• Title/Summary/Keyword: Hydrophilic group

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Self-assembled Micelle-based Fluorescence Sensor for Extremely Acidic pH Range (강산성 용액의 pH를 측정할 수 있는 미셀기반의 형광센서 개발)

  • Lee, Jeongmoo;Lee, Seoung Ho
    • Journal of Environmental Science International
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    • v.29 no.8
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    • pp.801-808
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    • 2020
  • In this study, an effective fluorescence pH sensor based on conjugated polyelectrolyte micelles (CPMs) was devised for detecting extremely acidic conditions. An amphiphilic coumarin derivative (CC12-N), a building block, was prepared, into which an ionizable amino group, aryl amine, was incorporated as a potential hydrophilic moiety. This monomer displays self-assembled micelle formation in extremely acidic pH ranges, giving a hydrophobic π-extended conjugated system at the inner part and hydrophilic functionality at the periphery, resulting in efficient fluorescence intensity enhancement. This new micelle-based fluorescence provides an efficient sensing platform for detecting very low pH values in the presence of competing substances.

Static Characteristic of Polyester Fiber by LT-Plasma Polymerization (저온플라즈마중합 처리한 폴리에스터 섬유의 대전특성)

  • 서은덕;강영립;박찬언
    • Textile Coloration and Finishing
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    • v.4 no.4
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    • pp.110-116
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    • 1992
  • For the modification of PET surface, Perfluoropropene and Methyl alcohol were LT-plasma polymerized on the PET fabrics as thin films by means of 13.56 MHz radio frequency generator. The surface properties of PET fabrics were modified from hydrophobic to hydrophilic by application of the postplasma reaction of thin films. The evidence of the modification was identified by observation of the presence of hydroxy group in IR spectrum and the evaluation of degree of hydrophilicity was performed by measuring frictional static voltage of PET fabric with cotton fabric. For the case of modification by PFP, the result performed at the condition of 25 W, 70 m torr has shown to be effective, and for MeOH, result performed at the condition of 25 W, 100 m torr effective. The effect of hydrophilic surface modification of MeOH plasma polymer was superior to that of PFP-plasma polymer.

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Synthesis of Low Molecular-weight Poly (Propylene Carbonate)-Poly (Ethylene Glycol) Block Copolymers through $CO_2$/Propylene Oxide Copolymerization (이산화탄소/프로필렌 옥사이드 공중합을 통한 저분자량 폴리(프로필렌 카보네이트)-폴리(에틸렌 글리콜) 블록 공중합체의 합성)

  • Lee, Sang-Hwan;Cyriac, Anish;Jeon, Jong-Yeob;Lee, Bun-Yeoul
    • Clean Technology
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    • v.17 no.3
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    • pp.244-249
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    • 2011
  • We synthesized low molecular-weight polymers bearing hydrophobic and hydrophilic parts in a chain through $CO_2$/propylene oxide copolymerization. When hydrophilic poly (ethylene glycol) bearing -OH group (s) at the end group (s) was added as a chain transfer agent in the $CO_2$/propylene oxide copolymerization catalyzed by a highly active catalyst, block polymers were formed. If poly (ethylene glycol) (PEG) bearing -OH group only at an end was fed, PEG-block-PPC diblock copolymer was obtained. When PEG bearing -OH group at both ends was fed, PPC-block-PEG-block-PPC triblock copolymer was obtained. We confirmed formation of block copolymers by $^1H$-NMR spectroscopy and GPC studies.

Formation of Liquid Crystal Gel with Hydrogenated Lecithin and Its Effectiveness

  • Kim In-Young;Lee Joo-Dong;Ryoo Hee-Chang;Zhoh Choon-Koo
    • Journal of the Society of Cosmetic Scientists of Korea
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    • v.29 no.2 s.43
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    • pp.181-191
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    • 2003
  • This study described about method that form liquid crystal gel (LCG) by main ingredient with hydrogenated lechin (HL) in OW emulsion system. Result of stability test is as following with most suitable LCG's composition. Composition of LCG is as following. To form liquid crystal, an emulsifier used $4.0\;wt\%$ of cetostearyl alcohol (CA) by $4.0\;wt\%$ of HL as a booster, Moisturizers contained $2\;wt\%$ of glycerin and $3.0\;wt\%$ of 1.3-butylene glycol (1,3-BG). Suitable emollients used $3.0\;wt\%$ of cyclomethicone, $3.0\;wt\%$ of isononyl isononanoate (ININ), $3.0\;wt\%$ of cerpric/carprylic triglycerides (CCTG), $3.0\;wt\%$ of macademia nut oil (MNO) in liquid crystal gel formation. On optimum conditions of LCG formation, the pHs were formed all well under acidity or alkalinity conditions. Considering safety of skin, PH was the most suitable $\pm61.0$ ranges. The stable hardness of LCG formation appeared best in $32\;dyne/cm^2.$ Particle of LCG is forming size of $1{\~}20\;{\mu}m$ um range, and confirmed that the most excellent LCG is formed in $1{\~}6\;{\mu}m$ range. According to result that observe shape of LCG with optical or polarization microscope, LCG could was formed, and confirmed that is forming multi-layer lamellar type structure around the LCG. Moisturizing effect measured clinical test about 20 volunteers. As a result, moisturizing effect of LCG compares to placebo cream was increased $30.6\%$. This could predicted that polyol group is appeared the actual state because is adsorbed much to round liquid crystal droplets to multi-lamellar layer's hydrophilic group. It could predicted that polyol group is vast quantity present phase that appear mixed because is adsorbed to round liquid crystal to multi-lamellar layer's hydrophilic group. This LCG formation theory may contribute greatly in cosmetics and pharmacy industry development.

