• Title/Summary/Keyword: surface functional groups

Search Result 572, Processing Time 0.031 seconds

Changes of Functional Properties of Acylated Fish Protein (Acyl화에 의한 어류 단백질의 이화학적 성질의 변화)

  • Bang, Chan-Sik;Kim, Ze-Uook
    • Applied Biological Chemistry
    • /
    • v.33 no.1
    • /
    • pp.52-61
    • /
    • 1990
  • Fish protein was acylated with acetic anhydride(AA), succinic anhydride(SA) and maleic anhydride(MA) in order to improve the functional properties of the protein. The surface hydrophobicity and functional properties of protein were measured to study the relationship between them. It was found that the extented acylation of nucleophilic groups such as amino and sulfhydryl groups of the amino acid residues of fish protein was higher than other groups when acylated with AA, and the degree of acylation was 89.5 % for amino groups and 72.2 % for sulfhydryl groups. The surface hydrophobicity of fish protein was decreased by succinylation and maleylation, whereas acetylation caused tittle change. The acylated fish protein concentrate(FPC) showed higher surface hydrophobicity than the acylated fish myofibrilla protein(FMP). Acylation with AA, SA and MA of fish protein resulted in a significant increase in protein solubility, emulsifier properties, foaming properties, water adsorption capacity and oil adsorption capacity. These properties of acylated FMP were more improved than those of acylated FPC. Decrease in protein hydrophobicity was highly correlated with increase in protein solubility, and emulsifier properties and foaming properties were largely dependent on the solubility as well as surface hydrophobicity. The water adsorption capacity of the protein was significantly affected by solubility. Surface hydrophobicity had greater influence on oil adsorption capacity, whereas it had tittle effect on water adsorption capacity.

  • PDF

Surface Treatment of Polypropylene using a Large Area Atmospheric Pressure Plasma-solution System (대면적 대기압 플라즈마-용액 시스템을 이용한 폴리프로필렌 표면 처리)

  • Tran, Chinh Quoc;Choi, Ho-Suk
    • Korean Chemical Engineering Research
    • /
    • v.49 no.3
    • /
    • pp.271-276
    • /
    • 2011
  • We investigated the possibility of introducing functional groups without damaging surface polymeric chains through the treatment of a polypropylene(PP) film immersed in liquid phase using an atmospheric pressure plasma with large area. The ionic liquid of 1-butyl-3-methylimidazolium tetrafluoroborate: $[BMIM]^{+}[BF_{4}]^{-}$- was successfully applied for generating stable plasmas in the plasma-solution system. We successfully treated the film surface using the plasma-solution system and confirmed various oxygen-containing functional groups formed on the surface of PP film. The surface free energy of PP film was increased with increasing plasma treatment time and power. It also showed a maximum value at the PP sample treated in the ionic liquid solution of 1.5 M. ATR-FTIR analyses revealed the increase of various carbonyl groups(1,726 $cm^{-1}$, 1,643 $cm^{-1}$) and OH groups$(3,100{\sim}3,500\;cm^{-1})$ after plasma treatment of PP film, and XPS also supported the ATR-FTIR result.

Dielectric Polymers for OTFT Application

  • Choi, Sung-Lan;Kim, Yeon-Ok;Kim, Hong-Doo
    • Journal of Information Display
    • /
    • v.11 no.3
    • /
    • pp.95-99
    • /
    • 2010
  • A series of new dielectric polymers with phenyl, epoxy, and carboxylicacid functional groups was prepared via free-radical polymerization. The effect of such dielectric polymers with various functional groups on the performance of OTFT was investigated. The nonpolar groups of terpolymer made the surface of the dielectric layer more hydrophobic and improved the crystal growth of pentacene on the gate insulator, resulting in higher mobility. By controlling the functional group, the electric characteristics of OTFT performance was varied, with $0.00017-0.15\;cm^2/V{\cdot}s$ mobility.

