• 전기화학회지
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• 제16권4호
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• pp.204-210
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• 2013

Thin pore-filled cation and anion-exchange membranes (PFCEM and PFAEMs, $t_m=25-30{\mu}m$) were prepared using a porous polymeric substrate for efficient all-vanadium redox flow battery (VRB). The electrochemical and charge-discharge performances of the membranes have been systematically investigated and compared with those of commercially available ion-exchange membranes. The pore-filled membranes were shown to have higher permselectivity as well as lower electrical resistances than those of the commercial membranes. In addition, the VRBs employing the pore-filled membranes exhibited the respectable charge-discharge performances, showing the energy efficiencies (EE) of 82.4% and 84.9% for the PFCEM and PFAEM, respectively (cf. EE = 87.2% for Nafion 1135). The results demonstrated that the pore-filled ion-exchange membranes could be successfully used in VRBs as an efficient separator by replacing expensive Nafion membrane.

• 한국세라믹학회지
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• 제20권3호
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• pp.205-210
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• 1983

The determination of charge density and charge distribution in montmorillonite are discussed. The method is based on cation exchange of the inorganic interlayer cations against decylammonium ion and molecular intercalation of n-alcanol. The results obtained from Yougil-bentonite show that charge density of 0.37 per unit formula and cation exchange capacity of 102.5 meq/100g.

• 한국실내디자인학회논문집
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• 제19권3호
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• pp.3-12
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• 2010

This study mainly focused on the intergenerational exchange as a plan to revitalize the social participation of the elderly. The purpose of the study is to propose a plan for revitalizing future intergenerational exchange through the present condition analysis in the aspects of activity, space and consciousness for the elderly-centered intergenerational exchange. The study scope is the local welfare level, broad sense of exchange for the aged, children, youths and local residents, and the study objects are the personnel in charge of welfare policy and the staff in charge of operating general social welfare centers and the users of the facilities users. A survey questionnaire type research was sent through post mail to 278 social welfare centers, and 384 government offices within the jurisdictions. Among them, the responses were collected from 22 general social welfare centers and 26 offices within the jurisdictions. A proposal of a plan to revitalize intergenerational exchange that needs to be implemented in future based on the consideration of the present condition and characteristics of the intergenerational exchange of general social welfare center.

• Journal of Astronomy and Space Sciences
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• 제21권4호
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• pp.343-350
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• 2004

수소와의 충돌에 의한 전하교환은 천체플라즈마의 물리적 특성에 매우 중요한 영향을 미친다. 이 논문에서는 탄소, 질소 및 산소에 대해 전하교환(charge exchange)을 고려하여 약 1,000--80,000K의 온도에서의 충돌이온화평형(collisional ionization equilibrium)상태를 연구하였다. 온도에 따른 이온함량비(ionic abundance fraction)를 기존의 전하교환을 고려하지 않은 경우와 비교하였다. 이 논문에서 계산된 이온함량비는 충돌이온화평형상태의 중온성간물질(warm interstellar medium, $T{\sim}10^4K$)의 분광학적인 특성을 이해하는데 사용될 수 있다. 또한, 산소의 이온화정도(degree of ionization)와 수소의 이온화정도의 비율이 충돌이온화가 중요하지 않은 경우에 잘 알려진 값과 많은 차이가 있음을 발견하였다. 이 차이는 중온성간물질에서의 충돌이온화에 대한 연구가 필요함을 의미한다.

• Korean Membrane Journal
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• 제7권1호
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• pp.67-70
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• 2005

It is well known as the role of ion exchange membrane with functional group in membrane matrix. Recently, we were reported that the charged mosaic membrane within parallel array of negative and positive charge groups. In this study we are reported the properties for the various transport coefficients of metal and heavy metal ions across charged mosaic membrane based on non-equilibrium thermodynamics is not based on equilibrium state.

• 한국산학기술학회논문지
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• 제3권3호
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• pp.194-197
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• 2002

이온교환은 액체상 이온과 고체상 이온간의 화학반응이며 연수 및 탈염공정, 특정물질의 제거 및 회수, 토양을 통한 이온성 물질의 이동에서 널리 이용되고 있다. 이온 선택도는 원자가가 높을수록, 수화반경이 작을수록 증가한다. 본 연구는 평형 이온교환에서 결정된 이온 선택도가 칼럼 이온교환에 적용되는 가를 조사하였다. 음이온 교환수지에 대한 이온 선택도 순서는 OH/sup -/ < F/sup -/ < HCO/sup -/ < Cl/sup -/ < Br/sup -/ ≤ NO₃/sup -/ < SO₄/sup 2-/ 이였으며, 음이온 칼럼교환에서도 동일하였다. 또한 바탕 양이온의 전하가 낮을수록 이온교환이 빠르게 진행됨을 알 수 있었다.

