• Journal of Korea Technical Association of The Pulp and Paper Industry
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• v.40 no.5
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• pp.42-46
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• 2008

The papers in preserved books and archives experience aging which was affected by a variety of factors. Thus, the studies concerning impacts of those factors on paper aging are required. In this research, a simulation of a short-time accelerated paper aging was conducted in order to examine the effects of acid and metals (alum, copper (II) sulfate, copper (II) chloride, and iron (III) chloride) on the natural paper aging for a long time. As a result of experiments, it is found that both acid and metals have impacts on paper aging. Alum resulted in the significant decrease of pH, brightness, folding endurance, and viscosity of paper. Both copper (II) chloride and iron (III) chloride also resulted in the decrease of brightness, folding endurance, and viscosity of paper. In more detail, paper aging by iron (III) chloride showed much more significant than that by copper (II) chloride. The paper aging in case of copper (II) sulfate coexisting sulfate ion, where metal absorbed moisture was higher than in case of paper treated only by alum. This result indicated that metal catalyzes paper aging by acid. Based on these results, it was revealed that both alum and metal are the major factors in paper aging. In particular, paper aging was far more accelerated in case when acid and metals existed in paper at the same time.

• Resources Recycling
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• v.2 no.2
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• pp.1-8
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• 1993

This study was carried out in order to define the effective collectors and the opitimum conditions for the removal of iron ion in waste water by flotation method. The results obtained in this study are summarized as follows. Fe(II) and Fe(III) were removed effectively at pH7 and 6 respectively by using sodium lauryl sulfate, an anionic collector. The anionic collector, aeropromotor 845, removed both Fe(II) and Fe(III) effectively in pH ranges of from 5 to 9. The cationic collector, trimetyl dodecyl ammonium chloride, removed both Fe(II) and Fe(III) effectively in pH ranges from 10 to 11 and from 4 to 10, respectively. Therefore, Fe(II) and Fe(III) could be effectively removed by forming the iron hydroxide precipitates by simple pH adjustment of the solutions above precipitation point of ferrous and ferric ion by flotation method. Then, the effective pH regulator and collector were NaOH and $Na_2CO_3$,aeropromotor 845 and trimetyl dodecyl ammonium chloride, respectively.

• Resources Recycling
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• v.17 no.6
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• pp.17-23
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• 2008

In order to simulate the leaching solution of copper sulfide ore in $FeCl_3$ solutions, synthetic solutions with composition of $FeCl_3$-$FeCl_2$-$CuCl_2$-CuCl-NaCl-HCl-$H_2O$ were prepared. The concentration of iron and copper chloride was varied from 0.1 to 1 m in synthetic solutions. The effect of composition on the mixed solution pH and potential at $25^{\circ}C$ was measured. When HCl concentration was constant, the increase of CuCl concentration increased solution pH. The increase of other solutes excluding HCl and CuCl decreased solution pH owing to the increase of the activity coefficient of hydrogen ion. A high CuCl concentration favored the redox equilibrium in the direction of Cu(I), while $FeCl_3$ had the opposite effect.

• Corrosion Science and Technology
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• v.4 no.2
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• pp.45-50
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• 2005

A 3% NaCl solution of 1 $dm^3$ circulated with 1.5 $dm^3/min$ by a pump for 24 h in the presence of magnetic field. An iron plate immersed in a $100cm^3$ of test solution for 24 h. The rest potential and pH on surface fixed after 3 h. Containing 0~120 ppm of Fe(II) ion, the dissolution in the magnetically treated solution rose comparing with that in the non-magnetically treated solution. The dissolution amount reached to maximum at 50 ppm, then fixed in the non-magnetically treated solution. When Fe(II) ion existed in the magnetically treated solution, dissolution accelerated a little. In the non-magnetic treated solution containing 10~125 ppm of Fe(III) ion existed, the dissolution accelerated. The dissolution amounts reached to maximum at 50 ppm, then decreased from maximum value. In the magnetically treated solution, the dissolution amounts reached to minimum until 50 ppm, then increased from minimum value. The dissolution amounts affected larger with increasing of magnetic flux density. Fe(II), Fe(III) ions and magnetic treatment affected to formation of $Fe(OH)_2$ and/or $Fe_3O_4$ films. The magnetically treated effects memorized about one month.

