Surface Adsorption of Polyethylene Glycol and Polyvinyl Alcohol with Variable Molecular Weights on Zinc Oxide Nanoparticles

Polymer adsorption by nanoparticles improves the stability of these types of suspensions against aggregation. In this work, the surface adsorption of polyethylene glycol (PEG) and polyvinyl alcohol (PVA) with different molecular weights onto the Zinc oxide (ZnO) nanoparticles is studied. The effects of solution pH value and temperature on the adsorption process are also investigated. The ZnO nanoparticles are then analyzed using Fourier transform infra red (FTIR), X-ray diffraction (XRD) and thermogravimetric analysis (TGA) techniques. The aggregation of nano particles before and after polymer adsorption is also investigated by scanning electron microscopy (SEM). The results show that by adsorbing the PEG and PVA, due to a relatively large electrostatic repulsive force between ZnO nano particles, the size of aggregated nanoparticles decreases. It has also been revealed that the low molecular weight polymers exhibit a higher adsorption rate on the particles’ surfaces in comparison to the polymers with high molecular weight.