Microemulsion approach to non-agglomerated and crystalline nanomaterials

A wide variety of different nanomaterials, including ZnO, (NH4)Y(C2O4)(2)center dot H2O, Y(OH)(3), Y2O3, In2O3:Sn, CePO4:Tb, CaCO3, CuS, Co-3[Co(CN)(6)](2), and K-3[Co(NO2)(6)] are realized by a microemulsion approach. While heating the micellar system to reflux (200 to 215 degrees C) highly crystalline materials can be realized, which are still nanosized and do not agglomerate afterwards. Furthermore, a phase separation is initiated by the addition of diethylene glycol, which allows a facile removal of the nanomaterials by the application of low solvent quantitities, and again excludes agglomeration. Both aspects - the realization of highly crystalline materials and the facile separation of non-agglomerated particles - represent a useful extension of microemulsion techniques. Besides the number and quality of the nanomaterials, the success of the experimental approach is further proven by the realization of physical properties that are restricted to crystalline materials. Namely, these are the bright colors of CO3[Co(CN)(6)](2) and K-3[Co(NO2)(6)] as pigments, the electrical conductivity of In2O3:Sn (ITO), and the luminescence of CePO4:Tb.