• 한국응용과학기술학회지
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• 제16권3호
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• pp.237-240
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• 1999

This study showed that the optimized cleaning process using non-aqueous cleaning solvents is adaptable in the industrial field for existing 1.1.1-TCE cleaning solvents which is an ozone depleting sustance. Alternative cleaning solvent system substituted for existing cleaning solvent against non-aqueous pollutants(cutting & flux oil), was evaluated for the cleaning efficiency using gravimetric analysis method and surface change of sample by Image analyzer. The results showed that alternative solvents and process had excellent cleaning efficiency.

• 융복합기술연구소 논문집
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• 제3권2호
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• pp.1-6
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• 2013

The ionic liquids are known to potential alternative solvents capable of replacing the commercial solvents in various processes including those in nuclear fuel cycle. As to the material, a number of studies have already reviewed the interesting results and addressed the spectroscopic as well as electrochemical behaviors of metal elements included in spent nuclear fuels. It has found that the important properties of metal ions in TBP dissolved ILs have led the development of alternative technologies to traditional solvent extraction processes. On the other hand, the electrochemical deposition of metal ions in ILs have been investigated for the application of the solvents to aqueous as well as to non-aqueous processes. In this work, a review on the application of ILs in nuclear fuel cycle is briefly presented to understand the notable researches on ILs focusing on aqueous processes.

• 전기화학회지
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• 제17권1호
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• pp.26-29
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• 2014

The corrosion behavior of stainless steel 304 (SS 304), titanium, nickel and aluminium is studied by immersion and anodic polarization tests in non-aqueous electrolytes. Tetraethyl ammonium tetrafluoroborate is used as a supporting electrolyte in the three kinds of solvents. The immersion test shows that chemical corrosion rate in propylene carbonate-based electrolyte is lower than those in acetonitrile- or ${\gamma}$-butyrolactone-based electrolytes. Surface analyses do not reveal any corrosion product formed after the immersion test. In the anodic polarization tests, a higher concentration of supporting electrolyte gives a higher current density. In addition, a higher temperature increases the current density in the active region and reduces the potential range in the passive region. SS 304 shows the highest corrosion potential while Al shows the lowest corrosion potential and the highest current density in all studied conditions. Based on the conducted corrosion tests, the corrosion resistance of metal substrates in the organic solvents can be sorted in descending order as follows: SS 304 - Ti - Ni - Al.

• Journal of the Korean Wood Science and Technology
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• 제10권4호
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• pp.101-110
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• 1982

• 한국재료학회지
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• 제13권11호
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• pp.725-731
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• 2003

The effect of organic processing parameters on the dispersion stability of the BaTiO$_3$-based dielectric particles and borosilicate glass particulate suspensions was investigated in a system where organic solvents, dispersant, binder and modifier were used as processing additives in a low temperature cofired ceramic fabrication processes. Two- and three-component organic solvents were used to disperse ceramic particles and it was found the better stability in the particulate suspension prepared in a bi-solvent, which was consists of toluene and ethanol in a non-azeotropic composition. The addition amount of organic additives had a great impact on dispersion in the present investigation. The flow curves of the suspensions prepared with binder and modifier were fitted according to the power-law equation, which indicates that the internal structure of the suspension could be disturbed under the applied shear stress. Finally, the LTCC green tapes were successfully tape-cast based upon the optimum formulation of LTCC suspension and its microstructure was compared with that of the hard-agglomerates.

• 한국염색가공학회지
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• 제9권4호
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• pp.20-27
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• 1997

As a non-aqueous dyeing method, organic solvent dyeing was discussed, The dye uptakes on PET and the solubilities of C. I. Disperse Violet 1 in 24 kinds of organic solvents including water were investigated, and the partition coefficients in PET- solvents system were also obtained from their isotherms. Contrary to in the other solvents, the dye uptake of C. I. Disperse Violet 1 on PET in hexane was even much higher, and also considerable in cyclohexane. The logarithmic plot of the dye uptakes versus the solubilities showed that the dye uptakes are linear and inversely proportional to the solubilities. The effect of $T_g$ decrease of PET in organic solvents to dye uptake seems to be very small relative to the effect of solubility, and so negligible.

• 대한화학회지
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• 제19권2호
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• pp.104-115
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• 1975

요오드의 전기화학적 환원과정을 여러가지 특성을 가진 물아닌 용매 속에서 polarography, chronopotentiometry, cyclic voltammetry, controlled potential coulometry 등의 전기분석적 방법을 이용하여 적하수은전극, 백금, 금 및 백금아말감전극등을 사용하여 상세히 조사하였다. 메탄올, 에탄올, 이소프로판올 및 피리딘과 같은 양쪽성 용매 속에서는 $I_2{\longrightarrow}I^-$의 I단계 환원과정을 거치며 아세톤, 디메틸포름아미드, 메틸에틸케톤, 디메틸술폭시드, 아세토니릴과 같은 반양성자 용매속에서는 $I_2{\longrightarrow}I_3^-{\longrightarrow}I^-$의 2단계 환원과정을 거쳤다. 적하수은전극, 고인 수은전극, 백금, 금 그리고 백금아말감전극등 전극조건을 다르게 하였을 때에도 $^'I_2$의 환원과정은 같았으며 사용한 모든 전극에서 확산지배적이었다. 반양성자용매에 물을 첨가하여 그 영향을 걸토한 결과 물의 첨가량이 약 $50v/v{\%}$ 이상일때 2단계의 환원과정이 1단계의 환원과정으로 줄어들었다. 또 chronopotentiometric data와 Send의 식으로부터 계산한 각 용매 속에서의 요오드의 확산계수는 $D_{I2}^{AN}=5.96{\times}10^{-6}cm^2/sec,\;D_{13-}^{AN}=9.63{\times}10^{-6}cm^2/sec,\;D_{I2}^{MeOH}=5.30{\times}10^{-6}cm^2/sec$이였다. 전기화학적 환원과정의 stoichiometry를 알아 보고저 controlled potential coulometry로 使用하였으며, 얻은 생성물은 은법적정으로 확인 및 정량하였다.

