Saline water electrolysis is an electrochemical process to produce valued chemicals by applying electric power. Perfluorinated sulfonic acid (PFSA) ionomers have been used as polymer electrolyte membrane (PEM) materials owing to their high sodium ion selectivity and barrier properties. However, sulfonic acid groups in PFSA ionomers are chemically decomposed under a basic catholyte condition, which makes the PEM materials lose their ionic selectivity and Faraday efficiency. In this study, double layered membranes were prepared by anchoring cross-linked hydrocarbon ionomers, as a protection layer to catholyte atmosphere, into the water channels, particularly, located at around the surface of a PFSA membrane. Here, each monomer results in the identical chemical architecture and different free volume content when polymerized.

Saline water electrolysis is a representative electrochemical conversion to produce chlorine gas and sodium hydroxide as major products by applying electric power. Perfluorinated sulfonic acid (PFSA) ionomers have been usually used as polymer electrolyte membrane materials owing to high sodium ion selectivity and strong resistance to acidic compounds (e.g., Cl2, HCl and so on) produced in anode. However, PFSA ionomers have been suffering from chemical degradation occurring when exposed under harsh basic condition in cathode. In this study, double layered chlor-alkali membranes were prepared by anchoring crosslinked hydrocarbon ionomer via radical polymerization technique in water channels located in a surface layer of PFSA ionomer membranes and electrochemically evaluated.

The Chlor-alkali (CA) membrane cell is a major electrolysis system to produce valued chemicals such as chlorine gas and sodium hydroxide. The CA membrane process has been attracted in the industries, since it has relatively low energy consumption when compared with other CA processes. The key component in CA process is perfluorinated sulfonic acid ionomer membranes, which provide ion-selectivity and barrier properties to produced gases. Unfortunately, there is limited information to determine which factors should be satisfied for CA applications. In this study, the influences of PFSA membranes on CA performances are disclosed. They include ion transport behaviors, gas evolution capability, and chemical/electrochemical resistances under CA operation conditions.

Salined water electrolysis is an electrochemical reaction to produce chlorine gas and sodium hydroxide as major products from salined water. Perfluorinated sulfonic acid (PFSA) ionomers and their derivatives have been usually used as polymeric electrolytes with high sodium ion selectivity and barrier property to chlorine and hydrogen gases. In spite of their industrial importance, there is little information on the relationship of their chemical features and electrochemical performances. In this study, membrane requirements for salined water electrolysis are described and fundamental and electrochemical characteristics of PFSA and hydrocarbon ionomer materials are compared each other. The obtained results are expected to provide membrane material design factors for low energy-consuming salined water electrolysis.

클로알칼리(CA) 멤브레인 셀은 대표적인 염수전해 시스템으로서 가성소다와 염소를 생산하는 염수전기분해 프로세스이다. CA 멤브레인 프로세스는 타 공정에 비해 낮은 에너지 소모량을 가져 CA산업에서 가장 선호되는 공정이다. CA프 로세스에 사용되는 과불소계 술폰화 이오노머막은 CA프로세스의 핵심구성 요소이며, 양이온을 선택적으로 이동시키는 역할 및 배리어적인 역할을 제공한다. 하지만, CA 구동을 위해 충족되어야 하는 요소들에 대한 정보가 제한적이기 때문에 알맞은 CA분리막 적용을 위한 제품 간의 연구가 필요하다. 본 연구에서는 실제 셀 구동을 바탕으로 하여 상용 고불소계 분리막의 이온전도경향 및 전기화학적 성능 등을 평가하였다.

Salined water electrolysis is an electrochemical reaction to produce chlorine gas and sodium hydroxide as major products from salined water. Perfluorinated sulfonic acid (PFSA) ionomers and their derivatives have been usually used as polymeric electrolytes with high sodium ion selectivity and barrier property to chlorine and hydrogen gases. In spite of their industrial importance, there is little information on the relationship of their chemical features and electrochemical performances. In this study, fundamental characteristics of commercially available PFSA family materials are compared each other. Their electrochemical performances are evaluated in the same salined water electrolysis cell. The obtained results are expected to provide membrane material design factors for low energy-consuming salined water electrolysis.

