Preparation and characterization of metal nanoparticles supported on polymeric

composites

M. Sisani1, U. Costantino1, F. Costantino1, F. Presciutti2, A. Bottino3, G. Capannelli3

VI Convegno Nazionale sulla Scienza e Tecnologia dei MaterialiPerugia 12-15 Giugno 2007

1Department of Chemistry, CEMIN, University of Perugia, Italy2ISTM-CNR, SMAART, University of Perugia, Italy3Department of Chemistry and Industrial Chemistry, University of Genova, Italy

INSTM – Perugia 12-15 Giugno 2007

3 dimensions at nanometric scale 3D particles Spherical silica, nanoclusters of semiconductors etc.

2 dimensions at nanometric scale tubular structureCarbon nanotubes, nanowires etc.

1 dimension at nanometric scale lamellaeLayered solids

NanocompositesNanocomposites

Nanometric particles dispersed into the organic matrix:Nanometric particles dispersed into the organic matrix:

INSTM – Perugia 12-15 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 12-15 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 12-15 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 matrixLayered compounds dispersed in a polymeric matrix

Macrocomposite:Macrocomposite:two separate phasestwo separate phases

Nanocomposite:Nanocomposite:The polymer is intercalatedThe polymer is intercalatedIn the interlamellar regionIn the interlamellar region

Nanocomposite:Nanocomposite:LamellaeLamellae

dispersed in the polymerdispersed in the polymer

PolymerPolymerLayered Layered microcrystalmicrocrystal

INSTM – Perugia 12-15 Giugno 2007

[1]

[1] M. Alexandre, P. Dubois, Materals Science and Engineering (2000), 28, 1-63

αα--Zirconium PhosphateZirconium PhosphateZr(HPOZr(HPO44))22 * H * H22OO

converted to converted to ZrCu(POZrCu(PO44))22 [3][3]

Polyvinylidene fluoridePVDF [2]

Polymeric matrix

Layered inorganic filler

Synthesis

INSTM – Perugia 12-15 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% PrNH2

1) Preparation of the colloidal dispersion of ZrCu(POZrCu(PO44))22

2) Exchange with Cu(CH3COO)2

Washing with DMFGel di ZrCu(POZrCu(PO44))22

in DMF

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Intercalation from solution with DMF as solvent

Colloidal dispersion in DMF of ZrCu(PO4)2 Solution of PVDF polymer in DMF

PVDF/ ZrCu(POZrCu(PO44))22

Nanocomposite

- Mixing- Stirring- Evaporation

2) Preparation of PVDF/ ZrCu(POZrCu(PO44))22 nanocomposite nanocomposite

INSTM – Perugia 12-15 Giugno 2007

3) Reduction and formation of metal nanoparticles

S2O4= + Cu2+ → 2SO3

= + Cu + 4H3O+

Pristine PVDF/ZrCu(PO4)2 nanocomposite

PVDF/ZrPCu nanocomposite after chemical reduction with dithionite

Several composites containing 2, 3, 5, 10, 15, 20 wt% of inorganic filler havebeen prepared and characterized by XRPD, UV-vis, AFM, HR-TEM techniques

INSTM – Perugia 12-15 Giugno 2007

1 cm 1 cm

XRPD patterns

UV-vis Spectra

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a) PVDF polymer

b) PVDF/ZrCu(PO4)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 12-15 Giugno 2007

a) PVDF polymer

b) PVDF/ZrCu(PO4)2 10 wt%

c) PVDF/ZrCu(PO4)2 20 wt%

d) PVDF/metal nanocomposite 10 wt%

e) PVDF/metal nanocomposite 10 wt%

f) PVDF/metal nanocomposite 20 wt%

HR-TEM images

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HR-TEM image of PVDF/metal nanocomposite 20 wt% after reduction and the magnification of a nanoparticle

INSTM – Perugia 12-15 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 12-15 Giugno 2007

Thanks for your kind attention

Staff:

Prof. G. Alberti Prof. G. Alberti Prof. U. CostantinoProf. U. CostantinoProf. M. CasciolaProf. M. CasciolaProf. R. VivaniProf. R. VivaniDr. F. Marmottini Dr. F. Marmottini Dr.ssa M. NocchettiDr.ssa M. NocchettiDr.ssa M. Pica (Ph D)Dr.ssa M. Pica (Ph D)Dr. F. Costantino (Ph D)Dr. F. Costantino (Ph D)Dr.ssa F. Montanari (Ph D)Dr.ssa F. Montanari (Ph D)Dr. M. Sisani (Ph D student)Dr. M. Sisani (Ph D student)Dr.ssa A. Donnadio (Ph D)Dr.ssa A. Donnadio (Ph D)Dr. M. Sganappa (Ph D student) Dr. M. Sganappa (Ph D student) Dr. R. Narducci (fellowship)Dr. R. Narducci (fellowship)Sig. R. Giulietti (technician)Sig. R. Giulietti (technician)

RESEARCH GROUPLaboratorio di Chimica Inorganica

Dipartimento di ChimicaUniversità di Perugia