• Title/Summary/Keyword: Chitin

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Preparation and Characterization of Microcrystalline Chitin from Crab Shell (게 껍질로부터 Microcrystalline Chitin 제조와 특성 규명)

  • 김성배
    • KSBB Journal
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    • v.11 no.4
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    • pp.481-488
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    • 1996
  • In spite of diverse applications of chitin derivatives, commercial use of chitin has been limited due to highly resistance to chemicals and the absense of proper solvents. One of methods to reduce such high resistance to chemicals is to make microcrystalline chitin(MCC) by hydrolysis of chitin. Presently, MCC is produced mainly by using high concentration of acid, but this treatment requires an extensive posttreatment to remove or recover acid. An alternative process for MCC production was developed by using dilute hydrochloric acid with ultrasound and hydrogen peroxide. The major parameters for this process were found to be acid concentration, swelling time and temperature, and irradiation time and frequency of ultrasound. The effects of these parameters on MCC molecular weight were investigated. The molecular weight of MCC produced at a typical condition was around 30,000 which was approximately 1/8 of that of chitin and approached to a constant value. This phenomenon was explained by introducing the model of molecular arrangement of cellulose. SEM analysis showed that both chitin and MCC had a fibrous shaped morphology and the fibril size of MCC was much smaller than that of chitin.

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A Study on Adsorption Characterics of Metallic Ions by Tannin Immobilized on Chitin and Chitosan (Chitin 및 Chitosan에의 고정화 탄닌의 금속이온 흡착특성에 관한 연구)

  • Kim, Chang-Ho;Chang, Byung-Kwon;Choi, Kyu-Suk
    • Applied Chemistry for Engineering
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    • v.4 no.1
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    • pp.204-215
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    • 1993
  • Epoxy-activated chitin was synthesized by the reaction of epichlorohydrin with chitin which was isolated from waste marine sources such as crab shell. Followed by the reaction of epoxy-activated chitin with hexamethylenediamine, the aminohexyl chitin was synthesized. The aminohexyl chitin was subsequently reacted with epichlorohydrin to prepare the epoxy-activated aminohexyl chitin. Finally, the tannin-immobilized chitin (Resin I) was synthsized by the reaction of tannin solution with epoxy-activated aminohexyl chitin. Using silane coupling agent, the tannin-immobilized chitosan(Resin II) was synthesized by the reaction of $\gamma$-glycidoxypropyltrimethoxy silane with chitosan which was prepared by the deacetylation of chitin. Upon the pH variation, adsorptivities of these immobilized tannins to the metal ions such as $Cu^{+2}$, $Ni^{+2}$, $Cr^{+6}$, $Co^{+2}$, $Ca^{+2}$, $Pb^{+2}$, $Ba^{+2}$, and $UO_2{^{+2}}$ ions were determined by batch method. The adsorptivity tendencies of these immobilized tannin to the most of metallic ions were increased with pH. Furthermore, the adsorptivities of Resin(I) and Resin(II) upon the variation of pH, contact time, amount of resin and concentration of metal ion were investigated. As a result, it was found that these immobilized tannin on both chitin and chitosan showed good adsorptivities for uranyl ion.

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Effects of pH and Molecular Weight on the Intrinsic Viscosity of Carboxymethyl Chitin (Carboxymethyl Chitin의 고유점도에 미치는 pH 및 분자량의 영향)

  • PARK Seong-Min;LEE Keun-Tai
    • Korean Journal of Fisheries and Aquatic Sciences
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    • v.28 no.4
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    • pp.487-491
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    • 1995
  • Effects of pH and molecular weight on the intrinsic viscosity of carboxymethyl chitin (CM-chitin) in dilute regime were studied. When the prepared CM-chitin was dissolved in 0.1M NaCl solution at $30^{\circ}C$, the intrinsic viscosity, molecular weight and degree of substitution of CM-chitin were 1.23dl/g, 15,500 and 0.62, respectively. The lower intrinsic viscosity $([\eta])$ of CM-chitin was showed at the lower pH than 7.0 and the higher pH (>7.0) did not result in any increase in intrinsic viscosity. Intrinsic viscosity decreased from 3.1dl/g to 2.55d1/g in water at $25^{\circ}C$ and from 15,500 to 12,600 as molecular weight for 20min of sonication treatment. The Mark-Houwink constant K and v of CM-chitin in water at $25^{\circ}C$ were $3.48\times10^-4$ and 0.94, respectively. So intrinsic viscosity could be expressed using molecular weight as followed equation; $[\eta]=3.48\times10^{-4}M^{0.94}$, consistent with random roil behaviour.

