Understanding the core-shell interactions in macrocapsules of organic phase change materials and polysaccharide shell

Area of Science:

• Materials Science
• Chemical Engineering
• Sustainable Energy

Background:

• Thermal energy storage (TES) is crucial for renewable energy integration.
• Developing sustainable and efficient TES materials is an ongoing challenge.
• Biodegradable materials offer an environmentally friendly alternative for energy applications.

Purpose of the Study:

• To prepare biodegradable macrocapsules containing organic phase change materials (PCMs) for thermal energy storage.
• To encapsulate three distinct PCMs: hexadecane (paraffin), butyl stearate (ester), and caprylic acid (fatty acid).
• To evaluate the encapsulation efficiency, thermal stability, and thermal buffering performance of the prepared capsules.

Main Methods:

• Utilized the ionic gelation method to encapsulate PCMs within a barium crosslinked pectin shell.
• Prepared millimeter-sized (≤2 mm) pectin-PCM capsules.
• Analyzed encapsulation efficiency, melting enthalpy, thermal stability, and thermal buffering capacity.

Main Results:

• Achieved high encapsulation efficiencies: 83.66 wt% (hexadecane), 83.21 wt% (butyl stearate), and 84.39 wt% (caprylic acid).
• Reported melting enthalpies of 184.89 kJ/kg (hexadecane), 116 kJ/kg (butyl stearate), and 118 kJ/kg (caprylic acid).
• Demonstrated significant improvement in thermal stability (70°C-130°C) and provided substantial thermal buffering (50-62 minutes).

Conclusions:

• Successfully prepared biodegradable pectin-PCM macrocapsules for thermal energy storage.
• The encapsulated PCMs exhibit enhanced thermal stability and effective thermal buffering.
• These findings highlight the potential of pectin-PCM capsules as a sustainable solution for TES applications.