클로알칼리(CA) 멤브레인법은 이온전도성 고분자전해질을 이용한 염수전기분해공정을 의미하며, 전통적으로는 가성소다와 염소 생산을 목적으로 하고 있다. CA 멤브레인법은 기존 클로알칼리 공정으로 사용되어왔던 수은법 및 격막법에 비해 환경적 유해성이 낮으며, 에너지비용을 상당히 감소시킬 수 있다는 장점을 나타낸다. 본 총설에서는 멤브레인법의 기본개념 및 특징, 핵심기술에 관한 내용을 다루고자 한다. 또한 높은 에너지비용을 갖는 염수전기분해에 대한 에너지 절감효과를 달성하기 위한 시스템 집적화기술, 산소탈분극전극 기술과 이종 기술과의 하이브리드를 통한 고도 CA 시스템기술의 예로서의 이산화탄소 직접전환기술에 대해 논할 것이다. 마지막으로, 멤브레인법에 기반한 국내외 CA 기술동향을 소개할 것이다.

The Chlor-alkali (CA) process is a representative electrolysis system to produce valued chemicals such as chlorine gas and sodium hydroxide. Membrane cell process has been obtaining the largest market shares, because it is free from environmental issues and low chemicals purity. For the CA process, commercially available membrane materials are perfluorinated sulfonic acid ionomers (PFSAs) with high chemical resistance. Unfortunately, there are limited data associated with the relationships between membrane material parameters and CA performances. It prevents the CA membrane development to be difficult. In this study, the influences of PFSA membrane thickness are disclosed, considering their ion transport behaviors, gas evolution capability, and chemical/electrochemical resistances under CA operation conditions.

F. occidentalis causes to decrease the yield of chrysanthemum flower economically because it is the major crop pest injuring the flower directly at flowering period in chrysanthemum artificial houses. The control of it with chemicals is very difficult because the resistance of it to chemicals is so high. F. occidentalis began to occur at early-May and increased rapidly mid-May after in standard chrysanthemum artificial houses, Yesan, Chungcheongnam-do. In case of a farm, the density of it increased continuously in spite of chemical control . The times of chemical control to depress the density of it was 6 or 7th for cultivation period of chrysanthemum. We put the flowering yellow pot-mum already (trap plant attracting F. occidentalis) in standard chrysanthemum PVC-houses and set the yellow sticky cards up at an interval of 5m from trap plant(TP). The more yellow sticky trap near to trap plant, the more F. occidentalis was attracted to yellow sticky trap. TP was more attractive to adult F. occidentalis up to distances of 10m. The numbers of it attracted to yellow sticky traps at different distance from TP was not different significantly when standard chrysanthemum bloomed. We put the TP in standard chrysanthumum PVC-house at an distance of 20m and released the natural enemies (Orius laevigatus) on TP at 3 times, an interval of 7 days. And then we set yellow sticky traps up at an distance of 5m from TP and compared the plot with TP+natural enemy(NE) to the plot without them. The density of F. occidentalis was rather lower at TP+NE plot than the plot without at the formative period of flower bud of standard chrysanthemum. Therefore, The yellow flowering chrysanthemum possesses great value of TP attracting F. occidentalis in chrysanthumum PVC-house up to flowering period of cultivating chrysanthemum, and if it is used with natural enemy and chemicals simultaneously, farmers can minimize the quantity of chemicals used.

A new single cross waxy corn hybrid, 'Mibaekchal' with white kernel was developed by the Maize Experiment Station (MES) of Gangwondo Agricultural Research and Extension Services (GARES) in Hongcheon in 2001. 'Mibaekchal', which has high yield and good gra