High‐Temperature Resistant Polyimide Aerogels With Extreme Condition Tolerance Constructed by In Situ Skeleton Encapsulation Growth

Advanced Functional Materials, Journal Year: 2025, Volume and Issue: unknown

Published: Feb. 25, 2025

Abstract Polyimide aerogel (PIA) can enable to withstand the extreme conditions in a great measure due their exceptional thermal stability and excellent mechanical toughness properties derived from rigid‐ring structures, which are rather promising alternatives terms of high‐performance protection materials for aerospace field. However, PIA usually suffers poor dimensional at high‐temperature atmosphere, accordingly leading into degradation macroscopic features, eventually restricting extreme‐ambient applications. Here, an situ skeleton encapsulation growth strategy is proposed modulate networking construction pattern, namely forming binary organic–inorganic nature skeletons originated nanoscale structures encapsulated with polymethylsilsesquioxane. The resulting demonstrates superior (linear shrinkage down 1.11% even experiencing 300 °C 3000 s) despite facing heat flux shock, suggesting resistant ability depending upon Si‐O‐phase‐layer formation intrinsic strong chemical bonds polyimide chains. Further, aerogels own extreme‐condition tolerance when subjected shock cycling (−196 °C—300 °C), fantastic flame retardancy 1200 °C. This approach developing broadens applicability holds significant potential protection, particularly conditions.

Language: Английский

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Gelation‐Constrained Freeze‐Casting Fabrication of Ultra‐Homogeneous Nanocomposite Aerogels with Superelasticity and Harsh Environment Tolerance

Advanced Functional Materials, Journal Year: 2025, Volume and Issue: unknown

Published: March 18, 2025

Abstract Freeze casting is a versatile technique for organizing low‐dimensional building blocks into ordered porous structural materials. However, the freeze‐casting fabrication of materials with robust and topologically elastic skeleton to withstand harsh conditions challenging. Herein, silanized ultra‐homogeneous nanocomposite aerogel fabricated using gelation‐constrained strategy. Diverging from traditional methods employing solution precursor, approach involves process utilizing rational‐designed supramolecular hydrogel as quasi‐solid precursor. The within hydrogel, enclosed in dense hydrogen‐bonded network, effectively mitigate secondary agglomeration caused by ice crystallization concentration enrichment during freeze‐casting. By forming cellular an interconnected nanoparticle resulting aerogels exhibit exceptional mechanical elasticity retaining over 98% height after 10 000 compression cycles, along superior electrical properties showing 78.9% increase conductivity compared conventional aerogels. Wearable piezoresistive sensors these demonstrate outstanding force sensing capabilities, broad linear range (0–17.6 kPa) high sensitivity (1.32 kPa −1 ). When integrated intermediate layer protective garments, offer insulation fire resistance, enabling them endure like repetitive extreme deformations, exposure high‐temperature flames, water‐erosion damages.

Language: Английский

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Penguin feather-inspired flexible aerogel composite films featuring ultra-low thermal conductivity and dielectric constant

Materials Horizons, Journal Year: 2025, Volume and Issue: unknown

Published: Jan. 1, 2025

Given extremely high porosity, aerogels have demonstrated remarkable advantages in serving as thermal insulation and wave-transparent materials. Unfortunately, their practical applications are greatly confined by inherent fragility. The recent emergence of polymer presents an ideal platform for the development flexible aerogel films. However, additional cross-linking agents necessitated constructing a robust structure, complicating production process. Herein, we report film based on meta-aramid composites, inspired porous structure penguin feathers. intermolecular hydrogen bonds function natural agents. Their disruption results dissolution fibers, while reconstruction facilitates localized rearrangement chains during sol-gel process, generating closed nanopores. Furthermore, fluorinated hollow glass microspheres filled, compressing nanopores situated near interface to 75-150 nm. This meets critical threshold required Knudsen effect, decreasing conductivity levels below that ambient air. At optimized doping ratio 3 wt%, is 21.6 mW m-1 K-1, achieving low dielectric constant 1.43. Simultaneously, films exhibit enhanced mechanical properties, also show benefits hydrophobicity, colorability, ultralightness, flame retardancy, making themselves multifunctional materials suitable applications.

Language: Английский

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Elastic, flexible, and tough hierarchical polyimide aerogels with dynamic reversible physical entanglement structure

Chemical Engineering Journal, Journal Year: 2025, Volume and Issue: unknown, P. 161429 - 161429

Published: March 1, 2025

Language: Английский

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