Manufacturing inorganic nanoparticles using microemulsion-mediated synthesis

Nanoparticulate materials impart improved properties for the devices, systems or formulations in which they are key components. Several novel inorganic nanoparticle manufacturing techniques have been commercialised recently to compete with long-established processes that provide nanosized particles with inferior properties. However, the specific attributes of the nanoparticle products of each process differ, and the respective applications will therefore differ significantly. This article describes a manufacturing process for inorganic nanoparticles that is appreciably different from these processes, which are primarily gas-phase syntheses. It is based on microemulsion-mediated chemical precipitation of the nanoparticles, which has been widely employed as a laboratory technique to synthesise small quantities of such materials while providing excellent control over particle size, particle size homogeneity and chemical composition. Economic scale-up requires efficient collection of product particles and recycling of microemulsion components (surfactants and non-polar organic fluid) for refuse Low-cost ceramic crossflow ultrafiltration is employed for particle harvesting and fluid phase recycling. Laboratory characterisation of the process and nanoparticle products is described, and projected product costs and applications are also discussed.