Chitosan-derived polymer-surfactants and their micellar properties.
Chitosan derivatives, sulfated N-acyl-chitosan (S-Cn-chitosan) possessing various lengths of alkyl chain, were prepared, and the properties of their aqueous solutions were examined. The 1H-NMR spectrum of D2O solutions of S-C12-chitosan showed broadening of the proton signals caused by aggregation of the alkyl chain. The solubility of a hydrophobic compounds, azobenzene, was small in the aqueous solutions of S-Cn-chitosan with shorter alkyl chains, but increased with increasing length of the chains above C10, showing that micelles had been formed. The ESR spectrum of a spin probe, TEMPO, in an S-C14-chitosan solution showed the existence of a hydrophobic region in the solution, but this region did not exist in the S-C2-chitosan solution. The rigidity of this region was examined by using a spin probe, 16-doxyl-stearic acid. From these results, it was revealed that S-Cn-chitosan with longer alkyl chains formed a novel type of micelle called a "polymer micelle," which was more stable than the ordinary micelles formed from low-molecular-weight surfactants.
Graduate School of Nutritional and Environmental Sciences, University of Shizuoka, Japan.
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Yoshioka
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Nonaka
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Fukuda
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Kazama
D000215:Acylation; D002686:Chitin / Q000031:analogs & derivatives* / Q000737:chemistry; D048271:Chitosan; D004337:Drug Carriers; D009682:Magnetic Resonance Spectroscopy; D008823:Micelles; D015394:Molecular Structure; D011108:Polymers / Q000737:chemistry; D012995:Solubility; D013431:Sulfates; D013501:Surface-Active Agents / Q000737:chemistry*
D004337:Drug Carriers; D008823:Micelles; D011108:Polymers; D013431:Sulfates; D013501:Surface-Active Agents; D002686:Chitin; D048271:Chitosan