Preparation and characterization of metal nanoparticles supported on polymeric composites M. Sisani 1, U. Costantino 1, F. Costantino 1, F. Presciutti 2, A. Bottino 3, G. Capannelli 3 VI Convegno Nazionale sulla Scienza e Tecnologia dei Materiali Perugia Giugno Department of Chemistry, CEMIN, University of Perugia, Italy 2 ISTM-CNR, SMAART, University of Perugia, Italy 3 Department of Chemistry and Industrial Chemistry, University of Genova, Italy INSTM – Perugia Giugno 2007

3 dimensions at nanometric scale  3D particles Spherical silica, nanoclusters of semiconductors etc. 2 dimensions at nanometric scale  tubular structure Carbon nanotubes, nanowires etc. 1 dimension at nanometric scale  lamellae Layered solids Nanocomposites Nanometric particles dispersed into the organic matrix: INSTM – Perugia Giugno 2007

The dispersion of a low loading (ca 5%) of inorganic particles of nanometric dimension into organic polymers allows the preparation of new composite materials with enhanced properties:  mechanical and thermal stability  gas barrier  flame retardant  electrical  optical  magnetic  biomedical  catalytic The presence of nanoparticles may induce new properties to the material: INSTM – Perugia Giugno 2007

 Automotive gas tanks, bumpers, interior and exterior panels  Construction (building sections and structural panels)  Aerospace (flame retardant panels and high performance components)  Electrical and electronics (electrical components and printed circuit boards)  Food packaging (containers and wrapping films)

Layered Inorganic ion exchangers posses unique properties to be active as filler of polymeric nanocomposites:  Exfoliation into single layers  Thickness of the layers at nanometric scale (about 1 nm)  High aspect ratio  Functionalization by ion exchange or grafting procedures of the layers increases the compatibility with the polymer and in some cases induces new properties for high-tech applications  Layered solids may intercalate polymeric chains into the interlayer region INSTM – Perugia Giugno 2007 Advantages of the incorporation of metal nanoparticles supported on polymeric composites:  Protect the metal nanoparticles from the oxidation  Control of the dimensions of the metal clusters  Very simple and effective method

Layered compounds dispersed in a polymeric matrix Macrocomposite: two separate phases Nanocomposite: The polymer is intercalated In the interlamellar region Nanocomposite:Lamellae dispersed in the polymer Polymer Layered microcrystal INSTM – Perugia Giugno 2007 [1] [1] M. Alexandre, P. Dubois, Materals Science and Engineering (2000), 28, 1-63

α-Zirconium Phosphate Zr(HPO 4 ) 2 * H 2 O converted to ZrCu(PO 4 ) 2 [3] Polyvinylidene fluoride PVDF [2] Polymeric matrix Layered inorganic filler Synthesis INSTM – Perugia Giugno 2007 Nanocomposite containing Cu metal nanoparticles Chemical reduction [2] G. Alberti, M. Casciola et al., Solid State Ionics (2005), 176, 39 [3] G. Alberti, M. Casciola, U. Costantino, R. Vivani, Adv. Mat. (1996), 8, 291

50% PrNH 2 ZrCu(PO 4 ) 2 1) Preparation of the colloidal dispersion of ZrCu(PO 4 ) 2 2) Exchange with Cu(CH 3 COO) 2 Washing with DMF ZrCu(PO 4 ) 2 Gel di ZrCu(PO 4 ) 2 in DMF INSTM – Perugia Giugno 2007

Intercalation from solution with DMF as solvent Colloidal dispersion in DMF of ZrCu(PO 4 ) 2 Solution of PVDF polymer in DMF ZrCu(PO 4 ) 2 PVDF/ ZrCu(PO 4 ) 2 Nanocomposite - Mixing - Stirring - Evaporation ZrCu(PO 4 ) 2 nanocomposite 2) Preparation of PVDF/ ZrCu(PO 4 ) 2 nanocomposite INSTM – Perugia Giugno 2007

3) Reduction and formation of metal nanoparticles S 2 O 4 = + Cu 2+ → 2SO 3 = + Cu + 4H 3 O + Pristine PVDF/ZrCu(PO 4 ) 2 nanocomposite PVDF/ZrPCu nanocomposite after chemical reduction with dithionite Several composites containing 2, 3, 5, 10, 15, 20 wt% of inorganic filler have been prepared and characterized by XRPD, UV-vis, AFM, HR-TEM techniques INSTM – Perugia Giugno cm

XRPD patterns UV-vis Spectra INSTM – Perugia Giugno 2007

a)PVDF polymer b)PVDF/ZrCu(PO 4 ) 2 c)PVDF/metal nanocomposite 5 wt% d)PVDF/metal nanocomposite 10 wt% AFM images 3D AFM image of the surface of the reduced nanocomposite (5 wt%) INSTM – Perugia Giugno 2007

a) PVDF polymer b) PVDF/ZrCu(PO 4 ) 2 10 wt% c) PVDF/ZrCu(PO 4 ) 2 20 wt% d) PVDF/metal nanocomposite 10 wt% e) PVDF/metal nanocomposite 10 wt% f) PVDF/metal nanocomposite 20 wt% HR-TEM images INSTM – Perugia Giugno 2007

HR-TEM image of PVDF/metal nanocomposite 20 wt% after reduction and the magnification of a nanoparticle INSTM – Perugia Giugno 2007

This approach showed that multifunctional polymeric materials, with tunable chemical/physical properties, can be obtained by an easy and inexpensive synthesis The use of a reducing agent on the copper exchanged α-Zr(PO4) 2, dispersed on the polymeric matrix, allows the formation of copper metallic nanoparticles with 5-10 nm size The metal nanoparticles are dispersed, as well as the fillers, over the entire polymer A film of metallic copper with nanometrical dimensions is also present on the polymer surface The size of nanoparticles on the surface of the samples is larger than the size of those placed inside the polymer Conclusion and further developments In the future Composites containing PVDF with Co, Ni and Fe with possible magnetic properties have been prepared Preparation of nanocomposites containing other metal atoms (Ag and Pt) Preparation of composites with polymers with enhanced thermal stability (Teflon or polystyrene) INSTM – Perugia Giugno 2007

Thanks for your kind attention Staff: Prof. G. Alberti Prof. U. Costantino Prof. M. Casciola Prof. R. Vivani Dr. F. Marmottini Dr.ssa M. Nocchetti Dr.ssa M. Pica (Ph D) Dr. F. Costantino (Ph D) Dr.ssa F. Montanari (Ph D) Dr. M. Sisani (Ph D student) Dr.ssa A. Donnadio (Ph D) Dr. M. Sganappa (Ph D student) Dr. R. Narducci (fellowship) Sig. R. Giulietti (technician) RESEARCH GROUP Laboratorio di Chimica Inorganica Dipartimento di Chimica Università di Perugia