A simple synthesis of size-reduce magnetite nano-crystals via aqueous to toluene phase-transfer method

A simple one-step liquid-liquid phase-transfer synthesis of magnetite nanocrystals affording enhanced size reduction is described. One- and two-step particle transfer methods are compared. In the one-step method, particles are synthesized in a biphasic medium where the particles are formed in the microdroplets and migrate to the organic phase simultaneously, whereas in the two-step method, particles are first prepared in an aqueous phase and subsequently transferred to the organic phase. In both methods, CTAB was used as both a stabilizer and a transferring agent. Data from FTIR and XRD suggest invariably that the particles obtained are of magnetite, Fe3O4. The aqueous to organic phase-transfer efficiency is >99.5% for both methods. In the one-step method the average particle size and standard deviation (σ) is half of that afforded in the two-step method (ca. 18.3+7.7nm cf. 42.2+17.6nm). This reduction in particle size is attributed to the formation of water in oil droplets that act as nanoreactors for the synthesis of magnetite particles