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S. G. Nedilko
keep the luminescent properties of the original oxide nanopowders. In addition,
optimization of the erbium dopant concentration was possible; thus it was found
that PMMA Er 3+ :Y 2 O 3 composites are available to a limited extent for solid laser
development [32].
We have examined above the cases where a polymer was used only as a matrix for
fixing an active optic component. Thus, interactions between matrix and filler and
their ability to determine the difference between optical properties of the composite
and optical properties of matrix and filler were practically ignored.
Below, we give positive examples of such type issues [34]. So, from the
physics of scintillation point of view, polymer scintillators possess some advantages
such as high operation speed, high light yield, and low cost of their production.
However, if compared with inorganic scintillators, the polymer scintillators due to
low absorption efficiency have to be of large sizes to register high-energy radiation.
Substantial increase of light output can be achieved by the way of embedding into
polymer matrix inorganic nanoparticles which are characterized by high atomic
numbers Z that promote higher efficiency of hard radiation absorption. Then,
excitation energy transfer from nanoparticles to polymer matrix determines larger
light yield of composite scintillator (up to 30 times). Thus, such type of PMM/NC
scintillators combine advantages of both polymer scintillators and scintillators
based on inorganic crystals: high light yield and short times scintillation decay,
respectively. Described possibility goes from overlapping luminescence spectra
with doped Pr 3+ ions LaPO 4 nanoparticles to absorption spectrum of polystyrene
matrix.
15.3 Cellulose-Based Micro-/Nanoscaled Polymer
Composites Incorporated with Oxide Compounds
There is a great request now to replace materials that are widely used both in
technology and production with newer environmentally friendly, are harmless to
humans, and have simultaneously cheap materials. The PMM/NCs, where polymer
host is micro-/nanocrystalline cellulose and fillers are some inorganic compounds of
micro-/nanoscale, are among them. These PMM/NCs are sustainable and renewable
materials and paid great attention in biomedical technologies (membranes and
filters, scaffolds, antimicrobial films, pharmaceuticals, drug delivery, etc. [35–38])
or as adsorbents for toxic chemical removal [39–41]. Due to their mechanical
flexibility, they can be useful in the manufacturing of electronic and optoelectronic
devices (solar cells, supercapacitors, lithium-ion batteries, “paper” electronics
[42–44], luminescence sensors [45–47]). Incorporated with luminescent oxides,
cellulose-based composites have showed their importance as advanced optical
materials [48–51]. That is why, the next part of this chapter is devoted to description
of the main properties of some cellulose-based materials.
S. G. Nedilko
keep the luminescent properties of the original oxide nanopowders. In addition,
optimization of the erbium dopant concentration was possible; thus it was found
that PMMA Er 3+ :Y 2 O 3 composites are available to a limited extent for solid laser
development [32].
We have examined above the cases where a polymer was used only as a matrix for
fixing an active optic component. Thus, interactions between matrix and filler and
their ability to determine the difference between optical properties of the composite
and optical properties of matrix and filler were practically ignored.
Below, we give positive examples of such type issues [34]. So, from the
physics of scintillation point of view, polymer scintillators possess some advantages
such as high operation speed, high light yield, and low cost of their production.
However, if compared with inorganic scintillators, the polymer scintillators due to
low absorption efficiency have to be of large sizes to register high-energy radiation.
Substantial increase of light output can be achieved by the way of embedding into
polymer matrix inorganic nanoparticles which are characterized by high atomic
numbers Z that promote higher efficiency of hard radiation absorption. Then,
excitation energy transfer from nanoparticles to polymer matrix determines larger
light yield of composite scintillator (up to 30 times). Thus, such type of PMM/NC
scintillators combine advantages of both polymer scintillators and scintillators
based on inorganic crystals: high light yield and short times scintillation decay,
respectively. Described possibility goes from overlapping luminescence spectra
with doped Pr 3+ ions LaPO 4 nanoparticles to absorption spectrum of polystyrene
matrix.
15.3 Cellulose-Based Micro-/Nanoscaled Polymer
Composites Incorporated with Oxide Compounds
There is a great request now to replace materials that are widely used both in
technology and production with newer environmentally friendly, are harmless to
humans, and have simultaneously cheap materials. The PMM/NCs, where polymer
host is micro-/nanocrystalline cellulose and fillers are some inorganic compounds of
micro-/nanoscale, are among them. These PMM/NCs are sustainable and renewable
materials and paid great attention in biomedical technologies (membranes and
filters, scaffolds, antimicrobial films, pharmaceuticals, drug delivery, etc. [35–38])
or as adsorbents for toxic chemical removal [39–41]. Due to their mechanical
flexibility, they can be useful in the manufacturing of electronic and optoelectronic
devices (solar cells, supercapacitors, lithium-ion batteries, “paper” electronics
[42–44], luminescence sensors [45–47]). Incorporated with luminescent oxides,
cellulose-based composites have showed their importance as advanced optical
materials [48–51]. That is why, the next part of this chapter is devoted to description
of the main properties of some cellulose-based materials.