Abstract
Several clay minerals were supersonically sprayed onto flexible substrates to form highly thermally and electrically insulating materials which could be wrapped onto protected surfaces. Among these clay minerals, montmorillonite (Mt) revealed the best thermal insulating properties.
•Kaolinite, bentonite and montmorillonite powders were entrained by supersonic gas jet and deposited onto flexible substrates.•The spray-deposited layers are a highly effective as a thermal barrier.•Montmorillonite was found to be the best thermally insulating material.