ISSN 1070-4272, Russian Journal of Applied Chemistry, 2008, Vol. 81, No. 1, pp. 153!157. + Pleiades Publishing, Ltd., 2008.
Original Russian Text + D.V. Novikov, 2008, published in Zhurnal Prikladnoi Khimii, 2008, Vol. 81, No. 1, pp. 157!161.
AND POLYMERIC MATERIALS
Adsorption of Gold Nanoparticles Obtained by Vacuum
Deposition on an Amorphous Polymer Surface
D. V. Novikov
Bonch-Bruevich St. Petersburg State University of Telecommunications, St. Petersburg, Russia
Received July 3, 2007
Abstract-Spatial distribution of gold nanoparticles obtained by vacuum deposition on the surface of amor-
phous polymers was studied within the limits of the cluster lattice model.
The formation of condensed phase particles on
a solid surface can be random, independent of the
topological structure of the substrate, or can preferen-
tially occur on active centers of the surface interacting
with adsorbed particles [1, 2]. Such centers can be
presented by structural defects of the surface and also
sites with an enhanced energy and noncompensated
electric charge, where, as a rule, essential local fluc-
tuations of electron density take place . The pre-
ferential formation of particles on active centers
results in decoration of the substrate surface, i.e.,
special features of its microstructure are revealed. This
finds use in the analysis of the topology of solid sur-
Of special interest is the use of vacuum deposition
of gold for the decoration of the surface of amorphous
and semicrystalline polymers . The decoration of
nano- and microdefects on the surface of polymers
favors revealing both well pronounced irregularities of
a geometrical microrelief, e.g., dislocations on a sur-
face of polymeric crystals , and heterogeneity of
an energy microrelief, e.g., impurity inclusions, sites
of localization of reactive functional groups, density
fluctuations of macromolecular packing, etc. .
At present, structural microheterogeneity of amor-
phous polymers is associated either with density fluc-
tuations or with a cluster structure of an object .
Usually by clusters are meant fractal aggregates of
structural units (in case of polymers, blocks of seg-
ments of macromolecules) having a higher local den-
sity compared to an average density of a substance
[7, 8]. Amorphous films obtained from solutions of
flexible-chain polymers are characterized by hetero-
geneity of the supramolecular scale, caused by density
fluctuations arising owing to the irreversible transition
from a solution to a solid state of the polymer .
Density fluctuations have a scale-invariant character
and can be described within the limits of the model of
fractal clusters [10, 11].
Cluster microheterogeneous structure of amorphous
polymers causes the heterogeneous character of the
surface energy microrelief and substantially influences
initial stages of the formation and growth of decorat-
ing gold particles [12, 13]. Most of defects of amor-
phous polymers are associated with density fluctua-
tions of packing of macromolecules and are localized
on boundaries of the clusters ; therefore, the
topography of decorating particles is connected with
the profile of a planar density distribution on the
polymeric support surface.
The character of the adsorption defines the depen-
dence of density fluctuations s
/N of a spatial
distribution of adsorbed particles on the degree of fill-
ing of the substrate surface with these particles .
The dependences of s
/N on the fraction q of the
surface area covered by adsorbed particles were deter-
mined by computer simulation of various mechanisms
of the adsorption of dispersed phase particles on
a solid surface [14, 15]. The random surface filling
with the particles corresponds to the random adsorp-
tion (RA) model , for which dependence  is
N =13 4q +3
) is a value of the third infinitesimal order.
This dependence was confirmed experimentally
by studying the adsorption of small particles of poly-
meric latexes from dilute solutions on a solid substrate