Al@SiO₂ Core-Shell Fillers Enhance Dielectric Properties of Silicone Composites

Area of Science:

• Materials Science
• Polymer Science
• Electrical Engineering

Background:

• Polysiloxane-based dielectric elastomers are promising soft electroactive materials.
• Low permittivity of polydimethylsiloxane limits practical applications.
• Need for enhanced dielectric properties in soft electroactive materials.

Purpose of the Study:

• To develop high-performance silicone rubber composites with enhanced dielectric properties.
• To investigate the effect of core-shell filler structure on dielectric behavior.
• To improve the dielectric constant and breakdown strength of silicone rubber.

Main Methods:

• Fabrication of silicone rubber/Al@SiO2 composites with controlled core-shell filler characteristics.
• Investigation of dielectric properties, including dielectric constant and loss.
• Analysis of dielectric relaxation processes, specifically Maxwell-Wagner-Sillars (MWS) relaxation.
• Study of the temperature dependence of MWS relaxation time.

Main Results:

• Achieved high dielectric constant, low dielectric loss, and high electrical breakdown strength.
• Core-shell fillers enhanced the MWS relaxation process.
• Reduced direct current conductance loss in silicone rubber composites.
• MWS relaxation time followed the Arrhenius equation with temperature variation.

Conclusions:

• Controlling shell layer thickness and core-shell filler content is key to optimizing composite properties.
• Core-shell structured fillers effectively enhance the permittivity of silicone composites.
• This strategy offers a pathway for developing other high dielectric constant materials.