Hematite nanoparticles have been successfully synthesized via two processing routes:(i) conventional precipitation route and (ii) reverse microemulsion route.The particle precipitation was carried out in a semibatch reactor.A microemulsion system consisting of water,chloroform,1-butanol and surfactant was loaded with iron nitrates to form iron nanoparticles precipitation.The precipitation was performed in the single-phase microemulsion operating region.Three technical surfactants,with different structure and HLB value are employed.The influence of surfactant characterization on the size of produced iron oxide particle has been studied to gain a deeper understanding of the important controlling mechanisms in the formation of nanoparticles in a microemulsion.Transmission electron microscopy (TEM),surface area,pore volume,average pore diameter,pore size distribution and XRD were used to analyze the size,size distribution,shape and structure of precipitated iron nanoparticles. Hematite nanoparticles have been synthesized via via two processing routes: (i) conventional precipitation route and (ii) reverse microemulsion route. The particle precipitation was carried out in a semibatch reactor. A microemulsion system consisting of water, chloroform, 1-butanol and surfactant was loaded with iron nitrates to form iron nanoparticles precipitation. The precipitation was performed in the single-phase microemulsion operating region. Three technical surfactants, with different structure and HLB value are employed. The influence of surfactant characterization on the size of produced iron oxide particle has been studied to gain a deeper understanding of the important controlling mechanisms in the formation of nanoparticles in a microemulsion. Transmission electron microscopy (TEM), surface area, pore volume, average pore diameter, pore size distribution and XRD were used to analyze the size , size distribution, shape and structure of precipitated iron nanoparticles.