Characterization of lignocellulose aerogels fabricated using a LiCl/DMSO solution

Lignocellulose aerogel has attracted great attentions in advanced renewable material research. Mostly, cellulose, hemicellulose or lignin should be separated tediously from the lignocellulose first then to fabricate the aerogel individually. Herein, lignocellulose mesoporous aerogels were prepared directly from lignocellulose/LiCl/DMSO solution. The soybean stem with different range of delignification were pretreated by ethylenediamine (EDA), then dissolved in LiCl/DMSO solvent followed by coagulating, solvent replacing and freeze drying sequentially. Rheology and compression tests were employed to measure the mechanical strength of the alcogel. Scanning electron microscopy (SEM), Brunauer-emmett-teller (BET), Thermo-gravimetric (TGA) and the gravimetric analysis were taken to characterize the morphology, porosity, thermal stability and swelling ability of the aerogels. Comparing these samples, the lignocellulose aerogel without delignification had the greatest swelling ability but a little lower porosity, mechanical strength and thermal stability. And as the delignification increased in a proper extent, which induce the lignin removal, the cellulose and hemicellulose dissociated certainly, the mechanical strength and thermal stability improved, a denser fibril network structure with lower pore diameter (D-pore) and a higher S-BET formed. While, exacerbate delignification could reduce the S-BET and the uniformity of the pores in the aerogels remarkably. The performance of the aerogels could be controlled to some extent, by adjusting the degree of the delignification.