In nanoparticle-based sunscreens, zinc oxide and titanium dioxide nanoparticles act as physical blockers. They absorb, scatter, and reflect ultraviolet (UV) radiation, offering protection against both UVA and UVB rays. Unlike chemical sunscreens that absorb UV radiation and dissipate it as heat, these nanoparticles provide a shield that prevents UV penetration through a combination of optical mechanisms.
