15 “Polymer–Oxide” Micro-/Nanocomposites: Background and Promises
251
As for the first statement, one can point out the very well-known example of
the polymer–oxide composite use. It is related with possible luminescent properties
of some polymer–oxide composites. Luminescent materials are attractive materials
as they show many areas of application. Luminescent modifiers can be introduced
to the various polymer materials and processed by different methods to produce
films, fibers, molded pieces, etc. Despite stated above, there is some information
about polymer matrices incorporated with inorganic compounds containing active
luminescence trivalent rare-earth ions or ions of transition elements (see, e.g.,
[25–28]). The various polymers were used for preparation of the polymer–oxide
composites. Those were nonpolar monofunctional monomer (isooctyl acrylate,
IOA) in combination with a multifunctional low polar monomer (bisphenol A
ethoxylate diacrylate SR349), and they were used in a weight ratio of 20 wt%
SR349:80 wt% IOA [25]. This polymer was incorporated with ZrO 2 doped with
Eu 3+ . The same oxide was taken for preparation of polymer composite with
polyurethane matrix [26]. Methyl methacrylate (MMA) and lauryl acrylate (LA)
polymer matrixes were used for doping by YVO 4 :Eu vanadate. The obtained
materials were highly transparent (transmission ∼90% at 600 nm) and showed
red photoluminescence upon UV excitation caused by Eu 3+ ion emission in the
composite materials [27]. The optical properties of lanthanide oxide nanoparticles
(Gd 2 O 3 :Tb) dispersed in the poly(ethylene oxide) (PEO) network as thermally
stable polymeric films were studied in [28]. Obtained films were still transparent
and keep their original mechanical properties.
One more example is a photoluminescence coating (PLC) of UV or blue
LEDs for white LED creation on their base. Indeed, it is a common knowledge
that most commercially attractive WLEDs contain the PLC made on the base of
yttrium aluminum garnet (YAG) doped with cerium, Y 3 Al 5 O 12 :Ce 3+ (YAG:Ce) and
dispersed in polymer (silicone) matrix [29]. Similarly, polymer matrix (polymethyl
methacrylate or polyvinyl acetate, etc.) incorporated with YAG co-doped with Pr
and Yb (YAG:Pr-Yb) or with Er and Yb (YAG:Yb-Er) is elaborated as PLC for
solar cells [30, 31].
Some examples of the successful creation of the polymer–oxide composites just
as optical materials are discussed below. So, let’s take a look at the chromium-doped
forsterite (Cr-Mg 2 SiO 4 ) in the tribromostyrene/naphthyl methacrylate matrix. This
system was directed to the solid-state laser material elaboration, so, polymer matrix
was taken with the average refractive index of forsterite (1.652 at 589.3 nm).
Performed optical measurements on the composite films to examine amplification
behavior showed good results [24]. The Cr diopside (Cr-CaMgSi 2 O 6 ) is a material
that manifests luminescence in the near-IR range (700–1200 nm). However, a
single crystal of this material cannot be prepared due to incongruent melting.
Composite system similar to described above, but containing Cr-CaMgSi 2 O 6 , is
an example of how the PMM/NC can be used to improve the process ability and
functionality of starting material (Cr-CaMgSi 2 O 6 ), which could not be obtained
by another way [24]. The set of composites based on polymethyl methacrylate
(PMMA) and doped with luminescent particles of the Pr 3+ :LaAlO 3 , Pr 3+ :Y 2 O 3 ,
and Er 3+ :Y 2 O 3 were manufactured and characterized [32, 33]. These materials
251
As for the first statement, one can point out the very well-known example of
the polymer–oxide composite use. It is related with possible luminescent properties
of some polymer–oxide composites. Luminescent materials are attractive materials
as they show many areas of application. Luminescent modifiers can be introduced
to the various polymer materials and processed by different methods to produce
films, fibers, molded pieces, etc. Despite stated above, there is some information
about polymer matrices incorporated with inorganic compounds containing active
luminescence trivalent rare-earth ions or ions of transition elements (see, e.g.,
[25–28]). The various polymers were used for preparation of the polymer–oxide
composites. Those were nonpolar monofunctional monomer (isooctyl acrylate,
IOA) in combination with a multifunctional low polar monomer (bisphenol A
ethoxylate diacrylate SR349), and they were used in a weight ratio of 20 wt%
SR349:80 wt% IOA [25]. This polymer was incorporated with ZrO 2 doped with
Eu 3+ . The same oxide was taken for preparation of polymer composite with
polyurethane matrix [26]. Methyl methacrylate (MMA) and lauryl acrylate (LA)
polymer matrixes were used for doping by YVO 4 :Eu vanadate. The obtained
materials were highly transparent (transmission ∼90% at 600 nm) and showed
red photoluminescence upon UV excitation caused by Eu 3+ ion emission in the
composite materials [27]. The optical properties of lanthanide oxide nanoparticles
(Gd 2 O 3 :Tb) dispersed in the poly(ethylene oxide) (PEO) network as thermally
stable polymeric films were studied in [28]. Obtained films were still transparent
and keep their original mechanical properties.
One more example is a photoluminescence coating (PLC) of UV or blue
LEDs for white LED creation on their base. Indeed, it is a common knowledge
that most commercially attractive WLEDs contain the PLC made on the base of
yttrium aluminum garnet (YAG) doped with cerium, Y 3 Al 5 O 12 :Ce 3+ (YAG:Ce) and
dispersed in polymer (silicone) matrix [29]. Similarly, polymer matrix (polymethyl
methacrylate or polyvinyl acetate, etc.) incorporated with YAG co-doped with Pr
and Yb (YAG:Pr-Yb) or with Er and Yb (YAG:Yb-Er) is elaborated as PLC for
solar cells [30, 31].
Some examples of the successful creation of the polymer–oxide composites just
as optical materials are discussed below. So, let’s take a look at the chromium-doped
forsterite (Cr-Mg 2 SiO 4 ) in the tribromostyrene/naphthyl methacrylate matrix. This
system was directed to the solid-state laser material elaboration, so, polymer matrix
was taken with the average refractive index of forsterite (1.652 at 589.3 nm).
Performed optical measurements on the composite films to examine amplification
behavior showed good results [24]. The Cr diopside (Cr-CaMgSi 2 O 6 ) is a material
that manifests luminescence in the near-IR range (700–1200 nm). However, a
single crystal of this material cannot be prepared due to incongruent melting.
Composite system similar to described above, but containing Cr-CaMgSi 2 O 6 , is
an example of how the PMM/NC can be used to improve the process ability and
functionality of starting material (Cr-CaMgSi 2 O 6 ), which could not be obtained
by another way [24]. The set of composites based on polymethyl methacrylate
(PMMA) and doped with luminescent particles of the Pr 3+ :LaAlO 3 , Pr 3+ :Y 2 O 3 ,
and Er 3+ :Y 2 O 3 were manufactured and characterized [32, 33]. These materials