Spectroscopic and photochemical studies of xanthene and azo dyes on surfaces:cellophane as a mimic of paper and cotton

Abbott, Laurence C.; MacFaul, Philip A.; Jansen, Lisinka; Oakes, John; Smith, John R. Lindsay; Moore, John N.

doi:10.1016/s0143-7208(00)00091-7

Cited by 17 publications

(10 citation statements)

References 8 publications

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“…The UV-visible spectrum of model dye 8 in cotton treated with artificial sweats showed no changes with different sweats pH. The red-shift in the absorption maximum of dye 8 observed on going from solution to cotton shows similar changes as in Abbott et al 26 It may be attributed to a change in the energy of either to ground and/or to the excited electronic state, probably arising from a small change in the structure of the dye on surface deposition, Abbott et al 26 The general shift in the UV-visible band positions with medium can be interpreted in terms of increasing polarity from cotton (e % 5) to water (e ¼ 80) that model dyes are more polar in the ground state than in the excited state, Abbott et al 27 Other effect will also influence the UV-visible spectra of model dyes. For example, specific intermolecular interactions with the medium, including hydrogen-bonding (evidenced by FTIR and FTR spectra), Pielesz et al 47,48 Other effect may include structural changes with the dyes that arise from surface adsorption, consistent with interpretation of the 13 C NMR data (Table I).…”

Section: Interactions Between Model Direct Dyes and Cottonsupporting

confidence: 76%

Spectroscopic study of interactions between model direct dyes and cotton

Pielesz

2007

J of Applied Polymer Sci

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Although examined for years, interactions between direct dyes and the chemical structure of cotton cellulose remain an interesting, and still not entirely known, chemical phenomenon occurring in the fiber. Ten model azo dyes have been studied in aqueous solution, as dye powders and on cotton fabric using 13 C MAS NMR and UV-visible spectroscopy. NMR spectroscopy indicates that model azo dyes, especially dye 8, interact by p-stacking at the central biphenyl group, and that there is hydrogen bonding with cellulose. Model azo dyes are present as the azo or hydrazone tautomer. The UV-visible l max indicate that shifts are attributed to adsorption of model azo dyes into cellulose surfaces.

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Section: Interactions Between Model Direct Dyes and Cottonsupporting

confidence: 76%

Spectroscopic study of interactions between model direct dyes and cotton

Pielesz

2007

J of Applied Polymer Sci

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“…For this reason, many studies have dealt with the reactivity of the dye in solution (aqueous solution or solutions mimicking the substrates) in an attempt to simplify the complex reactivity of the dye-substrate system. Of course, when dealing with a real object such as a drawing or a print, it is not possible to neglect the substrate reactivity [4] and a study of model systems for the dye on paper is necessary [5]. The objective of this work is to study the photo-fading of CV via HPLC-PDA, LC-MS and FORS both in aqueous solution and on paper in order to use the information obtained from the former system to best interpret the results of the study of the degradation of the dye on paper.…”

Section: Introductionmentioning

confidence: 99%

Crystal violet: Study of the photo-fading of an early synthetic dye in aqueous solution and on paper with HPLC-PDA, LC-MS and FORS

Confortin

Neevel

Brustolon

et al. 2010

J. Phys.: Conf. Ser.

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Disclaimer/Complaints regulationsIf you believe that digital publication of certain material infringes any of your rights or (privacy) interests, please let the Library know, stating your reasons. In case of a legitimate complaint, the Library will make the material inaccessible and/or remove it from the website. Please Ask the Library: http://uba.uva.nl/en/contact, or a letter to: Library of the University of Amsterdam, Secretariat, Singel 425, 1012 WP Amsterdam, The Netherlands. You will be contacted as soon as possible. Abstract. The photo-fading of crystal violet (CV), one of the earliest synthetic dyes and an ink component, is examined both in solution and on paper. Aqueous solutions of CV were exposed to UV light (365nm) and samples were taken at constant time intervals and analysed with a High Performance Liquid Chromatography-Photo Diode Array (HPLC-PDA) and Liquid Chromatography-Mass Spectroscopy (LC-MS). Demethylation products were positively identified. Also, deamination probably occurred. The oxidation at the central carbon likely generates Michler's ketone (MK) or its derivatives, but still needs confirmation. To study CV on paper, Whatman paper was immersed in CV and exposed to UV light. Before and after different irradiation periods, reflectance spectra were recorded with Fibre Optic Reflectance Spectrophotometry (FORS). A decrease in CV concentration and a change in aggregation type for CV molecules upon irradiation was observed. Colorimetric L*a*b* values before and during irradiation were also measured. Also, CV was extracted from paper before and after different irradiation periods and analysed with HPLC-PDA. Photo-fading of CV on paper produced the same products as in solution, at least within the first 100 hours of irradiation. Finally, a photo-fading of CV in the presence of MK on Whatman paper was performed. It was demonstrated that MK both accelerates CV degradation and is consumed during the reaction. The degradation pathway identified in this work is suitable for explaining the photo/fading of other dyes belonging to the triarylmethane group.

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“…Additionally, the radical species produced upon the photoexcitation of dyes can initiate deterioration processes of substrates, leading to the loss of mechanical and optical properties [14][15][16][17][18][19][20].…”

Section: Photooxidation Of Dyes On Paper Substratementioning

confidence: 99%

“…), and the photofading rates could be quite different on substrate surfaces (paper, polymer film) comparing to photodegradation in solvents. The investigations of triphenylmethane dyes photofading in polymer films [poly (vinyl alcohol), methylcellulose, gelatin] evidenced that the photochemical process is influenced by the ability of the substrate, or residual solvent within the substrate, to donate electrons, or hydrogen atoms, to the dyes; by the ability of dyes to form aggregates; and by the chemical and physical structure of the substrates [14][15][16][17][18][19][20].…”

Section: Introductionmentioning

confidence: 99%