Variety of photoluminescence intensity of fluorescent whitening agents introduced into polyacrylonitrile nanofibers

2006 ◽  
Vol 103 (4) ◽  
pp. 2382-2386 ◽  
Author(s):  
Shugang Wang ◽  
Qingbiao Yang ◽  
Jianshi Du ◽  
Jie Bai ◽  
Yaoxian Li
Keyword(s):  
Photoluminescence Intensity ◽  
Fluorescent Whitening Agents

Accumulation and elimination studies of four detergent fluorescent whitening agents in bluegill (

1973 ◽  
Vol 7 (10) ◽  
pp. 981-0
Author(s):  
C. R. Ganz ◽  
Janos Schulze ◽  
P. S. Stensby ◽  
F. L. Lyman ◽  
Kenneth Macek
Keyword(s):  
Fluorescent Whitening Agents

Sensitive Mechanocontrolled Luminescence in Cross-Linked Polymer Films

2019 ◽  
Author(s):  
Ayumu Karimata ◽  
Pradnya Patil ◽  
Eugene Khaskin ◽  
Sébastien Lapointe ◽  
robert fayzullin ◽  
...  
Keyword(s):  
Mechanical Stress ◽  
Polymer Films ◽  
Soft Matter ◽  
Small Strain ◽  
Visual Methods ◽  
Photoluminescence Intensity ◽  
Stimuli Responsive ◽  
Responsive Materials ◽  
Highly Sensitive ◽  
Mechanical Stretching

Direct translation of mechanical force into changes in chemical behavior on a molecular level has important implication not only for the fundamental understanding of mechanochemical processes, but also for the development of new stimuli-responsive materials. In particular, detection of mechanical stress in polymers via non-destructive methods is important in order to prevent material failure and to study the mechanical properties of soft matter. Herein, we report that highly sensitive changes in photoluminescence intensity can be observed in response to the mechanical stretching of cross-linked polymer films when using stable, (pyridinophane)Cu-based dynamic mechanophores. Upon stretching, the luminescence intensity increases in a fast and reversible manner even at small strain (< 50%) and applied stress (< 0.1 MPa) values. Such sensitivity is unprecedented when compared to previously reported systems based on organic mechanophores. The system also allows for the detection of weak mechanical stress by spectroscopic measurements or by direct visual methods.<br>

LUMINESCENT DETERMINATION OF SUGAR IN NATURAL HONEY

2020 ◽  
Vol 0 (4) ◽  
pp. 29-32
Author(s):  
B.M. GAREEV ◽  
◽  
A.M. ABDRAKHMANOV ◽  
G.L. SHARIPOV ◽  
◽  
...  
Keyword(s):  
Quantum Dots ◽  
Laboratory Test ◽  
Aqueous Solutions ◽  
Analytical Method ◽  
Sugar Content ◽  
Carbon Quantum Dots ◽  
Photoluminescence Intensity ◽  
Sucrose Content ◽  
Natural Honey

The photoluminescence of carbon quantum dots synthesized from natural honey and mixtures of honey and sugar has been studied. An increase in the sugar content leads to a decrease in the photoluminescence intensity without changing the shape of the luminescence spectrum of these quantum dots aqueous solutions, which is associated with a decrease in the yield of their synthesis in the sugar presence. The discovered effect can be used to detect sugar in honey. When examining five different market samples of flower honey using this method, two of them showed a significant decrease in the photoluminescence intensity. A laboratory test for compliance with GOST 19792-2017 Standard requirements established an excess of the sucrose content in these samples. Luminescent determination of sugar in honey does not require complicated equipment and can be used to develop a new analytical method for determining the sugar content in counterfeit natural honey.

The use of chemical and molecular microbial indicators for faecal source identification

2003 ◽  
Vol 47 (3) ◽  
pp. 39-43 ◽  
Author(s):  
B. Gilpin ◽  
T. James ◽  
F. Nourozi ◽  
D. Saunders ◽  
P. Scholes ◽  
...  
Keyword(s):  
Direct Pcr ◽  
Animal Group ◽  
Faecal Pollution ◽  
Molecular Assays ◽  
Chemical Indicators ◽  
Fluorescent Whitening Agents ◽  
Feral Animals ◽  
Oxidation Ponds ◽  
Specific Species ◽  
Faecal Sterols

Identifying the source of faecal pollution is important to enable appropriate management of faecal pollution of water. We are developing and evaluating a combination of these microbial and chemical indicators better able to identify the source of faecal pollution. These assays make use of a combination of direct PCR, culturing, and colony hybridisation to identify source specific species of Bifidobacterium, Rhodococcus and Bacteroides. In conjunction with assays for (a) fluorescent whitening agents and (b) faecal sterols and stanols, these indicators were able to identify human derived faecal pollution in river water containing inputs from septic tanks, municipal oxidation ponds, farmed animals and feral animals. Differentiating amongst the animal sources was more difficult and will require development of molecular assays for organisms specific to each animal group.

