【摘 要】
：
Oxidation has been profitably utilized to improve some properties of chitosan.However,only solvent-based oxidation procedures have been proposed so far,which are hardly feasible at industrial scale in an economic way because of product recovery cost.In th
【机 构】
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Green Intelligence Environmental School,Yangtze Normal University,Chongqing 408100,China;State Key J
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Oxidation has been profitably utilized to improve some properties of chitosan.However,only solvent-based oxidation procedures have been proposed so far,which are hardly feasible at industrial scale in an economic way because of product recovery cost.In this study,a solvent-free,rapid,and effective oxidation method is proposed.It is based on direct solid-state reaction between chitosan and oxidant powder in a mechanochemical reactor.Results prove that by short high energy ball milling(＜3 h)it is possible to achieve diverse physicochemical modifications employing different reagents.Apart from polysaccharidic chain shortening,persulfate provokes high amorphization and induces formation of ketonic groups;percarbonate heightens deacetylation degree,preserving in part crystallinity;calcium peroxide merely deprotonates amino groups and increases amorphization degree.Adsorption tests with the azo-dye reactive red 2 show that adsorption capacity of chitosan co-milled with persulfate(974 mg/g milled product),which is the best performing adsorbent,is twice that of pristine chitosan,while adsorption rate is outstandingly boosted(125 times).
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