Analysis on the presence of nanosized titanium dioxide (TiO2) and zinc oxide (ZnO) in compact powder

Abstract

In the present study, unmodified compact powders (JJ01, JJ02, SW01, and SW02) were examined to investigate the presence of potentially harmful nanosized materials, namely titanium dioxide (TiO2) and zinc oxide (ZnO). The X-ray diffraction (XRD) method, field emission scanning electron microscopy (FESEM), and energy dispersive X-ray (EDX) were used to study all selected samples. The XRD pattern confirmed the existence of nanosized ZnO in JJ01 and JJ02 samples, where the sharp peaks matched well with the orientation of the (100), (002), and (101) lattice planes of the cubic phase of hexagonal ZnO. The calculated crystallite size using the Scherrer equation was found to be between ∼ 34 nm and ∼ 80 nm. As for SW01 and SW02 samples, similar XRD patterns were observed for hexagonal ZnO, while other two dominant peaks observed, corresponding to the (022) and (221) crystallographic planes, which indicate the standard peaks of brookite TiO2. For these samples, the calculated crystallite size of ZnO using the Scherrer formula ranges from ∼ 25 nm to ∼ 85 nm, while the crystallite size of TiO2 ranges from ∼ 15 nm to ∼ 90 nm. FESEM results detected a similar surface morphology of flakes-like for all samples, where nanosized TiO2 and ZnO were hardly measured. The EDX then revealed the composition and confirmed the existence of Zn and O in JJ01 and JJ02 samples, and the addition of Ti elements in SW01 and SW02 samples. The obtained results confirm the presence of nanosized ZnO, and both nanosized ZnO and TiO2 in the JJ and SW samples, respectively, with a crystallite size of less than 100 nm that was not properly labelled by the manufacturer.