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Phase Diagram Characterization Using Magnetic Beads as Liquid Carriers
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Filler dimensionality effect on the performance of paraffin-based phase change materials
Avia Ohayon-Lavi1, Gennady Ziskind2, Oren Regev3
1Department of Chemical Engineering, Ben-Gurion University of the Negev, Beer-Sheva, Israel.
Journal of Colloid and Interface Science
|July 25, 2022
Summary
This study enhances thermal energy storage by incorporating carbon nanomaterials into phase change materials. The hybrid fillers significantly boost thermal conductivity and ensure material stability for improved performance.
Area of Science:
- Materials Science
- Nanotechnology
- Thermal Engineering
Background:
- Phase change materials (PCMs) offer high-density thermal energy storage but suffer from low thermal conductivity and poor shape stability.
- Thermally conductive nanomaterials can form 3D networks within PCMs to improve thermal performance.
- Encapsulation in a polymer matrix can enhance the shape stability of PCMs.
Purpose of the Study:
- To enhance the thermal conductivity and stability of paraffin-based phase change materials.
- To investigate the synergistic effects of hybrid carbon-based nanomaterials (carbon nanotubes, graphene nanoplatelets, graphite flakes) on PCM performance.
- To evaluate the thermal conductivity and latent heat capacity of the modified PCMs.
Main Methods:
- Paraffin wax was loaded with 1D carbon nanotubes, 2D graphene nanoplatelets, and 3D graphite flakes.
- Thermal conductivity was measured using the transient plane source method.
- Latent heat capacity was determined via differential scanning calorimetry.
- Thermal conductivity was modeled using the effective medium approach.
Main Results:
- A 55-fold increase in thermal conductivity was achieved, rising from 0.2 to 11 W/(m·K).
- Optimal enhancement resulted from a hybrid filler composition of 8 vol% graphite flakes and 12 vol% graphene nanoplatelets.
- Material compression (25 bar) further improved thermal conductivity.
- The resulting phase change material demonstrated complete stability during thermal cycling.
Conclusions:
- Hybrid carbon nanomaterials significantly enhance the thermal conductivity of paraffin-based phase change materials.
- The combination of graphene nanoplatelets and graphite flakes, along with compression, is effective for improving thermal energy storage.
- The developed composite materials are stable and suitable for high-density thermal energy storage applications.
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