• 한국염색가공학회지
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• 제6권3호
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• pp.15-26
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• 1994

Cotton fabrics were treated with the cellulase which is an enzyme to decompose cellulose and its actional mechanism is known. The optimum condition of the cellulase to the cotton fabrics and the weight losses, tensile strengths of the treated cotton fabrics were also obtained. The cellulase performs a specific catalytic action on the ${\beta}-1$, 4-glucosidic bonds of the cellulose molecules and hydrolyzes them. For that reason, the negative surface charges of the cotton fabrics were increased by additional generation. of hyrdoxyl groups. The increased surface charges cause the decrease of dye adsorption by inhibiting the approach of the anions of direct dyes. But, it was overcome by the use of enough amount of salt, it means that sodium ions of the salt neutralize the almost all of negative charges of the cotton fabrics. The improvement of the water absorbency is also due to the increased hydroxyl groups In addition, their handles including the mechanical properties were measured and caculated by KES system which is a measuring apparatus that numerizes and objectificates human's feeling, especially touch. As the results, we knew that KOSH(stiffness) and FUKURAMI(fulness & softness) were decreased and that NUMERI(smoothness) was increased.

• 한국환경과학회지
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• 제23권5호
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• pp.963-972
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• 2014

In this study, ibuprofen(IBP) degradation by the photochemical ($UV/S_2O{_8}^{2-}$) and sonochemical ($US/S_2O{_8}^{2-}$) processes was examined under various parameters, such as UV ($10{\sim}40{\pm}5W/L$) and US ($50{\sim}90{\pm}5W/L$) power density, optimum dosage of persulfate ion ($S_2O{_8}^{2-}$), temperature ($20{\sim}60^{\circ}C$) and anions effect ($Cl^-$, $HCO_3{^-}$, $CO{_3}^{2-}$). The pseudo-first-order degradation rate constants were in the order of $10^{-1}$ to $10^{-5}min^{-1}$ depending on each processes. The synergistic effect of IBP degradation in $UV/S_2O{_8}^{2-}$ and $US/S_2O{_8}^{2-}$ processes could investigated, due to the generation of $SO_4{^-}$ radical. This result can confirm from the produced $H_2O_2$ and $SO{_4}^{2-}$ concentration in each processes. IBP degradation rate affected by the $S_2O{_8}^{2-}$ dosage, temperature, power and anion existence parameters. In particular, IBP degradation rate increased with the increase of the temperature ($60^{\circ}C$) and applied power density (UV:$40{\pm}5W/L$, US:$90{\pm}5W/L$). On the other hand, anions effect on the IBP degradation was negative, due to the anion play as a the scavenger of radical.

• Membrane and Water Treatment
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• 제14권1호
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• pp.1-10
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• 2023

This study explored the feasibility of calcium-rich food waste, Mactra veneriformis shells (MVS), as an adsorbent for phosphate removal, and its removal efficiency was enhanced by the thermal activation process. The CaCO3 in MVS was converted to CaO by thermal activation (>800 ℃), which is more favorable for adsorbing phosphate. Thermal activation did not noticeably influence the specific surface area of MVS. The MVS thermally activated at 800 ℃ (MVS-800), showed the highest phosphate adsorption capacity, was used for further adsorption experiments, including kinetics, equilibrium isotherms, and thermodynamic adsorption. The effects of environmental factors, including pH, competing anions, and adsorbent dosage, were also studied. Phosphate adsorption by MVS-800 reached equilibrium within 48h, and the kinetic adsorption data were well explained by the pseudo-first-order model. The Langmuir model was a better fit for phosphate adsorption by MVS-800 than the Freundlich model, and the maximum adsorption capacity of MVS-800 obtained via the Langmuir model was 188.86 mg/g. Phosphate adsorption is an endothermic and involuntary process. As the pH increased, the phosphate adsorption decreased, and a sharp decrease was observed between pH 7 and 9. The presence of anions had a negative impact on phosphate removal, and their impact followed the decreasing order CO₃^2- > SO₄²- > NO₃^- > Cl^-. The increase in adsorbent dosage increased phosphate removal percentage, and 6.67 g/L of MVS-800 dose achieved 99.9% of phosphate removal. It can be concluded that the thermally treated MVS-800 can be used as an effective adsorbent for removing phosphate.

