Characterizing titanium dioxide and zinc oxide nanoparticles in sunscreen spray

Area of Science:

• Nanotechnology
• Materials Science
• Analytical Chemistry

Background:

• Commercial products, including sunscreens, often contain titanium dioxide (TiO2) and zinc oxide (ZnO) nanoparticles (NPs).
• Accurate characterization of these NPs is crucial for understanding their behavior and safety.
• Current labeling practices do not always disclose the presence of NPs in these products.

Purpose of the Study:

• To develop and validate effective methods for characterizing TiO2 and ZnO NPs in sunscreen sprays.
• To determine particle size, shape, composition, and aggregation/agglomeration characteristics.
• To ensure accurate and reliable NP analysis in complex formulations.

Main Methods:

• Utilized transmission electron microscopy (TEM) with a window-type microchip K-kit/copper grid.
• Employed X-ray diffraction (XRD) for particle characterization.
• Compared K-kit and conventional copper grid pre-treatment methods for TEM analysis.

Main Results:

• The K-kit method, combined with XRD, allowed direct measurement of NPs without pre-treatment, preserving sample integrity.
• XRD provided insights into particle size and crystal structure.
• Strong correlation observed between XRD and TEM measurements, validating the proposed methods.
• The K-kit approach avoided sample dilution, crucial for assessing agglomeration.

Conclusions:

• The developed measurement techniques are highly effective for characterizing oxide NPs in sunscreen sprays.
• The methods provide consistent and reliable information on NP properties and interactions within formulations.
• This approach enhances the accuracy of NP analysis in commercial products.