Biosynthesis of ZrO₂ from Phyllanthus niruri extracts and its PVA composite: mechanical, wear, dielectric, water absorption, and thermal conductivity properties

This study introduces a sustainable method for synthesizing zirconium dioxide (ZrO₂) nanoparticles using Phyllanthus niruri extracts. These nanoparticles were then incorporated into a polyvinyl alcohol (PVA) matrix to create a composite material. The mechanical, wear, and dielectric properties of this ZrO₂-PVA composite were characterized as per ASTM standards. Results revealed that the composition PV2 shows improved mechanical properties of 56.34 MPa tensile strength along with a 2.08 GPa tensile modulus and a tear strength of 28.4 N/mm, respectively. But PV4 exhibits a higher shore-D hardness of 39. However, wear resistance is substantially improved in the ZrO₂-PVA composite; thus, PV4 exhibits 0.26 coefficient of friction (COF) and a 0.008 mm³/Nm sp. wear rate, making it ideal for applications where wear reduction is critical. Additionally, the composite displayed enhanced dielectric properties influenced by ZrO₂ nanoparticle concentration, delivering high dielectric properties in the PV4 composite designation, creating opportunities for electronic and insulating applications. Additionally, PV4 stands out with a water contact angle of 63° and a thermal conductivity of 0.7 W/mK, highlighting its superior surface hydrophobicity and thermal insulating properties. In summary, this study offers a green synthesis route for ZrO₂ nanoparticles and demonstrates their value in reinforcing PVA matrices. The resulting composite exhibits enhanced mechanical strength, wear resistance, and adjustable dielectric properties, making it a promising material for various applications.