• Title, Summary, Keyword: Aqueous NaOH Solution

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Effect of Acid and Salt on Weight toss of Polyester (PET) fabric by Sodium Hydroxide (산과 염이 폴리에스터 직물의 알칼리 감량에 미치는 영향)

  • Do, Sung-Guk;Cho, Hwan
    • Textile Coloration and Finishing
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    • v.4 no.3
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    • pp.65-73
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    • 1992
  • To control the hydrolysis rate of PET fabric with NaOH, HCl and $CH_3$COOH(HAc), as regulating reagent, were added to the 0.5 M NaOH solution. The concentrations of acids in 0.5 M NaOH were varied. PET fabrics were treated with aqueous solutions of acids in 0.5 M NaOH under different conditions. The weight loss of PET fabric, the rate of hydrolysis, the apparent activation energy (E$_{\alpha}$), the handle value, the etched surface of treated PET fabric, and the effect of salts such as NaCl, $CH_3$COONa(NaAc), and NH$_4$Cl on the weight loss were discussed. Acids in the aqueous 0.5 M NaOH solution decreased the weight loss of PET fabric bacause of neutralization of OH- and the weight loss of PET fabrics treated with corresponding concentration of aqueous NaOH solution to the concentrations of the aqueous solutions of acids in 0.5 M NaOH was lower than that of PET fabrics treated with aqueous solutions of acids in 0.5 M NaOH. The addition of NaCl to aqueous NaOH solution accelerated the reaction of OH- with PET greatly, the addition of NaAc increased the weight loss slightly, but the addition of NH$_4$Cl decreased the weight loss. It was thought that the very remarkable result that NaCl in aqueous NaOH solution promoted the hydrolysis of PET with NaOH would contribute to the conservation of energy and NaOH in the weight loss finishing process of PET fabric. The etched surface and the handle value of treated PET fabric were independent of the difference in the kinds of acids and salts added.nd salts added.

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Effect of an Additives on Simultaneous Removal of NOx, $So_2$by Corona Discharge (코로나 방전에 의한 NOx, $So_2$동시제거에서 첨가제의 영향)

  • 박재윤;고용술;이재동;손성도;박상현
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.13 no.5
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    • pp.451-457
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    • 2000
  • Experimental investigations on the effect of two kinds of additives ; aqueous NaOH solution and ammonia(NH$_3$) for removal of NOx and SO$_2$ simultaneously by corona discharge were carried out. The simulated combustion flue gas was[NO(0.02[%])-SO$_2$(0.08[%])-$CO_2$-Air-$N_2$] Volume percentage of aqueous NaOH solution used was 20[%] and $N_2$flow rate was 2.5[$\ell$/min] for bubbling aqueous NaOH solution Ammonia gas(14.81[%]) balanced by argon was diluted by air. NH$_3$ molecular ratios(MR) based on [NH$_3$] and [NO+SO$_2$] were 1, 1.5 and 2.5 The vapour of aqueous NaOH solution and NH$_3$was introduced to the main simulated combustion flue gas duct through injection systems which were located at downstream of corona discharge reactor. NOx(NO+NO$_2$) removal rate by injecting the vapour of aqueous NaOH solution was much better than that by injecting NH$_3$however SO$_2$removal rate by injecting NH$_3$was much better than that by injecting the vapour of aqueous NaOH SO$_2$removal rate slightly increased with increasing applied voltage. When the vapour of aqueous NaOH solution and NH$_3$were simultaneously injection NOx and SO$_2$ removal rate were significantly increased.

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An Addition Effect of Amine and Cethyl Trimethyl Ammonium Bromide on Alkali-treatment of Polyester (폴리에스테르직물의 수산화나트륨 처리시 아민과 CTAB의 첨가효과)

  • Lee Jung Soon;Ryu Hyo Seon
    • Journal of the Korean Society of Clothing and Textiles
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    • v.16 no.3
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    • pp.335-344
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    • 1992
  • This study was conducted to investigate the influence of addition of cetyl trimethyl ammo­nium bromide (CTAB), and amine [ethylamine (EA) or ethylene diamine (EDA)] to aqueous sodium hydroxide (NaOH) solution on polyester alkaline hydrolysis, The experimental vari­ables such as CTAB concentration, EA or EDA concentration, NaOH concentration, tempera­ture and time were compared, and the changes in physical and chemical properties of alkaline­hydrolyzed PET fabrics depending on their treated conditions were measured, The results are as follows: 1. By adding CTAB and amine in aqueous NaOH solution, increasing effect on weight loss of PET fabrics was obtained in simultaneous addition of CTAB and EDA, but not in CTAB and EA. 2. By adding CTAB & EDA simultaneously, increasing effect on weight loss was obtained regardless of EDA concentration, time and temperature, and it was more effective at lower NaOH concentration. :l. The increase of void space (or irregularly grooved surface), of softness, of wickability, of dyeability on PET fabric, and the decrease of tensile strength, of molecular weight were observed according to the weight loss on the PET fabrics. These changes were equal to all alkaline-hydrolyzed PET fabrics regardless of addition of CTAB and amine. l. There was little changes on crystallinity, thermal behavior when PET fiber was treated with ,aqueous NaOH solution with CTAB and EDA. These results supported that increasing effect on weight loss take place without inducing of fine structural change of PET fibers.

