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Adsorption behaviors of optical brightening agents and precipitated calcium carbonate onto pulp fibers / Hongjie Zhang in Industrial & engineering chemistry research, Vol. 49 N° 19 (Octobre 2010) 

Public ISBD [article]  in Industrial & engineering chemistry research > Vol. 49 N° 19 (Octobre 2010) . - pp. 9407–9412 Titre : Adsorption behaviors of optical brightening agents and precipitated calcium carbonate onto pulp fibers Type de document : texte imprimé Auteurs : Hongjie Zhang, Auteur ; Lanfeng Hui, Auteur ; Yonghao Ni, Auteur Année de publication : 2010 Article en page(s) : pp. 9407–9412 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Optical  brightening  agents  Adsorption Résumé : High-yield pulps (HYPs) can be used in the production of high-quality fine paper grades. In such applications, optical brightening agents (OBA) and inorganic fillers, such as precipitated calcium carbonate (PCC) may be used to improve the paper properties, including optical properties, such as brightness, whiteness, opacity. In this study, some fundamental parameters regarding OBA and PCC adsorption onto pulp fibers were investigated. Results showed that OBA was preferably adsorbed onto bleached kraft pulp (BKP) fibers than onto HYP fibers when present in a mixed furnish. The OBA adsorption at a low adsorbed amount followed the Langmuir adsorption isotherm for both BKP and HYP; the adsorbed OBA in a monolayer was more for the BKP than for the HYP. The PCC adsorption behaviors on the same two pulp systems, however, are different from those of OBA: the HYP had more PCC adsorption than the BKP. The results on the adsorption of PCC onto the HYP and kraft pulp fibers showed that they also followed the Langmuir kinetics very well. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie1003976 [article] Adsorption behaviors of optical brightening agents and precipitated calcium carbonate onto pulp fibers [texte imprimé] / Hongjie Zhang, Auteur ; Lanfeng Hui, Auteur ; Yonghao Ni, Auteur . - 2010 . - pp. 9407–9412. Chimie industrielle Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 49 N° 19 (Octobre 2010) . - pp. 9407–9412 Mots-clés : Optical  brightening  agents  Adsorption Résumé : High-yield pulps (HYPs) can be used in the production of high-quality fine paper grades. In such applications, optical brightening agents (OBA) and inorganic fillers, such as precipitated calcium carbonate (PCC) may be used to improve the paper properties, including optical properties, such as brightness, whiteness, opacity. In this study, some fundamental parameters regarding OBA and PCC adsorption onto pulp fibers were investigated. Results showed that OBA was preferably adsorbed onto bleached kraft pulp (BKP) fibers than onto HYP fibers when present in a mixed furnish. The OBA adsorption at a low adsorbed amount followed the Langmuir adsorption isotherm for both BKP and HYP; the adsorbed OBA in a monolayer was more for the BKP than for the HYP. The PCC adsorption behaviors on the same two pulp systems, however, are different from those of OBA: the HYP had more PCC adsorption than the BKP. The results on the adsorption of PCC onto the HYP and kraft pulp fibers showed that they also followed the Langmuir kinetics very well. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie1003976

Adsorption of lignocelluloses dissolved in prehydrolysis liquor of kraft - based dissolving pulp process on oxidized activated carbons / Xin Liu in Industrial & engineering chemistry research, Vol. 50 N° 20 (Octobre 2011) 