A New Method For The Electronic And Chemical Passivation Of GaAs Surfaces Using CS2

1995 ◽  
Vol 406 ◽  
Author(s):  
Ju-Hyung Lee ◽  
Yanzhen Xu ◽  
Veronica A. Burrows ◽  
Paul F. McMillan
Keyword(s):  
Surface Passivation ◽  
Passivation Layer ◽  
Semiconductor Diode ◽  
Photoluminescence Intensity ◽  
Atmospheric Conditions ◽  
Metal Insulator ◽  
Insulating Layer ◽  
Capacitance Voltage ◽  
Chemical Passivation ◽  
Homogeneous Film

AbstractA new GaAs surface passivation method, CS2 treatment at moderate temperature was developed for effective passivation of GaAs surfaces. The CS2 treatment of GaAs surfaces at 350°C and 10 atm leads to deposition of a homogeneous film, with a thickness of several hundred Å. The passivation layer thus produced causes a significant enhancement in room temperature photoluminescence intensity and the passivation effect of the sulfide film was confirmed by Raman spectroscopy. The passivation layer remained electrically and chemically stable over a period of nine months under ambient atmospheric conditions. In-depth Auger electron spectroscopy (AES) revealed that the carbon and oxygen content in the film was negligible, whereas sulfur was uniformly distributed throughout the film. A metal-insulator-semiconductor diode whose insulating layer is produced by the CS2 treatment shows well-defined accumulation and depletion regions in its capacitance-voltage (CV) characteristics with low hysteresis.

Effects of Gamma Irradiation on Optical Properties of Colloidal Nanocrystals

2007 ◽  
Vol 1038 ◽  
Author(s):  
Nathan J Withers ◽  
Krishnaprasad Sankar ◽  
Brian A. Akins ◽  
Tosifa A. Memon ◽  
Jiangjiang Gu ◽  
...  
Keyword(s):  
Optical Properties ◽  
Gamma Irradiation ◽  
Irradiation Dose ◽  
Nanocrystalline Material ◽  
Light Output ◽  
Colloidal Nanocrystals ◽  
Photoluminescence Intensity ◽  
Photoluminescence Properties ◽  
Material Systems ◽  
Dose Radiation

AbstractThe effects of 137Cs gamma irradiation on photoluminescence properties, such as spectra, light output, and lifetime, of several types of colloidal nanocrystals have been investigated. Irradiation-induced damage testing was performed on CdSe/ZnS, LaF3:Eu, LaF3:Ce, ZnO, and PbI2 nanocrystals synthesized on a Schlenk line using appropriate solvents and precursors. Optical degradation of the nanocrystals was evaluated based on the measured dependence of their photoluminescence intensity on the irradiation dose. Radiation hardness varies significantly between various nanocrystalline material systems.

Correlation of Electrical, Structural, and Optical Properties of Erbium In Silicon

1993 ◽  
Vol 301 ◽  
Author(s):  
J. L. Benton ◽  
D. J. Eaglesham ◽  
M. Almonte ◽  
P. H. Citrin ◽  
M. A. Marcus ◽  
...  
Keyword(s):  
Root Function ◽  
Free Exciton ◽  
Excitation Power ◽  
Optically Active ◽  
Photoluminescence Intensity ◽  
Square Root ◽  
Structural And Optical Properties ◽  
X Ray ◽  
X Ray Absorption ◽  
Donor Activity

ABSTRACTAn understanding of the electrical, structural, and optical properites of Er in Si is necessary to evaluate this system as an opto-electronic material. Extended x-ray absorption fine structure, EXAFS, measurements of Er-implanted Si show that the optically active impurity complex is Er surrounded by an O cage of 6 atoms. The Er photoluminescence intensity is a square root function of excitation power, while the free exciton intensity increases linearly. The square root dependence of the 1.54μm-intensity is independent of measurement temperature and independent of co-implanted species. Ion-implantation of Er in Si introduces donor activity, but spreading resistance carrier concentration profiles indicate that these donors do not effect the optical activity of the Er.

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