• 대한화학회지
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• 제52권3호
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• pp.281-294
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• 2008

Potintiodynamic 분광작용과 임피던스 기술을 이용하여 요드화 이온으로 Azadirachta Indica 엑스가 존재하는 0.5 M HCI용액 속의 Al 에 대한 부식 방지 작용을 상승시켰다. 이는 0.5 M HCI 용액에서 AZI 엑스가 Al의 부식을 방지함을 발견하였다. AZI 엑스 농도가 24% v/v이전에는 농도가 커짐에 따라 방지효율도 따라서 커진다. 하지만 AZI 엑스 농도가 더 커지면 Inh. %는 오히려 작아진다. 요드화 이온의 증가는 방지효율을 상당한 양으로 강화시킨다. 요드화 이온이 혼합적으로 존재할 때 Inh. %값은 증가한다. 이는 낮은 AZI 엑스 농도에서 AZI 엑스는 joint adsorption을 통하여 insoluble complex을 형성한다. 하지만 높은 AZI 엑스 농도에서는 요드화 이온과 형성한 complex사이에 competitive adsorption이 나타나 낮은 Inh. %를 초래한다. At all studied요드화 이온의 농도에서 요드화 이온과 AZI 엑스가 동시에 존재할 때의 Inh. %값은 AZI 엑스만 존재할 때보다 감소된다. Synergism parameter Sq는 표면 Coverage 값으로 계산된다. 이 Parameter는 AZI 엑스경우 unity 보다 더 큼을 알 수 있다. 이는 요드화 이온의 증가로 인하여 방지효율이 강화 되였음을 제시한다.

• Bulletin of the Korean Chemical Society
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• 제35권3호
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• pp.865-870
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• 2014

Gold nanoparticles (AuNPs) were synthesized by laser (Nd:YAG, ${\lambda}$ = 1064 nm) ablation of a gold target immersed in various aqueous electrolyte solutions (7 mM of LiCl, NaCl, KCl, NaBr, and NaI) as well as in deionized water. The surface plasmon absorption and EDX of AuNPs so produced as well as their TEM images were analyzed to investigate the effects of ambient ions on the growth and aggregation of NPs. The size of AuNPs was reduced by laser ablation in the presence of chloride and bromide ions while it increased drastically when AuNPs were formed in iodide solution. Interestingly, triangular nanoplates were synthesized only in iodide solution. Surface chemistry on AuNPs in various electrolyte solutions was explored to elucidate the role of ions on the size and stability of AuNPs.

• Nuclear Engineering and Technology
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• 제51권4호
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• pp.1041-1046
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• 2019

In terms of long-term safety for radioactive waste disposal, the anionic iodide (I-129) with a long half-life ($1.6{\times}10^6yr$) is of a critical importance because this radionuclide migrates in geological media with limited interactions. Various studies have been performed to retard the iodide migration. Recently, some minerals that are likely generated from waste container corrosion, have been suggested to have a considerable chemical interaction with iodide. In this study, chalcocite and mackinawite were selected as candidate minerals for underground corrosion materials, and an iodide sorption experiment were carried out. The experiment was performed under anoxic and alkaline conditions and the pH effects on the iodide sorption were investigated in the range of pH 8 to 12. The results showed that both minerals demonstrated a noticeable sorption capacity on iodide, and the distribution coefficient ($K_d$) decreased as the pH increased in the experimental condition. In addition, when the alkalinity increased higher than a pH of 12, the sorption capacity of both minerals decreased dramatically, likely due to the competition of hydroxy ions with the iodide. This result confirmed that chalcocite was an especially good sorbing media for iodide under alkaline conditions with a pH value of less than 12.

• 한국표면공학회지
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• 제7권1호
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• pp.5-12
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• 1974

The interaction energy of water molecule over the surfaces of basal planes of silver iodide has been calculated , assuming 1-4-6--12 type potentials between the gas molecule and lattice ions in the silver iodide lattice. The heat of adsorption ranges from 12.25 to 12.75 kcal /mole at low coverage which is around the level of the latent heat of sublimaton of water.

