• 한국지하수토양환경학회지:지하수토양환경
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• 제8권3호
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• pp.23-29
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• 2003

Setschenow constants of six alkali and alkaline earth metal-based electrolytes (i.e., NaCl, KCl, CaCl$_2$, K$_2$SO$_4$, Na$_2$SO$_4$, NaClO$_4$) for three polycyclic aromatic hydrocarbons (PAHs) (i.e., naphthalene, pyrene, and perylene) were investigated to evaluate the influence of a variety of inorganic salts on the aqueous solubility of PAHs. Inorganic salts showed a wide range of K$\_$s/ values (L/mol), ranging from 0.1108 (NaClO$_4$) to 0.6680 (Na$_2$SO$_4$) for naphthalene, 0.1071 (NaClO$_4$) to 0.7355 (Na$_2$SO$_4$) for pyrene, and 0.1526 (NaClO$_4$) to 0.8136 (Na$_2$SO$_4$) for perylene. In general, the salting out effect of metal cations decreased in the order of Ca$\^$2+/>Na$\^$+/>K$\^$+/. The effect of SO$_4$$\^$2-/>Cl$\^$-/>ClO4$\^$-/ was observed for anions of inorganic salts. The K$\_$s/ values decreased in the order of perylene>pyrene>naphthalene for K$_2$SO$_4$. However, the order of decreasing salting out effect for NaCl, KCl, CaCl$_2$, and NaClO$_4$ was perylene>naphthalene>pyrene. Hydration free energy of the 1:1 and 2:1 alkali and alkaline earth metal-based inorganic salts solution was observed to have a meaningful correlation with Setschenow constants. Thermodynamic interactions between PAH molecules and salt solution can be of importance in determining the magnitude of salting out effect for PAHs at a given salt solution.

• 분석과학
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• 제8권2호
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• pp.187-193
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• 1995

N,N,N,N-Tetrabenzylethylenediamine 중성운반체를 이용하여 PVC 수소이온 선택성 막전극을 제조하였다. 가소제 종류(phthalates와 sebacate) 및 친지방성 첨가제(NaTPB)에 따른 막전극의 전기저항과 수소이온 감응범위 및 알칼리금속과 알칼리토금속의 존재하에서 방해효과를 조사하였다. 가소제 종류에 의한 전기저항은 영향을 거의 받지 않았고 NaTPB 0.7%의 경우 수소이온에 대한 Nernstian 기울기는 가장 이론값에 근접하였으며, 또한 알칼리금속 및 알칼리토금속에 의한 방해도 적게 받았다. pH-선택성 고분자 막전극은 pH 2~10 범위내에서 선형적이고, 산과 알칼리용액 중에서 안정성 및 재현성 시험 결과 매우 좋게 나타났다.

• Bulletin of the Korean Chemical Society
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• 제25권10호
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• pp.1474-1476
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• 2004

A sodium ion- selective electrode based on dibenzopyridino-18-crown-6 as membrane carrier was successfully prepared. The electrode exhibits a Nernstian response for $Na^+$ ions within the concentration range of $1.0\;{\times}\;10^{-4}-1.0\;{\times}\;10^{-1}$ M. The response time of the sensor is 20 s. The sodium ion-selective electrode exhibited comparatively good selectivities with respect to alkali, alkaline earth and some transition metal ions.

• 공업화학
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• 제16권6호
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• pp.857-864
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• 2005

탈알루미늄 및 알칼리/알칼리토금속 양이온으로 치환한 Y형 및 ZSM-5 제올라이트 촉매를 제조하였다. 전처리 후 Y형 및 ZSM-5 제올라이트의 Si/Al비는 증가하였고, bulk보다는 표면에서의 Si/Al비가 더 큰 것을 알 수 있었다. 전처리에 의해 제조된 Y형 및 ZSM-5 제올라이트의 골격구조 파괴는 주로 탈알루미늄 처리과정에서 Al 이온의 탈리에 의한 것이며, framework이 감소하고 non-framework이 증가하였다. 이러한 현상은 스팀처리 시간이 많아질수록 증가하였고, 양이온으로 치환함에 따라 더욱 심화되었음을 알 수 있었다. NO-TPD 실험결과, 전처리된 Y형 및 ZSM-5 제올라이트는 탈착봉우리가 저온으로 이동하였다. 또한 스팀처리 시간이 많은 촉매물질일수록 탈착온도가 더 낮은 온도로 이동하였다. 촉매의 활성은 치환된 양이온, Si/Al 함량비 및 탈알루미늄으로 변화된 골격구조에서 framework과 non-framework의 비율에 의존하였다.

