The optimization of thermal insulation-related properties of polysaccharide-based aerogel by the multi-layer combination method

• Published in: Journal of porous materials Vol. 30; no. 5; pp. 1449 - 1458
• Main Authors: Wu, Kao, Wang, Ru, Ye, Zijian, Tao, Yuxuan, Wu, Huaxin, Sun, Weiwei, Cheng, Junjie, Kuang, Ying, Jiang, Fatang, Chen, Sheng
• Format: Journal Article
• Language: English
• Published: New York Springer US 01-10-2023; Springer Nature B.V
• Subjects: Aerogels; Air flow; Catalysis; Characterization and Evaluation of Materials; Chemistry; Chemistry and Materials Science; Environmental protection; Freeze drying; Heat conductivity; Heat transfer; Insulation; Multilayers; Optimization; Physical Chemistry; Polysaccharides; Pore size; Relative humidity; Thermal conductivity; Thermal insulation; Thickness; Konjac glucomannan; Freeze drying; Multi-layer; Pore structure; Thermal insulation
• ISSN: 1380-2224; 1573-4854
• DOI: 10.1007/s10934-023-01438-y

The development of polysaccharide-based biodegradable thermal insulation aerogels benefited environmental protection. The thermal conductivity of polysaccharide-based aerogels prepared by the freeze-drying method was difficult to reduce to less than 0.3 W/(m·k), as the pore size was relatively large. Therefore, rather than reducing pore size, this study aimed to reduce the airflow/heat convection inside the aerogels by introducing aerogels with different air permeability as outer layers to combine dual-layer/triple-layer aerogels with lower thermal conductivity. Results showed that the triple-layer method had a more significant impact on reducing the thermal conductivity than the dual-layer method, due to the greater impact on reducing the airflow. Additionally, a thinner thickness of outer aerogel layers was preferred, and the thermal conductivity was significantly reduced to 0.0279 W/(m·k) from 0.0335 W/(m·k) by the triple-layer aerogel method. The thermal insulation stability of this triple-layer aerogel was also relatively high, and the hardness and resistance to relative humidity were both improved compared to the original aerogel. Considering the above, this triple-layer aerogel method could be used to improve the thermal insulation-related property of the polysaccharide-based aerogels by the freeze-drying method or with relatively large pore sizes.