“Rigid-Flexible” Anisotropic Biomass-Derived Aerogels with Superior Mechanical Properties for Oil Recovery and Thermal Insulation
Zhenrong Tan, Chang Geun Yoo, Dongjie Yang, Weifeng Liu, Xueqing Qiu, Dafeng Zheng
Abstract
Aerogels with low density, high mechanical strength, and excellent elasticity have a wide potential for applications in wastewater treatment, thermal management, and sensors. However, the fabrication of such aerogels from biomass materials required complex preparation processes. Herein, a sustainable and facile strategy was reported to construct lignin/cellulose aerogels (LCMA) with three-dimensional interconnected structures by introducing homologous lignin with a polyphenyl propane structure as a structural enhancer through a top-down directional freezing approach, prompting a 2036% enhancement in compressive modulus and an 8–12-fold increase in oil absorption capacity. In addition, the hydrophobic aerogels with superelasticity were achieved by combining the aligned polygon-like structure and flexible silane chains, which exhibited remarkable compressional fatigue resistance and superhydrophobicity (WCA = 168°). Attributed to its unique pore design and surface morphology control, the prepared aerogel exhibited excellent performance in immiscible oil–water separation and water-in-oil emulsion separation. Due to the ultra-low density (8.3 mg·cm –3 ) as well as high porosity (98.87%), the obtained aerogel showed a low thermal conductivity (0.02565 ± 0.0024 W·m –1 ·K –1 ), demonstrating a potential in insulation applications. The synthetic strategy and sustainability concept presented in this work could provide guidance for the preparation of advanced biomass-based aerogels with unique properties for a wide range of applications.