• Bulletin of the Korean Chemical Society
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• 제32권2호
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• pp.664-672
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• 2011

A series of hydrophilic chromophores was synthesized through introduction of dendritic sulfonate anions using click chemistry. A dendron structure bearing several sulfonate groups enhances hydrophilicity of attached chromophores. A click triazole formation connects chromophores with hydrophilic groups. A neutral trichloroethyl sulfonate has versatile features such as easy introduction, chemical endurance for isolation or storage, and convenient transformation to a hydrophilic anion. Zinc and OH mediated cleavage of trichloroethyl group from the neutral sulfonate undergoes to generate a water-soluble sulfonate anion. The solubility was examined with different counter cations and in different pH media and thus increased with the number of attached sulfonate ion. Two hydrophilic chromophores of stilbene-derived and azobenzene-derived dipolar structures exhibit clear negative and positive solvatochromism in protic solvents, respectively.

• Bulletin of the Korean Chemical Society
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• 제18권9호
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• pp.1002-1006
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• 1997

1H NMR spectra of D2O solutions containing 2,2-dimethylaziridine (1) or 2-methylaziridine (2) and [SiW11COⅡO39]6- (SiW11Co) or [SiW11NiⅡO39]6- (SiW11Ni) exhibit separate signals for the free ligand and the complex, indicating that the ligand exchange is slow on the NMR time scale. Identified are two linkage isomers with the methyl group of 2 at trans or cis position with respect to the metal. The isotropic shifts of 1 and 2 coordinated to SiW11Ni originate mainly from the contact shifts, and they agree reasonably with the relative values reported for similar ligands coordinated to bis(2,4-pentanedionato)nickel(Ⅱ). The isotropic shifts for the SiW11Co complexes were separated into contact and pseudocontact contributions. The pseudocontact shifts show that (χ∥-χ⊥) is positive, while that for the SiW11Co complexes of pyridine derivatives is negative. This result indicates that the ordering of dxy and dxz, dyz orbitals in SiW11Co complexes can be reversed by ligands.

• 대한약학회:학술대회논문집
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• 대한약학회 2003년도 Proceedings of the Convention of the Pharmaceutical Society of Korea Vol.1
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• pp.293.1-293.1
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• 2003

Electroosmotic flux during iontophoresis originates due to the net negative charge of the current passing channels (pores) in skin at physiological pH (pH 7.4). Thus, the channels are permselective to cations, and this causes the convective solvent flow from anode to cathodal direction. This solvent flow facilitates the flux of cations (from anode), inhibits that of anions (from cathode), and enables theenhanced transport of neutral, polar solutes. (omitted)

• 대한약학회:학술대회논문집
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• 대한약학회 2003년도 Proceedings of the Convention of the Pharmaceutical Society of Korea Vol.2-2
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• pp.233.3-234
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• 2003

Electroosmotic flux during iontophoresis originates due to the net negative charge of the current passing channel (pores) in skin at physiological pH (pH 7.4). Thus, the channel is permselective to cations, and this causes the convective solvent flow, from anode to cathode direction. This solvent flow facilitates the flux of cations (from anode), inhibits that of anions (from cathode), and enables the enhanced transport of neutral, polar solutes. In this work, we have investigated the effect of a series of polyethylene glycols (PEGs) with different molecular weights on the electroosmtic flow to get more detail understanding of this phenomena. (omitted)

• 한국환경생태학회지
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• 제38권2호
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• pp.217-226
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• 2024

