• Title/Summary/Keyword: ethanol solution

Search Result 838, Processing Time 0.023 seconds

Methyl Viologen Mediated Oxygen Reduction in Ethanol Solvent: the Electrocatalytic Reactivity of the Radical Cation

  • Lin, Qianqi;Li, Qian;Batchelor-McAuley, Christopher;Compton, Richard G.
    • Journal of Electrochemical Science and Technology
    • /
    • v.4 no.2
    • /
    • pp.71-80
    • /
    • 2013
  • The study of methyl viologen ($MV^{2+}$) mediated oxygen reduction in electrolytic ethanol media possesses potential application in the electrochemical synthesis of hydrogen peroxide mainly due to the advantages of the much increased solubility of molecular oxygen ($O_2$) and high degree of reversibility of $MV^{2+/{\bullet}+}$ redox couple. The diffusion coefficients of both $MV^{2+}$ and $O_2$ were investigated via electrochemical techniques. For the first time, $MV^{2+}$ mediated $O_2$ reduction in electrolytic ethanol solution has been proved to be feasible on both boron-doped diamond and micro-carbon disc electrodes. The electrocatalytic response is demonstrated to be due to the radical cation, $MV^{{\bullet}+}$. The homogeneous electron transfer step is suggested to be the rate determining step with a rate constant of $(1{\pm}0.1){\times}10^5M^{-1}s^{-1}$. With the aid of a simulation program describing the EC' mechanism, by increasing the concentration ratio of $MV^{2+}$ to $O_2$ electrochemical catalysis can be switched from a partial to a 'total catalysis' regime.

Antimicrobial Dyeing of Cotton and Silk Fabrics Using Houttuynia cordata Extract (어성초 추출물을 이용한 면과 견직물의 항미생물성 염색)

  • Kim, Sung-Jin;Kim, Byoung-Jin;Kim, Eun-Ji;Jung, Hee-Seon;Jang, Jinho
    • Textile Coloration and Finishing
    • /
    • v.27 no.3
    • /
    • pp.194-201
    • /
    • 2015
  • Cotton and silk fabrics were dyed with Houttuynia cordata extract using aqueous ethanol solution and the dyeing and post-treatment conditions were optimized to impart antimicrobial activity to the fabrics. The dried Houttuynia cordata can be extracted at $80^{\circ}C$ for 3 hours using an aqueous ethanol solution containing 70%(w/w) ethanol. For the highest color yields. Both cotton and silk fabrics can be dyed at $100^{\circ}C$ for 60min with 10g/L of NaCl under pH 4. Silk fabrics can be dyed to higher K/S than cotton fabrics. The color fastness properties of the dyed fabrics were good when either citric acid crosslinking or aluminum alum mordanting was carried out as a post treatment. The dyed silk and cotton fabrics with the post treatments showed excellent antimicrobial activity against both Staphylococcus aureus and Klebsiella pneumoniae.

A Study on Subchronic Toxicity Test and Method of Increasing Output of Scolopendrid Pharmacopuncture (오공약침의 아만성독성 시험 및 생산량 증가방안에 관한 연구)

  • Kim, Sung-Chul
    • Journal of Pharmacopuncture
    • /
    • v.11 no.4
    • /
    • pp.25-37
    • /
    • 2008
  • Purpose The purpose of this study was to investigate sub-chronic toxicity of scolopendrid pharmacopuncture in mouse and method of increasing output of scolopendrid pharmacopuncture. Methods In order to prove the clinical safety of scolopendrid pharmacopuncture during 90 days, We have observed the physical reaction(side effect) and clinical pathology test after scolopendrid pharmacopuncture treatment and investigated method of increasing Output of scolopendrid pharmacopuncture for 90%, 80%, 70% ethanol. Results In subchronic toxicity test, there was no significant sign in clinical sign, opthalmological values, body weights, hematological values and urinalysis values. And we could see that food consumptions and water consumptions increased significantly, albumin, triglycerides, GPT in blood chemical values and Liver, Testis(right) in organ weights changed significantly in some groups, compared with those in the S1 group. But these changes were observed within the scope of physiology. So there was no sign of toxication in subchronic toxicity test, and we can tell that NOAEL(No Observed Adverse Effect Level) is above 0.286mg/kg/day. And 70% ethanol solution of scolopendrid was yielded the most amount of substance. Conclusions This study demonstrates that scolopendrid pharmacopuncture is to treatment of safety for a long time and we can obtain much amount from 70% ethanol solution of scolopendrid.

