• 한국막학회:학술대회논문집
• /
• 한국막학회 2004년도 Proceedings of the second conference of aseanian membrane society
• /
• pp.166-169
• /
• 2004

Microfiltration membranes were prepared from aromatic polyethersulfone (PES) polymer, using aprotic solvent (N-methyl-2-pyrrolidone, NMP) and non-solvent additive (2-methoxy ethanol, 2-ME) by the phase inversion co-process of the vapor-induced phase inversion (VIPI) and the nonsolvent-induced phase inversion (NIPI). According to the change of the additive amount, the solvent amount and the relative humidity, membrane characterization was studied. The non-solvent additive in casting solution played an important role in membrane morphology. During the vapor-induced phase inversion, the relative humidity led to water sorption on the surface of casting dope at which pore formation was generated. The prepared membranes were characterized by scanning electron microscope observations, measurements of capillary flow porometer and pure water flux (PWP). Also the thermodynamic and kinetic properties of membrane-forming system were studied through coagulation value, light transmittance and viscosity.

• Advances in nano research
• /
• 제13권2호
• /
• pp.187-197
• /
• 2022

The synthesis of organic and hybrid organic-inorganic perovskites directly from solution improves the cost- and energy-efficiency of processing. To date, numerous research efforts have been devoted to investigating the influence of the various solvent parameters for the synthesis of lead halide perovskites, focused on the effects of different single solvents on the efficiency of the resulting perovskites. In this work, we investigated the effect of solvent blends for the first time on the structure and phase of perovskites produced via the Lewis base vapor diffusion method to develop a new synthetic approach for water-stable CsPbBr₃ particles with nanometer-sized dimensions. Solvent blends prepared with DMF and water-miscible solvents with different Gutmann's donor numbers (D_N) affect the Pb ions differently, resulting in a variety of lead bromide species with various colors. The use of a DMF/isopropanol solvent mixture was found to induce the formation of the Ruddlesden-Popper perovskite based on lead bromide. This perovskite undergoes a blue color shift in the solvated state owing to the separation of nanoplatelets. In contrast, the replacement of isopropanol with DMSO, which has a high DN, induces the formation of spherical CsPbBr₃ perovskite nanoparticles that exhibit green emission. Finally, the integration of acetone in the solvent system leads to the formation of lead bromide complexes with a yellow-orange color and the perovskite CsPbBr₃.

• 한국태양에너지학회 논문집
• /
• 제31권6호
• /
• pp.66-71
• /
• 2011

Various single solvents were tested to find the effective solvent for the extraction of algae oil from wet-form Chlorella minutissima. In the case of single solvents, their extractabilities for algae oil were increased with their polarity because the water in wet algae cell is to form a solvent shell around the lipids. Based on these results, the wet-form algae samples were treated with a polar alcohol solvent and then a nonpolar solvent was added in algae residue. In the algae oil extraction by ethanol/n-hexane, total lipid contents were 40-50% and composition of triglyceride in extracted oil was 46.50%. Considering solvent toxicity of conventional solvent mixture such as chloroform and methanol for algae oil extraction, the ethanol/n-hexane system was identified as the effective one for the oil extraction from wet-form Chlorella minutissima.

• 한국광물학회지
• /
• 제31권2호
• /
• pp.67-73
• /
• 2018

본 연구는 acid bake-water leaching system (AWS)를 이용하여 Au 정광으로부터 경제적이고 친환경적인 유용금속 용출을 위하여 황산염 용매제의 적용성을 파악하는 것이다. AWS 실험은 전기로를 이용하여 다양한 baking 온도($100^{\circ}C{\sim}500^{\circ}C$)와 황산염 용매제($H_2SO_4$, $K_2SO_4$, $(NH_4)_2SO_4$, $MgSO_4$, $CaSO_4$) 조건에서 수행하였다. Baking 온도가 $400^{\circ}C$까지 증가할수록 유용금속의 용출률은 증가하였다. 용출시간에 따른 AWS 실험결과, 최대 용출률 조건은 $(NH_4)_2SO_4$ 용매제이었다. 본 연구를 통하여 $(NH_4)_2SO_4$ 용매제가 AWS를 이용한 유용금속 용출에 있어 효과적인 용매제로 사용가능함을 입증하였다.

