2 edition of Studies in the photodegradation of dyes containing the stilbene chromophore. found in the catalog.
Studies in the photodegradation of dyes containing the stilbene chromophore.
Written in English
Thesis (Ph. D.)--The Queen"s University of Belfast, 1966.
|The Physical Object|
Taking the 4,5-diphenyl-substituted 2-dimethylaminoazacyclopentadienone (4) as an example its colour has been discussed in relation to different basic chromophores (parent chromophores). The parent chromophore can be defined either as the structure which has nearly the same absorption wavelength as the dye under consideration or as the substructure which is electronically most closely. A dye laser is a laser which uses an organic dye mixed in a solvent as the lasing medium. Some of the laser dyes include rhodamine, fluorescein, coumarin, stilbene, umbelliferone, tetracene and malachite green. Some of the solvents used include water, glycol, .
Azo Dyes Azo dye is a large class of synthetic organic dyes that contain nitrogen as the azo group −N=N− as primary chromophore their molecular structures. These dyes are highly coloured and are prepared by diazotizing an aromatic amine and coupling with suitable aromatic compound. Azo dyes account for approximately % of all dyes used. Organic dyes constitute one of the largest groups of wastewater’s pollutants. In general, they are released into the environment by textile industries. Approximately , dyes are widely used in the textile industry, and a large wastewater of dyestuff is generated annually. Among these, indigoid class is commercial dyes used mostly for cotton cloth dyeing.
The use of dyes is very ancient. Kermes (natural red 3) is identified in the bible book of Exodus, where references are made to scarlet coloured linen. Similar dyes are carmine (natural red 4) and lac (natural red 25). These three dyes are close chemical relatives, obtained from insects of the genus Coccus. All require a mordant. Organogels formed from novel organic gelators containing a cholesterol tethered to squaraine dyes or trans-stilbene derivatives have been studied from several different perspectives. The two types of molecules are active toward several organic liquids, gelling in some cases at .
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A recent book covers most of the information on stilbenes, bibenzyls, and related substances up to 45 In contrast to CHS-derived products, stilbenes and their derivatives appear to be rare in higher plants, in particular in important crop plant cultivars, with the exception of wine and peanut.
A large number of interesting bibenzyl-derived molecules (stilbenoids) occur in liverworts. There were reports of using 4,4′‐diaminostilbene‐2,2′‐disulfonic acid as a bridging group in reactive dyes and one report of stilbene participating in the chromophore.
Basic dyes reported were made by coupling the tetrazo of 4,4′‐diaminostilbene and quaternizing. Photodegradation of lignin is one of the major postprocessing problems in paper production, as this renders yellowing of the paper and reduced paper quality.
In this study, we have explored the photochemical properties of substituted stilbene derivatives believed to be key chromophores in the photodegradation of lignin derived from cinnamyl by: 8.
The photodegradation properties of six electro-optic chromophores in guest-host polymer formats were measured as a function of wavelength throughout the visible and up to μm in the near infrared.
Request PDF | Photodegradation of various electro-optic polymer families | The photostability of different chromophore families has been studied as a function of probe wavelength in the spectral.
EPA-P March A STUDY OF THE PHOTODEGRADATION OF COMMERCIAL DYES By John J. Porter Project EOX Project Officer Dr. Arthur W. Garrison Southeast Environmental Research Laboratory College Station Road Athens, Georgia Prepared for OFFICE RESEARCH AND MONITORING U.S. ENVIRONMENTAL PROTECTION AGENCY WASHINGTON.
Joanna Izdebska, in Printing on Polymers, Radiation Degradation. Photodegradation is a process that changes the basic structure of a polymer by cross-linking, chain scission, and oxidative processes.
The first two processes take place mostly in the amorphous part of the polymeric material and the photooxidation process is initiated at the surface.
Anthraquinone dyes Anthraquinone is the basic unit of this class of dyes. It is faint yellow in color which is sufficient to use it as a dye but it cannot be classified as a dye. Dyes containing anthraquinone unit belong to mordant, disperse and vat dyes. Its quinonoid system acts as a chromophore.
