UV-protection of textiles via biomaterial functionalisation and spray coating

Markus Oberthür, HAW Hamburg

Stephan Roth, DESY

The functionalisation of textiles is very important for improving their properties, e.g. water repellency, antimicrobial activity and UV light protection. Typically, synthetic polymers and/or nanoparticles are used as coatings, which are usually applied by padding. The synthetic polymers used are based on fossil resources, whereas nanoparticles, e.g. titania, might be related to health issues. For example, in certain holiday destinations, sun blockers incorporating titania nanoparticles are prohibited. Hence, the quest for non-harmful alternatives based on renewable resources is pressing. One suitable alternative is lignin, which is extracted from wood during cellulose pulp production. 

In this project, we plan to functionalize lightweight, highly transparent fabrics made of commercially available silk and cotton to improve their UV protection abilities. The goal is to achieve a UV protection factor (UPF) of 50, while maintaining transparency at higher wavelengths above the UV light region. The lignin will be applied by spray coating. Spray coating is increasingly used in the textile industry because of the reduced water consumption compared to padding processes. The mechanical properties of these functionalised textiles, the stability of the coatings and the UPF values will be investigated using industrially relevant methods. The molecular and nanoscale structure of the coating will be investigated using X-ray scattering and correlated to the macroscopic functionality.