Exploring Structure-Properties Relationships in Polymer-Matrix Nanocomposites Containing Barium Titanate Nanoparticles

The structural, dynamic, and property characterizations of barium titanate (BaTiO₃ or BTO) nanoparticles and composites consisting of BTO-filled polydimethylsiloxane (PDMS) will be the focus of this presentation. BTO is a ferroelectric perovskite that exhibits remarkable electrical polarizability because of its tetragonal lattice structure at room temperature. Studies into BTO have been motivated by its potential to significantly advance energy storage technologies. For example, multilayer capacitors used in voltage regulators and power supplies are composed of hundreds of dielectric layers, which makes miniscule BTO nanoparticles highly desirable in these applications. The dielectric constant of BTO impacts its ability to store energy, but the relationships between the size, structure, and dielectric constant of BTO are still not fully understood. BTO has a bulk dielectric constant of up to ~7,000 and decreasing the size of individual BTO nanoparticles has been shown to drastically increase the dielectric constant of the perovskite (~15,000 at a diameter of 70 nm). However, this result is highly contested. This talk will discuss the manufacturing, characterization, and modeling of PDMS-BTO nanocomposites. The relationships between BTO-PDMS nanocomposite properties, BTO particle size, and BTO dielectric constant will be revealed through (1) measurements of nanocomposite properties, (2) finite element modeling of BTO-filled PDMS, (3) transmission electron microscopy images of BTO nanoparticles in PDMS. The results will provide insight into factors that impact the properties of BTO and polymer-inorganic nanocomposite technologies that leverage the advantages of individual BTO nanoparticles.