Compared with traditional thermal insulation materials, silica aerogels have lower thermal conductivity and better thermal insulation properties. As a renewable natural polymer, biomass has become an ideal raw material for the preparation of aerogel materials. Through the inorganic hybrid biomass polymer composite aerogel, the mechanical and mechanical properties of the aerogel can be improved on the basis of ensuring the excellent thermal insulation properties of the aerogel.
Here we introduce a preparation method of biomass gelatin (GA)-based aerogel cogel and its thermal insulation application. This design method utilizes halloysite nanotubes (HNTs) to enhance the mechanical strength and thermal stability of aerogels by combining with polyethyleneimine (PEI) and (3-glycidyloxypropyl)-trimethoxysilane (GPTMS) chemical cross-linking and co-gelling of low-temperature physical gels enhance the interfacial interaction between HNTs and GA, and combine freeze-drying technology to prepare low-cost and environmentally friendly HNTs/GA composite aerogels. In this design method, the co-gel method enables the formation of uniform chemical and hydrogen bonds between GA and HNTs, and the HNTs show good dispersion and compatibility in the composite aerogel. The figure below shows the preparation process, mechanical properties and thermal insulation properties of the material.

Figure 1. (a) Schematic diagram of the preparation process of HNTs/GA composite aerogels; (b) photos of HNTs/GA composite aerogels with different shapes; (c) HNTs/GA composite aerogels standing on the stamens Photo; (d) Photo of HNTs/GA composite aerogel subjected to 1.5kg hydrothermal reactor.

Figure 2. (a) Stress-strain curves of uncrosslinked HNTs/GA aerogels; (b) axial stress-strain curves of GA aerogels and HNTs/GA aerogels; (c) GA aerogels Maximum compressive modulus and compressive strength of the gel and HNTs/GA composite aerogel; (d) HNTs/GA aerogel compared with the specific modulus of aerogel materials reported in literature; (e) HNTs/GA composite Compressive stress-strain curves of aerogels in the radial direction; (f) Compression cycling curves of HNTs/GA composite aerogels at 50% fixed strain.

Figure 3. (a) Density of pure GA aerogel and HNTs/GA composite aerogel and porosity of pure GA aerogel and HNTs/GA composite aerogel; (b) GA aerogel and HNTs/GA Axial and radial thermal conductivities of composite aerogels; (c) thermal conductivity and density comparison of HNTs/GA composite aerogels and aerogel-like materials; (d) possible HNTs/GA composite aerogels heat transfer mechanism. (e) The physical photo of the HNTs/GA composite aerogel insulation layer.

Figure 4. (a) Schematic diagram of the temperature test of the HNTs/GA composite aerogel placed on the surface of the fixed heat source; (b) the temperature curve of the upper and lower surfaces of the HNTs/GA composite aerogel with time; (c) the composite aerogel Infrared thermal images of the gel at different times; (d) Infrared thermal images of HNTs/GA composite aerogels with different thicknesses placed on a fixed heat source for 30 minutes after stabilization.