Influence of Plasma Treatment on Hydrogen Chloride Removal of Activated Carbon Fibers

  • Park, Soo-Jin;Kim, Byung-Joo;Ryu, Seung-Kon
    • Carbon letters
    • /
    • v.5 no.3
    • /
    • pp.103-107
    • /
    • 2004
  • The atmospheric pressure plasma treatments ($Ar/O_2$ and $Ar/N_2$) of activated carbon fibers (ACFs) were carried out to introduce hydrophilic functional groups on carbon surfaces in order to enhance the hydrogen chloride gas (HCl) adsorption. Surface properties of the ACFs were determined by XPS and SEM. $N_2$/77 K adsorption isotherms were investigated by BET and D-R (Dubinin-Radushkevich) plot methods. The HCl removal efficiency was confirmed by HCl detecting tubes (range:1~40 or 40~1000 ppm). As experimental results, it was found that all plasma-treated ACFs showed the decrease in the pore volume, but the HCl removal efficiency showed higher level than that of the untreated ACFs. This result indicated that the plasma treatments led to the conformation of hydrophilic functional groups on the carbon surfaces, resulting in the increase of the interaction between the ACFs and HCl gas.

  • PDF

Surface Characterization and Morphology in Ar-Plasma-Treated Polypropylene Blend

  • Weon, Jong-Il;Choi, Kil-Yeong
    • Macromolecular Research
    • /
    • v.17 no.11
    • /
    • pp.886-893
    • /
    • 2009
  • Surface modifications using a radio frequency Ar-plasma treatment were performed on a polypropylene (PP) blend used for automotive bumper fascia. The surface characterization and morphology were examined. With increasing aging time, there was an increase in wettability, oxygen containing polar functional groups (i.e., C-O, C=O and O-C=O) due to oxidation, the amount of tale, and bearing depth and roughness on the PP surface, while there was a decrease in the number of hydrocarbon groups (i.e., C-C and C-H). AFM indicated that the Ar-plasma-treatment on a PP blend surface transforms the wholly annular surface into a locally dimpled surface, leading to an improvement in wettability. SEM showed that the PP layer observed in the non-plasma-treated sample was removed after the Ar-plasma treatment and the rubber particles were exposed to the surface. The observed surface characterization and morphologies are responsible for the improved wettability and interfacial adhesion between the PP blend substrate and bumper coating layers.

The Changes of Lumbar Stabilization Exercise on Balance with a Variety of Supporting Surface in Chronic Hemiplegia (다양한 지지면에서의 요부안정화운동이 만성편마비환자의 균형에 미치는 변화)

  • Lim, Jinyong;Kim, Dayeon
    • Journal of The Korean Society of Integrative Medicine
    • /
    • v.3 no.3
    • /
    • pp.9-16
    • /
    • 2015
  • Purpose : The purpose of this study was to demonstrate the effects of lumbar stabilization exercise on static and dynamic balance performance with unstable supporting surface and an even surface. Methods : The subjects of this experimental study were 30 patients among hospitalized stroke patients. They were randomly divided into two groups: unstable supporting surface group(USS; n=15) and an even surface group(ES; n=15). The lumbar stabilization exercise program for patients in two groups went through 40 minute exercise sessions three times a week for 8 weeks. To analyze the effects of a variety of supporting surface, Functional reaching test(FRT), Berg's balance scale(BBS), and Overall stability index(static balance) were measured before and after the exercise. The paired t-test was used to compare mean differences between before and after exercis and the independent t-test was used to compare mean differences between groups. Results : After 8 weeks exercise program, there were significant differences between before and after exercise in FRT, BBS, and static balance. But there were not significant differences in balance between two groups. Conclusion : This study suggest that lumbar stabilization exercise on unstable supporting surface and an even surface can improve FRT, BBS, and a static balance.

A Study on the Adsorption Characteristic of Low Concentration Phenol by Activated Carbon (저농도(低濃度) 페놀의 활성탄(活性炭)에 대한 흡착특성(吸着特性)에 관(關)한 연구(硏究))

  • Kwon, Dae-Young;Park, Chung-Hyun
    • Journal of Korean Society of Water and Wastewater
    • /
    • v.8 no.1
    • /
    • pp.34-43
    • /
    • 1994
  • It is well known that the adsorption character of activated carbon is dependent on the specific surface area and pore volume, but the relationship between the surface-chemical structure and the adsorption character has not been studied very often. The purpose of this study is to investigate the effect of the acidic surface functional groups of activated carbon and the adsorption characteristics of low concentration phenol. So three types of activated carbons and four different treatments were introduced to this isotherm experiment. These treatments were nontreatment, 1N $HNO_3$ treatment, 6N $HNO_3$ treatment, $H_2O_2$ treatment. The conclusions of this study are as followings. If the initial concentration of phenol is high as 5mg/l, the adsorption is dependent on the specific surface area. If the initial concentration of phenol is low as $100{\mu}g/l$, the adsorption is dependent on the average pore volume. The acidic surface functional groups prevent the adsorption of phenol molecules to activated carbon. And the adsorbed amount decreases more for $HNO_3$ treatment than for $H_2O_2$ treatment and more for concentrated $HNO_3$ treatment than for dilute $HNO_3$ treatment.

