TITLE

Nucleation, growth and characterization of metal nanoparticles.

STAFF

G. Campi, A. Pifferi, A. Ranieri

KEYWORDS

Nanoparticles, Nucleation and Growth, Nanostructures formation mechanism, Time Resolved X-ray Scattering

COLLABORATIONS

CNR-ISM (http://www.ism.cnr.it); Austrian Academy of Science IBN; (http://www.ibn.oeaw.ac.at/beamline/home.html); University of Rome "La Sapienza".

DESCRIPTION

Understanding nucleation and growth of nanoparticles as well as their assembly, is essential for a practical design strategy in the synthesis of nanostructured systems; a widely used method in the nanoparticle fabrication consists of using macromolecules, e.g. (bio)polymers in aqueous chemical reactions to template the size and shape of forming nanostructures. In this context, in collaboration with the ISM-CNR (http://www.ism.cnr.it), we recently exploited the possibility to control the morphology of silver nanocrystals during the reduction of silver nitrate with ascorbic acid in the presence of a polynaphtalene sulphonate polymer in aqueous phase [1]. In situ observation of nanostructure formation process, by time resolved Small Angle X-ray Scattering measurements, allowed us to get signatures of non-standard Multi Step Crystallizzation (MSC) strategy controlling particle size and shape [2, 3]. In situ SAXS technique is also used for investigating metal (e.g. Fe, Al, Zn) assembly in ferritin proteins [4] in collaboration with Physics Department of Rome University; further work in progress concerns the characterization of different metal nano-composites as well as the monitoring of their kinetic in solutions with different molecules as template.

Fig. 1: A) SEM images of nanostructure obtained at different temperatures. B) Experimental setup of in situ time resolved SAXS experiment. C) Time evolution of 3D SAXS normalized profiles during the AgNO3 reduction at 40°C.

[1] L. Suber, G. Campi, C. La Mesa, A. Pifferi, R. Cocco, W. Plunkett, H. Amenitsch, P. Andreozzi, Polymer-Assisted Synthesis of Two-Dimensional Silver Meso-Structures, J. Phys. Chem. C, 113, 11198-11203 (2009)
[2] G. Campi, A. Mari, H. Amenitsch, A. Pifferi, C. Cannas and L. Suber, Monitoring early stages of silver particle formation in a polymer solution by in situ and time resolved Small Angle X ray Scattering, Nanoscale, 2, 2447-2455 (2010)
[3] G. Campi, A. Pifferi, A. Mari, H. Amenitsch and L. Suber, Dynamic templating role of polynaphtalene sulphonate in the formation of silver nanocrystals in aqueous solution, submitted to Journal of Nanoparticle Research
[4] G. Ciasca, M. Chiarpotto, G. Campi, B. Bocca, M. Rodio, A. Pino, A. Ricci, N. Poccia, C. Rossi, A. Alimonti, H. Amenitish, P. De Sole, and A. Bianconi, Reconstitution of aluminium and iron core in horse spleen apoferritin, submitted to Journal of Nanoparticle Research

CONTACTS

Gaetano Campi
Email : gaetano.campiATic.cnr.it
Tel : +39/06/90672624