.png){kind=icon}
.png){kind=icon}
Return
Designable Organic-inorganic Layered Polyimide/Alumina Composite Aerogels via the Combining strategy of density-driven sol stratification and Side-bidirectional freezing
.png){kind=icon}
PRE
AI
C
Y
Y
X
X
W
M
F
DOI：10.1016/j.ceramint.2026.08.129.png)
.png){kind=icon}
Original request for help.png){kind=icon}
Share.png){kind=icon}
Save
Abstract
En 中文
Lightweight and flexible thermal insulating aerogels are critical for spacecraft thermal protection. However, conventional inorganic aerogels are intrinsically brittle, while organic counterparts generally suffer from insufficient thermal stability at elevated temperatures. Inspired by the spontaneous stratification phenomenon in layered “cocktails”, this work explored a strategy that combines density-driven solution stratification with side-bidirectional freezing to construct tri-layered polyimide/alumina composite aerogels (PACAs). A stepwise solution-based assembly method enabled the formation of stable tri-layered slurry, which was subsequently transformed into a well-defined macroscopic architecture through side-bidirectional freezing and freeze-drying. This approach yields a highly ordered lamellar microstructure with pronounced anisotropic heat transport. The cross-plane thermal conductivity of the polyimide layer reaches as low as 19 mW m-1 K-1, while the in-plane value is more than 4 times higher. Benefiting from the hierarchical layered design and deformation coordination between organic and inorganic components, PACA exhibits a 1.5-fold increase in elastic stress limit and a 6-fold enhancement in elastic strain limit compared with monolithic alumina aerogels. More importantly, under thermal exposure at 300 °C, 600 °C, and 900 °C for 480 s, a 25 mm-thick PACA maintains remarkably low cold-side temperatures of 34.1 °C, 40.2 °C, and 67.1 °C, respectively, demonstrating outstanding high-temperature thermal insulation. The adjustable layer thickness further enables the design flexibility of thermal management, highlighting the potential of organic-inorganic layered PACAs for advanced aerospace thermal protection.
Journal
IF:
5.6
Papers:
5.0W
Citations:
15.5W
Organization
Cited Papers