The effect of antioxidant/quenchers and a fluorescent whitening agent on the quantum yield of photoinduced degradation of tryptophan in a rigid, oxygen-permeable medium

1995 ◽  
Vol 86 (1-3) ◽  
pp. 267-273 ◽  
Author(s):  
P.D. Auer ◽  
M.T. Pailthorpe
2011 ◽  
Vol 183-185 ◽  
pp. 1692-1695
Author(s):  
Wen Hua Gao ◽  
Ke Fu Chen ◽  
Ren Dang Yang ◽  
Fei Yang ◽  
Xiao Bin Chen

Fluorescent whitening agent is relatively small dosage in the coating, but it has great influence on the properties of the coating and ink-jet printing qualities. With the increase of fluorescent whitening agent dosage, the PH of the coating rose but the viscosity was hardly to change. The brightness of coated ink-jet printing paper and color density of the printing image firstly presented the trend of increasing then decreasing. What’s more, when the brightness of the coated paper achieved to the maximum, color density and contact angle properties were the largest. Chromatic aberration property of the image reduced from 1.87 to 1.75, when the addition of fluorescent whitening agent rose from 0.1% to 0.5%. While the dosage was rose to 0.9%, chromatic aberration increased to 2.15. The gloss of coated paper decreased with the dosage of fluorescent whitening agent increasing. In sum, fluorescent whitening agent can enhance the brightness of the coated paper as well as the printing properties. The results show that the best brightness and printing qualities of coated ink-jet printing paper are obtained, when the fluorescent whitening agent is 0.5%( relative to pigment).


1975 ◽  
Vol 28 (9) ◽  
pp. 2083 ◽  
Author(s):  
IH Leaver ◽  
GC Ramsay ◽  
LJ Stephens

The photochemistry of the sulphonated pyrazoline fluorescent whitening agent sodium 4-(3?-phenyl-2?-pyrazolin-1?-yl)benzenesulphonate has been examined in aqueous solution, in films of poly(vinyl alcohol) and in the wool fibre. Photooxidation to give the pyrazole occurs almost quantitatively in solution, but accounts for only half of the photoproducts formed in the polymer. In the wool fibre, pyrazole formation accounts for more than half of the pyrazoline whitener destroyed during exposure to simulated sunlight.


2012 ◽  
Vol 27 (2) ◽  
pp. 418-425 ◽  
Author(s):  
Ludovic Gustafsson Coppel ◽  
Mattias Andersson ◽  
Magnus Neuman ◽  
Per Edström

Abstract We present an extension of a Kubelka- Munk based fluorescence model in which we introduce an apparent scattering (SUV) and absorption (KUV) coefficient for all wavelengths below 400 nm. We describe a method for modelling the total radiance factor of multi-layer papers and for estimating the optical parameters (S, K and Q) of each layer. Assuming that the fluorescent whitening agent only absorbs below 400 nm, we are able to determine SUV, KUVand the apparent quantum efficiency, Q(UV,λ) for 400 nm<λ<700 nm, from spectral radiance measurements in the visual part of the electromagnetic spectrum. We test the proposed method on different layered constructions made of three individual pilot paper layers. The proposed method allows the papermaker to determine the illumination independent fluorescence characteristics of single- and multilayer paper layers using a conventional singlemonochromator spectrophotometer operating in the visible part of the electromagnetic spectrum, and also to predict the radiance factor of fluorescing layered papers.


Author(s):  
Dong-Hoon Shin ◽  
Jang-Seung Choi ◽  
Seung-Han Ryu ◽  
Jin-Ho Kim ◽  
Sang-Hun Lee ◽  
...  

In this study, ozone oxidation experiment was carried out for the removal of fluorescent whitening agent which is widely used in textile dyeing and paper industry. The stilbene fluorescent whitening agent has been industrialized since the earliest, and the amount of current production is the highest. Due to the characteristics of the fluorescent whitening agent that cannot be removed by conventional wastewater treatment methods, the fluorescent whitening agent in wastewater treatment has difficulty in using as recycled water in the process. Pre-treatment ozone oxidation experiment was conducted prior to the introduction of Membrane Bio Reactor (MBR) treatment process by converting biodegradable materials into biodegradable materials. The removal efficiencies of fluorescent whitening agents, a diaminostilbene disulfonic acid derivative by ozone oxidation were evaluated by UV254 Scan, COD, T-N and color using a synthetic wastewater sample (COD=433.0 mg/ℓ) and paper and paper mill wastewater (COD=157.2 mg/ℓ).


2009 ◽  
Vol 85 (6) ◽  
pp. 1314-1321 ◽  
Author(s):  
Jolon M. Dyer ◽  
Stefan Clerens ◽  
Charisa D. Cornellison ◽  
Chris J. Murphy ◽  
George Maurdev ◽  
...  

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