Dissolution and vaporization of superheated droplets and capsules

Intumescent coatings form a family of specialized paints used in modern architecture for fire protection. When exposed to heat, they greatly expand through bubble generation, i.e., intumesce, and subsequently act as a thermal barrier that delays structural collapse. Current intumescence technology relies on melamine as a chemical source of gas for bubble generation (blowing agent). However, melamine’s carcinogenic nature and its tendency to create uncontrolled bubbles limit the coating’s effectiveness and impacts both people’s health and the environment. It is therefore on the upcoming list of restricted substances. Fire protection technologies are thus in dire need of a new paradigm for bubble generation. Furthermore, a novel concept for bubble generation may prove invaluable to improve the coating’s mechanical
resistance and insulation properties, provided that it also allows control over the intumescence process. In this thesis, we explore the possibility of using physical means rather than chemical reactions to generate bubbles in coatings. More specifically, we aim at designing liquid precursors and exploiting controlled vaporization as a source of intumescence.