Novel biomimetically based ice-nucleating coatings

Abstract Ice nucleation and ice repellence are properties which appear to be contradictory. Both are of great importance: The former for ice generation in the food and cooling industry and the latter for avoiding the adhesion of ice to structures. By mimicking a peculiar survival mechanism of some cold-adapted organisms a new type of coating system, able to both nucleate and repel the ice was developed. A heterogeneous surface containing locally isolated nucleation points in a low surface energy matrix were synthesised by a sol-gel process. The ice nucleating and ice releasing performance of the new ice nucleating coatings (INC) has been tested in a specially designed crystallisation chamber in comparison to commercial low surface energy coating systems. A mixture of demineralised water and a water freezing point depressant was used in the experiments. Compared to the commercial coatings, the INC surfaces showed a much higher ice nucleation rate but also a distinctly better ice releasing ability. Obviously the novel concept of local embedded nucleation points improves the ice repellent properties of surfaces.