Authors: C. Solans, J. Esquena, J. Nolla
Affilation: CSIC, Spain
Pages: 719 - 721
Keywords: emulsion, nano-emulsion, highly concentrated emulsion, nanoparticle, meso/macroporous
The preparation of nanostructured materials by emulsion templating is of particular interest among the soft nanotechnology processes. The use of emulsions allows good control of size and morphology, mild reaction conditions and technological feasibility. This presentation will focus on the use of nano-emulsions and highly concentrated emulsions as templates for the preparation of nanoparticles and meso/macroporous materials, respectively. Nano-emulsions, characterized by droplet size in the range 20-200 nm, appear transparent or translucent and possess stability against sedimentation or creaming. It will be shown that organic and inorganic nanoparticles with controlled size and low polydispersity have been obtained by our group from nano-emulsions prepared by low-energy methods. Highly concentrated emulsions, characterized by an internal phase volume fraction higher than 0.74, consist of deformed (polyhedrical) droplets separated by a thin film of continuous phase, a structure resembling gas-liquid foams. We have obtained meso/macroporous materials in highly concentrated emulsions with a nanostructure in the continuous phase. The resulting materials combine the advantages of high specific surface area (due to the presence of mesopores) with the accessible diffusion pathways (associated with macropores). These properties make the meso/macroporous materials very important in many industrial applications.