• 대한화학회지
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• 제20권6호
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• pp.486-493
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• 1976

AgI 가루에 PVC를 섞어 Infrared Pellet Presser로 눌러 만든 Pellet을 이용하여 막전극을 만들고 이것을 지시전극으로 사용하여 $Ag^+$의 활동도에 대한 전위를 측정하였다. 이 막전극의 특성을 순수한 AgI pellet와 PVC로 표면을 입힌 AgI pellet을 이용한 두 막전극의 특성과 비교하였다. 이들 막전극의 은이온 활동도에 대한 감응은 은이온의 농도가 $10^{-1}$M에서 $10^{-6}$M 까지의 범위에서 좋은 직선을 보여준다. 그러나 그 중에서도 AgI가루에 PVC를 섞어서 만든 막전극이 Nernstian 기울기에 가장 잘 맞고 견고하고 장시간 사용할 수 있어 가장 우수함을 알 수 있었다. 이 전극은 은이온 이와의 다른 양이온에 대하여는 거의 감응하지 않고 할로겐화이온, 즉$I^-,CI^-,Br^-,CN^-$에 대한 감응도는 $10^{-1}$M에서 $10^{-6}$M까지 직선관계를 유지하였다. 이 전극은 단일 할로겐화이온 뿐 아니라 할로겐화이온의 혼합시료 용액의 전위차 은법적정에 지시전극으로 이용될 수 있음을 알았다.

• Nuclear Engineering and Technology
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• 제46권1호
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• pp.93-100
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• 2014

The paper deals with the application of radio isotopic non-destructive technique in the characterization of two industrial grade anion exchange resins Indion GS-300 and Indion-860. For the characterization of the two resins, $^{131}I$ and $^{82}Br$ were used as tracer isotopes to trace the kinetics of iodide and bromide ion-isotopic exchange reactions. It was observed that the values of specific reaction rate ($min^{-1}$), amount of iodide ion exchanged (mmol), initial rate of iodide ion exchange (mmol/min) and log $K_d$ were calculated as 0.328, 0.577, 0.189 and 19.7 respectively for Indion GS-300 resin, which was higher than the respective values of 0.180, 0.386, 0.070 and 17.0 calculated for Indion-860 resins when measured under identical experimental conditions. Also at a constant temperature of $40.0^{\circ}C$, as the concentration of labeled iodide ion solution increases 0.001 M to 0.004 M, the percentage of iodide ions exchanged increases from 75.16 % to 78.36 % for Indion GS-300 resins, which was higher than the increases from 49.65 % to 52.36 % compared to that obtained for Indion-860 resins. The overall results indicate that under identical experimental conditions, Indion GS-300 resins show superior performance over Indion-860 resins.

• Nuclear Engineering and Technology
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• 제1권2호
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• pp.87-90
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• 1969

Trans-cinnamyl chloride와 bromide의 방사성 Cl$^{-}$, Br$^{-}$ 및 I$^{-}$와의 교환 반응을 아세톤 용액에서 반응속도론적으로 연구하였다. 상대적인 할로겐 이온들의 친핵성과 이탈능을 HSAB 원리를 이용하여 논의하였다.

• Bulletin of the Korean Chemical Society
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• 제5권1호
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• pp.44-49
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• 1984

The ionic association constant (K) of N-methyl pyridinium iodide (NMPI) ion in several ethanol-water mixtures were determined by the combination of UV spectroscopy and conductance measurements using the Shedlovsky function as a correction factor. The measurement of electrical conductance and UV absorption were performed in 95, 90, 80 and 60 volume percentages of ethanol in the solvent mixture at 15, 25, 35 and 45 $({\pm}0.1)^{\circ}C$. The ion size parameter $(r_A+_D-)$ and the dipole moment $({\mu}_A+_D-)$ of NMPI ion were obtained from he linear plots of ln K vs. (1/D) and (D-1)/(2D+1), respectively. These ${\mu}_A+_D-$ values were in good agreement with the values of transition moment calculated from the equation, ${\mu}_{nm}=6.5168{\times}10^{-2}{\times}({\varepsilon}_{max}{\frac{\bar{\nu}_{\frac{1}{2}}}{\bar{\nu}_{max}})^{\frac{1}{2}}$ (Debye) which we have derived. The thermodynamic parameters indicate (1) that the water dipoles have an ordered rearrangement around the dipolar NMPI ions rather than the configuration existing in bulk free waters; and (2) that the equilibrium state between NMPI ion and its component ions are controlled by entropy.

