UV-absorbance of oxidized xylan and monocarboxyl cellulose in alkaline solutions

Bikova, T.

doi:10.1016/j.carbpol.2003.10.005

Cited by 53 publications

(22 citation statements)

References 13 publications

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“…The 190~230 nm wavelength area often results from n−σ* and/or π−π* transitions, which are found in many functional groups such as amine, carboxyl, carbonyl, and ester. Absorbance within the 260~280 nm range is commonly attributed to π−π* elec tron transitions in aromatic and poly-aromatic compounds found in most conju- gated molecules, including proteins [20,21]. These results indicate that A. platensis EPS are very large and complicated substances that contain multiple UV-absorbing groups.…”

Section: Uv-visible Analysesmentioning

confidence: 88%

Partial characterization of extracellular polysaccharides produced by cyanobacterium Arthrospira platensis

Trabelsi

M’sakni

Ouada

et al. 2009

Biotechnol Bioproc E

147

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In this study, the physico-chemical characteristics of extracellular polysaccharides (EPS) produced by Arthrospira platensis were evaluated. Elemental analysis and a bicinchoninic acid (BCA) reaction indicated that the EPS were heteropolysaccharides that contain carbohydrate (13%) and protein (55%) moieties. Analysis of the infrared spectrum and elemental analysis revealed the presence of a sulfate group (0.5%). The UV-visible spectrum showed high UV absorption at 190~230 nm and a shoulder at 260~280 nm. In addition, this spectrum indicated that EPS can form aggregates with mycosporine-like amino acids and/or scytonemin. Gas chromatography analysis of the carbohydrate portion of the EPS indicated that it was composed of seven neutral sugars: galactose (14.9%), xylose (14.3%), glucose (13.2%), frucose (13.2%), rhamnose (3.7%), arabinose (1%), and mannose (0.3%) and two uronic acids, galacturonic acid (13.5%) and glucuronic acid (0.9%). © KSBB

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Section: Uv-visible Analysesmentioning

confidence: 88%

Partial characterization of extracellular polysaccharides produced by cyanobacterium Arthrospira platensis

Trabelsi

M’sakni

Ouada

et al. 2009

Biotechnol Bioproc E

147

View full text Add to dashboard Cite

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“…Previous studies have reported that lignin generates active species when exposed to ultraviolet (UV) and visible light, which cause photodegradation of lignocellulosic materials into materials with lower molecular weights (Kringstad 1969;Hon 1983;Davidson 1996;Bikova and Treimanis 2004). Thus, the detected changes in lignin structure are highly related to the degradation of lignin.…”

Section: Effect Of Photo Pre-treatment On O-stage's Selectivitymentioning

confidence: 90%

“…Some studies report that lignin is capable of absorbing wavelengths in the range of 280 to 400 nm (Bikova and Treimanis 2004;George et al 2005). According to Sun et al (1996) and Chong et al (2013b), the addition of peroxide-aided photo treatment in a TCF bleaching sequence can successfully increase bleaching selectivity and hence shows the potential to improve O-stage selectivity.…”

Section: Introductionmentioning

confidence: 99%

“…The exposure of the woody material to ultraviolet and visible light, known as photo treatment, has been regularly reported to cause the degradation of lignin and carbohydrates (Kringstad 1969;Hon 1983;Davidson 1996;Bikova and Treimanis 2004). Based on these studies, which mostly focus on the irradiation absorption by synthesized lignin of ultraviolet and visible light, it was found that during photo treatment, active species, especially radicals, are generated.…”

Section: Introductionmentioning

confidence: 99%

“…Based on these studies, which mostly focus on the irradiation absorption by synthesized lignin of ultraviolet and visible light, it was found that during photo treatment, active species, especially radicals, are generated. Thus, lignin degrades into a lower molecular weight by radical-induced depolymerisation (Bikova and Treimanis 2004;Chong et al 2013b). Lignin shows a higher absorbency of the radiation than carbohydrates, even at different wavelengths, as it contains various chromophoric structures.…”

Section: Introductionmentioning

confidence: 99%

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Application of Photo, Peracetic Acid, and Combination Pre-treatments in Improving Totally Chlorine-Free Bleaching Selectivity

Chong¹,

Daud²,

Poh³

et al. 2015

BioResources

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The application of totally chlorine-free bleaching (TCF) is well recognised for its environmental compatibility. However, its application is restricted in comparison to a chlorine-based bleaching sequence. TCF bleaching produces pulp with relatively lower brightness and strength properties. Oxygen delignification (O-stage) is commonly used as a first bleaching stage; therefore its selectivity influences TCF bleaching performance. In this study, the selectivity of the O-stage and hydrogen peroxidereinforced O-stage (Op-stage) on tropical hardwood kraft pulp were 0.53 and 0.71, with 37.8% and 55.5% kappa number (Kn) reductions, respectively. The addition of photo pre-treatment prior to the O-stage and Op-stage improved the Kn reduction to 53.7% and 59.2%; consequently the selectivity was enhanced to 1.0 and 0.73, respectively. The Fourier transform infrared spectra showed that photo pre-treatments improved the selectivity by protecting the cellulose from carbonyl-induced degradation. This protective effect was more prominent in the O-stage than the Op-stage. However, the combination of peracetic acid and photo treatment did not further increase bleaching selectivity in either stage. In short, blue light and UV irradiation treatment with or without the prior addition of peracetic acid to ordinary or hydrogen peroxidereinforced oxygen delignified pulp displayed a similar bleaching effect on the resultant pulp.

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Color and Color Reversion of Cellulosic and Lignocellulosic Fibers

Castellan

Grelier

2016

Lignocellulosic Fibers and Wood Handbook

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UV-absorbance of oxidized xylan and monocarboxyl cellulose in alkaline solutions

Cited by 53 publications

References 13 publications

Partial characterization of extracellular polysaccharides produced by cyanobacterium Arthrospira platensis

Partial characterization of extracellular polysaccharides produced by cyanobacterium Arthrospira platensis

Application of Photo, Peracetic Acid, and Combination Pre-treatments in Improving Totally Chlorine-Free Bleaching Selectivity

Color and Color Reversion of Cellulosic and Lignocellulosic Fibers

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