Antibacterial performance of glucose-fructose added MW based zirconia coatings - Possible treatment for bone infection.

Use of ceramic coatings has increased dramatically in orthopedics by improving their wear resistance and consequent long-term stability. Such stability involves not only the strength of material but also its resistance toward bacterial attacks. Amongst all ceramics, zirconia is selected in the present study due to its white color and high value of hardness making it a potential candidate to be used as implants and their coatings. In the present study effect of varying microwave powers (i.e. 100W, 200W, 300W, 400W, 500W, 600W, 700W, 800W, 900W and 1000W) on sol-gel synthesized glucose and fructose added zirconia coatings has been investigated. Formation of mixed tetragonal - monoclinic phases has been observed at relatively low microwave powers, i.e. 100-500W. However, at 600-1000W phase pure tetragonal zirconia is observed without any post heat treatment. FTIR analysis confirms formation of tetragonal phase of zirconia at 600-1000W microwave power. XPS results confirm the binding energies of Zr 3d and O 1s of microwave assisted zirconia coatings. High value of transmittance, i.e. ~90%, is observed at higher microwave powers. Variation in microwave powers is observed to tune the energy band gap of zirconia coatings in the range of 4.2-5.1 eV. Dielectric constant of 8-10 at log f = 4 is observed. High value of hardness and fracture toughness i.e. 1231 HV and 24.85 MPam, respectively, is observed for stabilized tetragonal zirconia coatings. Stabilized glucose fructose added zirconia shows strong antioxidant activity. Zirconia coatings are tested against Staphylococcus aureus bacteria for their potential application to treat bone infection. Results suggest that stabilized tetragonal zirconia can be successfully employed for orthopedic coatings.