• Bulletin of the Korean Chemical Society
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• 제12권5호
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• pp.490-494
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• 1991

The ${\beta} to {\alpha}$ phase transition in silver iodide is studied with the (N, V, E) and (N, P, T) molecular dynamics (MD) method. In experiments, the phase transition temperature is 420 K. Upon heating of ${\beta}$ form, the iodine ions undergo hcp to bcc transformation and silver ions become mobile. MD simulations for the ${\beta}$ and ${\alpha}$ phases are carried out at several temperatures and the radial distribution functions (rdf) are obtained at those temperatures in the (N, V, E) ensemble. But the phase transition is not found in our calculation. Next the phase transition is studied with the (N, P, T) MD and we find some evidences of phase transition. At 3 Kbars and 2 Kbars the phase transition temperatu re is about 300 K. For 3.55 Kbars, the phase transition is higher (420 K) than the low pressure case. The phase transition temperature is somewhat dependent on the pressure in our calculations.

• Bulletin of the Korean Chemical Society
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• 제27권5호
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• pp.679-686
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• 2006

The positions of $PbI _2$ molecule synthesized into the molecular-dimensioned cavities of $\mid K_6 (Pb _4I_2)(PbI_2) _{0.67}-(H_2O)_2\mid [Si _{12}Al _{12}O _{48}]$-LTA have been determined. A single crystal of $\mid Pb _6\mid [Si _{12}Al _{12}O _{48}]$-LTA, prepared by the dynamic ion-exchange of $\mid Na _{12}\mid [Si _{12}Al _{12}O _{48}]$-LTA with aqueous 0.05 M $Pb _(NO _3)_2$ and washed with deionized water, was placed in a stream of flowing aqueous 0.05 M KI at 294 K for three days. The resulting crystal structure of the product $( \mid K_6 (Pb _4I_2)(PbI_2) _{0.67}(H_2O)_2\mid [Si _{12}Al _{12}O _{48}]$-LTA, a = 12.353(1) $\AA$) was determined at 294 K by single-crystal X-ray diffraction in the space group Pm3 m. It was refined with all measured reflections to the final error index $R_1$ = 0.062 for 623 reflections which $F_o$ > 4$\sigma$($F_o$). 4.67 $Pb ^{2+}$ and six $K^+$ ions per unit cell are found at three crystallographically distinct positions: 3.67 $Pb ^{2+}$ and three $K^+$ ions on the 3-fold axes opposite six-rings in the large cavity, three $K^+$ ions off the plane of the eight-rings, and the remaining one $Pb ^{2+}$ ion lies opposite four-ring in the large cavity. 0.67 $Pb ^{2+}$ ions and 1.34 $I^-$ ions per unit cell are found in the sodalite units, indicating the formation of a $PbI _2$ molecule in 67% of the sodalite units. Each $PbI _2$ (Pb-I = 3.392(7) $\AA$) is held in place by the coordination of its one $Pb ^{2+}$ ion to the zeolite framework (a $Pb ^{2+}$ cation is 0.74 $\AA$ from a six-ring oxygens) and by the coordination of its two $I^-$ ions to $K^+$ ions through six-rings (I-K = 3.63(4) $\AA$). Two additional $I^-$ ions per unit cell are found opposite a four-ring in the large cavity and form $Pb _2K_2I^{5+}$ and $Pb _2K_2I^{3+}$ moieties, respectively, and two water molecules per unit cell are also found on the 3-fold axes in the large cavity.