Investigation of the Adsorption Phenomena of Surfactant on Hydrophilic Surface by Spectroscopic Method (분광학적 방법에 의한 계면활성제의 친수성 표면에 대한 흡착양상 연구)

  • Kim, Dong-Su
    • Journal of Korean Society of Environmental Engineers
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    • v.22 no.12
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    • pp.2215-2226
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    • 2000
  • Adsorption characteristics for homologous xanthates on quartz surface has been investigated by FT-IR spectroscopy to understand the adsorption mechanism in relation with verification of the influence of surfactants on the stability of hydrophilic suspended solids in aqueous system. Contact angle measurement for water droplets on quartz surface treated with xanthate was also conducted as a supplementary study for spectroscopic investigation to grant a reliability to the interpretation of experimental results. It has been observed that monolayer of ethyl xanthate was formed on quartz surface as the adsorption progressed and double layer of ethyl xanthate was formed eventually through the reverse oriented adsorption of xanthate molecules on the monolayer. Similar trend of adsorption to the case of ethyl xanthate was found for propyl and butyl xanthates and adsorption was observed to occur more rapidly as the number of carbon atom in alkyl group of xanthate homologs increased. Thermodynamic aspect of adsorption was discussed using Young's equation and the variation in adsorption rate was examined according to the concentration of ethyl xanthate. Based on the result, it has been concluded that the adsorption features of surfactant on substrate in aquatic system is governed by molecular structure and concentration of surfactant and its residual time in aqueous environment as dissolved state also influences greatly the stability of hydrophilic suspended particles.

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Synthesis and characterization of hydrophobic and hydrophilic cellulose derivative by esterification (친수성과 소수성을 동시에 가지는 아세틸화 셀룰로스 에테르의 합성 및 특성 평가)

  • Kim, Taehong;Lee, Sangku;Son, Byunghee;Paik, Hyun-Jjong;Yoon, Sanghyeon;Lee, Heesoo
    • Journal of the Korean Crystal Growth and Crystal Technology
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    • v.23 no.1
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    • pp.31-36
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    • 2013
  • Acetylated Cellulose Ether (ACE), cellulose-based amphiphilic polymer with hydrophilic and hydrophobic, was synthesized and investigated in terms of its solubility and wettability for organic solvents and water. Acetyl group was substituted to the cellulose ether in a hydrophilic polymer by esterification. As a result of FT-IR, the peak corresponding to the hydroxyl group decreased and carboxyl acid peak increased with increasing reaction time and temperature, which signified the increase in the degree of acetylation of the ACE. There were similar thermal decomposition behaviors before and after esterification reaction until $800^{\circ}C$ so that the reaction occurred without significant structural changes of cellulose backbones. The solubility parameter of the ACE had a range of 18.5~26.4, and its viscosity and turbidity were controlled according to the solubility parameter of organic solvents. The ACE showed the hydrophilicity because the contact angle of the ACE was higher than the cellulose ether. These results confirmed that the ACE had the hydrophobicity and hydrophilicity due to the ether which was glucosidic bonding between the glucose units and un-reacted hydroxyl functional groups in the ACE.

Fluorination of Polymethylmethacrylate (PMMA) Film and Its Surface Characterization (폴리메틸메타아크릴레이트(PMMA) 필름의 불소화 및 그 표면특성)

