Comparison of Antibacterial Activity of ZnO Nanoparticles Fabricated by Two Different Methods and Coated on Tetron Fabric
Authors: Karimi Ebrahim Zohourvahid , Ansari Mohammad 
Published: August 2018

Background:
Zinc Oxide Nanoparticles (ZnO NPs) have wide applications in various industries, especially they have been known for their antibacterial effects in polymers and textile fibers. ZnO NPs were produced by two different solutions and milling methods. Different techniques were used in order to select the most effective methods for coating the fabric with ZnO NPs. The microstructures and the composition of the ZnO NPs were investigated using Field Emission Scanning Electron Microscopy (FE-SEM) coupled with Energy Dispersive X-ray Spectroscopy (EDS) and X-ray diffraction analysis (XRD). Additionally, the antibacterial activity of the treated fabric against Staphylococcus aureus and Escherichia coli bacteria was investigated. The overall experimental findings show that the highest inhibitory effect against Staphylococcus aureus in the sample of fabric which covered with ZnO NPs synthesized by the solution method.

Methods:
In the solution method, ZnO NPs were synthesized by dissolving zinc chloride in 1, 2 Ethanediol and mixing with aqueous solution of sodium hydroxide. In milling method, firstly, zinc sulfide nanoparticles were prepared through reaction between zinc acetate and Thioacetamide and then by milling and oxidation the zinc sulfide nanoparticles, ZnO NPs were synthesized. In order to deposition ZnO NPs on the Tetron fabric, it was fully drawn and fixed on a frame. After that, acrylic copolymer resin was added into distilled water and ZnO NPs were added in another beaker to ethanol. The two beakers were then placed in the ultrasonic bath for a certain time. Finally, the fabric was dipped into the beaker containing resin for some moment and then immersed into the beaker containing ZnO NPs. During these processes, both beakers were in the ultrasonic bath. After drawing out the fabric from second beaker, it was dried in air. This procedure was performed for both types of ZnO NPs fabricated by two mentioned methods. Antibacterial activity of ZnO NPs coated on the fabric against two types of bacteria was studied by agar diffusion method.

Results:
XRD patterns of synthesized powders from both methods were identified as ZnO NPs. Sharp diffraction peaks indicate good crystallinity of ZnO NPs. The morphology of the ZnO NPs fabricated by both methods which was analyzed by field emission SEM shows that the ZnO particles synthesized by milling and solution methods are in nano scale at the range of 26 - 29 nm and 9 - 11 nm, respectively. The highest inhibitory effect against Staphylococcus aureus was shown for the fabric which coated by ZnO NPs produced by the solution method. It was seen, the antibacterial activity of ZnO NPs fabricated by solution method was higher than that of milling method.

Conclusion:
ZnO NPs were synthesized by two different methods and the antibacterial activity of Tetron fabric coated with ZnO NPs was studied. Distribution and stability of ZnO NPs on the fabric depend on fabrication method and particle size which means that the smaller particles have more stability and better distribution than larger particles. The particle size and deposited concentration of ZnO NPs were effective on antibacterial activity, so that the smaller particles tend less agglomeration and have more surface area and because of that better antibacterial activity. Overall the results demonstrated a good antibacterial activity against Staphylococcus aureus than Escherichia coli.in the sample of fabric which covered with ZnO NPs synthesized by the solution method.