Determination of the Mark-Houwink equation for chitosans with different degrees of deacetylation

Wang, Wei; Bo, Shuhui; Liu, Shuqing; Qin, Wen

doi:10.1016/0141-8130(91)90027-r

Cited by 450 publications

(139 citation statements)

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“…The molecular weight was calculated based on the Mark-Houwink-Sakurada equation (η = KM a ) as described by Flory (1953) and Tanford (1961), where η is the intrinsic viscosity, K and a are viscometric parameters depending on the solvent. For a chitosan dissolved in 0.5M CH 3 COOH/0.2M CH 3 COONa as in the present study the K and a were found to be 3.5 × 10 -4 and 0.76, respectively, according to Wang et al (1991).…”

Section: Methodsmentioning

confidence: 88%

Nematicidal activity of a biopolymer chitosan at different molecular weights against root-knot nematode, Meloidogyne incognita

Khalil¹,

Badawy²

2012

Plant Prot. Sci.

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Khalil M.S., Badawy M.E.I. (2012): Nematicidal activity of a biopolymer chitosan at different molecular weights against root-knot nematode, Meloidogyne incognita. Plant Protect. Sci., 48: 170-178.The nematicidal activity of four molecular weights (2.27 × 10 5 , 3.60 × 10 5 , 5.97 × 10 5 , and 9.47 × 10 5 g/mol) of a biopolymer chitosan was assayed against the root-knot nematode, Meloidogyne incognita, in vitro and in pot experiments. In laboratory assays, the nematode mortality was significantly influenced by exposure times and chitosan molecular weight. Low molecular weight chitosan (2.27 × 10 5 g/mol) was the most effective in killing the nematode with EC 50 of 283.47 and 124.90 mg/l after 24 and 48 h of treatment, respectively. In a greenhouse bioassay, all the compounds mixed in soil at one-and five-fold concentrations of the LC 50 value significantly reduced population, egg mass, and root galling of tomato seedlings compared with the untreated control. In general, the nematicidal activity of these compounds was increased dramatically with a decrease in the molecular weight. The results suggest that the chitosan at low molecular weight may serve as a natural nematicide.

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Section: Methodsmentioning

confidence: 88%

Nematicidal activity of a biopolymer chitosan at different molecular weights against root-knot nematode, Meloidogyne incognita

Khalil¹,

Badawy²

2012

Plant Prot. Sci.

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“…Viscosity of chitosan in acetic acid tends to increase with decreasing pH but decrease with decreasing pH in HCl, giving rise to the definition of 'Intrinsic Viscosity'. Intrinsic viscosity is an important rheological parameter which is used to characterize the hydrodynamic properties of polymers and also to determine the weight average molecular weight of polymers by use of the Mark-Houwink's equation (Wang et al, 1991). 'Intrinsic Viscosity' of chitosan is the function of the degree of ionization as well as ion Strength (Moorjani et al, 1975).…”

Section: Intrinsic Viscositymentioning

confidence: 99%

“…From the intrinsic viscosity, the molecular weight was determined employing the Mark-Houwink equation (Wang et al, 1991):…”

Section: Deacetylationmentioning

confidence: 99%

Production and characterization of chitosan from shrimp waste

Hossain

Iqbal

2014

J Bangladesh Agric Univ

166

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Chitosan has been produced from shrimp waste by chemical method involving demineralization, deproteinization and deacetylation. The quality of chitosan depends on the conditions of the chemical extraction process. The results showed that 3% HCI and 4% NaOH were suitable concentration for demineralization and deproteinization, respectively at ambient temperature (28±2 o C). Chitosan with a high degree of deacetylation (81.24%) and high solubility (97.65%) was obtained by deacetylation with 60% NaOH for 24 hours at 60°C. Purified chitosan was characterized for intrinsic viscosity (13.2dl/g), molecular weight (1.05×10 6 Dalton), FBC (427.98%), WBC (537.29%) as well as yield (15.4%).

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“…For chitosan K=1.464·10 -4 ; α=0.885 in acetate buffer solution. [20] Photosens was kindly supplied by the Institute of Organic Intermediates and Dyes (Moscow, Russia). This photosensitizer is a mixture of sulfonated aluminum phthalocyanines with different degrees of sulfonation (n=2, 3, and 4).…”

Section: Methodsmentioning

confidence: 99%

Supramolecular Complexation of Sulfonated Aluminum Phthalocyaninеs and Chitosan in the Mixed Aqueous Solutions

Lipatova¹,

Chernova²,

Yusova³

2017

MHC

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Determination of the Mark-Houwink equation for chitosans with different degrees of deacetylation

Cited by 450 publications

References 10 publications

Nematicidal activity of a biopolymer chitosan at different molecular weights against root-knot nematode, Meloidogyne incognita

Nematicidal activity of a biopolymer chitosan at different molecular weights against root-knot nematode, Meloidogyne incognita

Production and characterization of chitosan from shrimp waste

Supramolecular Complexation of Sulfonated Aluminum Phthalocyaninеs and Chitosan in the Mixed Aqueous Solutions

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