This study investigates how oxygen plasma treatment alters the properties of SnO2 and Mn2O3 nanoparticles and, in turn, influences the dielectric behavior of nematic liquid crystals. The findings show that the duration of plasma exposure plays a significant role in modifying particle size, morphology, and surface chemistry. XRD analysis confirm that the tetragonal structure of SnO2 and cubic structure of Mn2O3 remain intact, through both exhibit a slight decrease in crystallite size following treatment. SEM analysis reveals that plasma processing smoothens and compacts the surface of SnO2, whereas Mn2O3 undergoes partial surface etching and localized reagglomeration, consistent with its higher reactivity. FTIR spectra indicate strengthened oxygen-related features and enhanced surface functionalization, which facilitate more pronounced interfacial polarization. Consequently, the liquid crystal doped with Mn2O3 nanoparticles reaches its maximum dielectric anisotropy after 14 min of plasma exposure. Overall, controlled plasma treatment can effectively tailor nanoparticle-liquid crystal interactions and enhance dielectric performance.