  • PDF

Dispersion Characteristics of Surface-Modified Graphene Nanoplate in Organic Solvent for Development of Graphene / Epoxy Paint to Protect Concrete (콘크리트 보호용 그래핀/에폭시 도료개발을 위해 표면개질한 그래핀 나노플레이트의 유기용매 분산특성)

  • Seo, Won-Woo;Kim, Gyu-Yong;Yoon, Min-Ho;Lee, Sang-Kyu;Hwang, Eui Chul;Son, Min-Jae
    • Proceedings of the Korean Institute of Building Construction Conference
    • /
    • 2017.05a
    • /
    • pp.244-245
    • /
    • 2017
  • This study aims to develop high durability graphene / epoxy paint for durability improvement of construction structure. For the development of graphene / epoxy coatings, first, graphene must remain stable in the polymer. Second, the integrity of graphene and polymer should be ensured. Accordingly, in order to obtain dispersibility, surface modification of graphene nanoplate(GnP) with CH and COOH functional groups and its dispersibility in organic solvents were investigated. Also, Fourier Transform Infrared Spectroscopy(FT-IR) analysis and Atomic Force Microscope(AFM) analysis were performed to confirm whether the functional groups were synthesized by surface modification. As a result, FT-IR and AFM analysis did not confirm the surface modification, but GnP was found to be stable when dispersed in an organic solvent.

  • PDF

Activated Carbon Fibers from Chemically Modified Coal Tar Pitches

  • Ryu, S.K.;Shim, J.W.;Yang, K.S.;Mochida, I.
    • Carbon letters
    • /
    • v.1 no.1
    • /
    • pp.6-11
    • /
    • 2000
  • Coal tar pitch was chemically modified with 10 wt% benzoquinone (BQ) to raise the softening point of isotropic pitch precursor and the precursor was melt-spun into pitch fibers, stabilized, carbonized and activated with steam at $900^{\circ}C$. The weight loss of carbon fiber-benzoquinone (CF-BQ) increased with the increase of activation time like other fibers, but was lower than those of Kureha fiber at the same activation time in spite of larger geometric surface area. Those adsorption isotherms fitted into 'Type I' according to Brunauer, Deming, Deming and Teller classification. However, there was very thin low-pressure hysteresis that lower closure points of the hysteresis are about 0.42-0.45. From the pore size distribution curves, there might be some micropores having narrow-necked bottle; a series of interconnected pore is more likely than discrete bottles. FT-IR studies showed that the functional groups such as carboxyl, quinone, and phenol were introduced to ACFs-BQ surface after steam activation. Methylene blue decolorization and iodine adsorption capacity of ACF-BQ increased linearly with the increase of specific surface area and was larger than that of ACF-Kureha at the same specific surface area.

  • PDF

Comparison of the Effects of Balance Training on the Stable and Unstable Supporting Surfaces for the Functional Ankle Instability (기능적 발목 불안정성에 대한 안정지지면과 불안정지지면에서의 균형훈련의 효과 비교)

  • Kim, Young-Min
    • The Journal of Korean Academy of Orthopedic Manual Physical Therapy
    • /
    • v.20 no.2
    • /
    • pp.1-7
    • /
    • 2014
  • Purpose: The purpose of this study was to compare the effects of the balance training on the stable and unstable supporting surfaces for the subjects with functional ankle instability. Methods: Twenty-nine subjects with functional ankle instability were randomly assigned to the stable group (n=14) and the unstable group (n=15). Balance training was conducted twenty minutes a day on the stable surface for the stable group and on the airostep for the unstable group three times a week for four weeks. Balance training program was consisted of ten steps by eye opened or closed and two or one leg standing. X-speed for transverse balance and Y-speed for longitudinal balance were measured with eye opened and closed in affected leg standing position. Results: There were significant improvements of balance ability in eye opened (p<.01) and eye closed standing (p<.01) in stable group. Unstable group also showed significant improvements of balance ability in eye opened (p<.01) and eye closed standing (p<.01). There were no statistical differences in the magnitude of improvement between the groups (p<.05). Conclusions: Based on such results, it can be said that balance training on the stable surface is effective as much as training on the unstable surface for the subjects with functional ankle instability.