• Analytical Science and Technology
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• v.8 no.2
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• pp.187-193
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• 1995

A PVC membrane ion-selective electrodes based on N,N,N,N-tetrabenzylethylenediamine as neutral carrier has been prepared by addition of plasticizers such as phthalates and sebacate and liphophillic additives such as NaTPB. The membrane electrodes were investigated to the electric resistance, response range to hydrogen ion and the interfering effect of alkali and alkline earth metals. A electric resistance hardly had on effect of plasticizers. In case of 0.7% NaTPB added to membrane, response of the electrodes were shown the values near to theoretical Nernstian slope and interferences by alkali and alkaline earth metal were few influenced. The performances of pH-selective electrodes were shown linerality to hydrogen ion between pH 2 and 10 in the presense of alkali and alkaline earth ions. Reproducibility and stability tests were shown good results in the same pH range.

• Proceeding of EDISON Challenge
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• 2017.03a
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• pp.484-486
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• 2017

포스포린에 대한 관심이 높아지면서 그 기계적 성질을 아는 것이 중요해졌다. 포스포린의 표면에 알칼리 금속 원자를 흡착시켰을 때, 그렇지 않았을 때보다 강성이 감소하는 것이 계산되었다. 또한 흡착된 원자의 절대적인 크기가 클수록 강성을 더욱 감소시킬 수 있음을 암시하는 결과가 발견되었다.

• Proceedings of the KSEEG Conference
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• 2005.04a
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• pp.297-303
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• 2005

• Korean Chemical Engineering Research
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• v.51 no.1
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• pp.53-57
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• 2013

For the purpose of development of the extraction process of lithium ion from concentrated water eliminated from desalination process, an experimental research on the solvent extraction of lithium ion from aqueous solutions was performed. The effects of operating parameters, such as concentration of extractant, ratio of extracting solution/aqueous solution, pH of aqueous solution, were examined. The effect of sodium chloride, the major component of sea water, was also examined. Lithium ion in aqueous solutions of pH=10.2~10.6 adjusted by ammonia solution was most effectively extracted by extracting solution composed of 0.02 M TTA and 0.04 M TOPO in kerosine. The addition of sodium chloride in lithium aqueous solution significantly interfered the extraction of lithium ion.

• Applied Chemistry for Engineering
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• v.21 no.3
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• pp.301-305
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• 2010

In this study, the alkaline degreasing agent was developed for electroplating pretreatment process, and the efficiency and the durability was predicted. The alkaline deeping degreasing agent was prepared by blending sodium hydroxide (NaOH), sodium carbonate ($Na_2CO_3$), sodium silicate ($Na_2SiO_3$), and sodium lauric sulfate (SLS). The performance tests of the degreasing agent were evaluated in the $40{\sim}50^{\circ}C$ of the degreasing temperature and 30~40 min of the degreasing time. The efficiency and durability of the prepared degreasing agent were tested by the waterdrop formation test and Hull-cell plating test. The optimum ratio of alkaline degreasing agent was NaOH (30 g/L) + SLS (6.0 g/L) + $Na_2SiO_3$ (2.0 g/L) + $Na_2CO_3$ (40 g/L). Also, the optimum degreasing conditions were $50^{\circ}C$ of the degreasing temperature and 35 min of the degreasing time.

• Journal of the Korea Institute of Building Construction
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• v.10 no.6
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• pp.61-66
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• 2010

As global warming has had harmful effects on the environment, the construction industry has made efforts to reduce the amount of $CO_2$ generated in the process of cement production. There is an urgent need for an alternative material that can replace cement. To improve the initial strength and economical efficiency pointed out as problems, this research was conducted for Blast Furnace Slag (BFS), an industrial byproduct. Non-sintering cement (NSC) was used by minimizing the amount of high-priced alkali activators. By using Nano-technology, fineness has been maximized, to enhance the initial strength of BFS. This research is based on non-sintered cement replaced by nano-slag using alkali activators, and the fundamental properties and quality of the non-sintered cement were investigated. A variety of activators were used, up to 10 percent of the slag weight. This research aims to present fundamental data through a comparative analysis of flexural strength, compressive strength, time of setting, diabetic temperature, and rising heat.