Anthraquinone dyes have excellent. photocatalytic degradation have been studied in a photoreactor cell containing high pressure mercury lamp to obtain the optimum conditions.
COD removal was found to be 65–71% confirming consider-able mineralization. The photodegradation of the dye obeyed a pseudo-first order kinetics according. containing compounds in order to remove their natural color, and if the fabric is to be sold white and not dyed, optical brightening agents are added .
Dyeing is the aqueous application of color to the textile substrates, mainly using synthetic organic dyes and frequently at elevated temperatures and pressures in some of the steps [37,38].
Summary This chapter contains sections titled: Azo Chromophore Introduction General Synthesis Principal Properties Anthraquinone Chromophore Introduction General. Photodegradation in the environment is part of the process by which ambergris evolves from its fatty precursor.
Photodegradation also destroys paintings and other artifacts. Light - induced polymer degradation, or photodegradation, includes the physical and chemical changes caused by irradiation of polymers with ultraviolet or visible light.
The most important stilbene dyes are those known for more than fifty years. In that case, go with sequential stream processing.: (English) AICS Chemical ID. be able to is NOT an auxiliary verb (it uses the verb be as a. 8 x mol mL 1. Stilbene dye. P a g e | 1 Chemistry Internal Assessment The Photodegradation of Dyes – Chemistry IA Introduction This Internal Assessment provides experimentation and analysis into the topic of the photodegradation of dyes.
Dyes, as a broad class of compounds, have many diverse and unique uses in industry today, whether it be to colour clothes, food, or even buildings. Occasionally dye fading may be attributable to reduction of the dye chromophore, at the expense of oxidation of the polymer host.
In such cases, antioxidants may still have a beneficial effect, and this was demonstrated by Allen et al.  with disperse anthraquinone dyes in epoxy resin films.
They. Amongst functional macromolecules, the combination of polymers and dyes is a research field of great potential with regard to high-performance materials.
Accordingly, colored polymers have become increasingly important as materials for miscellaneous technical applications in recent years while also being a major part of everyday life.
For instance, dye-containing polymers are nowadays widely. However, most of fluorescent chromophores fall short of the full potential due to the absence of the combination of such different nonlinear upconversion behaviors. Here, we demonstrate that an exceptional fluorescent stilbene dye could exhibit efficient two- and three-photon absorption under the excitation of femtosecond pulses in solution phase.
Although it is expected that, the C=C bond strength will increase after introducing the cyano side-group, thus its photo-stability should be improved.
But after careful study, we found that when exposed to light, the introduction of cyano group makes the new molecule alpha'-cyano-4'-nitroN, N-dimethylaminostilbene (CNDS) to isomerize much easier than 4'-N,N-dimethylamino-nitrostilbene. Photodegradation and Light Stabilization of Heterochain Polymers.
xipo. Protect from Light Photodegradation and Protein Biologics. In the case study of the Eriochrome black T (EBT) dye, it is observed that EBT molecules with negatively-charged chromophores play a competent structure-directing role in restraining the oriented growth of ZnO nanowires along the c-axis.
This effect, however, can be partially counteracted by introducing UV light irradiation into the growth. Acid dyes are water-soluble anionic dyes, containing one or more sulfonic acid substituents or other acidic groups.
An example of the class is Acid Yellow Acid dyes are applied from acidic dye baths to nylon, silk, wool, and modified acrylics. They are also used to some extent for paper, leather, ink-jet printing, food, and cosmetics.Dyestuff: Dyestuffs are organic and inorganic substances which consists of chromophore groups, can change the physical and chemical properties of any substance, can absorb light and reflect lights to show color.
They are unsaturated complex compound. Characteristics of dyestuff: It must contain chromophore group Chromophore group can be different types like -NO2,-NH2,-CO-,-N=O.of methyl orange with different photocatalyst.
The photodegradation of dyes are increase with decreasing the concentration of dyes with the photocatalyst. Figure 1 Effect of concentration on photodegradation Methyl Orange with TiO.
2. and Co: La: TiO. 2. Effect of catalyst amount. Degradation of dye is affected by the amount of the.