12 2 Nanoparticles – Nanocomposites
or graphene (two-dimensional) as a filler, a very important application is found in
the field of optically transparent electrical conductors. Because of the large aspect
ratio of these particles, electrical conductivity is obtained already with extremely
small concentrations of these particles.
Practically, the composites, as depicted in Figures 2.4a,b exist primarily using
a polymer matrix. In all the other cases, there is the possibility that there is a
mutual solubility between the nanoparticles and the matrix. To avoid dissolution
of the particles, often it is necessary to coat the particles with a diffusion barrier.
This situation is depicted in Figure 2.8.
Figure 2.8 displays the oldest, man-made type of nanocomposite with more or
less spherical nanoparticles. This composite is realized in the well-known goldruby glass. It consists of a glass matrix with gold nanoparticles as second phase.
Figure 2.7 Transmission electron
micrograph of a zero-dimensional
nanocomposite. It depicts a composite
zirconia particles embedded in an alumina
matrix. The specimen was produced from
zirconia particles coated with alumina. This
micrograph was taken from an ion-beamthinned sample. It is essential to realize that
there is a high probability that particles are
not touching each other, because they are
lying in different planes [3]. (Reproduced with
permission by Springer.)
10 nm
10 nm
Figure 2.8 Zero-dimensional nanocomposite. To avoid dissolution in the matrix, the particles
are coated with a diffusion barrier.
Matrix
NanoparƟcle
Diffusion
barrier
or graphene (two-dimensional) as a filler, a very important application is found in
the field of optically transparent electrical conductors. Because of the large aspect
ratio of these particles, electrical conductivity is obtained already with extremely
small concentrations of these particles.
Practically, the composites, as depicted in Figures 2.4a,b exist primarily using
a polymer matrix. In all the other cases, there is the possibility that there is a
mutual solubility between the nanoparticles and the matrix. To avoid dissolution
of the particles, often it is necessary to coat the particles with a diffusion barrier.
This situation is depicted in Figure 2.8.
Figure 2.8 displays the oldest, man-made type of nanocomposite with more or
less spherical nanoparticles. This composite is realized in the well-known goldruby glass. It consists of a glass matrix with gold nanoparticles as second phase.
Figure 2.7 Transmission electron
micrograph of a zero-dimensional
nanocomposite. It depicts a composite
zirconia particles embedded in an alumina
matrix. The specimen was produced from
zirconia particles coated with alumina. This
micrograph was taken from an ion-beamthinned sample. It is essential to realize that
there is a high probability that particles are
not touching each other, because they are
lying in different planes [3]. (Reproduced with
permission by Springer.)
10 nm
10 nm
Figure 2.8 Zero-dimensional nanocomposite. To avoid dissolution in the matrix, the particles
are coated with a diffusion barrier.
Matrix
NanoparƟcle
Diffusion
barrier