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Hydrolysis of Sarin(GB) in Aqueous NaOH Solution (가성소다 수용액에서 사린(GB)의 가수분해)

  • Lee, Yong-Han;Lee, Jong-Chol;Hong, Deasik
    • Korean Chemical Engineering Research
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    • v.45 no.2
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    • pp.172-177
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    • 2007
  • The hydrolysis reaction of sarin(GB), one of the nerve agents was studied in aqueous sodium hydroxide(NaOH) solutions to find the experimental conditions which can convert GB into the less toxic compounds. 10 wt% of GB was added into the aqueous NaOH(2.05 eq) in a small-scale jacket-attached reactor connected to a circulator. The reaction rate constants were measured at three temperatures(50, 70 and $90^{\circ}C$) and the reaction times required to degrade the material to > 99% were calculated at different temperatures. In this study, 10 wt% of GB was degraded to 99.99% in 1.2hr at $90^{\circ}C$ by the aqueous NaOH solution. The major hydrolysate of GB was isopropyl methylphosphonate.

Thermal / Electrical Conductivities of Graphites Treated in Aqueous NaOH Solution (수산화나트륨 수용액으로 처리한 흑연의 열/전기전도 특성)

  • Song, Seung Won;Min, Eui Hong;Lee, Dong Won;Kim, Jungsoo;Nam, Dae-Geun;Oh, Weontae
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.29 no.10
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    • pp.659-664
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    • 2016
  • Thermal and electrical conductivities of the natural, artificial, and expandable graphites were analyzed after treatment in NaOH aqueous solution. In order to investigate the elimination of the oxidized groups and impurities on the graphite surfaces after NaOH treatment, the graphite samples were structurally characterized by using XRD, XPS, Raman, FE-SEM. The thermal and electrical conductivities of the graphite samples were significantly improved after NaOH treatment. These results were caused by the structural rehabiliation.

On Crystallization of Korean Bentonite Treated with Aqueous Sodium Hyeroxide Solution (국산 Bentonite의 수산화나트륨 수용액 처리에 의한 결정의 변화)

  • Myun Sup Kim
    • Journal of the Korean Chemical Society
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    • v.17 no.1
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    • pp.47-52
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    • 1973
  • Korean bentonite was treated with aqueous NaOH solution under the reaction conditions such as concentration of NaOH, 0.5-6N; ratio of $Na_{2}O$ to $SiO_2$, 1-4; reaction time, 2-30 days; reaction temperature, $70^{\circ}C-90^{\circ}C$. The products were examined by X-ray diffraction patterns. When it was treated with 2N NaOH at $70^{\circ}C$, zeolite species $P_1$ was formed with good yield. In higher concentration and at higher temperature than above, zeolite species $P_1$ was converted to hyeroxysodalite. Together with these crystals, some faujasite type zeolite, sodium A zeolite, mordenite type zeolite etc. was formed depending upon reaction conditions.

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On Crystallization of Hadong Kaolin Treated with Aqueous Sodium Hydroxide Solution (하동고령토의 Sodium Hydroxide 용액 처리에 의한 결정의 변화)

  • Kwon Ei Yol;Kim Myun Sup
    • Journal of the Korean Chemical Society
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    • v.16 no.4
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    • pp.249-256
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    • 1972
  • Hadong-Kaolin was treated with aqueous sodium hydroxide solution. The crystalline structure was studied by X-ray powder diffraction method. The optimum conditions for various crystal formation were as follows: Crystal Concentration Temp. reating time Halloysite 1~4 N NaOH $60^{\circ}C$ 0.5${\sim}$4 hr Sodium A zeolite 0.5${\sim}$2 N NaOH 80${\sim}$$100^{\circ}C$ 6${\sim}$20 hr Hydoxysodalite > 4 N NaOH 80${\sim}$$100^{\circ}C$ > 4 hr The ratio of $Na_2O to SiO_2$ for crystallizing sodium A zeolite was 0.5-1.5. The $Ca^{++}$ ion exchange capacity of produced sodium A zeolite for 0.2 N $CaCl_2$ solution at $25^{\circ}C$ was amounted to 65% of theoretical value.

