cationic polymer, and laser dyes. The extent to which molecular aggregates were
formed or changed with the deposition of new layers was determined. The desorption of part of the dyes from the outer surface during the deposition of new layers
was clearly identified, but the stability of the layers inside the film was
confirmed [40].
Composites of Luminescent Polymers
Various materials derived from polymeric substances with photoactive groups have
been reported. For example, materials with the properties of light-emitting diodes
were produced as nanocomposites of conjugated polymers and organoclays
[75]. Two-dimensional composite materials have been shown to be the most effective at polychromatic light emission, with high efficiency and good environmental
stability. Energy migration played a significant role in the photophysical properties
of such materials [75]. In a few cases, merely the presence of inorganic particles may
induce a higher photoactivity of luminescent polymer substances. An example is the
mixture of a luminescent poly(fluorene) with kaolinite [79]. No intercalation of the
polymer chains took place, but the positive effect of the clay mineral on the
photoactivity of the polymer was apparent. There are about a dozen examples of
FRET occurring in hybrid materials based on nanoparticles which also include
luminescent polymeric substances, if we omit energy migration between the same
type of luminophores and fluorescence quenching, which are more frequent. For
example, two-step FRET has been achieved in blue light-emitting materials based on
zeolite and several photoactive substances [80]. Before preparing the composite,
zeolite was modified with oxonine dye, which was incorporated inside the cavities of
the host. The external surface of the zeolite was grafted with thiophene-based
fluorophores and modified with a fluorene-based copolymer. The photoactive
luminophores interacted via FRET starting from the polymeric phase, via the dye
molecules anchored on the external surface and ending inside the zeolite cavities
[80]. Slightly different arrangements were adopted for the hybrids based on layered
nanoparticles. The intercalation of both the polymeric and non-polymeric luminescent substances is the most frequent procedure for the preparation of such materials.
One example is FRET from a luminescent organosilicon compound – polyhedral
oligomeric silsesquioxane – to RB intercalated in Sap [81]. The structure of polymer
molecules can be significantly changed upon their intercalation between layered
particles. This may secondarily affect the conjugation of the polymer [82]. For
example, the conjugated polymer poly(9,9-dioctylfluorene), which emits in the
blue light region, was intercalated between the layers of the layered metal
dichalcogenides MoS 2 and SnS 2 . The polymer formed two distinct phases that
differed in their extent of polymer conjugation: The phase of the planar-extended
conjugation, which was identified as a fraction of the polymer present in the
interlayer spaces, exhibited a red-shifted absorption with respect to the common
form of the polymer. An efficient energy transfer occurred from the bulk phase to the
planar one, resulting in a shift in the wavelength of emitted light [82].
Resonance Energy Transfer in Hybrid Systems of Photoactive Dye Molecules and. . .
229
formed or changed with the deposition of new layers was determined. The desorption of part of the dyes from the outer surface during the deposition of new layers
was clearly identified, but the stability of the layers inside the film was
confirmed [40].
Composites of Luminescent Polymers
Various materials derived from polymeric substances with photoactive groups have
been reported. For example, materials with the properties of light-emitting diodes
were produced as nanocomposites of conjugated polymers and organoclays
[75]. Two-dimensional composite materials have been shown to be the most effective at polychromatic light emission, with high efficiency and good environmental
stability. Energy migration played a significant role in the photophysical properties
of such materials [75]. In a few cases, merely the presence of inorganic particles may
induce a higher photoactivity of luminescent polymer substances. An example is the
mixture of a luminescent poly(fluorene) with kaolinite [79]. No intercalation of the
polymer chains took place, but the positive effect of the clay mineral on the
photoactivity of the polymer was apparent. There are about a dozen examples of
FRET occurring in hybrid materials based on nanoparticles which also include
luminescent polymeric substances, if we omit energy migration between the same
type of luminophores and fluorescence quenching, which are more frequent. For
example, two-step FRET has been achieved in blue light-emitting materials based on
zeolite and several photoactive substances [80]. Before preparing the composite,
zeolite was modified with oxonine dye, which was incorporated inside the cavities of
the host. The external surface of the zeolite was grafted with thiophene-based
fluorophores and modified with a fluorene-based copolymer. The photoactive
luminophores interacted via FRET starting from the polymeric phase, via the dye
molecules anchored on the external surface and ending inside the zeolite cavities
[80]. Slightly different arrangements were adopted for the hybrids based on layered
nanoparticles. The intercalation of both the polymeric and non-polymeric luminescent substances is the most frequent procedure for the preparation of such materials.
One example is FRET from a luminescent organosilicon compound – polyhedral
oligomeric silsesquioxane – to RB intercalated in Sap [81]. The structure of polymer
molecules can be significantly changed upon their intercalation between layered
particles. This may secondarily affect the conjugation of the polymer [82]. For
example, the conjugated polymer poly(9,9-dioctylfluorene), which emits in the
blue light region, was intercalated between the layers of the layered metal
dichalcogenides MoS 2 and SnS 2 . The polymer formed two distinct phases that
differed in their extent of polymer conjugation: The phase of the planar-extended
conjugation, which was identified as a fraction of the polymer present in the
interlayer spaces, exhibited a red-shifted absorption with respect to the common
form of the polymer. An efficient energy transfer occurred from the bulk phase to the
planar one, resulting in a shift in the wavelength of emitted light [82].
Resonance Energy Transfer in Hybrid Systems of Photoactive Dye Molecules and. . .
229