Welcome to my Stavros group webpage!

History

After graduating with my BSc in Maths from Warwick in 2016, I joined the group in May 2017 as an MSc project student from the Molecular Analytical Science Centre for Doctoral Training. More information about me, and links for more information on the doctoral training centre itself, can be found on my personal MAS CDT webpage.

My MSc project, in partnership with Lubrizol, was ten weeks in duration, during which time I studied the ultrafast photoprotection properties of the sunscreen filter octocrylene in solution and thin films. I thoroughly enjoyed my time with the group, so I'm back for my next challenge...

PhD Project

My PhD project, in conjuction with my industrial supervisors (Dr Laurent Blasco, Lubrizol and Dr Juan Cebrián, Lipotec) currently focuses on the photodynamics of avobenzone (AB), a UV filter found in sunscreen that is known to be photounstable.

The first part of my project involved solution-phase experiments to determine how AB behaves when mixed with additional UV filters, and whether its stability is positively or negatively affected by the presence of these filters. During the next stage, emollients were added to the mixture, to see whether these molecules have a detrimental impact upon the photoprotection properties of a sunscreen formulation, a so called "bottom-up" approach.

This early work was presented at the Australian Society of Cosmetic Chemists conference in Canberra, where my paper "Laser Spectroscopy for Suncare Applications: Tracking the Photostability of Avobenzone with Sunscreen Filters and Emollients in Real-time" won the Lester Conrad Award for the best paper presented at the conference.

Future work will continue to optimise this sunscreen mixtures to optimise the photostability of avobenzone, with a view to improving the UVA protection that is currently provided by this molecule in formulations. I would also like to conduct some fundamental analysis on classes of sunscreen molecules that have yet to be characterised and learn more about potential new families of UV filter, such as those derived from nature.

The main aims of my PhD are: to understand the photochemical and photophysical mechanisms of a suncreen containing AB on a fundamental level to improve the safety and efficacy of sunscreen products, to advance the capabilities of our ultrafast setup to include temperature-controlled measurements and thin films, and to advocate our ultrafast technology for industrial use, particularly for cosmetics and personal care.

Publications

1. E.L. Holt and V. G. Stavros, Applications of ultrafast spectroscopy to sunscreen development, from first principles to complex mixtures, Int. Rev. Phys. Chem, 2019, 2, 242-285. doi: 10.1080/0144235X.2019.1663062
2. M. D. Horbury, E. L. Holt, L. M. M. Mouterde, P. Balaguer, J. Cebrián, L. Blasco, F. Allais and V. G. Stavros, Towards symmetry driven and nature inspired UV filter design, Nat. Commun., 2019, 10, 4748. doi: 10.1038/s41467-019-12719-z
3. E. L. Holt, K. M. Krokidi, M. A. P. Turner, P. Mishra, T. S. Zwier, N. d. N. Rodrigues, V. G. Stavros, Insights into the photoprotection mechanism of the UV filter homosalate, Phys. Chem. Chem. Phys., 2020, 22, 15509-15519, doi: 10.1039/d0cp02610g
4. E. L. Holt, N. d. N. Rodrigues, J. Cebrián, V. G. Stavros, Determining the photostability of avobenzone in sunscreen formulation models using ultrafast spectroscopy, Phys. Chem. Chem. Phys., 2021, 23, 24439-24448, doi: 10.1039/D1CP03610F

Emily L. Holt

MAS CDT, Senate House, University of Warwick, Coventry, CV4 7AL

Email: e.l.holt at warwick.ac.uk