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).

氧化已被有利地用于改善壳聚糖的某些性能。然而，到目前为止，仅提出了基于溶剂的氧化方法，由于产品回收成本，在工业规模上以经济方式几乎是不可行的。在这项研究中，提出了一种无溶剂，快速，有效的氧化方法。它基于机械化学反应器中壳聚糖和氧化剂粉末之间的直接固态反应。结果证明，通过短时间的高能球磨（<3 h），可以使用不同的试剂实现多种物理化学修饰。除缩短多糖链外，过硫酸盐还引起高度非晶化并诱导酮基的形成。过碳酸盐提高脱乙酰度，部分保留结晶度；过氧化钙仅使氨基去质子化并增加无定形度。偶氮染料活性红2的吸附试验表明，与过硫酸盐（974毫克/克研磨产物）共同研磨的壳聚糖的吸附能力是性能最好的吸附剂，是原始壳聚糖的两倍，同时显着提高了吸附速率。 （125次）。