Polymer-Grafted Nanoparticles with Variable Grafting Densities for High Energy Density Polymeric Nanocomposite Dielectric Capacitors

Bhausaheb V Tawade; Maninderjeet Singh; Ikeoluwa E Apata; Jagadesh Veerasamy; Nihar Pradhan; Alamgir Karim; Jack F Douglas; Dharmaraj Raghavan

doi:10.1021/jacsau.3c00022

Polymer-Grafted Nanoparticles with Variable Grafting Densities for High Energy Density Polymeric Nanocomposite Dielectric Capacitors

JACS Au. 2023 Apr 26;3(5):1365-1375. doi: 10.1021/jacsau.3c00022. eCollection 2023 May 22.

Authors

Bhausaheb V Tawade¹, Maninderjeet Singh², Ikeoluwa E Apata¹, Jagadesh Veerasamy², Nihar Pradhan³, Alamgir Karim², Jack F Douglas⁴, Dharmaraj Raghavan¹

Affiliations

¹ Department of Chemistry, Howard University, Washington, D.C. 20059, United States.
² Department of Chemical and Biomolecular Engineering, University of Houston, Houston, Texas 77204, United States.
³ Department of Chemistry, Physics and Atmospheric Science, Jackson State University, Jackson, Mississippi 39217, United States.
⁴ Material Science and Engineering Division, National Institute of Standards and Technology, Gaithersburg, Maryland 20899, United States.

Abstract

Designing high energy density dielectric capacitors for advanced energy storage systems needs nanocomposite-based dielectric materials, which can utilize the properties of both inorganic and polymeric materials. Polymer-grafted nanoparticle (PGNP)-based nanocomposites alleviate the problems of poor nanocomposite properties by providing synergistic control over nanoparticle and polymer properties. Here, we synthesize "core-shell" barium titanate-poly(methyl methacrylate) (BaTiO₃-PMMA) grafted PGNPs using surface-initiated atom transfer polymerization (SI-ATRP) with variable grafting densities of (0.303 to 0.929) chains/nm² and high molecular masses (97700 g/mL to 130000 g/mol) and observe that low grafted density and high molecular mass based PGNP show high permittivity, high dielectric strength, and hence higher energy densities (≈ 5.2 J/cm³) as compared to the higher grafted density PGNPs, presumably due to their "star-polymer"-like conformations with higher chain-end densities that are known to enhance breakdown. Nonetheless, these energy densities are an order of magnitude higher than their nanocomposite blend counterparts. We expect that these PGNPs can be readily used as commercial dielectric capacitors, and these findings can serve as guiding principles for developing tunable high energy density energy storage devices using PGNP systems.