Improving the structural, morphological, mechanical, vibrational and photocatalytic properties of CuO/starch/PVA ternary nanocomposite for packaging and wastewater remediation

Abstract

Synthetic polymers are increasingly used in daily activities due to their desirable mechanical properties, cost affordability, and convenience. Despite this, they generate substantial hazardous waste that is detrimental to the ecosystem, prompting industries to adopt eco-friendly, compatible and non-toxic nanocomposites. In this work, copper oxide (CuO) nanoparticles were incorporated into polyvinyl alcohol (PVA) and starch via a precipitation-casting approach to form a CuO/starch/PVA ternary nanocomposite film. This composite causes a significant shift of dominant peaks with enhanced intensity in the infrared (IR) spectra. SEM images reveal a homogeneous distribution of tiny CuO nanoparticles on the starch/PVA surface. The XRD analysis validates the coexistence of the crystalline CuO monoclinic phase and the semi-crystalline starch/PVA composite. CuO/starch/PVA exhibits improved mechanical tensile strength and Young's modulus compared to pure starch and starch/PVA. The photocatalytic degradation was performed on rhodamine 6G (R6G) dye solution under continuous ultraviolet (UV) irradiation. The kinetic reaction rate constant is found to be 2.22 × 10^-4 min^-1 (R² ≈ 0.9930), which decomposes R6G about 1.5 times faster than CuO (1.50 × 10^-4 min^-1). CuO/starch/PVA can potentially be applied in many sustainable sectors, especially packaging and photocatalysis.