Waste transformation as the source to valuable materials is an effective strategy for the high-valued valorization in view of socioeconomic and environmental issues. Inspired from the concept of organic–inorganic hybrid, we proposed the utilization of cellulose nanocrystals (CNCs, extracted from biomass waste) and red mud (RM, from industrial waste) to fabricate composite aerogels as potential construction materials with the multifunction of adsorption, thermal insulation, acoustic resistance, and flame retardancy. For equal loading level of modified CNC (Si-CNC) and RM (1:1, w/w) components, the obtained aerogel was chemically cross-linked with diisocyanate to enhance its structural stability and mechanical properties. It exhibited an improved compression modulus of 3.7 MPa together with high porosity (98.8%) and specific surface area (73.23 m²/g). As a result of the intrinsic features of organic Si-CNC (skeleton) and inorganic RM (particles aggregate), the Si-CNC/RM-1/c composite aerogel displayed significant functional performances such as magnetic conductivity, rapid oil adsorption of 30 times its mass, 20.8% reduction in thermal conductivity, 24.5% increase in sound-absorption coefficient, and highly efficient self-extinguishing behavior within 2 s.

中文翻译：

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基于纤维素纳米晶体和红色泥浆中有机和无机废物平衡的高吸附性，自熄性，热和抗声气凝胶

考虑到社会经济和环境问题，废物转化为有价值材料的来源是实现高价值增值的有效策略。受有机-无机杂化概念的启发，我们建议利用纤维素纳米晶体（CNC，从生物质废物中提取）和赤泥（RM，从工业废物中）来制造​​复合气凝胶，作为具有潜在的建筑材料的复合材料，具有吸附，热能的多功能性。隔热，隔音和阻燃性。对于相同含量的改性CNC（Si-CNC）和RM（1：1，w / w）组分，将获得的气凝胶与二异氰酸酯化学交联以增强其结构稳定性和机械性能。它显示出改进的3.7 MPa压缩模量以及高孔隙率（98.8％）和比表面积（73.23 m）² / g）。由于有机Si-CNC（骨架）和无机RM（颗粒聚集体）的固有特征，Si-CNC / RM-1 / c复合气凝胶显示出显着的功能性能，如磁导率，快速吸油30倍它的质量，20.8％的导热系数降低，24.5％的吸声系数增加以及2 s内的高效自熄性。