• Resources Recycling
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• v.26 no.6
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• pp.91-96
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• 2017

Tungsten (W) recovery from tungsten carbide (WC) was researched by alkali melt followed by water leaching. The experiments of alkali melt were carried out with the change of the sort of alkali material, heating temperature, and the heating duration. Water leaching of W was performed in the fixed conditions ($25^{\circ}C$, 2 hr., slurry density: 10 g/L). From the mixture of WC and sodium nitrate ($NaNO_3$) in the molar ratio of 1:2, treated at $400^{\circ}C$ for 6 hours, only 63.3% of W might be leached by water leaching. With the increase of sodium hydroxide (NaOH) as a melting additive, the leachability increased. Finally it reached to 97.8 % with the melted mixture of ($WC:NaNO_3:NaOH$) in the ratio of (1:2:2). This imply that NaOH may play a role as a reaction catalyst by lowering Gibb's free energy for alkali melt reaction for WC.

• Journal of the Korean Recycled Construction Resources Institute
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• v.3 no.1
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• pp.50-57
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• 2015

Portland cement production is under critical review due to high amount of $CO_2$ gas released to the atmosphere. Attempts to increase the utilization of a by-products such as fly ash and ground granulated blast-furnace slag to partially replace the cement in concrete are gathering momentum. Many researchs on alkali-activated concrete that does not need the presence of cement as a binder have been carried out recently. Instead, the sources of material such as fly ash, that are rich in Silicon(Si) and Aluminium(Al), are activated by alkaline liquids to produce the binder. Hence concrete with no cement is effect reduction of $CO_2$ gas. In this study, we investigated the influence of the fluidity, air content and compressive strength of mortar on alkaline activator in order to develop cementless fly ash and ground granulated blast-furnace slag based alkali-activated mortar with superplasticizer. In view of the results, we found out that Pn of fluidity and compressive strength is the best in four type of superplasticizer, and PNS of powder type of fluidity is better than that of liquid type in the case of AA.

• Journal of the Korea Institute of Building Construction
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• v.14 no.4
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• pp.301-307
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• 2014

In order to reduce the emission of carbon dioxide($CO_2$), this research use blast furnace slag in concrete manufacture, as 100% replacement of cement. The aim of this study is to investigate the density and strength properties of alkali-activated lightweight composites with alkali activators of different types and different amounts. The bubble for achieving the lightweight of alkali-activated lightweight composites was generated in the reaction between the paper ash and the alkali activators instead of using a foaming agent. Lightweight formed concrete was conducted basic experimental for determining replacement ratio of paper ash. Then, the density and strength were measured according to the types and the contents of the alkali accelerator that can react with the paper ash. As results, the optimum replacement ratio of the paper ash was 5%. The alkali activator containing NaOH 12.5% obtained the lowest weight of $1.13g/cm^3$. Also, compressive strength were relatively high. Therefore, this study demonstrated that alkali accelerator with a certain amount of NaOH can achieve relatively high strength and lightweight alkali-activated lightweight composites.

• Journal of Adhesion and Interface
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• v.14 no.2
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• pp.88-94
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• 2013

Because of recent requirement for environmentally-friendly adhesive, water and/or alkali soluble pressure sensitive adhesives are being developed and produced. Our research laboratory newly developed the test method for measuring the water and alkali solubility of the adhesives. Also, we made the test method published both in KS and ISO. In this research, the test of measuring the water and/or alkali solubility of the test adhesive samples as a function of time at various temperatures was carried out using the proposed test method. The results showed this proposed test method made stable output data for the change of solubility as a function of time in the proper range of temperature.