Phase Change Materials Composite Based on Hybrid Aerogel with Anisotropic Microstructure.

Area of Science:

• Materials Science
• Nanotechnology
• Thermal Engineering

Background:

• Phase change materials (PCMs) are crucial for thermal energy storage.
• Enhancing the thermal conductivity of PCMs is essential for efficient heat transfer.
• Graphene-based aerogels offer potential for thermal enhancement due to their unique structures.

Purpose of the Study:

• To develop an anisotropic reduced graphene oxide (rGO)/expanded graphite (EG) aerogel composite for enhanced phase change materials.
• To investigate the effect of the anisotropic aerogel microstructure on the thermal conductivity of PCMs.
• To evaluate the impact of the rGO/EG aerogel on the phase change behavior and latent heat of the composite PCM.

Main Methods:

• Preparation of rGO/EG aerogel via directional freezing of graphene oxide and expanded graphite suspensions.
• Freeze-drying and thermal reduction at 250 °C to form the anisotropic aerogel structure.
• Characterization using scanning electron microscopy (SEM), thermal conductivity tests, and infrared imaging.

Main Results:

• Anisotropic microstructure of the rGO/EG aerogel composite was successfully fabricated and confirmed.
• Significant enhancement in thermal conductivity of PCMs: 50-300% increase longitudinally and 25-150% transversally compared to pure paraffin.
• Improved thermal pathways and reduced interfacial thermal resistance attributed to the rGO/EG aerogel.
• No chemical interaction between rGO/EG aerogel and paraffin, preserving phase change behavior.
• Slight increase in the latent heat of the composite PCM observed.

Conclusions:

• Anisotropic rGO/EG aerogel effectively enhances the thermal conductivity of phase change materials.
• The developed composite PCMs show improved thermal performance without compromising phase change characteristics.
• This approach offers a promising strategy for advanced thermal energy storage applications.