15 “Polymer–Oxide” Micro-/Nanocomposites: Background and Promises
249
15.2 Embedded with Inorganic Oxide Polymer Matrix
Micro-/Nanocomposites as Optical Materials
The wide set of polymers are suitable to be used as matrix components of the
PMM/NC, e.g., vinyl polymers, condensation polymers, polyolefin, and so on. As
for the fillers, various inorganic crystalline compounds have been used. Those were
SiO 2 , TiO 2 , and other simple metal oxides, but layered silicates were of the most
attractive some time ago [10, 11]. No doubt they are the most suitable just due to
low particle sizes, peculiarities of surface structure, morphology, and well-known
chemistry of their intercalation [11, 12]. Details of the procedures of the polymer
matrix composites fabrication are the same either for micro- or nanocomposites,
and description of these techniques can be found in [13–18] or elsewhere. The
most important ones are the following: intercalation of the polymer or prepolymer
from solution, in situ intercalative polymerization, in situ polymerization, template
synthesis, melt intercalation, direct mixture of polymer and fillers, and sol–gel
process. It seems the last four of them are more suitable for preparation of the
PMM/NC incorporated with oxide particles, e.g., with TiO 2 , SiO 2 , Fe 2 O 3 , AgNO 3 ,
NiSO 4 , and CuSO 4 . Despite of well elaborated different procedures of the PMM/NC
preparation there are many factors influence of which on the made products is
unforeseen, especially if new “matrix – oxide” combinations are under studies.
Those can be size, morphology of the particles, their optimal concentration, and
distribution over the sample volume and surface. Therefore, composites made by
new methods have to be comprehensively investigated using both experimental
and theoretical approaches, and their mechanical, thermal, electrical, and optical
characteristics have to be evaluated as well.
Micro-/nanosized components of the PMM/NC usually are in the form of
particles, whiskers, fibers, nanotubes, etc. They are classified according to their
dimensions [19]. When all three dimensions are of the same micro- or nanoscale
range, they are called as iso-dimensional particles [19]. The second kind is
constructed from the units that possess two dimensions of the same scale, and the
third dimension is larger. (The carbon nanotubes and cellulose whiskers are the
patterns of this type.) The third type is characterized by only one dimension in
the micro-/nanometer range. In this case, the filler has a view of sheet of one to
a few micro-/nanometers thick and hundreds to thousands micro-/nanometers long.
The PMM/NCs made on the base of such type fillers are called polymer-layered
micro-/nanocomposites [19, 20].
Really, it is difficult to perform composites of perfect structure, e.g., to
polyester/TiO 2 [14]. The authors noted that up to the TiO 2 concentration 3 vol.
%, the samples showed excellent dispersion of the particles. If concentration was
4 vol. %, a considerable agglomeration took place (see Fig. 15.1a). The similar
is also true for the PMM/NC-K 2 Eu(PO 4 )(MoO 4 ) made and studied by author of
this work. A lot of K 2 Eu(PO 4 )(MoO 4 ) rodlike particles of sizes near 20–30 nm
cover the surface of the polymer matrix. At the same time, their large agglomerates
of lateral sizes near 1–2 μm and up to 400 nm pierce through composite surface
249
15.2 Embedded with Inorganic Oxide Polymer Matrix
Micro-/Nanocomposites as Optical Materials
The wide set of polymers are suitable to be used as matrix components of the
PMM/NC, e.g., vinyl polymers, condensation polymers, polyolefin, and so on. As
for the fillers, various inorganic crystalline compounds have been used. Those were
SiO 2 , TiO 2 , and other simple metal oxides, but layered silicates were of the most
attractive some time ago [10, 11]. No doubt they are the most suitable just due to
low particle sizes, peculiarities of surface structure, morphology, and well-known
chemistry of their intercalation [11, 12]. Details of the procedures of the polymer
matrix composites fabrication are the same either for micro- or nanocomposites,
and description of these techniques can be found in [13–18] or elsewhere. The
most important ones are the following: intercalation of the polymer or prepolymer
from solution, in situ intercalative polymerization, in situ polymerization, template
synthesis, melt intercalation, direct mixture of polymer and fillers, and sol–gel
process. It seems the last four of them are more suitable for preparation of the
PMM/NC incorporated with oxide particles, e.g., with TiO 2 , SiO 2 , Fe 2 O 3 , AgNO 3 ,
NiSO 4 , and CuSO 4 . Despite of well elaborated different procedures of the PMM/NC
preparation there are many factors influence of which on the made products is
unforeseen, especially if new “matrix – oxide” combinations are under studies.
Those can be size, morphology of the particles, their optimal concentration, and
distribution over the sample volume and surface. Therefore, composites made by
new methods have to be comprehensively investigated using both experimental
and theoretical approaches, and their mechanical, thermal, electrical, and optical
characteristics have to be evaluated as well.
Micro-/nanosized components of the PMM/NC usually are in the form of
particles, whiskers, fibers, nanotubes, etc. They are classified according to their
dimensions [19]. When all three dimensions are of the same micro- or nanoscale
range, they are called as iso-dimensional particles [19]. The second kind is
constructed from the units that possess two dimensions of the same scale, and the
third dimension is larger. (The carbon nanotubes and cellulose whiskers are the
patterns of this type.) The third type is characterized by only one dimension in
the micro-/nanometer range. In this case, the filler has a view of sheet of one to
a few micro-/nanometers thick and hundreds to thousands micro-/nanometers long.
The PMM/NCs made on the base of such type fillers are called polymer-layered
micro-/nanocomposites [19, 20].
Really, it is difficult to perform composites of perfect structure, e.g., to
polyester/TiO 2 [14]. The authors noted that up to the TiO 2 concentration 3 vol.
%, the samples showed excellent dispersion of the particles. If concentration was
4 vol. %, a considerable agglomeration took place (see Fig. 15.1a). The similar
is also true for the PMM/NC-K 2 Eu(PO 4 )(MoO 4 ) made and studied by author of
this work. A lot of K 2 Eu(PO 4 )(MoO 4 ) rodlike particles of sizes near 20–30 nm
cover the surface of the polymer matrix. At the same time, their large agglomerates
of lateral sizes near 1–2 μm and up to 400 nm pierce through composite surface