organic fluorophores derived from pyrazoline for plastic
TRANSCRIPT
Organic Fluorophores Derived From Pyrazoline for Plastic Scintillators Valery N. Bliznyuk, Ayman Seliman, Timothy DeVolDepartment of Environmental Engineering and Earth Science, Clemson University, Clemson, SC 29634 USA
Nadezhda A. Derevyanko, Alexander A. Ishchenko
Institute of Organic Chemistry, National Academy of Science of Ukraine, Kiev, Ukraine
LSC 2017, Copenhagen, DenmarkMay 1-5, 2017
Application to Water Monitoring
Decreased performance of Sr ScintEx resin
Efficient Scintillation Detection
High absorptivity for high energy electromagnetic radiation or particles, e.g. in UV and deep UV
Efficient Förster resonance energy transfer (FRET) Efficient harvesting of the absorbed energy and its concentration on the
emitting centers
High quantum yield – i.e., the ratio of the # of emitted photons to the # of absorbed photons
Large Stokes Shift – to minimize self-absorption Maximum of the emission wavelength to match the maximum
absorption wavelength of photodetector typically achieved by application of a mixture of primary and
secondary fluorophores Optical transparency in visible range High stability of properties under harsh conditions of chemical,
radiation, light and temperature exposure
Pyrazoline and its derivatives
1,3,5-triphenyl-2-pyrazolinehttp://www.chemspider.com/ImageView.aspx?mode=3d&id=86609
Pyrazoline core
Synthesis of PZ compounds
Simple
Uses common compounds
High yield
Can be scaled upto industrial level
V.N.Bliznyuk et al, ACS Applied Materials & Interfaces, 2016, 8, 12843
Characterization
• 1H NMR • Raman
Absorption and Emission Spectra
vPZ1PZ1
Fluorescence quantum yield Φfof PZ fluorophores relative to 9,10-Diphenylanthracene (DPA)
FluorophoreΦf %
Cyclohexane Toluene
PZ1 109 116vPZ1 74 79PZ2 107 114PZ3 111 116
0.5% vPZ1 0.5% vPZ1 3% vNPO
Laser = 30.0% Laser = 100.0%Laser = 5.0%
Confocal laser microscopy
Quantum Yield and Fluorescence Spectroscopy
Radioluminosity
Luminosity spectra of PVT beadscontaining (a) vPZ1 or (b) vNPO (αNPO)fluorophores depending on the fluorophoreconcentration.
Radioluminosity Measurement
0.5%
Energydepositionevent
Emission of light
excitationof fluor
Nanostructured design for efficient energy harvesting
~10 nm or ~ 30 monomer units
fluor
V.N.Bliznyuk et al, ACS Applied Materials & Interfaces, 2016, 8, 12843
Covalently bound fluor:● Reduced aggregation● Coupling to the matrix● Chemical stability
radiative or nonradiative energy transfer
NN
Br
> 10-5 Mfluorophore concentration
NN
NN
1
2
34
5
HN
N HN
N12
3
Quantum Mechanical Modeling
Main Features:• “Two in one” chromophore with non-planar “3D antenna”
structure
• Simultaneous primary and secondary fluorophore action
• Reduced aggregation and enhanced coupling with the matrix
• Concentration can be reduced close to the theoretical minimum
1,3,5-triphenyl-2-pyrazoline (TPhH)
Phenylhydrazine benzaldehyde (PhHB)
Chromophore II
Chromophore I
Conclusions
1,3,5-triphenyl-2-pyrazol
- Hetero-substituted PZ derivatives are soluble in common organic solvents and therefore can be incorporated in a polymer matrix
- 3 times higher fluorescence
- ~10% higher radioluminosity in comparison to existing analogs
- 10% higher Quantum Yield
- Enhanced stability0
1000
2000
3000
4000
5000
6000
7000
8000
0 100 200 300 400 500 600 700
Cou
nts
Channel
0.1% vPZ1
0.5% vPZ1
0.1% NPOα
Acknowledgements
Funding from the Defense Threat Reduction Agency, Basic Research Award # HDTRA1-12-1-0012