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Enhancement of polymer endurance to UV light by incorporation of semiconductor nanoparticles.

Rudko G, Kovalchuk A, Fediv V, Chen WM, Buyanova IA - Nanoscale Res Lett (2015)

Bottom Line: UV protection is achieved by diminishing the probability of photo-activated formation of defects in polymer.The sources of polymer protection are the lowering of the efficiency of polymer excitation via partial absorption of incident light by the embedded nanoparticles as well as the de-excitation of the macromolecules that have already absorbed UV quanta via energy drain to nanoparticles.Within the nanoparticles, the energy is either dissipated by conversion to the thermal energy or reemitted as visible-range photoluminescence quanta.

View Article: PubMed Central - PubMed

Affiliation: V. Lashkaryov Institute of Semiconductor Physics of National Academy of Sciences of Ukraine, 45, Pr. Nauky, Kiev, 03028 Ukraine.

ABSTRACT
Improvement of polyvinyl alcohol stability against ultraviolet (UV) illumination is achieved by introducing cadmium sulfide (CdS) nanoparticles into the polymeric matrix. Enhancement of stability is analyzed by optical characterization methods. UV protection is achieved by diminishing the probability of photo-activated formation of defects in polymer. The sources of polymer protection are the lowering of the efficiency of polymer excitation via partial absorption of incident light by the embedded nanoparticles as well as the de-excitation of the macromolecules that have already absorbed UV quanta via energy drain to nanoparticles. Within the nanoparticles, the energy is either dissipated by conversion to the thermal energy or reemitted as visible-range photoluminescence quanta.

No MeSH data available.


Related in: MedlinePlus

Spectral dependences of the transmittance of the samples in the visible range. Unloaded polymer (a) and CdS/PVA nanocomposite (b). Curves 1 and 2 correspond to the untreated sample and the UV-exposed sample, respectively. Diagrams in the inserts show the relative changes of the integrated visible-range transmittance of the samples caused by UV treatment: 100%, integrated transmittance before UV-exposure; 4% and 85%, integrated transmittance of PVA and CdS/ PVA after UV exposure, respectively.
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Fig2: Spectral dependences of the transmittance of the samples in the visible range. Unloaded polymer (a) and CdS/PVA nanocomposite (b). Curves 1 and 2 correspond to the untreated sample and the UV-exposed sample, respectively. Diagrams in the inserts show the relative changes of the integrated visible-range transmittance of the samples caused by UV treatment: 100%, integrated transmittance before UV-exposure; 4% and 85%, integrated transmittance of PVA and CdS/ PVA after UV exposure, respectively.

Mentions: These visible qualitative differences were quantitatively analyzed by optical characterization techniques. Figure 2 shows visible-range transmittance spectra of the unloaded polymer (Figure 2a) and CdS/PVA nanocomposite (Figure 2b) measured before the UV treatment and after it (within the damaged part of the sample).Figure 2


Enhancement of polymer endurance to UV light by incorporation of semiconductor nanoparticles.

Rudko G, Kovalchuk A, Fediv V, Chen WM, Buyanova IA - Nanoscale Res Lett (2015)

Spectral dependences of the transmittance of the samples in the visible range. Unloaded polymer (a) and CdS/PVA nanocomposite (b). Curves 1 and 2 correspond to the untreated sample and the UV-exposed sample, respectively. Diagrams in the inserts show the relative changes of the integrated visible-range transmittance of the samples caused by UV treatment: 100%, integrated transmittance before UV-exposure; 4% and 85%, integrated transmittance of PVA and CdS/ PVA after UV exposure, respectively.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4385109&req=5

Fig2: Spectral dependences of the transmittance of the samples in the visible range. Unloaded polymer (a) and CdS/PVA nanocomposite (b). Curves 1 and 2 correspond to the untreated sample and the UV-exposed sample, respectively. Diagrams in the inserts show the relative changes of the integrated visible-range transmittance of the samples caused by UV treatment: 100%, integrated transmittance before UV-exposure; 4% and 85%, integrated transmittance of PVA and CdS/ PVA after UV exposure, respectively.
Mentions: These visible qualitative differences were quantitatively analyzed by optical characterization techniques. Figure 2 shows visible-range transmittance spectra of the unloaded polymer (Figure 2a) and CdS/PVA nanocomposite (Figure 2b) measured before the UV treatment and after it (within the damaged part of the sample).Figure 2

Bottom Line: UV protection is achieved by diminishing the probability of photo-activated formation of defects in polymer.The sources of polymer protection are the lowering of the efficiency of polymer excitation via partial absorption of incident light by the embedded nanoparticles as well as the de-excitation of the macromolecules that have already absorbed UV quanta via energy drain to nanoparticles.Within the nanoparticles, the energy is either dissipated by conversion to the thermal energy or reemitted as visible-range photoluminescence quanta.

View Article: PubMed Central - PubMed

Affiliation: V. Lashkaryov Institute of Semiconductor Physics of National Academy of Sciences of Ukraine, 45, Pr. Nauky, Kiev, 03028 Ukraine.

ABSTRACT
Improvement of polyvinyl alcohol stability against ultraviolet (UV) illumination is achieved by introducing cadmium sulfide (CdS) nanoparticles into the polymeric matrix. Enhancement of stability is analyzed by optical characterization methods. UV protection is achieved by diminishing the probability of photo-activated formation of defects in polymer. The sources of polymer protection are the lowering of the efficiency of polymer excitation via partial absorption of incident light by the embedded nanoparticles as well as the de-excitation of the macromolecules that have already absorbed UV quanta via energy drain to nanoparticles. Within the nanoparticles, the energy is either dissipated by conversion to the thermal energy or reemitted as visible-range photoluminescence quanta.

No MeSH data available.


Related in: MedlinePlus