UV-Absorbing Colloids for Advanced Photoprotection and Functional Materials

Abstract

Protection against UV radiation is an essential issue within consumer products, particularly cosmetic sunscreens and food-packaging materials. However, there are currently many concerns regarding the photostability of the UV absorbing components (a.k.a. organic UV filters), their adverse health effects, and their detrimental environmental impact (e.g. coral reef degradation). Therefore, we have developed biobased nanoparticles from biopolymers ethyl cellulose and zein as carriers for multiple organic UV filters together with photostabilizing antioxidants, as well as “green” UV-absorbing plant extracts. The encapsulation of the organic UV filters together with antioxidants improves photostability, whilst the encapsulation of UV-absorbing plant extracts reduces the health and environmental impact involved in photoprotection. Furthermore, we have used these novel biobased nanoparticles to prepare advanced functional and sustainable materials. For example, we have developed a potential sustainable replacement for plastic food packaging materials by combining the biobased nanoparticles with thin cellulose nanofibrils. The resulting materials are (i) highly transparent, which is attractive for consumers, and (ii) UV-blocking, which suppresses food degradation. In another line of research, we have developed novel particle structures which contain the UV-absorbing compound titanium dioxide. Titanium dioxide is a material with many unique properties. Therefore, the development of novel particle structures from unique materials like titanium dioxide and the assembly of these particles is a route towards a new generation of materials with advanced/tailorable properties.