• 멤브레인
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• 제19권2호
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• pp.129-135
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• 2009

바나듐 레독스-흐름 전지용 격막으로 사용하기 위해 폴리설폰(Psf)에 폴리페닐렌설파이드설폰(PPSS)을 블록 공중합 시킨 폴리머를 사용하여 양이온교환막을 제작하여, 막 특성을 평가하였다. 제작한 양이온교환막은 Nafion117보다 열적 안정성이 뛰어나다는 것을 TG분석을 통해 알 수 있었고, 1몰 황산용액에서의 막 저항은 3 cc의 CSA를 도입하였을 때 $0.96{\Omeg}{\cdot}cm^2$로 제일 작은 저항 값을 나타냈다. 제작한 양이온교환막의 바나듐 레독스-흐름 전지에서의 전기화학적 특성에 대해 평가하였다. 제작한 양이온교환막을 사용한 바나듐 레독스-흐름 전지의 100% 충전상태에서의 기전력은 바나듐 레독스-흐름 전지의 기전력 값인 1.4V를 나타냈으며, 각 충전상태에서의 충 방전 셀 저항은 Nafion117을 사용한 전지의 값보다 작은 값을 나타냈다.

• Nuclear Engineering and Technology
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• 제23권4호
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• pp.420-425
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• 1991

SNU 1.5-MV 직렬형 반데그라프 가속기의 헬륨음이온원으로서 Rb 전하교환기를 제작하였다. 교환기의 최적운전조건을 결정하기 위해 특성실험을 수행하였다. Duoplasmatron 이온원에서 인출된 1~10 keV 에너지의 첼륨양이온빔을 Rb 증기속에 통과시킴으로써 2 단계 전하교환반응, 즉 $He^{+}\;+\;Rb\;{\rightarrow}\;He^{\circ\ast}\;+\;Rb^{+}\;과\;He^{\circ\ast}\;+\;Rb\;{\rightarrow}\;He^{-}\;+\;Rb^{+}$에 의해 헬륨음이온을 얻었다 실험결과로부터 헬륨음이온의 최대생성률이 헬륨양이온에너지가 7 keV일때 얻어짐을 알 수 있었다. Oven과 Canal의 최적온도는 각각 $370^{\circ}C{\;}와\;95^{\circ}C$로 결정되었다. 최적동작조건하에서 최대 헬륨음이온 생성률은 $2.42\pm002\;%$이었다. 본 전하교환기는 헬륨음이온생성에 효과적인 장치임이 입증되었다.

• Journal of Photoscience
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• 제6권3호
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• pp.91-96
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• 1999

Zeolites and microporouos materials continue to attract attention as novel hosts for photochemical reactions. Zeolities are attractive because of their ability to selectivity exchange and incorporate species within the void spaces and interconnecting channels, providing a spatial arrangement of molecules. Our research has primarily focused on intrazeolitic electron transfer from excited Ru(bpy)32+ in supercages of zeolite Y to a series of bipyridinium ions. In the Ru(bpy)32+ viologen-zeolite Y samples, the slowing of the back electron transfer from the bipyridinium radical cation to Ru(bpy)32+ allows for charge propagation via self exchange between diquat molecules. This provides an opportunity for permanent charge separation. When the migrating charge on the diquat radical within the zeolite reaches the surface, it can be transferred to a neutral viologen (PVS) in solution, resulting in permanent charge separation. The advantage of long-lived charge separation can be exploited for useful chemistry if suitable catablysts can be assembled on the zeolities. We have studied Ru(bpy)2 as water oxdiation catalysts. We have demonstrated that synthesis of RuO2 fibers on a zeolite via thermal decomposition of Ru3(CO)12 leads to the most active water decomposition catalyst reported to date. Because of the extensive interest of photochemical water reduction to H2, much is known about catalytic systems usin gone electron catalyst, and even more importantly, that no reaction of viologen occurred with H2 over this catalyst. The present challenge is to incorporate all these elements of the system into an architecture and we are examining zeolite membranes for this purpose.

• 한국세라믹학회지
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• 제22권6호
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• pp.53-57
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• 1985

Korean montmorillonite from Youngil district was characterized by Alkylammonium derivatives. This method was very sensitive to the basal plane spacing d and the charge in the layer charge. The result include the values of average layer charge, charge distribution, equivalent area. interlayer cationic exchange capacity (C, E, C) and total C. E. C.