, transportation as well as electronic power generation purposes. To develop a high performance direct methanol fuel cell(DMFC), a competent electrolyte membrane is needed. The electrolyte membrane should be durable and methanol crossover must be low. One of the approaches to increase the stability of generally used polymer electrolyte membranes such as Nafion against swelling or thermal degradation is to bond it with an inorganic material physically or chemically. In Noritake Company, we have developed a novel method of reinforcing the polymer electrolyte matrix with inorganic fibers. Methanol crossover values measured were significantly lower than the original polymer electrolyte membranes. These fiber reinforced electrolyte membranes (FREM) were used for DMFC study and stable power output values as high 160 mW/$\textrm{cm}^2$ were measured. The details of the characteristics of the membranes as well as I-V data of fuel cell stacks are detailed in the paper.

• 한국신재생에너지학회:학술대회논문집
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• 2009.06a
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• pp.378-378
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• 2009

The ionic liquid-based sulfonated hydrocarbon composite membranes was prepared for use in anhydrous high temperature-polymer electrolyte fuel cells (HT-PEFCs). Ionic liquid behaves like water in the composite membranes under anhydrous condition. However the composite membranes show a low conductivity and high gas permeability as the content of ionic liquid increases due to its high viscosity and content of ionic liquid, respectively. Hence, in order to enhance the proton conductivity and to reduce the gas permeability of the composite membranes with low content of ionic liquids, the acid containing a common ion of ionic liquid was added to the composite membranes. The characterization of composite membranes was carried out using small-angle X-ray scattering (SAXS), thermogravimetric analyzer (TGA) and impedance spectroscopy. As a result, the composite membranes containing acid showed higher proton conductivity than those with no acid under the un-humidified condition due to a decrease in viscosity. In addition, the proton conductivity of composite membranes increased with increasing mole concentration of acid.

• Journal of the Korean Chemical Society
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• v.67 no.2
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• pp.89-98
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• 2023

The cell membrane, also known as the biological membrane, surrounds every living cell. The main components of cell membranes are lipids and therefore called as lipid membranes. These membranes are mainly made up of a two-dimensional lipid bilayer along with integral and peripheral proteins. The complex nature of lipid membranes makes it difficult to study and hence artificial lipid membranes are prepared which mimic the original lipid membranes. These artificial lipid membranes are prepared from phospholipid vesicles (liposomes). The liposomes are formed when self-forming phospholipid bilayer comes in contact with water. Liposomes can be unilamellar or multilamellar vesicles which comprises of phospholipids that can be produced naturally or synthetically. The phospholipids are non-toxic, biodegradable and are readily produced on a large scale. These liposomes are mostly used in the drug delivery systems. This paper offers comprehensive literature with insights on developing basic understanding of lipid membranes from its structure, organization, and phase behavior to its potential use in biomedical applications. The progress in the field of artificial membrane models considering methods of preparation of liposomes for mimicking lipid membranes, interactions between the lipid membranes, and characterizing techniques such as UV-visible, FTIR, Calorimetry and X-ray diffraction are explained in a concise manner.

• 한국신재생에너지학회:학술대회논문집
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• 2009.11a
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• pp.150-153
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• 2009

Anion exchange polymer electrolyte pore-filling membranes consisting of the whole hydrocarbon materials were prepared by photo polymerization with various quaternary ammonium cationic monomers and characterized on the properties for applying to solid alkali fuel cell (SAFC). Hydrocarbon porous substrates such as polyethylene were used for the preparation of the pore-filling membranes. The hydroxyl ion conductivity of the polymer electrolyte membranes prepared in this research was dependent on the composition ratio of an electrolyte monomer and crosslinking agents used for polymerization. Furthermore, these pore-filling membranes have commonly excellent properties such as smaller dimensional affects when swollen in solvents, higher mechanical strength, lower fuel crossover through the membranes, and easier preparation process than those of traditional cast membranes.

• Journal of environmental and Sanitary engineering
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• v.12 no.1
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• pp.77-83
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• 1997

An experimental research was conducted in order to study the treatment of waste reuse system using the membrane. Cell tester which supplied by Amicon was used to compare the fluxes of various membranes. Specially investigated items in the experiment were carried out by using 5 species of microfiltration membranes as to various MLSS concentrations. From the results, it is recognized from the cell test that 0.2 $\mu $m pore-sized membrane have the most effective performance at 2000mg/L of MLSS, and physical properties of membranes such as strength, deflection, elongation, structure of pore are more important than chemical properties in microfiltration membrane.