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Evaluation of Cleaning Ability of Aqueous Cleaning Agents according to their Additives (수계세정제의 첨가제에 따른 세정성 평가연구)

  • Kim, Hansung;Bae, Jae Heum
    • Clean Technology
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    • v.12 no.1
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    • pp.1-9
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    • 2006
  • Aqueous cleaning agents which are considered to be environmental-friendly and promising alternative ones among various industrial cleaning agents were evaluated in this words. In order to formulate aqueous cleaning agents, primary alcohol ethoxylates with 3, 5 and 7 moles of ethylene oxides among nonionic surfactants were selected as main surfactants. And anionic surfactants and alcohols were chosen as their cosurfactants. Builders such as NaOH, KOH, $Na_2CO_3$ and $NaHCO_3$ were also evaluated as additives for improvement of cleaning efficiency of aqueous cleaning agents. The experimental results of cleaning ability tests show that introduction of anionic surfactant TLS as cosurfactant in alcohol ethoxylate-based aqueous solution gives the best cleaning efficiency for removing mixed soil of cutting oil and grease. NaOH and $Na_2CO_3$ are also shown to play an important role for improvement of cleaning efficiency in a aqueous cleaning agent.

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Effects of NaOH Concentration on the Structure of PEO Films Formed on AZ31 Mg Alloy in PO43- and SiO32- Containing Aqueous Solution (인산 및 규산 이온이 포함된 수용액에서 AZ31 마그네슘 합금의 플라즈마 전해산화 피막의 구조에 미치는 수산화나트륨 농도의 영향)

  • Kwon, Duyoung;Moon, Sungmo
    • Journal of the Korean institute of surface engineering
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    • v.49 no.1
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    • pp.46-53
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    • 2016
  • The structure of plasma electrolytic oxidation (PEO) coatings was investigated as a function of NaOH concentration in 0.06 M $Na_2SiO_3$ + 0.06 M $Na_3PO_4$ solution by using SEM and epoxy replica method. The PEO film was formed on AZ31 Mg alloy by the application of anodic pulse current with 0.2 ms width and its formation behavior was studied by voltage-time curves during the formation of PEO films. It was found that the addition of NaOH into $PO_4{^{3-}}$ and $SiO_3{^{2-}}$ containing aqueous solution causes a decrease in the PEO film formation voltage, suggesting that dielectric breakdown of the PEO becomes easier with increasing $OH^-$ ion concentration in the solution. With increasing $OH^-$ ion concentration, thickness of the PEO film increased and surface roughness decreased. The size of pores formed in the PEO layer became smaller and the number of cracks in the PEO layer increased with increasing $OH^-$ ion concentration. Based on the experimental results obtained in the work, it is suggested that $OH^-$ ions in the solution can contribute not only to the dielectric breakdown but also to the formation of PEO films in the presence of $PO_4{^{3-}}$ and $SiO_3{^{2-}}$ ions in the solution.

The removal characteristics of No, SOx for plasma reactor separated flue gas duct from discharge domain (연소가스관로와 방전영역 분리형 플라즈마 반응기에서 Nox, SOx 제거특성)

  • Park, J.Y.;Koh, Y.S.;Lee, J.D.;Song, W.S.;Park, S.H.;Lee, D.C.
    • Proceedings of the KIEE Conference
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    • pp.2007-2009
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    • 1999
  • In this paper, discharge domain of wire-cylindrical plasma reactor was separated from a gas flow duct to avoid unstable discharge by aerosol particle deposited on discharge electrode and grounded electrode. The NOx, SOx removal was experimentally investigated by a reaction induced to ammonium nitrate, ammonium sulfate using a low price of aqueous NaOH solution and a small quantity of ammonia. Volume percentage of aqueous NaOH solution used was 20% and $N_2$ flow rate was 2.5[$\ell$/min] for bubbling aqueous NaOH solution. Ammonia gas(14.82%) balanced by argon was diluted by air and was introduced to a main simulated flue gas duct through $NH_3$ injection system which was in downstream of reactor. The $NH_3$ molecular ratio[MR] was determined based on $NH_3$ to [NO+$SO_2$]. MR is 1.5. The NOx removal rates increased in the order of DC, AC and pulse, but SOx removal rates was not significantly effected by source of electricity. The NOx removal rate slightly decreased with increasing initial concentration but SOx removal rate was not significantly effect by initial concentration, and NOx, SOx removal rates decreased with increasing gas flow rate.

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