Preparation of functionalized halloysite reinforced polyimide composite aerogels with excellent thermal insulation properties

Facile construction of flame‐retardant, heat‐insulating agar/polyvinyl alcohol composite aerogels via in situ formation of magnesium hydroxide and palygorskite‐assisted strategy

“…[20] Figure 6C shows the density of aerogel samples. The density of pure AP sample is only 0.068 g/cm 3 , and the density of APM60 increases to 0.113 g/cm 3 . However, the density of aerogel samples containing Pal decreased compared with that of APM60, which was due to the one-dimensional long-diameter structure of Pal that made the aerogel samples loose.…”

“…Weight and dimension data of aerogel samples were measured by analytical balance and digital calipers, apparent density of dry aerogel was calculated, and the average value was obtained after four repeated tests. The porosity was calculated by the method reported in the literature, [40] where the densities of AG, PVA, MH, and Pal used in the calculation were 1.8, 1.3, 2.36, and 2.05 g/cm 3 , respectively. The specific modulus value of aerogel samples is calculated by the ratio of compression modulus to density.…”

“…Aerogels, a type of material with porous structure, are made from SiO 2 or polymers. [1][2][3] The ultra-low density and ultra-high porosity considerably reduce the quality and thermal conductivity of aerogels. [4,5] Polymer-based aerogels have shown excellent effects in the field of heat insulation compared to traditional insulation materials such as rock wool board, glass wool, and polystyrene foam.…”

Thermal Insulation and Flame Retardancy of the Hydroxyapatite Nanorods/Sodium Alginate Composite Aerogel with a Double-Crosslinked Structure

“…Aerogels are open porous solid materials formed by self-assembly of nanostructures or molecular chains. − Their pores are filled with a large amount of air medium and exhibit unique physical characteristics, such as low volume density, highly porous structure, large surface area, and low thermal conductivity, which are considered the most suitable properties in the field of heat insulation. − A typical inorganic aerogel (SiO 2 ) exhibits extremely low thermal conductivity, but the poor mechanical properties limit wide practical applications . Some organic aerogels (for example, RF, PU, PI, etc) with good formability are suitable choices, but the synthesis processes are complex and involve toxic solvents and raw materials, which will cause environmental pollution problems. , Compared to these traditional aerogels, development of aerogels based on natural polymers has attracted extensive attention to partially replace petroleum-based derivatives. , Due to the abundant sources, low price, and sustainable environmental protection, they represent an important development direction for organic aerogels. , The as-prepared aerogel does not involve toxic compounds and complex chemical synthesis and exhibits a rich porous structure, better thermal insulation, and extensible chemical function. , However, there are some inherent shortcomings, such as flammable skeleton and inconspicuous mechanical characteristics.…”

Cogel Strategy for the Preparation of a “Thorn”-Like Porous Halloysite/Gelatin Composite Aerogel with Excellent Mechanical Properties and Thermal Insulation

“…19−21 A low-cost mineral clay is used to enhance the physical structure of biopolymer aerogels, including mechanical strength and thermal insulation. 2 Among them, halloysite nanotubes [Al 2 (OH) 4 Si 2 O 5 , HNTs] are 1:1-type silicate clay minerals. 22 Its structural unit layer is composed of a silica tetrahedron in the outer layer and an alumina octahedron in the inner layer.…”