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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.


PL spectra. (a) Unloaded polymer and (b) CdS/PVA nanocomposite. Curves 1 and 2 correspond to the untreated sample and the UV-exposed sample, respectively.
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Fig3: PL spectra. (a) Unloaded polymer and (b) CdS/PVA nanocomposite. Curves 1 and 2 correspond to the untreated sample and the UV-exposed sample, respectively.

Mentions: Information about the UV-induced changes in the samples under the study can also be obtained from PL measurements. Figure 3 shows the variation of light-emitting properties of the polymer (a) and nanocomposite (b) under the UV exposure. The UV treatment of the unloaded PVA causes a very strong red shift (about 70 nm) of the PL band. It should be noted that the PL spectrum of the pure PVA is related to the defects of macromolecules [11,12]. Thus, the changes of the PL band reflect the UV-induced changes in the defect subsystem of the polymer [13], in full agreement with the results presented in Figure 2a.Figure 3


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)

PL spectra. (a) Unloaded polymer and (b) CdS/PVA nanocomposite. Curves 1 and 2 correspond to the untreated sample and the UV-exposed sample, respectively.
© Copyright Policy - open-access
Related In: Results  -  Collection

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

Fig3: PL spectra. (a) Unloaded polymer and (b) CdS/PVA nanocomposite. Curves 1 and 2 correspond to the untreated sample and the UV-exposed sample, respectively.
Mentions: Information about the UV-induced changes in the samples under the study can also be obtained from PL measurements. Figure 3 shows the variation of light-emitting properties of the polymer (a) and nanocomposite (b) under the UV exposure. The UV treatment of the unloaded PVA causes a very strong red shift (about 70 nm) of the PL band. It should be noted that the PL spectrum of the pure PVA is related to the defects of macromolecules [11,12]. Thus, the changes of the PL band reflect the UV-induced changes in the defect subsystem of the polymer [13], in full agreement with the results presented in Figure 2a.Figure 3

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.