Public ISBD [article]  in Industrial & engineering chemistry research > Vol. 50 N° 20 (Octobre 2011) . - pp. 11706–11711 Titre : Adsorption of lignocelluloses dissolved in prehydrolysis liquor of kraft - based dissolving pulp process on oxidized activated carbons Type de document : texte imprimé Auteurs : Xin Liu, Auteur ; Pedram Fatehi, Auteur ; Yonghao Ni, Auteur Année de publication : 2011 Article en page(s) : pp. 11706–11711 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Adsorption  Lignocelluloses Résumé : The prehydrolysis stage is essential in producing high-purity cellulose from the kraft-based process and is effective in removing hemicelluloses from wood chips. To convert hemicelluloses and other dissolved materials of the prehydrolysis liquor (PHL) into value-added products, they must first be recovered from the PHL. In this work, we investigated the use of activated carbon (AC) to adsorb such materials from the PHL. The adsorption of hemicelluloses on unmodified AC was significantly higher in neutral than acidic environment. To improve the adsorption performance of AC, the AC was oxidized with H2O2 or H2SO4. The H2O2- and H2SO4-modified ACs prepared under milder conditions had higher capacities than those prepared under stronger conditions for adsorbing hemicelluloses, lignin, and furfural. Additionally, the modifications increased the adsorption rate of dissolved materials on the AC, especially that of hemicelluloses. Oxidized activated carbon is a promising adsorbent for lignocellulosic materials of the PHL that can be employed in biorefinery processes conducted during the kraft-based dissolved pulp production process DEWEY : 660 ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie201036q [article] Adsorption of lignocelluloses dissolved in prehydrolysis liquor of kraft - based dissolving pulp process on oxidized activated carbons [texte imprimé] / Xin Liu, Auteur ; Pedram Fatehi, Auteur ; Yonghao Ni, Auteur . - 2011 . - pp. 11706–11711. Chimie industrielle Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 50 N° 20 (Octobre 2011) . - pp. 11706–11711 Mots-clés : Adsorption  Lignocelluloses Résumé : The prehydrolysis stage is essential in producing high-purity cellulose from the kraft-based process and is effective in removing hemicelluloses from wood chips. To convert hemicelluloses and other dissolved materials of the prehydrolysis liquor (PHL) into value-added products, they must first be recovered from the PHL. In this work, we investigated the use of activated carbon (AC) to adsorb such materials from the PHL. The adsorption of hemicelluloses on unmodified AC was significantly higher in neutral than acidic environment. To improve the adsorption performance of AC, the AC was oxidized with H2O2 or H2SO4. The H2O2- and H2SO4-modified ACs prepared under milder conditions had higher capacities than those prepared under stronger conditions for adsorbing hemicelluloses, lignin, and furfural. Additionally, the modifications increased the adsorption rate of dissolved materials on the AC, especially that of hemicelluloses. Oxidized activated carbon is a promising adsorbent for lignocellulosic materials of the PHL that can be employed in biorefinery processes conducted during the kraft-based dissolved pulp production process DEWEY : 660 ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie201036q

Effect of pulp fines on the dye−fiber interactions during the color-shading process / Hongbin Liu in Industrial & engineering chemistry research, Vol. 49 N° 18 (Septembre 2010) 

Public ISBD [article]  in Industrial & engineering chemistry research > Vol. 49 N° 18 (Septembre 2010) . - pp. 8544–8549 Titre : Effect of pulp fines on the dye−fiber interactions during the color-shading process Type de document : texte imprimé Auteurs : Hongbin Liu, Auteur ; Shuhui Yang, Auteur ; Yonghao Ni, Auteur Année de publication : 2010 Article en page(s) : pp. 8544–8549 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Paper  properties Résumé : Fines play a very important role in the papermaking process and paper properties. High-yield pulp (HYP) contains a large amount of higher specific surface area fines, which may lead to the absorption of more dye at the wet end section. Better understanding of the dye−fines interaction will help improve the dye efficiency in HYP-containing furnish. This study was focused on the fines from high-yield pulp and hardwood bleached kraft pulp (HBKP) on optical properties, particularly on the CIE (Commission Internationale d’Eclairage) whiteness and b* (negative values indicate blue, and positive values indicate yellow). The characteristics of both HYP fines and HBKP fines were presented, and their effects on dyeing (color-shading) process were investigated. Fines have a higher specific surface area and more dissolved and colloidal substances (DCS) than do the fibers. It was found that for a system made of HYP fibers, HYP fines had a negative effect, while HBKP fines had a positive effect on the color shading process. For a system made of HBKP fibers, a low content (5%) of HYP fines can increase the dye effectiveness, although when the HYP fine content increased further, the dye performance showed a decrease; HBKP fines retarded the dye effectiveness for the HBKP fiber system. For the mixture of HYP fines and HBKP fines, the turbidity measurement was used to explain the interactions between the HYP fines and HBKP fines. The dyes and HYP fines can form complexes, which then retain in the fiber network, thus improving the dye effectiveness and resulting in a higher CIE whiteness and lower b* of the paper sheets. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie101169s [article] Effect of pulp fines on the dye−fiber interactions during the color-shading process [texte imprimé] / Hongbin Liu, Auteur ; Shuhui Yang, Auteur ; Yonghao Ni, Auteur . - 2010 . - pp. 8544–8549. Industrial chemistry Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 49 N° 18 (Septembre 2010) . - pp. 8544–8549 Mots-clés : Paper  properties Résumé : Fines play a very important role in the papermaking process and paper properties. High-yield pulp (HYP) contains a large amount of higher specific surface area fines, which may lead to the absorption of more dye at the wet end section. Better understanding of the dye−fines interaction will help improve the dye efficiency in HYP-containing furnish. This study was focused on the fines from high-yield pulp and hardwood bleached kraft pulp (HBKP) on optical properties, particularly on the CIE (Commission Internationale d’Eclairage) whiteness and b* (negative values indicate blue, and positive values indicate yellow). The characteristics of both HYP fines and HBKP fines were presented, and their effects on dyeing (color-shading) process were investigated. Fines have a higher specific surface area and more dissolved and colloidal substances (DCS) than do the fibers. It was found that for a system made of HYP fibers, HYP fines had a negative effect, while HBKP fines had a positive effect on the color shading process. For a system made of HBKP fibers, a low content (5%) of HYP fines can increase the dye effectiveness, although when the HYP fine content increased further, the dye performance showed a decrease; HBKP fines retarded the dye effectiveness for the HBKP fiber system. For the mixture of HYP fines and HBKP fines, the turbidity measurement was used to explain the interactions between the HYP fines and HBKP fines. The dyes and HYP fines can form complexes, which then retain in the fiber network, thus improving the dye effectiveness and resulting in a higher CIE whiteness and lower b* of the paper sheets. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie101169s

