Infrared-opacified Al2O3–SiO2 aerogel composites reinforced by SiC-coated mullite fibers for thermal insulations

Fabrication and characterization of low-cost and green vacuum insulation panels with fumed silica/rice husk ash hybrid core material

“…According to the Rossland equation, λ rad of the optically thick HCM specimen was calculated by [29,30]:…”

Synthesis of a novel Al2O3–SiO2 composite aerogel with high specific surface area at elevated temperatures using inexpensive inorganic salt of aluminum

“…It possessed a large specific surface area of 47 m 2 /g at 1200 1C; however, the alumina alkoxides were very expensive and were readily hydrolyzed by water, which produced aluminum mono-or tri-hydroxides. Because the formed mono-hydroxide is the only material that can be peptized to a clear sol, a highly complex procedure is needed to obtain a clear solution [8][9][10]. Hurwitz et al [11] directly employed boehmite powder as an alumina source to prepare Al 2 O 3 -SiO 2 aerogel.…”

“…Thus, many researchers have focused on Al 2 O 3 -SiO 2 aerogel with a significant low bulk density and a silica-doped effect to obtain a composite with high heat resistance and a large specific surface area at elevated temperatures. Osaki et al [8][9][10] proposed a method using aluminum isopropoxide as alumina source and tetraethyl orthosilicate as the silicon source to prepare Al 2 O 3 -SiO 2 aerogel. The addition of silica particles surrounding the γ-Al 2 O 3 inhibited the contact of Al 2 O 3 particles, decreased the probability of crystal nucleation, and significantly inhibited the α-Al 2 O 3 phase transition.…”

Mechanical and thermal conductive properties of fiber‐reinforced silica‐alumina aerogels

“…10 However, Al 2 O 3 -SiO 2 aerogels are highly fragile. 11 Recently, mullite fiber reinforced Al 2 O 3 -SiO 2 aerogels have been reported in the literature, 12 in which tetraethoxysilane and aluminum sec-butoxide were used as precursors. The thermal conductivity of mullite fiber reinforced Al 2 O 3 -SiO 2 aerogels was (0.062 W/mK) at 1000°C.…”