• Journal of Environmental Health Sciences
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• v.24 no.3
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• pp.48-53
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• 1998

Chitin is known as biodegradable natural polymer. But, in spite of various application of chitin from waste marine sources, commercial use of chitin has been limited due to highly resistance to chemicals and the absense of proper solvents. We made various viscosity of chitosan from chitin by change of Mima's method through the deacetylation which is various condition of NaOH concentration, reaction time and temperature. Also, Polyvinyl alcohol/chitosan blend films were prepared by different solution blends containing the ratio of 5, 10, 15 and 20% chitosan and low, medium, high molecular weight of chitosan to find a more useful biodegradable polymer. Thermal and mechanical properties of PVA/chitosan blend films such as DSC, impact strength, tensile strength and morphological changes by SEM were determined. The 10-15% PVA/chitosan(low, medium) blend films were similar to PVA. Also, PVA/chitosan blend films at the laboratory soil test(Pot Test) were completely degraded in month with four kinds of soils by microorganisms.

• Macromolecular Research
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• v.14 no.3
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• pp.267-271
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• 2006

Polyelectrolyte complex films were prepared with two compounds, chitosan and poly(ethylene glycol)-monosuccinate, using a casting in order to synthesize a polyelectrolyte complex film with various mole ratios of chitosan and poly(ethylene glycol)-monosuccinate. The solution properties of isolated PEC were investigated for the effects of FTIR, pH value, Brookfield viscosity and cell viability assay using MTT staining. The PEC films were evaluated for mechanical properties by typical stress-strain curve, far thermal properties by DSC and TGA and for surface morphology Properties by SEM. Furthermore, the surface resistance, moisture regain and water content of the films were characterized. The solution properties were affected by several factors including the chitosan content in the PEC, the mixing ratio of PEG and chitosan, and pH. Several PEC in acidic conditions exhibited film formation under appropriate conditions of mixing ratio and chitosan concentration in the mixing process. These PEC films were found to have sufficiently flexible and stable properties due to their hydrophilic structure, which was farmed by the oppositely charged interaction between PEG-MS and chitosan matrix. The results showed the potential applicability of chitosan and poly(ethylene glycol)-monosuccinate films as a biocompatible polymer.

• Journal of Environmental Health Sciences
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• v.24 no.2
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• pp.104-109
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• 1998

The objective of this study was to examine the effect of polymer coating on the initial microorganism attachment and the biofilm growth. Such as nonion(polyacrylamine), anion(CMC-Na) and cation polymer coagulant(chitosan and PEI) were used for coating material of the support carrier(acryl plate). When polymer coagulant was coated with 5, 10, 20, 35, 50, 100 and 200 mg/l on the surface of acryl plate, initial microorganism attachment increased and optimum concentration for the attachment was 35 mg/l. Biofilm growth experiments were conducted with the substrate loading of 12.7gSCOD/$m^2\cdot$ day using RBC. The polymer coagulants such as CMC-Na, polyacrylamide, PEI and chitosan coating on the acryl plate facilitated the biofilm growth of microorganisms. Until the biofilm dry weight grows up to 0. 0038g/cm$^2$, biofilm growth on the plate coated with cation polymer like chitosan was better than that on the coated plate of nonion(polyacrylamine), anion(CMC-Na) polymer coagulant.

• Membrane Journal
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• v.28 no.3
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• pp.205-213
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• 2018

In this study, cross-linked membrane were successfully prepared by using brominated PPO (Br-PPO) as the main polymer chain. Chitosan and quaternary ammonium modified chitosan (QA-chitosan) was used as the cross linking agents. The cross linked membranes were post-functionalized by using trimethylamine solution. The degree of cross linking was also controlled by varying the ratio of cross linking agent. The applicability of the cross-linked membrane (A-PPO + chitosan, A-PPO + QA-chitosan) as ion exchange membranes was verified through various characterization techniques. The cross-linked membrane using QA-chitosan as cross linking agent was found to be better in performance than the membrane using pristine chitosan cross linking agent. As the percentage of QA-chitosan increased, the ion exchange capacity from 1.18 meq/g to 1.53 meq/g and water uptake from 21.6% to 42.2% was improved.

• Polymer(Korea)
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• v.38 no.5
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• pp.588-595
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• 2014

A semi-interpenetrating polymer network (semi-IPN) hydrogel composed of crosslinked chitosan and poly (acrylic acid-co-crotonic acid) was prepared in the presence of glutaraldehyde (GA) as a crosslinker. Fourier-transform infrared, thermogravimetric analysis and scanning electron microscopy were employed to confirm the structure of the semi-IPN hydrogel. The swelling capacity of hydrogel was shown to be affected by the monomers weight ratio, chitosan content, initiator and GA concentrations. The results also indicated that the semi-IPN hydrogel had different swelling capacity at various pHs. Additionally, the swelling behavior of the hydrogel was investigated in aqueous solutions of NaCl, $CaCl_2$, and $AlCl_3$.

