Enhanced dielectric and structural properties of HDPE nanocomposites reinforced with HfO 2 , TiO 2 , and Ta 2 O 5 nanoparticles under high-voltage gas discharge conditions

This study investigates the structural, morphological, and dielectric performance of high-density polyethylene (HDPE) nanocomposites reinforced with HfO 2 , TiO 2 , and Ta 2 O 5 nanoparticles, with special emphasis on their behavior under high-voltage microsecond pulsed gas discharge. SEM and TEM analyses confirm uniform nanoparticle dispersion and surface morphology. FTIR spectroscopy reveals distinct metal-oxygen vibrational bands, assigned as Ti–O (∼533 cm -1 ), Hf–O (∼496 cm -1 ), and Ta–O (∼644 cm -1 ). FTIR results indicate increased crystallinity and the emergence of –OH-related vibrations (3600–4000 cm -1 ) induced by discharge. Breakdown measurements show that HDPE/HfO 2 exhibits the highest post-discharge breakdown strength (0.132×10 9 V/m), outperforming neat HDPE. Dielectric measurements demonstrate enhanced permittivity and reduced loss tangent at high frequencies for all nanocomposites, with HDPE/TiO 2 showing the lowest tan δ after discharge. Overall, metal-oxide-reinforced HDPE nanocomposites show improved electrical stability and structural resilience, offering strong potential for high-voltage insulation applications.