The Sandia National Laboratories clinic project is investigating how the dielectric constant of barium titanate (BTO) nanoparticles varies with particle size when embedded in a PDMS polymer matrix. Achieving this goal requires two subteams, one focused on experimental lab work and the other focused on computational simulation work. The experimental team fabricated high-volume-loading BTO–PDMS composites across multiple BTO particle sizes, measuring capacitance and using finite-element modeling to extract the effective dielectric constant associated with each particle size. In parallel, the computational team ran DFT simulations to understand BTO surface interactions with a surfactant, tBuPa, and how these surface interactions can inhibit PDMS crosslinking. By investigating how BTO nanoparticle size and surface chemistry influence dielectric behavior in polymer composites, this work will guide the design of next-generation high-energy-density capacitors and other advanced energy storage technologies.