Reaction Conditions and Mechanism of Electrolytic Reduction of Dibenzoylmethane$^\dag$

  • Kang, Sung-Chul;Chon, Jung-Kyoon
    • Bulletin of the Korean Chemical Society
    • /
    • v.8 no.5
    • /
    • pp.414-418
    • /
    • 1987
  • Electrochemical reduction of dibenzoylmethane was studied on mercury electrode by means of cyclic voltammetry, polarography and potentiostatic measurements in ethanol-water system. In acidic solutions monomeric pinacol was produced by irreversible two-electron process while monomeric and dimeric pinacol were competitively produced by the same process in neutral solution. However, in basic solution the dimeric pinacol was mostly produced through radical by irreversible one-electron transfer process. Mechanisms of the reduction of dibenzoylmethane are deduced from Tafel slope, pH dependance and reaction order with respect to the concentration of dibenzoylmethane in the solution of various pH.

The Dissociation Constant of Phenol Red Indicator in Mixed Solvents (혼합용매중의 지시약 Phenol Red의 해리정수)

  • 김양배
    • YAKHAK HOEJI
    • /
    • v.20 no.1
    • /
    • pp.41-43
    • /
    • 1976
  • The dissociation constant of phenol red indicator in mixed solvents was studied. Methanol and ethanol were employed as solvents and studied the changes of pK values of indicator according to the kind and concentration of organic solvent which is mixed into water solution. The effect of methanol solvent on pK is negligible at 40%, 60% and 80% mixing. While in the case of ethanol, the effect of above 40% mixing is not negligible.

  • PDF

Concentration of cell-free fermentation broth containing poly (${\gamma}-glutamic acid$) by ultrafiltration

  • Do, Jin-Hwan;Jang, Ho-Nam;Lee, Sang-Yeop
    • 한국생물공학회:학술대회논문집
    • /
    • 2000.11a
    • /
    • pp.45-46
    • /
    • 2000
  • After cell removal from fermentation broth the supernatant containing poly (${\gamma}-glutamic acid$) (${\gamma}-PGA$) was concentrated by ultrafiltration in order to reduce the amount of organic solvents such as methanol, ethanol, propanol required for the recover of ${\gamma}-PGA$ with precipitation. The concentration and volume reduction of cell-free solution by ultrafiltration could reduce 3 times the amount of ethanol for the recover of ${\gamma}-PGA$ from cell-free fermentation broth.

  • PDF

Technical Feasibility of Ethanol as a Fuel for Farm Diesel Engines (농용(農用) 디이젤 엔진 연료(燃料)로서의 에타놀 이용(利用)에 관(關)한 연구(硏究))

  • Ryu, Kwan Hee;Bae, Yeong Hwan;Yoo, Soo Nam
    • Journal of Biosystems Engineering
    • /
    • v.6 no.2
    • /
    • pp.1-8
    • /
    • 1982
  • The objective of this study was to find out the technical feasibility of ethanol-diesel fuel blends as a diesel engine fuel. Fuel properties essential to the proper operation of a diesel engine were determined for blends containing several concentrations of ethanol in No. 2 diesel fuel. A single-cylinder diesel engine for a power tiller was used for the engine tests, in which load, speed and fuel consumption rate were measured. The fuels used in tests were No. 2 diesel fuel and a blend containing 10-percent ethanol and 90-percent No. 2 diesel fuel. The results of the study are summarized as follows. 1. It was not possible to blend ethanol and No. 2 diesel fuel as a homogeneous solution even though anhydrous ethanol was used. The problem of blending ethanol in No. 2 diesel fuel could be solved by adding butanol about 5% of the amount of ethanol in the blends. 2. Because ethanol had a much lower boiling point ($78.3^{\circ}C$ under atmospheric pressure) than a diesel fuel, it was necessary to store ethanol-diesel fuel blends airtight in order to prevent them from evaporation losses of ethanol. 3. The addition of ethanol to No. 2 diesel fuel lowered the fuel viscosity and the cetane rating, but a blend of 10% ethanol and 90% diesel fuel had a viscosity and a cetane rating well above the KS minimum values for No. 2 diesel fuel. 4. At the rated speed, the specific fuel consumption of No.2 diesel fuel was lower than that of the 10% ethanol blend for the almost entire range of load. However, under the overload condition the specific fuel consumption was lower for the 10% ethanol blend. 5. Under the variable-speed full-load tests, both fuels produced approximately the same torque and power. At the speeds of 1600rpm or below, the specific fuel consumption of No. 2 diesel fuel was lower than that of the 10% ethanol blend. At the speeds of 1600rpm or above, however, the specific fuel consumption was lower for the 10% ethanol blend. 6. At the ambient temperature above $15^{\circ}C$, the use of the 10% ethanol blend in the engine created a vapor lock in the fuel injection pump and stalled the engine. The vapor locking problem was overcome by chilling the surroundings of the fuel injection pump and the cylinder head with water.