Influence of Soda−Air−AQ Pulping of Straw on Silica Precipitation, Paper Strength, and Performance of CPVA as a Dry Strength Additive / Pedram Fatehi in Industrial & engineering chemistry research, Vol. 48 N° 23 (Décembre 2009) 

Public ISBD [article]  in Industrial & engineering chemistry research > Vol. 48 N° 23 (Décembre 2009) . - pp. 10190–10195 Titre : Influence of Soda−Air−AQ Pulping of Straw on Silica Precipitation, Paper Strength, and Performance of CPVA as a Dry Strength Additive Type de document : texte imprimé Auteurs : Pedram Fatehi, Auteur ; Ahmet Tutus, Auteur ; Yonghao Ni, Auteur Année de publication : 2010 Article en page(s) : pp. 10190–10195 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Influence--Soda−Air−AQ--Pulping--Straw--Silica--Precipitation--Paper  Strength--Performance--CPVA--Strength  Additive Résumé : In this study, the impact of soda−air−anthraquinone (AQ) pulping conditions on delignification and silica precipitation onto pulp fibers and paper sheets was studied. The results showed that the yield and silica precipitation slightly increased upon application of AQ in soda−air pulping. Scanning electron microscopy (SEM) and elemental analysis confirmed the deposition of silica-related particles on fibers and on paper sheets for both soda−air and soda−air−AQ pulping. Furthermore, increasing the cooking temperature had a stronger impact on delignification and silica deposition than did increasing the cooking time for soda−air−AQ pulping. In another set of experiments, the influence of cationic poly(vinyl alcohol) (CPVA) with two different molecular weights on improving the strength properties of straw pulps produced under various soda−air−AQ pulping conditions was studied. The adsorption of CPVA onto straw pulp and its effect on silica retention for paper sheets were comprehensively investigated. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie901273m [article] Influence of Soda−Air−AQ Pulping of Straw on Silica Precipitation, Paper Strength, and Performance of CPVA as a Dry Strength Additive [texte imprimé] / Pedram Fatehi, Auteur ; Ahmet Tutus, Auteur ; Yonghao Ni, Auteur . - 2010 . - pp. 10190–10195. Industrial chemistry Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 48 N° 23 (Décembre 2009) . - pp. 10190–10195 Mots-clés : Influence--Soda−Air−AQ--Pulping--Straw--Silica--Precipitation--Paper  Strength--Performance--CPVA--Strength  Additive Résumé : In this study, the impact of soda−air−anthraquinone (AQ) pulping conditions on delignification and silica precipitation onto pulp fibers and paper sheets was studied. The results showed that the yield and silica precipitation slightly increased upon application of AQ in soda−air pulping. Scanning electron microscopy (SEM) and elemental analysis confirmed the deposition of silica-related particles on fibers and on paper sheets for both soda−air and soda−air−AQ pulping. Furthermore, increasing the cooking temperature had a stronger impact on delignification and silica deposition than did increasing the cooking time for soda−air−AQ pulping. In another set of experiments, the influence of cationic poly(vinyl alcohol) (CPVA) with two different molecular weights on improving the strength properties of straw pulps produced under various soda−air−AQ pulping conditions was studied. The adsorption of CPVA onto straw pulp and its effect on silica retention for paper sheets were comprehensively investigated. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie901273m