Andre Jung's doctoral thesis deals with the application of gels in and on cementitious materials. His first publication, "Preparation and characterisation of highly alkaline hydrogels for the re-alkalisation of carbonated cementitious materials", describes the preparation and properties of a special ion exchange gel that can be used to re-alkalise mortars and concretes non-destructively. Soft Matter has chosen this contribution to design the cover of its 40th edition.