• 한국물환경학회지
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• 제36권1호
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• pp.48-54
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• 2020

This paper presents a screening protocol for the selection of solvents available for the solvent extraction desalination process. The desalination solvents hypothetically and theoretically require the capability of (1) Forming hydrogen bonds with water, (2) Absorbing some water molecules into its non-polar solvent layer, (3) Changing solubility for water-solvent separation, and (4) Rejecting salt ions during absorption. Similar to carboxylic acids, amine solvents are solvent chemicals applicable for desalination. The key parameter for selecting the potential solvent was the octanol-water partitioning coefficient (Kow) of which preferable value for desalination was in the range of 1-3. Six of the 30 amine solvents can absorb water and have a variable, i.e., temperature swing solubility with water molecule for water-solvent separation. Also, the hydrogen bonding interaction between solvent and water must be stronger than the ion-dipole interaction between water and salt, which means that the salt ions must be broken from the water and only water molecules absorbed for the desalination. In the final step, three solvents were selected as desalination solvents to remove salt ions and recover water. The water recovery of these three solvents were 15.4 %, 2.8 %, 10.5 %, and salt rejection were 76 %, 98 %, 95 %, respectively. This study suggests a new screening protocol comprising the theoretical and experimental approaches for the selection of solvents for the desalination method which is a new and challenges the desalination process in the future.

• 공업화학
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• 제19권4호
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• pp.370-375
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• 2008

비수계 분산(NAD : non-aqueous dispersion) 중합을 이용하여 친환경적인 아크릴 수지를 합성시 최적의 중합조건에 대해 연구하였다. 중합된 고분자 입자들 간의 응집을 방지하기 위한 안정제의 적정량은 20 wt%로 나타났고 안정된 NAD 상태를 유지하기 위한 혼합 용매의 적정 혼합비는 지방족과 방향족 용매의 비율이 80 : 20인 것으로 나타났다. NAD 수지의 점도는 반응시간뿐만 아니라 개시제의 양 및 교반 속도 등에 의해 영향을 받는 것으로 나타났다. 또한 NAD 수지의 입자 크기 및 분포도, 안정제의 양, 개시제의 농도 등에 의해 영향을 받는 것을 확인하였다. 단량체의 투입시기는 단량체를 초기에 모두 투입하면 용매의 극성이 증가하여 입자의 크기가 커져서 입자의 안정성이 저하되므로 단계별로 지속적으로 투입할 필요가 있는 것으로 관찰되었다.

• Membrane and Water Treatment
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• 제10권3호
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• pp.207-212
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• 2019

Non-aqueous solvents (NASs) are generally known to be barely miscible, and reactive with polar compounds, such as water. However, water can interact with some NASs, which can be used as a new means for water recovery from saline water. This study explored the fate of water and salt in NAS, when saline water is mixed with NAS. Three amine solvents were selected as NAS. They had the same molecular formula, but were differentiated by their molecular structures, as follows: 1) NAS 'A' having the hydrophilic group ($NH_2$) at the end of the straight carbon chain, 2) NAS 'B' with symmetrical structure and having the hydrophilic group (NH) at the middle of the straight carbon chain, 3) NAS 'C' having the hydrophilic group ($NH_2$) at the end of the straight carbon chain but possessing a hydrophobic ethyl branch in the middle of the structure. In batch experiments, 0.5 M NaCl water was blended with NASs, and then water and salt content in the NAS were individually measured. Water absorption efficiencies by NAS 'B' and 'C' were 3.8 and 10.7%, respectively. However, salt rejection efficiency was 98.9% and 58.2%, respectively. NAS 'A' exhibited a higher water absorption efficiency of 35.6%, despite a worse salt rejection efficiency of 24.7%. Molecular dynamic (MD) simulation showed the different interactions of water and salts with each NAS. NAS 'A' formed lattice structured clusters, with the hydrophilic group located outside, and captured a large numbers of water molecules, together with salt ions, inside the cluster pockets. NAS 'B' formed a planar-shaped cluster, where only some water molecules, but no salt ions, migrated to the NAS cluster. NAS 'C', with an ethyl group branch, formed a cluster shaped similarly to that of 'B'; however, the boundary surface of the cluster looked higher than that of 'C', due to the branch structure in solvent. The MD simulation was helpful for understanding the experimental results for water absorption and salt rejection, by demonstrating the various interactions between water molecules and the salts, with the different NAS types.