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Optimal Production of N-acetyl-$\beta$-D-glucosamine Using Chitinolytic Enzyme (Chitinolytic Enzyme을 이용한 N-acetyl-$\beta$-D-glucosamine의 최적생산)

  • 이천우;이은영장상목김광
    • KSBB Journal
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    • v.11 no.6
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    • pp.696-703
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    • 1996
  • The bacterium Serratia marcescens QM Bl466 produces selectively large amount of chitinolytic enzymes(about 1mg/L medium). Enzymatic hydrolysis of chitin to N-acelyl-${\beta}$-D-glucosamine(NAG) is performed by a system consisting of two hydrolases : chitinase and chilobiase. Objectives of this study included optimization of a microbial host by using chitin particles for chitinase/chitobiase production and secretion and also development of batch fermentation system for high cell density cultivalion of S. marcescens QM B1466. Also, the influence of chitin source and carboxymethyl(CM) chitin on chitinase/chitobiase production and NAG production was investigated. When carboxymethyl chitin was substituted for colloidal and practical grade chitin, the chitinase activity was increased about 7∼10U/mL. In this case, the ratio of chitinase/chitobiase was 30.03U/3.44U(9:1). The highest amounts of NAG(3.0g/L) was obtained.

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Mechanical Reinforcement of Electrospun Poly(L-lactic acid)(PLLA) Nanofibers with Chitin (키틴을 이용한 폴리(L-젖산)(Poly(L-lactic acid)(PLLA)) 전기방사 나노섬유의 기계적 보강)

  • Moon, Hyunwoo;Choy, Seunghwan;Hwang, Dong Soo
    • Journal of Marine Bioscience and Biotechnology
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    • v.11 no.2
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    • pp.36-41
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    • 2019
  • This study was conducted to analyze the difference in mechanically improved properties by distinguishing α-chitin and β-chitin for Poly(L-lactic acid)(PLLA). First, dissolution of chitins was established by mixing polar solvents hexafluoroisopropanol (HFIP) and trifluoroacetic acid (TFA) in appropriate proportions. Under these conditions, the dissolved chitin was used for electrospinning with other polymers. The electrospun nanofibers of the PLLA and chitins were successfully produced. Compared to the pristine state, when chitin was added to PLLA, the tensile strength increased 1.41 times (α-chitin), by 1.61 times (β- chitin), respectively. Based on this, it was confirmed that α- and β- chitin could be strategically used for different polymers. The results also suggest that chitin can be applied to various fields as good reinforcing material as well as electrospinning.

Decoloration in Dyebath by Dye Absorption of Chitin(Part I) (키틴의 염료 흡착에 의한 염액의 색소제거에 관한 연구(제1보))

  • 유혜자;이혜자;이전숙
    • Journal of the Korean Society of Clothing and Textiles
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    • v.24 no.3
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    • pp.385-392
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    • 2000
  • The adsorption ability of dyes on chitin, a natural polymer was investigated for decolorization of dye wastewater. Chitin was manufactured in lab by decalcification in dilute aqueous HCI solution and deproteination in dilute aqueous NaOH solution with shrimp shells. Absorbance of residue solution of dyebaths after dye adsorptions of chitin were measured in varieties of dye concentration and dipping periods. Four kinds of dyestuffs were used, C.I.Acid Blue 29. C.I.Direct Blue 6, C.I.Reactive Orange 12 and C.I.Basic Red 18. When chtin 1g was dipped in 0.05% of dyebath with stirring, maximum adsorption ratio of each kind of dyes was exhibited as 91.6% for C.I.Acid Blue 29, 95% for C.I.Direct Blue 6, 58.2% for C.I.Reactive Orange 13 and 75.8% for C.I.Basic Red 19. It shows that chitin has better adsorption abilities of ionic dyes of acid, direct and basic dye than non-ionic reactive dye. And chitin has better adsorption abilities of anionic acid direct dyes than cationic basic dye because of the presence of nitrogen atoms. All kinds of dyestuffs used showed speedy absorption effects by chitin, so chitin can absorb much amount of dyes in 5 mimutes reach to equilibrium of adsorption in 2 hours after dipping. Basic dye was absorbed the most speedily in 5 minutes, although maximum adsorption ratio is not high. That reason can be thought that chitin surface is essentially negatively charged due to polar funtional groups.