• 한국의류학회지
• /
• 제23권7호
• /
• pp.1030-1039
• /
• 1999

The effect of surfactant mixture 9on detergency and soil redeposition in a dry-cleaning system was investigated employing Aerosol OT as an anionic surfactant and Span 80 as a nonionic surfactant. The effect of charge system on soil deposition was also investigated in order to determine the optimum condition at which soil redeposition is minimum,. Soil deposition instead of soil redeposition on cotton, polyester and wool fabrics was measured employing petroleum solvent and perchloroethylene as organic solvents. The results were as follows. 1. Surface tension or interfacial tension was not changed by the addition of any surfactant or surfactant mixtures. In petroleum solvent however interfacial tension between solrent and water decreased when surfactants were added and increased when surfactants were mixed,. 2. The maximum amount of water solubilization increased as the mole fraction of Aerosol OT increased and more water was solubilized in petroleum solvent than in perchloroethylene. 3. The detergency of cotton was greater and the soil deposition rate was lower in Span 80 solution than in Aerosol OT solution. The soil deposition on cotton fabric decreased when water was solubilized in Aersol OT solution 4. The detergency and soil deposition rate of polyester fabric did not change by the surfactant type of the addition of surfactant mixture and soil deposition rate increased bywater solubilization. 5. Soil deposition on wool fabric was very high when Arosol OT was employed in perchloroethylene and the soil deposition did not change greatly by water solubilization.

• 동의생리병리학회지
• /
• 제17권6호
• /
• pp.1409-1411
• /
• 2003

The indirect carbonization without solvent for the extraction of the natural undiluted solution has been studied. The following results have been obtained. 1. The traditional wood undiluted solution distillation can be embodied with the indirect carbonization without solvent of the airtight space. The system of the indirect carbonization without solvent is the indirect dry distillation apparatus. It is composed of the high-temperature stove, the exterior can, material bag, interior can, collect water can and air-fan.

• 한국자기공명학회논문지
• /
• 제24권4호
• /
• pp.96-103
• /
• 2020

A new NMR method to monitor solvent-localized NMR signals in the two-phase liquid system is suggested. This method based on intermolecular single-quantum coherence (iSQC). Here, we exploited the feature of the local action of distant dipolar field (DDF) effect in order to filter out specific NMR signals dissolved in different solvents. This solvent specific iSQC spectroscopy was carried out on a model two-phase liquid system (D-glucose in water/palmitic acid in chloroform), and showed solvent-localized NMR signals. We believe our approaches might be useful in metabolic analysis such as two-phase liquid extraction scheme for labile chemical species.

• 한국염색가공학회지
• /
• 제13권1호
• /
• pp.55-60
• /
• 2001

Cotton fabric was deed with a reactive dye in water/dichloromethane two-phase immiscible solvent media. In order to minimize dye loss due to its hydrolysis, the reactive dyeing was carried out in dichloromethane containing a small amount of water. With only 2ml of water in 23m1 of dichloromethane, 1.0g of cotton fabric could be dyed perfectly. The uptake ratio was increased greatly, compared with that of normal reactive dyeing in a waters medium. It would seem that the one of hydrophobic solvents, dichloromethane, can assist the eden dyeing as it disperses a small amount of dye-dissolved water phase and conveys this water phase to the fabric entirely and uniformly.

• 한국식품영양학회지
• /
• 제11권6호
• /
• pp.678-682
• /
• 1998

A strain of Streptomyces sp. SK-862, isolated from soil in Wonju city, was able to prodce a biologically active substance that has a strong inhibitory activity against proteolsis by trypsin. The inhyibitory substance was extracted by n-butanol, and then purified by the adsorption chromatography followed by the reverse-phase high performacne liquid chromatography. The purified substance was stable over the pH range from 2 to 10, but was unstable when treated at 8$0^{\circ}C$ for 60 min. This substance was soluble in water, methanol, ethanol nd butanol, but insoluble in chlorofrom and ethylacetate. The Rf value of the purified substance on the thin layer chromatography were 0.56 in n-butanol : methanol : water(5 : 3 : 1v/v) solvent system compare dto 0.23 in ethanol : ammonium hydoxide : water(8 : 1 : 1v/v) solvent system. This substance has maximum absorption at 259 nm. The chemical reaction of the substance was negative for sugar but positive for ninhydrine and iodine reaction.

• 한국염색가공학회지
• /
• 제26권3호
• /
• pp.209-217
• /
• 2014

Detergency and soil redeposition of wool fabric in drycleaning solvents, i.e. petroleum solvent, perchloroethylene (PCE), decamethylcyclopentasiloxane($D_5$), with commercial detergents were studied. The detergency of wool soiled cloth in drycleaning solvents without detergents were the order of PCE > petroleum solvent > $D_5$. When commercial detergents were added to the system, the detergency were greatly improved. When 1.0% water was added to solvents/commercial detergents system, the detergency of petroleum solvent and PCE improved whereas that of $D_5$ decreased. The soil redeposition prevention effects of solvents were the same order of detergency, i.e. PCE > petroleum solvent > $D_5$. When commercial detergents were added to the system, the soil redeposition changed depending on solvents and detergents. The soil redeposition in $D_5$ became higher with a commercial detergent, therefore it is important to develop appropriate detergents for $D_5$. Three silicone surfactants were tested for detergency and soil redeposition in $D_5$ to find candidate surfactants for drycleaning detergent formulations. Silicone surfactant PEG/PPG-19/19 Dimethicone was found to be the best surfactant for $D_5$ drycleaning detergents.