• Journal of Korea Technical Association of The Pulp and Paper Industry
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• v.40 no.3
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• pp.36-41
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• 2008

It is known that ethanolamines play a critical role for deacidification of paper sized by alum-rosin. However, amines also are effective as a chelating agent of metal. The present work was focused on whether amines could scavenge metals and prevent from the aging of paper. Metals such as alum, copper(II) and iron(III) was added to paper, and the paper treated with amines was aged in a thermo-hygrostat for 3-6 days. In the case of paper added to alum, the amines efficiency against paper aging was good in the oder of triethanolamine, diethanolamine and monoethanolamine attributable to the intensity of basicity and steric effect. Even in the case of paper treated with copper(II) chloride, iron(III) chloride, and copper(II) chloride, the significant preservation efficiency was shown by ethanolamine during accelerated aging. This outcome pinpoints the fact that ethanolamine can prevent paper aging not only from acid by neutralizing acid contained in paper but also from metals by producing of complexes with metals. These consequences above convince that ethanolamine makes it possible for mass deacidification for paper which contains acid and metals. Future studies should be conducted concerning whether, in reality, the treatment of its gas mode, in a single or multiple applications, has significant effect on lessening paper aging.

• Journal of the Korean Chemical Society
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• v.17 no.5
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• pp.346-352
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• 1973

The quantitative separations of a mixture containing equal amounts of each cation such as Mn(Ⅱ), Cr(Ⅲ), V(Ⅴ), Cu(Ⅱ), Ni(Ⅱ), Co(Ⅱ), and Fe(Ⅲ) are carried out by the elution through $35cm{\times}3.14cm^2$ column of cation exchange resin, $Dowex 50w{\times}12$. The eluents are a mixture of 0.6 M sodium chloride and 0.1 M sodium tartrate (pH = 2.00 and 4.50) for Fe(Ⅲ), V(Ⅴ), Cu(Ⅱ), Ni(Ⅱ) and Co(Ⅱ), and a mixture of 3 M sodium chloride and 0.1 M sodium tartrate (pH = 4.50) or a mixture of 0.7 M sodium chloride and 0.5 M sodium oxalate (pH = 4.50 and 5.00) for Mn(Ⅱ) and Cr(Ⅲ). The subsidiary cations in a standard iron mixture such as V(Ⅴ), Cu(Ⅱ), Ni(Ⅱ), Mn(Ⅱ) and Cr(Ⅲ) are separated together from the large amount of Fe(Ⅲ) through $15cm{\times}3.14cm^2$ column of the resin, $Dowex 1{\times}8$, by elution with the eluent of 4.0 M hydrochloric acid. A small amount of Fe(Ⅲ), however, is eluted together with Cu(Ⅱ). V(Ⅴ), Ni(Ⅱ), Mn(Ⅱ) and Cr(Ⅲ) eluted together are separated quantitatively through $10cm{\times}3.14cm^2$ column of the resin,$Dowex 50w{\times}12$. Cu (Ⅱ) and a small amount of Fe(Ⅲ) are separated quantitatively through $10cm{\times}3.14cm^2$ column of the resin, $Dowex 50w{\times}12$, by the elution with a mixture of 0.6 M sodium chloride and 0.1 M sodium tartrate (pH = 2.00 and 4.50) as an eluent. By the conditions obtained in the separations of the standard iron mixture, Fe(Ⅲ) and all of the subsidiary cations in steel are quantitatively separated.

• The Journal of the Korean Society for Microbiology
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• v.35 no.1
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• pp.1-8
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• 2000

