INFIQC   05475
INSTITUTO DE INVESTIGACIONES EN FISICO- QUIMICA DE CORDOBA
Unidad Ejecutora - UE
congresos y reuniones científicas
Título:
Modelling free and surfactant-protected metal nanoparticles
Autor/es:
J. A. OLMOS ASAR; M. LUDUEÑA; A. SPITALE; M. M. MARISCAL
Lugar:
Cancún
Reunión:
Simposio; XX International Materials Research Congress - Nanostructured Materials and Nanotechnology Symposium; 2011
Resumen:
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Metallic
nanoparticles are perhaps one of the most outstanding applications of
nanotechnology due to potential use of these nanostructures on
diverse fields, i.e. biosensors, catalysis, drug delivery and
construction of nano-circuitsi,ii,iii..
Preparation,
conservation and protection of metallic nanoparticles require
passivation with organic ligand molecules if they will remains in a
colloidal suspension. When nanoparticles are made of gold, a
relatively easy way of protect them is through organic molecular
self-assembly, particularly with thiols molecules due to the strong
interaction between sulfur and gold atoms. Self-assembly monolayers
(SAMs) have been intensively studied, at experimentaliv,v,vi
and theoretical levelvii,viii,ix,x,
on extended gold (111) surfaces. Nevertheless, a clear understanding
about some fundamental structural aspects of passivated Au
nanoparticles in the range of 1-10 nm still does not exist.
In
the present talk we show the application of a new semiempirical
potential recently developed in our Lab to describe molecule-metal
interfaces in a realistic way. Using Density Functional calculations
(DFT) in combination with the bond-order concept we have developed a
new semiempirical framework which is very simple and easy to
implement in standard molecular dynamics codes. In particular we show
the effect of soft and hard surfactant on the structure of gold
nanoparticles.
Finally,
we will show very recent studies which involve the nucleation and
growth processes of bimetallicl NP´s carried out in solution under
control of the chemical potential of the metal ions.
i
A. Manna, T. Imae, K. Aoi, M. Okazaki, Mol.
Simul. 29
(2003) 661
ii
R. Hong, G. Han, J. M. Fernández, B. J. Kim, N. S. Forbes, V. M.
Rotello, J. Am. Chem. Soc. 128
(2006) 1078
iii
M. M. Mariscal and S. A. Dassie, Recent
Advances in Nanoscience, Research Signpost
Pub. - Trivandrum, India (2007).
iv
A. Ulman, S. D. Evans, Y. Shnidman, R. Sharma,
E. Eilers, J. C. Chang, J.
Am. Chem.
Soc. 113 (1991) 1499
v
D. J. Lavrich, S. M. Wetterer, S. L. Bernasek, G. Scoles, J.
Phys. Chem. B
102
(1998) 3456
vi
C Vericat, G A
Benitez, D E Grumelli, M E Vela and R C Salvarezza, J.
Phys.: Condens. Matter
20 (2008) 184004
vii
J. Hautman, M. Klein, J.
Chem. Phys. 91
(1989) 4994
viii
A. Pertsin, M. Grunze.
Langmuir
10
(1994) 3668
ix
Y. Yourdshahyan, A. M. Rappe, J. Chem. Phys.
117 (2002) 825
x
M. J. Esplandiú, M. L. Carot, F. P. Cometto, V. A. Macagno, E. M.
Patrito, Sur. Sci.
600 (2006) 155