Outline
The present invention relates to a core-shell heat storage microcapsule having a core containing a phase change heat storage material and a coating of amorphous glassy alginate, which coating has at least two layers and at least one layer contains nanoparticles, and the surfaces of the core and the coating are in direct or spaced contact, and the microcapsule core has a solid or internal cavity. The invention also relates to the preparation and use of the microcapsule. The object of the invention is to provide a heat storage microcapsule with which a rapid and uniform, i.e. congruent, crystallization of the heat storage material can be achieved in a simple and safe manner, wherein the coating of the microcapsule effectively prevents the release of the phase change material or components from the microcapsule. The aim is also to produce microcapsules with improved mechanical and thermal properties and reliable long-term stability.