淡竹纳米纤维素的制备及特征分析

The Isolation and Characterization of Cellulose Nanofiber from Phyllostachys glauca

以淡竹为原料，首先经过抽提处理除去抽提物，再经过次氯酸钠和氢氧化钠溶液处理，除去其中的木质素与半纤维素而得到α-纤维素，将得到的α-纤维素通过33wt．％硫酸溶液与超声波处理相结合的方式分离出淡竹纳米纤维素。通过扫描电镜（SEM）与透射扫描电镜（TEM）对纳米纤维素的形态特征进行了分析，结果表明纳米纤维素平均直径约5～15nm。傅里叶红外光谱（FFIR）分析显示淡竹中木质素以及半纤维素已被完全分离，α-纤维素与纳米纤维素化学成分基本一致。X射线衍射（XRD）分析表明在各个分离阶段所得产物中，α-纤维素以及纳米纤维素晶体的结晶度得较大提高，且均呈现了典型的纤维素结构。热重分析（TGA）显示分离出慈竹纤维中的半纤维素与木质素后，仪一纤维素与纳米纤维素热稳定性明显增加，但纳米纤维素的热稳定性略低于仪一纤维素。

The α-cellulose was extracted from removing the lignin and hemicelluloses through Phyllostachys glauca by Soxhlet extracting, and treatments with sodium hypochlorite and sodium hydroxide solution. Then, the cellulose nanofiber was isolated from α--cellulose with the combination of （33wt. % ） sulphuric acid and ultrasonic treatment. According to the analysis of scanning electron microscopy （SEM） and transmission electron microscopy （TEM）, the average diameters of the cellulose nanofiber were about 5 - 15 nm. The analysis of Fourier transform infrared （FTIR） spectroscopy showed that the hemicelluloses and lignin were removed extensively from raw material, and the chemical constituents between a-cellulose and cellulose nanofiber were completely the same. The results of X-ray diffraction （XRD） showed that the degrees of crystallinity of α-cellulose and cellulose nanofiber were significantly increased, furthermore, all samples at different purification stages presented the same I- cellulose structure. In terms of thermogravimetric analysis （TGA）, the thermal stabilities of the a-cellulose and cellulose nanofiber at different purification stages were found to increase, however, the thermal stability of cellulose nanofiber was lower than that of α-cellulose.