  • Jung, Min-Jung;Lim, Jae-Won;Park, In-Jun;Lee, Young-Seak
    • Applied Chemistry for Engineering
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    • v.21 no.3
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    • pp.317-322
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    • 2010
  • In this study, poly(methyl methacrylate) (PMMA) was treated with changing mixing ratios of $F_2$ and $O_2$ using oxyfluorination method for hydrophilic modification of PMMA film. For the characterizations of oxyfluorinated PMMA surface, contact angle, surface free energy, X-ray photoelectron spectroscopy (XPS) and optical transmittance (UV-vis) were carried out. After the oxyfluorination, PMMA surface became more hydrophilic showing the decrease of water contact angle from $69^{\circ}$ to $44^{\circ}$. So, surface free energy of oxyfluorinated PMMA film was increased from 46 to $58\;mN\;m^{-1}$. These results are attributed to hydrophilic functional groups such as hydroxyl group formed oxyfluorination method on the PMMA surface. From XPS results, it was confirmed that O/C concentration ratio on the surface of PMMA was increased, the amount of C-OH bonding which shows hydrophilicity was also largely increased from 6.7 to 24.8% with increasing fluorine partial-pressure via the oxyfluorination, The oxyfluorination conditions, room temperature, 1 bar with one mixture ratio of $F_2$ to $O_2$ had little influence on optical transmittance properties of PMMA film but enhanced its surface hydrophilicity. This result suggests that oxyfluorination method could be useful to change hydrophobic PMMA surface to hydrophilic.

Analysis of the Correlation between Social Factors and the Use of Hydrophilic Facilities by Age Group - Case Study at the Samrak and Daejeo Ecological Park (사회적 요인 및 연령대별 친수공원 이용에 관한 상관관계 분석 - 삼락과 대저생태공원을 대상으로)

  • Choi, In-Ho;Lee, Min-Young;Yoon, Hee-Ra;Kim, Seong Jun;Kim, Chang Sung
    • Ecology and Resilient Infrastructure
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    • v.8 no.4
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    • pp.273-280
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    • 2021
  • In the past, the government made a total of 357 hydrophilic districts into parks to create rest areas in the national river with the four major river projects. According to the results of the survey, 60 water-friendly districts with low utilization were lifted in January 2017, and 297 water-friendly districts are currently being managed. Local governments are in charge of the maintenance costs necessary to maintain these hydrophilic districts, which require considerable costs, so it is necessary to accurately grasp the characteristics and needs of local residents at the operation stage after designation. In this study, the characteristics of local residents in the hydrophilic district were analyzed by correlating social factors with river users, crawling social network data to analyze visit patterns, and derived related Keywords, and analyzed the characteristics of the hydrophilic district. The study target areas are Samrak and Daejeo Ecological Park, located downstream of the Nakdonggang River. Social factors analyzed real estate transaction price data, economic activity income, households, stress perception rate, and pet breeding status through public data provided by Statistics Korea, and analyzed user visit patterns and image keywords on weekends.

Pattern of Molecular Aggregation of Ginsenosides in Aqueous Solution (수용액(水溶液)에서 인삼배당체(人蔘配糖體)의 분자결합양상(分子結合樣相))

  • Park, Hoon;Lee, Mee-Kyoung;Park, Qwi-Hee
    • Applied Biological Chemistry
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    • v.29 no.2
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    • pp.198-206
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    • 1986
  • For the information on micellization at each ginsenoside level aqueous solution of purified saponin of Panax ginseng root was dialyzed through dialysis tubing (MW 12,000) or eluted through Bio-Gel P-2 (MW 200-2,000) and analysed for ginsenosides by high performance liquid chromatography. Ginsenosides can be classified into three groups depending upon molecular aggregation pattern and spatial arrangement of hydrophilic parts in molecule. Group I that is large micelle former(aggregation number: above 10) and one side hydrophilic part (HP) includes $ginsenoside\;Rb_1$, $Rb_2$, Rc and Rd (diols). Group II thai is small micelle former (aggregation number:>10-1) and semi-two sales HP includes $Rg_2$, Rf (triol) and $Rg_3$ (diol). Group III that is no micelle former (aggregation number: 1) and two sides HP includes Re and $Rg_1$ (triol).

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Effect of Fractionated Organic Matter on Membrane Fouling (분류된 천연유기물질을 이용한 막 오염 특성 평가)

  • Lee, Byung-Gu;Son, Hee-Jong;Roh, Jae-Soon;Hwang, Young-Do;Jung, Chul-Woo;Kang, Lim-Seok
    • Journal of Korean Society of Environmental Engineers
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    • v.27 no.12
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    • pp.1321-1326
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    • 2005
  • As a results of this research, the Nakdong River consisted of 43% of hydrophobic fraction, 39% of hydrophilic fraction, and 18% of transphilic fraction. The hydrophobic fraction in this raw water was mostly fulvic acid. Fulvic acid comprised of 62% and the rest was humic acid(38%). There was more carboxylic acid functional roup(64%) than phenolic group(36%). HPI-N and HPI-C comprised of 17% and 22% in the hydrophilic portion, respectively. The results of the membrane fouling test using UF membrane according to NOM fractions. HPI-N caused more fouling than HPI-C. Humic acid caused more fouling than fulvic acid probably due to higher adsorption capacity. Since humic acid has higher adsorption capacity than fulvic acid, it would be more adsorbed onto the membrane pores. The carboxylic acid functional group caused more fouling than the phenolic group.