Fabrication of hard-shell microcapsules containing inorganic materials

The fabrication method of silica hard shell microcapsules containing disodium hydrogen phosphate dodecahydrate (Na2HPO4⋅12H2O) has been developed. The effects of the mixing rates for the emulsification, of the volume ratios of solutions and of surfactant concentrations on the size of hollow microcapsules have been also studied. From the results, it was confirmed that silica hard shell microcapsules can contains Na2HPO4⋅12H2O with the present method using hollow microcapsules. The present micro-encapsulated Na2HPO4⋅12H2O was also found to cause the supercooling depression effect. As the fabricated microcapsules have no flammability, the present microcapsule was concluded to be a promising item not only for latent heat transportation media but also for the static thermal storage materials for architectural structures. From the studies on the fabrication parameters, it was concluded that the control of the surfactant concentration is effective for controlling the size of microcapsule.