• Macromolecular Research
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• v.15 no.3
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• pp.195-201
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• 2007

Non-viral vectors, including lipid- or polymer-based systems, have attracted much attention to date as a gene delivery vehicle, due to safety issues with viral vectors. Chitosan, a naturally existing cationic polymer, has shown great potential as a gene delivery carrier, as it has low immunogenicity and toxicity, excellent transcellular transport ability, and is relatively easy to chemically modify. This review summarizes and discusses the general features of chitosan and its applications as a delivery carrier of DNA and RNA.

• Macromolecular Research
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• v.17 no.4
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• pp.265-270
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• 2009

Noble thermosensitive nanoparticles, based on a PNIPAAm-co-AA core and a chitosan shell structure, were designed and synthesized for the controlled release of the loaded drug. PNIPAAm nanoparticles containing a carboxylic group on their surface were synthesized using emulsion polymerization. The carboxylic groups were conjugated with the amino group of a low molecular weight, water soluble chitosan. The particle size of the synthesized nanoparticles was decreased from 380 to 25 nm as the temperature of the dispersed medium was increased. Chitosan-conjugated nanoparticles with $2{\sim}5$ wt% MBA, a crosslinking monomer, induced a stable aqueous dispersion at a concentration of 1mg/1mL. The chitosan-conjugated nanoparticles showed thermo sensitive behaviors such as LCST and size shrinkage that were affected by the PNIPAAm core and induced some particle aggregation around LCST, which was not shown in the NIPAAm-co-AA nanoparticles. These chitosan-conjugated nanoparticles are also expected to be more biocompatible than the PNIPAAm core itself through the chitosan shell structures.

• Proceedings of the Polymer Society of Korea Conference
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• 2006.10a
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• pp.183-183
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• 2006

Hyaluronic acid and chitosan-based poly(ethylene oxide) (HA-PEO and Chitosan-PEO) hydrogels have been employed as unique biomedical polymeric materials with properties such as bioactivity from polysaccharide, biocompatibility of HA and chitosan as well as PEO and control release of bioactive molecules from the hydrogel itself. We here examine in situ hydrogels based on hyaluronic acid and chitosan in terms of their synthesis, mechanical properties, morphologies and in vitro cellular interactions on their surface and inside. In vivo bone regeneration of HA-PEO and Chitosan-PEO hydrogels was compared with in mouse model.

• Membrane and Water Treatment
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• v.1 no.4
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• pp.231-251
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• 2010

The sulfatation of chitosan, by reaction with chlorosulfonic acid under controlled conditions, allowed increasing the pH range of chitosan solubility. The biopolymer was characterized using FTIR and $^{13}C$-NMR spectroscopy, elemental analysis and titration analysis and it was tested for mercury recovery by polymer enhanced ultrafiltration (PEUF). In slightly alkaline conditions (i.e., pH 8) mercury recovery was possible and at saturation of the polymer the molar ratio $-NH_2$/Hg(II) tended to 2.6. Polymer recycling was possible changing the pH to 2 and the polymer was reused for 3 cycles maintaining high metal recovery. The presence of chloride ions influences metal speciation and affinity for the polymer and "playing" with metal speciation allowed using the PEUF process for mercury separation from cadmium; at pH 11 the formation of hydroxo-complexes of Hg(II) limits it retention. Cake formation reveals the predominant controlling step for permeation flux.

• Journal of Environmental Health Sciences
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• v.23 no.4
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• pp.50-56
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• 1997

Applied for Drug Delivery System, polymer drug was prepared with chitosan and phthalylsulfathiazole. In spite of various application of chitin derivatives, commercial use of chitin has been limited due to highly resistance to chemicals and the absense of proper solvents. In this study, Chitosan were prepared from chitin which were deacetylated under various condition. The synthetic procedures of polymer drug were performed by acid chloride methods. The antibiotic activities of polymer drug exhibited growth-inhibitory activity against Staphylococcus aureus, Staphylococcus epidermidis, E. coli, Salmonella typhimurium, Klebsiella pneumoniae at the concentration of 471-514 $\mu$g/ml in general. Comparatively, Polymer drug exhibited broad antibacterial activity on MICs 897-1280 $\mu$g/ml against Gram-positive and Gram-negative bacteria including Staphylococcus aureus, Staphylococcus epidermidis and E. coli.