SUNSCREEN SCIENCE
Sunscreens are lotions made specifically to protect our skin against ultraviolet radiation (UVR) from the Sun. The active ingredients in sunscreen lotions are molecules that absorb or scatter the UVR that reaches us from the Sun, before it has a chance to damage skin cells. However, if UVR can cause damage to the skin, what does it do to the sunscreen molecules themselves? My PhD research focused on answering this question by mapping how the energy from sunlight is absorbed and distributed in sunscreen molecules.
Different types of light have different effects on molecules. The UVR that is absorbed my sunscreen molecules excites their electrons to high energy states, referred to as excited states. The excess energy
Photochemistry
Sunscreens are lotions made specifically to protect our skin against ultraviolet radiation (UVR) from the Sun. The active ingredients in sunscreen lotions are molecules that absorb or scatter the UVR that reaches us from the Sun, before it has a chance to damage skin cells.
However, if UVR can cause damage to the skin, what does it do to the sunscreen molecules themselves?
My PhD research focused on answering this question by mapping how the energy from sunlight is absorbed and distributed in sunscreen molecules.
What's the main conclusion?
Sunscreen molecules can dissipate the excess energy they get from absorbing sunlight very efficiently by cis-trans isomerization. We have observed this mechanism in many derivatives of the cinnamates, some of which are used in sunscreen lotions, and the better sunscreens are the ones that undergo this process the fastest. As such, we have focused on making new molecules for which this process is optimized; we have now achieved almost complete energy dissipation in approximately 300 femtoseconds, even when we place our novel sunscreen molecule on a skin mimic (you can read the paper about this here).
Want to know more?
If you'l like to know more about sunscreen photodynamics, you can freely access my PhD thesis here. Alternatively, please go to Publications for a complete list of my articles on this and other topics.
I am also available to tell you more or write about sunscreen science to non-scientific audiences; please use the Contact form to discuss.