Sandwich-Structured Fluorinated Polyimide Aerogel/Paraffin Phase-Change Composites Simultaneously Enables Gradient...

Area of Science:

• Materials Science
• Aerospace Engineering
• Electromagnetics

Background:

• Emerging need for materials with combined thermal insulation and electromagnetic wave transparency.
• Existing materials often compromise one function for the other.
• Polyimide (PI) aerogels show promise due to their tunable properties.

Purpose of the Study:

• To develop a novel polyimide aerogel-based sandwich composite.
• To achieve simultaneous thermal protection and electromagnetic wave-transparent transmission.
• To explore applications in aerospace and communication systems.

Main Methods:

• Fabrication of a three-layer composite: unidirectional fluorinated PI aerogel (lower), conventional PI aerogel (middle), and fluorinated PI aerogel/paraffin phase-change material (upper).
• Characterization of microstructures, dielectric properties, and thermal performance.
• Evaluation of paraffin leakage prevention by the middle layer.

Main Results:

• The composite exhibits an ultralow dielectric constant (1.04) in the lower layer.
• The upper layer demonstrates dynamic temperature regulation with high latent heat capacity (242.7 J/g).
• The middle layer effectively prevents paraffin leakage, ensuring structural integrity.

Conclusions:

• The developed sandwich composite provides gradient thermal protection and excellent wave transparency.
• The rational integration of functional layers creates a high-performance material.
• Potential applications include aircraft, spacecraft, radar, and satellite communication systems.