• Journal of Hydrogen and New Energy
• /
• v.33 no.1
• /
• pp.19-27
• /
• 2022

A series of QPAE/TiO₂-x (x = 1, 4, 7 and 10 wt%) organic/inorganic composite membranes were prepared as electrolyte membranes for alkaline anion exchange membrane fuel cells by controlling the content of inorganic filler with quaternized poly(arylene ether) (QPAE) random copolymer. Among the prepared QPAE/TiO₂-x organic/inorganic composite membranes, the highest ionic conductivity was 26.6 mS cm^-1 at 30℃ in QPAE/TiO₂-7 composite membrane, which was improvement over the ionic conductivity value of 6.4 mS cm^-1 (at 30℃) of the pristine QPAE membrane. Furthermore, the water uptake, swelling ratio, ionic exchange capacity, and thermal property of QPAE/TiO₂-x composite membranes were improved compared to the pristine QPAE membrane. The results of these studies suggest that the fabricated QPAE/TiO₂-x composite membranes have good prospects for alkaline anion exchange membrane fuel cell applications.

• Bulletin of the Korean Chemical Society
• /
• v.27 no.12
• /
• pp.1985-1988
• /
• 2006

The polymeric membrane electrodes based on urea derivative as an ionophore were prepared and studied for the iodide-ion selective electrode. This membrane exhibits a linear stable response over a wide concentration range ($1.0\;{\times}\;10^{-5}\sim1.0\;{\times}\;10^{-2}$) with a slope of -57.7 mV/decade, a detection limit of log[$I^-$] = -5.63, and a selectivity coefficient for iodide against perchlorate anion (log$K^{pot}_{I^-,j}$ = -1.42). The selectivity series of the membrane gives the follow as $I^-$ > $SCN^-$, $Sal^-$ > $ClO_4^-$ > $NO_3^-$ > $Br^-$ > $NO_2^-$ > $Cl^-$ > $F^-$. The proposed electrode showed good selectivity and response for iodide anion over a wide variety of other anions in pH 5.0 buffer solutions.

• Journal of Electrochemical Science and Technology
• /
• v.8 no.4
• /
• pp.265-273
• /
• 2017

Solid-state alkaline water electrolysis is a promising method for producing hydrogen using renewable energy sources such as wind and solar power. Despite active investigations of component development for anion exchange membrane water electrolysis (AEMWE), understanding of the device performance remains insufficient for the commercialization of AEMWE. The study of assembled AEMWE devices is essential to validate the activity and stability of developed catalysts and electrolyte membranes, as well as the dependence of the performance on the device operating conditions. Herein, we review the development of catalysts and membranes reported by different AEMWE companies such as ACTA S.p.A. and Proton OnSite and device operating conditions that significantly affect the AEMWE performance. For example, $CuCoO_x$ and $LiCoO_2$ have been studied as oxygen evolution catalysts by Acta S.p.A and Proton OnSite, respectively. Anion exchange membranes based on polyethylene and polysulfone are also investigated for use as electrolyte membranes in AEMWE devices. In addition, operation factors, including temperature, electrolyte concentration and acidity, and solution feed methods, are reviewed in terms of their influence on the AEMWE performance. The reaction rate of water splitting generally increases with increase in operating temperature because of the facilitated kinetics and higher ion conductivity. The effect of solution feeding configuration on the AEMWE performance is explained, with a brief discussion on current AEMWE performance and device durability.

• Proceedings of the Membrane Society of Korea Conference
• /
• 2002.05a
• /
• pp.65-68
• /
• 2002

• Membrane Journal
• /
• v.27 no.2
• /
• pp.109-120
• /
• 2017

The reverse electrodialysis (RED) is an energy generation system to convert chemical potential of saline water directly into electric energy via the combination of current derived from a redox couple electrolyte and ionic potential obtained when cation ($Na^+$) and anion ($Cl^-$) pass through cation exchange membrane (CEM) and anion exchange membrane (AEM) into fresh water, respectively. Ion exchange membrane, a key element of RED system, should satisfy requirements such as 1) low swelling behavior, 2) a certain level of ion exchange capacity, 3) high ion conductivity, and 4) high perm-selectivity to achieve high power density. In this paper, research trends and prospects of ionomer materials and ion exchange membranes are dealt with.