• Bulletin of the Korean Chemical Society
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• 제29권3호
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• pp.567-570
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• 2008

A new pyrene appended diaza-18-crown-6 ether derivative 1 has been prepared and its fluoroionophoric properties toward transition metal ions were investigated. Compound 1 exhibited a high Hg2+-selectivity over other transition metal ions as well as alkali and alkaline earth metal ions in aqueous acetonitrile solution. The ratiometric analysis of the monomer and excimer emissions of pyrene successfully signals the presence of Hg2+ ions. The detection limit for Hg2+ ions was found to be 3.1 ´ 10-6 M in 50% aqueous acetonitrile solution at pH 8.1. Competition experiments also suggest that the compound could be utilized as a selective and sensitive fluorescent chemosensor for the analysis of micromolar Hg2+ ions in physiological and environmental samples.

• Bulletin of the Korean Chemical Society
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• 제19권2호
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• pp.207-211
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• 1998

Potentiometric characteristics of DOS plasticized PVC-based membranes containing upper-rim calix[4]crown neutral carrier to various metal cations and protonated alkylamines have been examined. Although the calix[4]crown-based membrane electrodes exhibited substantial emf responses to alkali and alkaline earth metal cations, their high detection limits (- log[Cs+]=4.5) and sub-Nernstian response slopes (48 mV/pCs+) to the most selective cation, cesium, indicate that the metal cation complexing ability of calix[4]crown is much weaker than that of macrocyclic crown ethers. However, the calix[4]crown-based membrane electrodes exhibited near-Nernstian response slopes (56 mV/decade for hexylNH3+) with low detection limits (log[hexylNH3+]= - 6.7) to most alkylammonium ions compared to those of blank (DOS plasticized PVC membrane with no ionophore) or crown ether-based membranes. While the selectivity patterns of blank and crown ether-based membranes are determined primarily by the lipophilicity of alkylammonium ions, the membranes doped with calix[4]crown ionophore could effectively discriminate the steric shapes of nonpolar alkyl groups of alkylammonium ions.

• 한국대기환경학회지
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• 제25권4호
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• pp.316-324
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• 2009

Carbon based sorbents for $CO_2$ adsorption were prepared by impregnation with alkali metals ($Li^+$, $K^+$) and alkaline earth metals ($Ca^{2+}$, $Mg^{2+}$). BET surface area of test sorbents was lower than the intrinsic activated carbon. In particular, impregnation of $Ca^{2+}$ or $Mg^{2+}$ resulted in lower surface area of specific adsorption sites than that of $Li^+$ or $K^+$. While the adsorption capacity for $CO_2$ was high in the sorbents containing $Ca^{2+}$ and $Mg^{2+}$, strong interaction with $CO_2$ would cause to drop the capacity after regeneration. The adsorption was found high relatively in the flow with a high concentration of $CO_2$ and in a low flow rate. The adsorption isotherm for the present modified AC sorbents fits well with the Freundlich model.

• Bulletin of the Korean Chemical Society
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• 제32권5호
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• pp.1599-1603
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• 2011

Novel chemosensors based on 2-(2'-hydroxyphenyl)quinoline were prepared and evaluated for sensing metal cations. The photophysical properties of chemosensors 1-3 were examined and their ion-selectivity was evaluated by measuring their fluorescent emission responses to alkali, alkaline earth, and transition metal ions. Chemosensors 1, 2 and 3 show ratiometric and enhanced fluorescence changes with transitional metals that are efficient fluorescence quenchers, especially 3 has a high binding constant with $Hg^{+2}$ in $CH_3CN$.

• Bulletin of the Korean Chemical Society
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• 제29권3호
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• pp.620-622
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• 2008

A new thiacalix[4]arene diamide (TCAm) has been prepared and its electrochemical property and complexation behavior toward various metal ions have been investigated by voltammetry. p-tert-Butylthiacalix[4]arene diamide (TCAm) exhibited selectivity toward Sr2+ ion over alkali, alkaline earth and transition metal ions while conventional calix[4]arene diamides showed selective binding property with Ca2+ ion. This is probably due to the bigger size of thiacalix[4]arene than those of calix[4]arene.

• 방사성폐기물학회지
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• 제19권2호
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• pp.255-266
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• 2021

Solid-state mechanochemical reduction combined with subsequent melting consolidation was suggested as a technical option for the oxide reduction in pyroprocessing. Ni ingot was produced from NiO as a starting material through this technique while Li metal was used as a reducing agent. To determine the technical feasibility of this approach for pyroprocessing, which handles spent nuclear fuels, thermodynamic calculations of the phase stabilities of various metal oxides of U and other fission elements were made when several alkaline and alkali-earth metals were used as reducing agents. This technique is expected to be beneficial, not only for oxide reduction but also for other unit processes involved in pyroprocessing.