WAN Caichao, LU Yun, SUN Qingfeng, LI Jian
To obtain novel lignocellulose aerogels, the raw material, namely waste wheat straw, was purified, dissolved, replaced and dried in sequence via corresponding chemical pretreatment, dissolution and regeneration as well as freeze drying. Furthermore, a green, non-toxic and inexpensive NaOH/PEG aqueous solution was chosen to dissolve cellulose. The morphological feature, pore size distribution, crystal form, chemical construction and thermostability of the novel lignocellulose aerogel were analyzed using scanning electron microscopy (SEM), BET measurement, X- ray diffraction (XRD), fourier transform infrared spectroscopy (FTIR) and thermogravimetric analysis (TGA). The results show that the obtained novel lignocellulose aerogel has a continuous and tiered threedimensional network structure. Moreover, its specific surface area reaches 99.17 m2/g, and total pore volume reaches 0.45 cm2/g. The crystal form of the novel lignocellulose aerogel is transformed from the cellulose I crystalline structure to cellulose Ⅱ crystalline structure, and the crystallinity reaches 72.3%, increasing by 23.4% as compared with that of the raw material straw. Meanwhile, the thermostability is slightly improved. Moreover, trimethylchlorosilane (TMCS) was used to hydrophobically modify the lignocellulose aerogel. In this article, a new and effective solvent for preparing lignocellulose aerogels is offered, and the novel lignocellulose aerogel having superior adsorptive properties, excellent weight capacity and high crystallinity has great application potentials as a new-style functional material.