In order to explore the potential of ascorbic acid supplementation for the prevention and treatment of herpes simplex viral diseases, plaque reduction assays were performed. Ascorbic acid as well as copper chloride/ferric chloride were added to wells containing Vero cells infected with herpes simplex virus type 1 (HSV-1), and the infectivity of HSV-1 was determined. Since copper and iron are major transition metals in human plasma, near the normal human plasma concentrations of them were used for experiments. When Cu(II) and Fe(III) were applied, there were no significant differences between virus control and Cu(II)/Fe(III)-treated groups. But, when appropriate concentrations of ascorbic acid were added to wells, meaningful differences between control and ascorbate-treated groups were found. In the presence of Cu(II)/Fe(III) at $5.8/3.7\;{\mu}M$, 72-h treatment with ascorbate at $50\;{\mu}M$ reduced HSV-1 infections to $10.77%{\pm}4.25%$ (P < 0.001) and $500\;{\mu}M$ did to $3.06%{\pm}1.62%$ (P < 0.001). Moreover, the cytotoxicities for Vero cells at those concentrations were insignificant (P > 0.05). Current recommended dietary allowance (RDA) of ascorbic acid is 60 mg/day, and the oral intake of 60 mg/day of ascorbic acid yields plasma ascorbic acid at 45 to $58\;{\mu}M$ in a healthy adult man. Therefore, the results of this study suggest that the maintenance of appropriate level (more than $50\;{\mu}M$) of ascorbic acid in human plasma by appropriate amount (more than the RDA) of ascorbic acid supplementation may be helpful for the prevention and treatment of diseases caused by HSV -1 in an adult man. In addition, this study also suggests that ascorbic acid may be useful for the prophylaxis of fatal HSV-1 infections in neonates and the prevention of HSV-1 reactivation in immunocompromised hosts.

• Journal of the Korean Chemical Society
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• v.68 no.2
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• pp.82-86
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• 2024

This paper presents the solid-state synthesis of insoluble Prussian blue (Fe₄[Fe(CN)₆]₃·xH₂O, PB) in a ball mill, utilizing the fundamental components of PB. Solid-state synthesis offers several advantages, such as being solvent-free, quantitative, and easily scalable for industrial production. Traditionally, the solid-state synthesis of PB has been limited to the reaction between iron(II/III) ions and hexacyanoferrate(II/III) complex ions, essentially an extension of the solution-based coprecipitation method to solid-state reaction. Taking a bottom-up approach, a reaction is designed where the reactants consist of the basic building blocks of PB: Fe²⁺ ions and CN^- ions. The reaction, with a molar ratio of Fe²⁺ and CN^- corresponding to 1:2.8, yields PB, while a ratio of 1:6.6 results in a mixture of potassium hexacyanoferrate(II) (K₄Fe(CN)₆), potassium chloride (KCl), and potassium cyanide (KCN). This synthetic approach holds promise for environmentally friendly methods to synthesize multimetallic PB with maximum entropy in nearly quantitative yield.

• Korean Chemical Engineering Research
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• v.46 no.4
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• pp.769-776
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• 2008

The stereoselective synthesis of chiral terminal epoxide is of immense interest due to their utility as versatile starting materials as well as chiral intermediates. In this study, new chiral Co(salen) complexes bearing cobalt(II) chloride, iron(III) chloride and zinc(II) nitrate have been synthesized and characterized. The mass and EXAFS spectra provided the direct evidence of formation of complex. Their catalytic activity and selectivity have been demonstrated for the asymmetric ring opening of terminal epoxides such as styrene oxide and phenylglycidylether by hydrolytic kinetic resolution technology and for the synthesis of glycidyl buthylate. The easily prepared complexes exhibited very high enantioselectivity for the asymmetric ring opening of epoxides with $H_2O$ nucleophile, providing enantiomerically enriched terminal epoxides (>99% ee). The newly synthesized chiral salen showed remakablely enhanced reactivity with substantially low loadings. The system described in this work is very efficient for the sinthesis of chiral epoxide and 1,2-diol intermediates.

• Journal of the Korean Society of Safety
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• v.4 no.1
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• pp.71-74
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• 1989

The $\alpha$-Fe$_2$O$_3$ gas sensor, prepared by the precipitation of Fe(OH)$_3$ from a solution of iron(III) sulfate and tin (IV) chloride, was composed of fine particles and was superior in sensitivity to other $\alpha$-Fe$_2$O$_3$. The gas sensitivity was found to depend on the amounts of remaining sulfate ion the microstructure and a small amount of iron(II) species generated through the reduction of $\alpha$-Fe$_2$O$_3$. The sensing mechanism of $\alpha$-Fe$_2$O$_3$gas sensor was confirmed to be due to the reduction of $\alpha$-Fe$_2$O$_3$ to the low resistive Fe$_3$-xO$_4$ by combustible gas and to depend on the crystral structure.