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The Production of Ginsenosides from Ginseng Hairy Root by Treatment of the Chitin and Chitosan (Chitin과 Chitosan 처리에 의한 인삼모상근으로부터 Ginsenosides 생산)

  • 오승용;박효진;최경화;맹성주;양계진;양덕춘
    • Journal of Ginseng Research
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    • v.24 no.2
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    • pp.68-73
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    • 2000
  • To elucidate the effect of chitin and chitosan on the production of ginsenosides and growth, ginseng hairy root was cultured on the 1/2 MS medium supplemented with chitin and chitosan of various concentrations and culture period. The highest growth was obtained with 1 mg/L of chitin. However, the growth was inhibited by 20 mg/L or above. The contents and productivity of ginsenosides were the highest when ginseng hairy roots were cultured on 40 mg/L chitin and applied of the third-weeks of culture period. Ginseng hairy root culture with 1 mg/L of chitosan resulted in the best growth, but the highest ginsenosides level was appeared in 30 mg/L chitosan. Ginsenosides content was increased when it was treated at the forth-week after culture as 30 mg/L of chitosan.

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Development of New Biocompatible Fiber form Composite of Chitin and Cellulose (카틴과 셀룰로우스의 복합체로부터 새로운 생체흡수성 봉합사의 개발)

  • 이충우;홍영근이화섭윤정원
    • KSBB Journal
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    • v.8 no.3
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    • pp.237-242
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    • 1993
  • Chitin-based fibers have low mechanical strength and hence cannot be used as surgery fiber due to fast degradation In tissues. A new fiber Chitulose was made by mixing chitin with cellulose, both of which have similar structure. A mixture of dimethylacetamide (DMAc) and 6% lithium chloride (LiCl) was found to be an effective solvent system for dissolvoing chitin and cellulose. The Chitulose fiber made by wet spinning of a mixture of chitin and cellulose resulted in the highest degree of strength and flexibility when the ratio of chitin to cellulose was 1.5; 0.2. The fiber maintained mechanical structure even after autoclaving, indicating thermal stability. A biodegradability test of the Chitulose fiber by imbeding in a rat showed that degradation was initiated in 14 days and completely done in 40 days.

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Characteristics of Chitin and Chitosan Derived from Caridina japonica (토하(Caridina Japonica) 로부터 추출, 제조한 Chitin , Chitosan의 특성)

  • 박원기;김희경;김광윤;범희승;김지열
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.23 no.2
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    • pp.353-357
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    • 1994
  • The aim of the present study was to investigate the characteristics of chitin and chitosan derived from Caridina japonica (CJ) which is using as one of fermented products in the chonnam province of Korea. Percent of chitin produced from CJ was 9.6 $\pm$0.2%. Percent of chitosan derived from chitin was 72.5$\pm$3.6% . Viscosities of chitin and chitosan were 94.4 and 96.7 cps. Molecular weight of them were 4,398,900 and 4,101.100 , respectively. Percents of protein bound to chitin and chitosan were 2.7% and 2.6%, respectively.

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Preparation and Evaluation of Chitin Derivatives and Their Utilization for Waste-water Treatement

  • Aly, Aly Sayed;Jeon, Byeong-Dae;Kim, Young-Jun;Park, Yun-Heum
    • Proceedings of the Korean Fiber Society Conference
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    • 1996.10a
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    • pp.53-58
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    • 1996
  • The Chitin Thiocarbonate-Fe(II)-H2O2 redox initiator system was investigated for the graft copolymerization of acrylonitrile(AN) and acrylic acid(AA) monomers onto chitin powder. The reactions with vinyl monomers onto chitin were carried out under various the graft copolymerization conditions to elucidate the polymerization behavior in terms of graft yield. Reactions of chitin-acrylonitrile graft copolymer with hydroxyl amine hydrochloride and those with sodium hydroxide were conducted in order to obtain chitin-(amidoxime-co-acrylonitrile) and chitin-(acrylate-co-acrylamide) graft copolymers, respectively. The reaction efficiency was observed to depend on the alkali concentration, time, temperature, and the reactant concentrations. The prepared chitin derivatives were evaluated to find potential applications for use in wastewater treatments for adsorption and desorption of heavy metal ions as well as acidic and basic dyes.

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