• Journal of the Korean Wood Science and Technology
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• v.25 no.4
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• pp.92-98
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• 1997

To make good use of chitosan forming complex with heavy metals in wood preservative treatment, woods impregnated with chitosan and copper sulfate were prepared. Amounts of leached copper, decay resistance, anti-mold efficacy, iron corrosion rates, moisture regain rates and degradation pattern in chitosan pre-treated and untreated wood were compared. After leaching test, amounts of leached copper from chitosan pre-treated wood had a much smaller than chitosan untreated wood, and good decay resistance was retained even after leaching test. From these results, it was proved that chitosan-copper complex formed in wood played and important role for decay durability. In chitosan pre-treated wood, damage values by test molds became remarkably smaller, but the growth of test molds was not perfectly inhibited. Distinct differences in iron corrosion rates between chitosan pre-treated and untreated woods was not recognized but chitosan pre-treated wood showed the lower moisture regain rates than chitosan untreated wood because of water insoluble chitosan membrane formed in wood. After leaching test, the tracheid walls in the wood treated with 2.0% copper sulfate only were eroded by the fungal attacks, but those in the wood pre-treated with chitosan remained almost intact.

• The Plant Pathology Journal
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• v.40 no.3
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• pp.261-271
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• 2024

Sulfur is one of the inorganic elements used by plants to develop and produce phytoalexin to resist certain diseases. This study reported a method for preparing a material for plant disease resistance. Sulfur nanoparticles (SNPs) stabilized in the chitosan-Cu²⁺ (CS-Cu²⁺) complex were synthesized by hydrolysis of Na₂S₂O₃ in an acidic medium. The obtained SNPs/CS-Cu²⁺ complex consisting of 0.32% S, 4% CS, and 0.7% Cu (w/v), contained SNPs with an average size of ~28 nm as measured by transmission electron microscopy images. The X-ray diffraction pattern of the SNPs/CS-Cu²⁺ complex showed that SNPs had orthorhombic crystal structures. Interaction between SNPs and the CS-Cu²⁺ complex was also investigated by ultraviolet-visible. Results in vitro nematicidal effect of materials against Meloidogyne incognita showed that SNPs/CS-Cu²⁺ complex was more effective in killing second-stage juveniles (J2) nematodes and inhibiting egg hatching than that of CS and CS-Cu²⁺ complex. The values of LC₅₀ in killing J2 nematodes and EC₅₀ in inhibiting egg hatching of SNPs/CS-Cu²⁺ complex were 75 and 51 mg/l, respectively. These values were lower than those of CS and the CS-Cu²⁺ complex. The test results on the nematicidal effect against M. incognita on coffee pots showed that the SNPs/CS-Cu²⁺ complex was 100% effective at a concentration of 150 mg/l. Therefore, the SNPs/CS-Cu²⁺ complex could be considered as a biochemical material with potential for agricultural applications to control root-knot nematodes.

• Macromolecular Research
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• v.10 no.2
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• pp.103-107
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• 2002

High purity water soluble chitosans (WsCs) were employed as a flocculant to remove heavy metal ions from wastewater of industrial plating wastewater treatment complex. Their weight average molecular weights and polydispersities were 272,000~620,000 g/mol and 1.4~1.9 range, respectively and were readily soluble in water in the pH range of 3~11. Heavy metal ions such as chromium, iron and copper were removed well by WsCs. When WsCs was blended with either sodium N, N-diethyldithiocarbamate trihydrate (SDDC$_{T}$) or sodium salicylate (SSc), the removal efficiency was further increased primarily due to the excess amount of hydrophilic sulfonic and carboxylic groups. Especially, in the case of WsCs-SSc the remaining chromium and copper concentrations were 0.1 mg/L and 9.5 mg/L, which are 1/15 and 1/3 compared with that of pure WsCs, respectively. The former is within the acceptable limit, but the latter is not. Therefore, the effective copper flocculant remains to be studied.d.

• Journal of Electrochemical Science and Technology
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• v.9 no.3
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• pp.169-175
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• 2018

Cu-Salen complex was prepared and attached into chitosan (Cs) polymer backbone. Nanocomposite of the synthesized polymer was prepared with functionalized carbon nano-particles (Cs-Cu-sal/C) to modify the electrode surface. The surface morphology of (Cs-Cu-sal/C) nanocomposite film showed a homogeneous distribution of carbon nanoparticles within the polymeric matrix. The cyclic voltammogram of the modified electrode exhibited a redox behavior at -0.1 V vs. Ag/AgCl (3 M KCl) in 0.1 M PB (pH 7) and showed an excellent hydrogen peroxide reduction activity. The Cs-Cu-sal/C electrode displays a linear response from $5{\times}10^{-6}$ to $5{\times}10^{-4}M$, with a correlation coefficient of 0.993 and detection limit of $0.9{\mu}M$ (at S/N = 3). The sensitivity of the electrode was found to be $0.356{\mu}A\;{\mu}M^{-1}\;cm^{-2}$.