For the first time, a highly efficient Cr(NO₃)₃ catalysis system was proposed for optimization the yield and crystallinity of nanocellulose end product. A five-level three-factor central composite design coupled with response surface methodology was employed to elucidate parameters interactions between three design factors, namely reaction temperature (x₁), reaction time (x₂) and concentration of Cr(NO₃)₃ (x₃) over a broad range of process conditions and determine the effect on crystallinity index and product yield. The developed models predicted the maximum nanocellulose yield of 87% at optimum process conditions of 70.6 °C, 1.48 h, and 0.48 M Cr(NO₃)₃. At these conditions, the obtained nanocellulose presented high crystallinity index (75.3%), spider-web-like interconnected network morphology with the average width of 31.2 ± 14.3 nm. In addition, the yielded nanocellulose rendered a higher thermal stability than that of original cellulosic source and expected to be widely used as reinforcement agent in bio-nanocomposites materials.

中文翻译：

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新型Cr（III）催化水解生产高结晶度纳米纤维素的最佳条件的研究：响应面法

首次提出了一种高效的Cr（NO ₃）₃催化体系，以优化纳米纤维素终产物的收率和结晶度。采用五级三因素中心复合设计与响应面方法相结合，阐明了反应温度（x ₁），反应时间（x ₂）和Cr（NO ₃）₃（₃）浓度这三个设计因素之间的参数相互作用。X ₃）在广泛的工艺条件下确定对结晶度指数和产品收率的影响。所开发的模型预测，在70.6°C，1.48 h和0.48 M Cr（NO ₃）_3的最佳工艺条件下，纳米纤维素的最大产率为87％。在这些条件下，获得的纳米纤维素呈现出高结晶度指数（75.3％），蜘蛛网状的互连网络形态，平均宽度为31.2±14.3 nm。另外，所产生的纳米纤维素具有比原始纤维素来源更高的热稳定性，并有望被广泛用作生物纳米复合材料中的增强剂。