3.2. Preparation of Bagasse Crude Cellulose

The preparation of the crude cellulose from sugarcane bagasse was based on the method of Luo Suqin, with slight modifications [19]. We added 50 g of dried sugarcane bagasse powder to distilled water and heated the mixture in a 75 ℃ water bath for 2 h. Then, the bagasse was washed with distilled water until the water was clear, and the water was drained with gauze, which was followed by a bleaching treatment for lignin removal. Then, a 7.5% sodium chlorite solution of pH 3.8–4.4 was added to the washed bagasse, and the reaction system was also bleached at 75 ℃ for 5 h. After the reaction, the bagasse was washed with water until the bagasse was pure white, and then the bagasse was washed and filtered with 95% ethanol to avoid cellulose agglomeration. It was then dried and set aside. Finally, the treated bagasse was mixed with 250 mL of 10% NaOH solution for an alkalization treatment to remove the hemicellulose and other impurities, and then it was washed with distilled water for the heavy suspension sedimentation to return to neutral. It was then dispersed with 95% ethanol for drying and then crushed and sieved to obtain 100-mesh-sieved bagasse coarse fiber with a white color.