“Rigid-Flexible” Anisotropic Biomass-Derived Aerogels with Superior Mechanical Properties for Oil Recovery and Thermal Insulation

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.

Designing magnetic and superhydrophobic cellulose nanofibers based‐aerogel for efficient oil water separation

“…As shown in Figure 3A–A, pure CNF is composed of large sheets, which is the effect of the freezing of the CNF aqueous solution in the mold by liquid nitrogen, and the ice crystals grow from bottom to top, squeezing the CNF fibers into sheets 25 . The CNF layers form a three‐dimensional network structure through the connection of fibers, which provides a large oil storage space for the system 9,26 . A lot of oil adsorbents cannot be recovered in time after absorbing waste oil, which causes secondary pollution to the Marine environment.…”

Renewable biomass-based aerogels: from structural design to functional regulation

“…These anisotropic aerogels exhibit high strength and rigidity along their orientation direction and excellent compression rebound performance perpendicular to the orientation direction compared to their disordered counterparts. 299–301 These improvements significantly bolster the entire mechanical performance of the orientated aerogels. 302–304 The ordered structures in aerogel can be constructed using two distinct approaches: top-down and bottom-up strategies.…”

Magnetic Hyperporous Elastic Material with Excellent Fatigue Resistance and Oil Retention for Oil–Water Separation

“…Oily wastewater is a serious threat to the environment, especially to water resources, raising urgent demands for effective strategies for oil–water separation. − The commonly used oil–water separation technologies mainly include combustion, purification, membrane technology, and absorption. − Among them, absorption is the most potential development direction at present due to the advantages of recoverability and low secondary pollution to the environment. Traditional absorbents commonly exploit porous materials such as activated carbon, , aerogel, − modified sponge, − fabrics, − etc. In particular, sponges with interconnected pores have gained widespread attention due to their large absorption capacity, high efficiency, and good mechanical properties as well as multifunctionalities. − However, the following challenges still exist in practical applications.…”