Impact of Dopamine-Based Coupling Agents on the Electroactive Properties of Barium Titanate/P(VDF- co -TrFE) 55/45 Composites

Electroactive composites combining ceramic nanoparticles with fluorinated polymers present great potential for applications in flexible electronics, sensors, and energy harvesting. However, the poor interfacial compatibility between the two constituents often limits their performance. In this study, barium titanate (BTO) nanoparticles were functionalized with six different dopamine-based coupling agents and then incorporated into a P(VDF- co -TrFE) 55/45 matrix. The objective was to assess the impact of the chemical structure of the coupling agents on the morphology and electroactive performance of the resulting composites. Microscopic analyses revealed that all coupling agents promote better dispersion of BTO nanoparticles within the polymer matrix. Furthermore, dielectric and ferroelectric measurements highlighted the crucial influence of the coupling agents’ dipole moment. Dopamine-based coupling agents integrating high dipoles such as nitro and sulfanyl groups significantly enhance the dielectric constant and remnant polarization of the composites. These results emphasize the importance of selecting coupling agents with appropriate molecular properties to optimize the electroactive performance of ceramic/polymer composites.