Influence of NiO and La <sub>2</sub> O <sub>3</sub> nanoparticles on the optical, mechanical and electrical properties of PVAc–PMMA blend: a comparative study
Adel M. El Sayed, S. El‐Gamal
Abstract
Abstract Nano-sized metal oxides are fascinating materials as fillers used for improving the polymeric materials’ performance and expanding their multifunctionality. Two metal oxides; NiO and La 2 O 3 nanoparticles (NP) were prepared and introduced into poly(vinyl acetate)/poly(methyl methacrylate), PVAc/PMMA blend via solution casting route. XRD and HR-TEM analysis confirmed the preparation of a cubic NiO and a hexagonal La 2 O 3 NP with an average crystallite size of 59.85 and 29.13 nm, respectively. Introducing NiO and La 2 O 3 increases the films’ amorphous structure. FTIR analysis confirmed the existence of all blend’ functional groups and hydrogen bond formation. SEM investigation showed that NiO or La 2 O 3 loading affects the blend surface morphology. A UV–vis-NIR study showed that NiO narrowed the direct bandgap of the blend from 4.1 to 3.3 eV, whereas La 2 O 3 reduced it to 3.4 eV. 1.0 wt% NiO significantly improved the various optical constants of the blend. DMA revealed that storage modulus G′ increased with loading of 1 wt% NiO or La 2 O 3 by 79.3% and 51.0%, respectively while G′ decreased with heating. The dielectric behavior of films is analyzed using several dielectric parameters. The maximum σ ac reported for 1.0 wt% NiO/blend film is 5.8 × 10 −6 (S/cm). The AC conduction mechanism is discussed for all films in the temperature and frequency ranges (298−373 K) and (5 Hz−2 MHz). 1.0 wt%/PVAc/PMMA nanocomposite showed enhanced optical and mechanical properties, making it suitable for architectural, flexible display screens, and photovoltaic cell devices. Moreover, loading NiO and La 2 O 3 improved the dielectric properties of the blend to be used in the semiconductor industry, besides energy storage devices and supercapacitors.