pH Effects on Zeta Potential of ZnO Nanofluids to Inspect Stability and its Antibacterial Activities Against E. Coli DH10B

In this work, ZnO nanoparticles were radially synthesized via sol-gel technique and ZnO nanofluids in distilled water (ZnO-W) and in methanol (ZnO-Me) were produced by two step method. The prepared ZnO nanoparticles are characterised by X-ray diffraction characterized by XRD. Average particle size of synthesized ZnO nanoparticles has been estimated by Debye-Scherrer formula. It was found to be about 30 nm. The particle size distributions of the synthesized nanofluid are measured through acoustic particle sizer (APS-100). The observed features of ZnO nanofluids are discussed in correlation with zetapotential, thermal conductivity and sound velocity. Master ZnO nanofluids with a pH value of about 7 were prepared and stored for different periods under the light and in dark for the evaluation of its antibacterial activities against E coli DH10B by estimating the reduction ratio of the bacteria treated with ZnO.