Jang Si-hyeon, a Master's student in the Dept.of Carbon Composites Convergence Materials Engineering at Jeonbuk National University (JBNU), developed a sunscreen material technology that transmits visible light while selectively blocking ultraviolet (UV) radiation.

This research was published under the title ‘Hollow Polystyrene Nanoparticles Inducing Nanocavities in Newtonian Fluids for Selective Visible Transparency and Ultraviolet Blocking’ in the latest issue of the international journal ACS Applied Polymer Materials.

Conventional sunscreens are broadly classified into organic and inorganic UV filters. Organic filters use organic compounds that absorb ultraviolet radiation, but issues such as durability and heat generation during use have been raised.

In contrast, inorganic filters such as zinc oxide (ZnO) or titanium dioxide (TiO₂) can effectively block UV radiation, but they also scatter visible light, resulting in a whitening (white cast) effect where the skin appears pale.

To address this issue, the research team focused on nanoporous structures that selectively scatter light in the ultraviolet region. By using nanopores, visible light can be relatively transmitted while ultraviolet light is effectively scattered, which in principle can reduce the whitening effect of conventional inorganic sunscreens. However, the key challenge was to stably maintain the nanoporous structure within a fluid matrix such as a sunscreen.

The team synthesized polymer nanoparticles with hollow structures and ensured that the nanoporous architecture could be stably formed and maintained even within viscous fluids.

As a result, the developed material exhibited selective optical properties, showing high transmission in the visible region while demonstrating relatively high blocking performance in the ultraviolet region. This approach is evaluated as a new method that can reduce the whitening effect—a representative limitation of conventional inorganic UV filters—while continuously providing UV-blocking functionality.

Professor Kim Geon-woo of JBNU, who supervised the research, stated, “This study is significant in that it proposed a new sunscreen material design method that effectively blocks ultraviolet radiation while ensuring visible light transmissivity.” He added, “We have completed a patent application for the related technology and are conducting follow-up research with commercialization in mind for actual sunscreen and cosmetic materials.”

This study demonstrated that by utilizing polymer hollow nanoparticles to realize selective light-scattering properties, it presents a new possibility to overcome the limitations of existing UV-blocking materials. Its application in the fields of functional cosmetics and UV-blocking materials is therefore expected.