  • PDF

Antimicrobial and Water Repellency Effect of Functional Cotton Fiber with ODDMAC(octadecyl dimethyl(3-triethoxy silylpropyl) ammonium chloride) (ODDMAC를 이용한 항균성 및 발수성 동시 발현이 가능한 기능성 면섬유)

  • Jeon, Hyeji;Lee, Jaewoong
    • Textile Coloration and Finishing
    • /
    • v.31 no.4
    • /
    • pp.276-287
    • /
    • 2019
  • In this study, cotton fibers were coated with a different weight percentage of octadecyl dimethyl(3-triethoxy silylpropyl) ammonium chloride(ODDMAC) to improve antimicrobial and water repellent properties. First, the ODDMAC dissolved in ethanol to prepare a solution. Then the cotton fibers were immersed in the ODDMAC/ethanol solution for 10 minutes at ambient temperature and dried at 80℃ for 3 minutes followed by curing. The treated cotton fibers were characterized by scanning electron microscopy(SEM) and x-ray photoelectron spectroscopy(XPS). The treated cotton fibers revealed sufficient antimicrobial activity against Klebsiella pneumoniae(ATCC 4352) and Staphylococcus aureus(ATCCBAA-1707). The hydrophobic nature of the treated cotton fibers was characterized by contact angle measurement. The results showed that the cotton fibers treated with the ODDMAC showed excellent hydrophobic properties which improved to 121°.

Synthesis and Characterization of Physical Properties of Titania Nanoparticle for Electronic Paper (전자종이용 티타니아 나노입자의 합성 및 물성 평가)

  • Hong, Sung-Jei;Han, Jeong-in
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
    • /
    • v.18 no.10
    • /
    • pp.929-935
    • /
    • 2005
  • In this paper, synthetic conditions of titania nanparticle was investigated to enhance its uniformity of the particle size as a child particle on organic mother particle of liquid powder type electronic paper. The physical properties are very important to improve the uniformity of electrical charging properties Concentration of titania raw material ($C_9H_{19}NO_4Ti$) in the ethanol solvent, pH, and concentration of the solution in the D.I. water were selected as parameters. As a result, ultrafine and well crystallized titania nanoparticle with good uniformity could be synthesized as the concentration of the $C_9H_{19}NO_4Ti$ in the ethanol solvent, pH of the solution, and the amount of the D.I. water were increased. Using the optimized conditions, the titania nanparoticle with uniformly ultrafime size of 10 nm could be synthesized.

Hydrothermal Synthesis of $CeO_2$ Powder (수열법에 의한 $CeO_2$ 분말 합성)

  • Lee, K.J.;Park, B.K.;Lee, T.K.;Hwang, Y.;Kim, C.J.;Choi, S.C.
    • Korean Journal of Crystallography
    • /
    • v.11 no.1
    • /
    • pp.52-57
    • /
    • 2000
  • Hydrothermal synthesis of find CeO₂ powder has been investigated. Synthesis was performed with Ce(NO₃)₃·6H₂O, in ethanol and water solution. Mineralizer were NH₄OH and KOH and reaction for the powder synthesis has performed at 130℃. The morphology of CeO₂ was nearly spherical in using NH₄OH and cubic form in KOH. Particle size increased with addition of NH₄OH. Ethanol solution was effective to reduced the agglomeration.

  • PDF