The effect of cationic, anionic and nonionic surfactants on morphology and antibacterial properties of zinc oxide

ABSTRACT

In this study, zinc oxide was synthesized through wet chemical method at room temperature (RT), 40 °C and 60 °C without surfactant and at the presence of cetyltrimethylammonium bromide (CTAB), sodium dodecyl sulfate (SDS) and polyethylene glycol (PEG 6000) as cationic, anionic and non-ionic surfactants, respectively. Field emission scanning electron microscopy (FESEM) was used to investigate the effect of temperature and type of surfactants on the morphology of zinc oxide. FESEM images showed that the morphology of zinc oxide changed from rod-like at room temperature with increasing temperature. The morphology of zinc oxide samples synthesized by CTAB, SDS, and PEG surfactants was worm-like, nut-like and rod-like, respectively. The results of X-ray diffraction spectroscopy (XRD) analysis indicated the presence of zinc oxide phase in all samples. Zn(OH)₂ phase was also detected in the sample synthesized with PEG 6000. Fourier-transform infrared spectroscopy (FTIR) analysis was used to evaluate the functional groups. Antibacterial activity of zinc oxide samples against Staphylococcus aureus (S. aureus) and Escherichia coli (E. coli) strains was evaluated by using disc diffusion technique and colony-forming unit (CFU) method. Both methods confirmed the antibacterial activity of all samples. Moreover, the highest antibacterial activity was shown for the sample synthesized in the presence of PEG as a surfactant.

Keywords
Zinc oxide; Surfactant; Antibacterial activity; Morphology