Otero Pino, AndreaSayagués, M. J.Romero Landa, Francisco JavierGotor, F. J.Moriche Tirado, Rocío2025-06-132025-06-132025Otero Pino, A., Sayagués, M.J., Romero Landa, F.J., Gotor, F.J. y Moriche Tirado, R. (2025). Piezoelectric and Dielectric Response of BaTiO3/PVDF-TrFE Composites with High β-Phase Content. ACS Applied Polymer Materials, 7 (12), 7848-7858. https://doi.org/10.1021/acsapm.5c00620.2637-6105https://hdl.handle.net/11441/174322The search for flexible piezoelectric materials to build adaptable sensors, electronics, and nanogenerators has becomea key area of interest. The addition of piezoceramic particles to piezoelectric polymers, such as the copolymer poly(vinylidenefluoride-trifluoroethylene) (PVDF-TrFE), is one of the strategies used to enhance the piezoelectric response. In this work, the effectof BaTiO3 content on the β-phase formation, crystallization, and piezoelectric and dielectric properties of the polymer-basedcomposites is investigated. High-energy ball milling was used as an effective, greener technique to achieve well-dispersed mixturescompared to those obtained using organic solvents. During the dispersion process, amorphization and reduction of the crystallinedomain size occur. After compression molding and postprocessing, the crystallinity was recovered and was strongly dependent onthe filler content. Although significant differences in the β-phase fraction were not observed, conformational defects are induced withhigh BaTiO3 contents. The interlayer distances became smaller due to the presence of the ceramic particles after compressionmolding and remained almost unchanged after postprocessing. For the composites, the minimum voltage required to obtain ameasurable piezoelectric coefficient (d33) was significantly reduced compared to neat PVDF-TrFE, even for low contents, which iskey for real applications. Three different piezoelectric behaviors were found depending on the BaTiO3 fraction. For composites with40 vol %, where both matrix and filler contribute to the overall piezoelectric response, the use of a two-step poling method induced asynergistic effect with an increase in d33 of ∼180%. However, the relaxation of the ceramic contribution after 24 h returns the valueof d33 to that obtained by applying a one-step poling strategy.application/pdf11 p.engAttribution 4.0 Internationalhttp://creativecommons.org/licenses/by/4.0/PVDF-TrFEβ-phaseBarium titanatePiezoelectric propertiesDielectric propertiesinfo:eu-repo/semantics/articleinfo:eu-repo/semantics/embargoedAccesshttps://doi.org/10.1021/acsapm.5c00620