Creating, Characterizing, and Modeling Nanocomposites of Silicone and Barium Titanate Nanoparticles*

Experimental and computational studies into the structure-property relationships of silicone-matrix nanocomposites containing barium titanate (BTO) nanoparticles will be discussed in this presentation. BTO is a ferroelectric perovskite that is used in capacitors because of its high dielectric constant (up to 7,000). Research has shown that the dielectric constant of BTO drastically increases to 15,000 at a BTO particle diameter of 70 nm, which is an intriguing but highly contested result. Investigations aimed at determining the dielectric constants of BTO nanoparticles by incorporating BTO into polymers have indicated that particle size does have an impact on the dielectric constant of the perovskite. However, previous results showed that (1) the low maximum loading of BTO in thermosetting and thermoplastic polymers limits the insight into the dielectric properties of BTO and (2) more advanced modeling methods are needed to better understand how filler-matrix interfaces affect the properties of BTO-filled nanocomposites. Here we present the fabrication, structure, properties, and density functional theory modeling of highly loaded elastomer-matrix nanocomposites containing BTO nanoparticles with diameters ranging from 50 nm to 500 nm. The results from this project will advance our understanding of the particle size dependence of the dielectric constant of BTO and demonstrate an avenue toward manufacturing flexible elastomer-perovskite nanocomposites for energy storage applications.        

SNL is managed and operated by NTESS under DOE NNSA contract DE-NA0003525. This study was also supported by the National Science Foundation under Grant No. 1943599.