L’eau en poudre

Abstract

Water-rich powders, also called "dry water", containing up to 98% (by weight) of water and still maintaining the same flow properties as a dry powder were prepared by a simple mixing process. Dry water particles are a very convenient carrier system that can be easily produced at industrial scale. Water can be released by evaporation or under mechanical stress. The structure of individual particles bas been studied by electronic microscopy after freeze fracture or water sublimation. Each particle consist in a micrometric water droplet (average diameter of 150 μm) surrounded by a network build up by association of hydrophobic fumed silica particles. Two types of mixing processes were used: high shear processes and atomization processes such as granulators. The quality of the final product depends on the energetic contribution of the process and on the solid/liquid contact angle (evaluated by water intrusion). Potential applications are numerous in the food, pharmaceutical, and cosmetics industry.