• 한국신재생에너지학회:학술대회논문집
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• 2009.06a
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• pp.278-281
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• 2009

Proton exchange membrane is the key material for proton exchange membrane fuel cells (PEMFC). Currently widely-used perfluorosulfonic acid membranes have some disadvantages, such as low thermal stability, easy swelling, excessive crossover of methanol and high price etc. Other membranes, including sulfonated polymer, radiation grafted membranes, organic-inorganic hybrids and acid-base blends, do not satisfy the criteria for PEMFC, which set a barrier to the development and commercialization of PEMFC. Pore-filling type proton exchange membrane is a new proton exchange membrane, which is formed by filling porous substrate with electrolytes. Compared with traditional perfluorosulfonic acid membranes, pore-filling type proton exchange membranes have many advantages, such as non- swelling, low methanol permeation, high proton conductivity, low cost and a wide range of materials to choose. In this research, preparation methodology of pore-filling membranes by particularly using all hydrocarbon polymers and fuel cell performances with the membranes are evaluated.

• Macromolecular Research
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• v.15 no.4
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• pp.379-384
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• 2007

Sulfonation of polyetheretherketones (PEEK) was carried out in order to fabricate commercial perfluorosulfonic acid membrane alternatives, which were characterized in terms of their ion exchange capacity, ionic conductivity, water swelling, methanol crossover and electrochemical performance in their direct application as a methanol fuel cell. A high ion exchange capacity, 1.88, was achieved with a sulfonation reaction time of 8 h, with a significantly low methanol crossover low compared to that of Nafion. However, the morphological stability was found to deteriorate for membranes with sulfonation reaction times exceeding 8 h. Electrochemical cell tests suggested that the fabrication parameters of the membrane electrode assembly based on the sulfonated PEEK membranes should be optimized with respect to the physicochemical properties of the newly prepared membranes.

• Korean Journal of Materials Research
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• v.21 no.2
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• pp.125-132
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• 2011

Fibrous chitosan membranes were fabricated as a substrate for skin applications using an electro-spinning process with different solvents and varying concentrations. Scanning electron microscopy (SEM) images confirmed that the formation of the chitosan fibrous membrane in trifluoroacetic acid was better than that in acetic acid. Fourier transform infrared spectroscopy showed that the chitosan fibers were cross-linked with glutaraldehyde, and that the cytotoxicity of the aldehyde groups was reduced by glycine and washing by NaOH and DI water. Chitosan cross-linked fibrous membranes were insoluble in water and could be washed thoroughly to wash away glycine and excess NaOH and prevent the infiltration of other water soluble bio-toxic agents using DI water. MTT assay method was employed to test the cytotoxicity of chitosan membranes during fabricating, treating and washing processes. After the dehydration of cell cultured chitosan membranes, cell attachment behavior on the material was evaluated using SEM method. Effect of the treatment processes on the biocompatibility of the chitosan membranes was shown by comparing of filopodium and lamellipodium of fibroblast cells on grown washed and unwashed chitosan fibrous membrane. The MTT assay and SEM morphology confirmed that the washed chitosan fibrous membrane increased cell attachment and cell growth, and decreased toxicity compared to results for the unwashed chitosan fibrous membrane.

• Transactions of the Korean hydrogen and new energy society
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• v.28 no.1
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• pp.24-29
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• 2017

A fluorinated polybenzimidazole (FPBI) was synthesized from 3,3-diaminobenzidine (DAB) of tetraamine, 2,2-bis(4-carboxyphenyl)hexafluoropropane of aromatic biscarboxylic acid, and 4,4-sulfonyldibenzoic acid of aromatic biscarboxylic acid in polyphosphoric acid (PPA). A FPBI was easily cast and made into clear films. The structure of condensation polymers and corresponding membranes were analyzed using GPC (gel permeation chromatography), $^1H$-NMR ($^1H$ nuclear magnetic resonance) and FT-IR (fourier transform infrared). TGA (thermogravimetric analysis) analysis showed that the prepared membranes were thermally stable, so that elevated temperature fuel cell operation would be possible. The proton conductivity of the FPBI membranes increased with increasing temperatures in the polymer. A FPBI membrane has a maximum ion conductivity of 45 mS/cm at $90^{\circ}C$ and 100% relative humidity.