A relevant part of the research activity is focused on the optimization of innovative "wet chemistry" synthesis processes through three general approaches:
- nucleation and growth from solution
A first approach is based on the combination of hydrothermal treatments with oxalates co-precipitation. This approach has been used for the production of nanomaterials with interesting magnetic properties, in particular ferrites and manganites, with crystallite domains with average sizes ranging between 5 and 50 nm.
This approach has also been adapted to the synthesis of oxides and sulfides of zinc, doped with transition metals or lanthanides. These nanostructures have shown photocatalytic activity in the degradation of organic pollutants and excellent response as H2S sensors. A second part of the research activity is concentrated on the study of nucleation and growth processes of nanostructures synthesized via colloidal routes. For example, the influence of different solvents on the formation of nanocrystalline ZnO or CuS in colloidal suspension was investigated. In particular, the solvent viscosity and its dielectric constant were found to strongly affect the growth and the final morphology. The same materials were also prepared under non- standard conditions, exploiting inverse miniemulsions. Thanks to their characteristics, miniemulsions are perfectly suited for obtaining monodispersed nanoparticles, with a good control on both their dimensions and morphology. In these particular emulsions, the processes of growth and nucleation of the nanosystems are confined within the droplets volume and are thus very different from the bulk. For example, crystalline structures obtained in the bulk at high temperature can be obtained, in miniemulsions, at room temperature.
By this approach, it is also possible to easily introduce doping ions with luminescence properties within the inorganic hosting lattices. In the case of biocompatible matrices, luminescent materials can be exploited as nanostructured probes for applications in optical bioimaging. For these applications, on the other hand, it is necessary to engineer the nanoparticles surface in order to maximize the dispersibility in a physiological environment and the biocompatibility. For this reason, a further part of the research activity is focused on the study of the surface chemo-physical properties of zinc sulfide, a compound widely used but of which, contrary to the oxide counterpart, no functionalization protocol is found in the literature. This study encompasses a combined experimental-theoretical approach. The theoretical modelling aims at describing in detail the structure and reactivity of the surface, in order to clarify the mechanisms of surface chemisorption.
colloids hydrothermal synthesis miniemulsions wet chemistry crystallization surface engineering
S. Diodati, P. Dolcet, M. Casarin and S. Gross
Pursuing the Crystallization of Mono- and Polymetallic Nanosized Crystalline Inorganic Compounds by Low-Temperature Wet-Chemistry and Colloidal Routes
Chem. Rev, 2015, 115, 11449–11502
G. Morgese, V. Causin, M. Maggini, S. Corrà, S. Gross and E. M. Benetti
Ultra-stable Suspensions of Polyoxazoline-Functionalized ZnO Single Nanocrystals
Chem. Mater., 2015, 27, 2957-2964
P. Dolcet, S. Diodati, M. Casarin and S. Gross
Very low temperature wet-chemistry colloidal routes for mono- and polymetallic nanosized crystalline inorganic compounds
J. Sol-Gel Sci. Technol., 2015, 73, 591-604
P. Dolcet, A. Mambrini, M. Pedroni, A. Speghini, S. Gialanella, M. Casarin and S. Gross
Room temperature crystallization of highly luminescent lanthanide-doped CaF2 in nanosized droplets: first example of the synthesis of metal halogenide in miniemulsion with effective doping and size control
RSC Advances, 2015, 5, 16302-16310
5. S. Diodati, L. Pandolfo, S. Gialanella, A. Caneschi and S. Gross
Green and low temperature synthesis of nanocrystalline transition metal ferrites by simple wet chemistry routes
Nano Res., 2014, 7, 1027-1042
- S. Diodati, P. Dolcet, M. Casarin and S. Gross