Remodeling of waste corn stalks into renewable, compressible and hydrophobic biomass-based aerogel for efficient and selective oil/organic solvent absorption

Renewable biomass-based aerogels with excellent absorption properties for oil and organic solvent have been concerned recently. However, the development of cost-effective and compressible green aerogel is still a great challenge and a research hotspot. In this work, a novel hydrophobic konjac glucomannan/corn stalk fibers (KGM/CSFs) aerogel with porous three-dimensional structure featured low density, high porosity, good compressibility and hydrophobicity (146°) were prepared and used to selectively remove different organic liquids from oil/water mixtures. The effects of the amount of corn stalk fibers (CSFs) on the physical properties such as density, porosity and mechanical properties of the aerogel were investigated in detail. The obtained hydrophobic KGM/CSFs aerogel exhibited high absorption capacity (24.76 g/g-58.07 g/g) for various organic liquids. After 10 cycles, the adsorption capacity of the aerogel for chloroform and diesel remained above 90% of the initial adsorption capacity, showing excellent reusability. More importantly, the oils or organic solvents could be selectively absorbed by the hydrophobic KGM/CSFs aerogel from oil/water mixtures with a separation efficiency of over 99.38%. Considering the advantages of eco-friendliness, low cost and simple preparation process, the hydrophobic biomass-based aerogel prepared from waste corn stalks can be used as a promising absorbent for efficient and selective absorption of oils or organic solvents.