Hydrophobic properties are of great importance for numerous surfaces, in the case of textiles especially for outdoor products and surgical textiles, but also to protect fibres from microbial decomposition. In a joint project between Hohenstein and the Fraunhofer IGB in Straubing, a protein-based water- and dirt-repellent functionalisation for textiles was developed as a possible alternative to fluorocarbon chemistry.
The goal was an economically and sustainably stable functionalisation of cellulose-containing textiles and surfaces through biotechnologically produced fusion proteins. The function is based on hydrophobins - proteins that occur naturally in fungi, for example, to protect them from water and dirt - and the anchoring to the textile surface on specific cellulose binding domains. The fusion of the proteins by biotechnological production ensures effective binding to cellulose-containing structures and imparts water-repellent effects to the surface. The principles developed in the project can be transferred to numerous other applications and questions.