• Journal of Applied Biological Chemistry
• /
• v.42 no.2
• /
• pp.85-91
• /
• 1999

The incubation study was conducted under aerobic and anaerobic conditions to study the release of the kinetically labile forms (i. e. chelating ion or anion forms) of Cd, Cu and Zn in sludge-untreated soil ("Control"), sludge 50 and $100dry\;Mg\;ha^{-1}$ treated soils ("Soil-Sludge mixtures"), and sewage sludge ("Sludge"). The chelating ion and anion exchange membranes were embedded into the samples and incubated for 16 weeks under aerobic and anaerobic condition. The total amounts of chelating ion or anionic forms of Cd were too little to be measured during both aerobic and anaerobic incubation. On the other hand, the total amounts of chelating ion or anionic forms of Cu and Zn slightly increased throughout the incubation period under both incubation conditions. For "Control" and "Soil-Sludge mixtures" treatments, the total amounts of Cu and Zn in chelating ion and anion exchange membrane were little difference between aerobic and anaerobic condition, and the total amounts of chelating ion form of Cu and Zn were not different from the those of anionic form of Cu and Zn. However, for "Sludge" treatment, the total amounts of Cu and Zn in anion and chelating ion exchange membrane were greater under aerobic condition than under anaerobic condition, and the total amounts of chelating ion form of Cu and Zn were greater than those of anion form of Cu and Zn under both incubation conditions.

• Membrane Journal
• /
• v.33 no.2
• /
• pp.77-86
• /
• 2023

In this study, pore-filled ion exchange membranes with low membrane resistance and high hydroxide ion conductivity was developed. To improve alkali durability, a porous substrate made of polytetrafluoroethylene was used, and a copolymer was prepared using monomers 2-(dimethyl amino) ethyl methacrylate (DMAEMA) and vinyl benzyl chloride (VBC) for pores. divinyl benzene (DVB) was used as the cross-linker, and ion exchange membranes were prepared for each cross-linking agent content to study the effect of the cross-linker content on DMAEMA-DVB and VBC-DMAEMA-DVB copolymers. As a result, chemical stability is improved by using a PTFE material substrate, and productivity can be increased by enabling fast photo polymerization at a low temperature by using a low-pressure UV lamp. To confirm the physical and chemical stability of the ion exchange membrane required for an anion exchange membrane fuel cell, tensile strength, and alkali resistance tests were conducted. As a result, as the cross-linking degree increased, the tensile strength increased by approximately 40 MPa, and finally, through the silver conductivity and alkali resistance tests, it was confirmed that the alkaline stability increased as the cross-linking agent increased.

• Membrane Journal
• /
• v.24 no.6
• /
• pp.463-471
• /
• 2014

While poly(styrene)-based anion exchange membranes have the advantage like easy and simple manufacturing process, they also possess the disadvantage of poor durability due to their brittleness. Acrylonitrile-butadiene rubber was used here as an additive to make the membranes have improved flexibility and durability. For the preparation of the anion exchange membranes, a PP mesh substrate was immersed into monomer solutions with vinylbenzyl chloride, styrene, divinylbenzene and benzoyl peroxide, then thermally polymerized & crosslinked. The prepared membranes were subsequently post-aminated using trimethylamine to result in $-N+(CH_3)_3$ group-containing composite membranes. Various contents of vinylbenzyl chloride and acrylonitrile-butadiene rubber were investigated to optimize the membrane properties and the prepared membranes were evaluated in terms of water content, ion exchange capacity and electric resistance. It was found that the optimized composite membranes showed higher IEC and lower electric resistance than a commercial anion exchange membrane(AMX) and have excellent flexibility and durability.

• Membrane Journal
• /
• v.32 no.5
• /
• pp.283-291
• /
• 2022

Hydrogen energy has received much attention as a solution to the supply of renewable energy and to respond to climate change. Hydrogen is the most suitable candidate of storing unused electric power in a large-capacity long cycle. Among the technologies for producing hydrogen, water electrolysis is known as an eco-friendly hydrogen production technology that produces hydrogen without carbon dioxide generation by water splitting reaction. Membranes in water electrolysis system physically separate the anode and the cathode, but also prevent mixing of generated hydrogen and oxygen gases and facilitate ion transfer to complete circuit. In particular, the key to next-generation anion exchange membrane that can compensate for the shortcomings of conventional water electrolysis technologies is to develop high performance anion exchange membrane. Many studies are conducted to have high ion conductivity and excellent durability in an alkaline environment simultaneously, and various materials are being searched. In this review, we will discuss the research trends and points to move forward by looking at the research on anion exchange membranes based on commercial polystyrene-b-poly(ethylene-co-butylene)-b-polystyrene (SEBS) block copolymers.

• Journal of the Korean Society of Industry Convergence
• /
• v.12 no.4
• /
• pp.193-202
• /
• 2009

In the preparation of anion charged asymmetric ultrafiltration membranes by the conventional phase inversion method, several variables could be adjusted to control membrane permeations. The anion charged materials and its original polymer have good solubility in N-methyl-2-pyrrolidone. The membranes having a hydrophilic property were less fouled the membrane prepared from the original polymer. The preparation conditions, operation conditions, and hydrophilicity of polymer have played an important role in determining the permeation properties of membranes.