Mr. Xudong Wu - Ph.D. Candidate
07/11/2024
ZOOM
14:30 (Jerusalem time) | 20:30 (Beijing time)
High dielectric constant (K), high breakdown strength, and low loss tangent are important factors for using polymer dielectrics in important fields, such as power electronics, electric vehicles, and power grids. In the past few years, we utilized atomic layer deposition (ALD) to fabricate core-shell nanoparticles, fibers, and multilayer organic-inorganic films and found significant improvement in the dielectric performance of polymer composites. In this seminar, the summary of past work will be presented and in particular, we will report recent process focusing on dielectric loss reduction in polymer composites.
Dielectric loss is a crucial factor in determining the long-term endurance for security and energy loss of dielectric composites. Chain-like semiconductive fibers of titanium oxide, indium, and niobium-doped titanium oxide (TINO) are used for enhancing the complex dielectric properties of a polymer through composite construction. The chain-like fibers significantly enhance the dielectric constant owing to the special morphology and their interfacial polarization. The dielectric loss and electrical conductivity of the composites are substantially reduced across the entire investigated temperature range, achieved by passivating the fiber surface with an alumina shell using ALD. The as-deposited alumina shell transformed from an amorphous to a crystalline phase through thermal annealing resulting in a porous shell and more effective suppression of the loss tangent and electrical conductivity.
Supervisors: Assoc. Prof. Yachin Ivry (Technion)
Prof. Daniel Q. Tan (GTIIT)