본 연구는 공기 중 음이온이 미세먼지(PM10, PM2.5) 정화에 미치는 영향을 파악하고, 식물이 공기 중 음이온 발생과 미세먼지 정화에 미치는 영향을 평가하기 위하여 음이온 발생요인별 음이온 발생량을 측정하고, 각 요인별, 식물 용적별 미세먼지 저감 모형을 구축하여 비교하였다. 음이온 발생요인별 특성은 Type N.I(Negative ion generator; 204,133.33ea/cm³) > Type P₃₀(Plant Vol. 30%; 362.55ea/cm³) > Type C(Control; 46.22ea/cm³)의 순으로 음이온 발생량을 살펴보면 무처리구에 비하여 음이온 발생기 처리구에서 약 4,417배, 식물 배치구에서 약 8배 많았다. 이에 따른 음이온 발생원별 미세먼지 저감 특성은 PM10에서 Type NI가 Type C에 비하여 정화효율이 2.52배, Type P30이 1.46배 높았으며, PM2.5의 경우, Type NI가 Type C에 비하여 정화효율이 2.26배, Type P30이 1.31배 높은 것으로 분석되었다. 식물의 용적별 미세먼지 정화 효율은 Type P₂₀(84.60분) > Type P₃₀(106.50분) = Type P₂₅(115.50분) = Type P₁₅(117.60분) > Type P₅(125.25분) = Type P₁₀(129.75분)의 순이었으며, 초미세먼지의 경우 Type P₂₀ (104.00분) > Type P₃₀(133.20분) = Type P₂₅(144.00분) = Type P₁₅(147.60분) > Type P₅(161.25분) = Type P₁₀ (168.00분)의 순이었다. 이렇게 음이온의 미세먼지 정화 능력과 식물의 미세먼지 정화능력을 정량적으로 분석하였으며, 향후 미세먼지 정화를 고려한 녹지계획 및 식물식재에 고려해야할 사항을 제안하였다.

• 상하수도학회지
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• 제23권1호
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• pp.113-119
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• 2009

The feasibility of using cork oak bark for phosphorus removal from wastewater was evaluated in this study. Recently, development of more cost-effective media while maintaining high efficiency in pollutants removal has received concern. Barks have a negative surface charge and, hence, tend to show a high affinity to bind cations, and they need to undergo chemical modification to increase their adsorption capacity of anions. Bark was hydrolyzed by HCl solution and it received modification using an aqueous solution of high molecular weight polyethylenimine(PEI). Surface modification with HCl and PEI resulted in a decrease of specific surface area of the bark from $1.932 m^2/g$ to $1.094 m^2/g$. The adsorption experiments were carried out in batch tests and the data were fitted to the Langmuir isotherm and Freundlich isotherm equations. Phosphate removal rate was higher at the lower solution pH possibly due to the form of phosphate ion in solution. For the initial phosphate concentration of 10 mg/L, maximum adsorption was 20.88 mg P/g at pH 3 and 12.02 mg P/g at pH 5. Mechanism of phosphorus sorption onto the HCl-PEI bark was examined through FT-IR spectrometer. Ion exchange between $NH^+$ and $H_2PO_4{^-}$ appeared to be a key mechanism of phosphate adsorption onto the HCl-PEI bark surface.

• Bulletin of the Korean Chemical Society
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• 제34권12호
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• pp.3659-3664
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• 2013

Eight representative explosives (ammonium perchlorate (AP), ammonium nitrate (AN), trinitrotoluene (TNT), 2,4-dinitrotoluene (DNT), cyclonite (RDX), cyclotetramethylenetetranitramine (HMX), pentaerythritol tetranitrate (PETN), and hexanitrostilbene (HNS)) were comprehensively analyzed with an ion trap mass spectrometer in negative ion mode using direct infusion electrospray ionization. MS/MS experiments were performed to generate fragment ions from the major parent ion of each explosive. Explosives in salt forms such as AP or AN provided cluster parent ions with their own anions. Explosives with an aromatic ring were observed as either $[M-H]^-$ for TNT and DNT or $[M]^{{\cdot}-}$ for HNS, while explosives without an aromatic ring such as RDX, HMX, and PETN were detected as an adduct ion with a formate anion, i.e., $[M+HCOO]^-$. These findings provide a guideline for the rapid and accurate detection of explosives once portable MS instruments become more readily available.