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Application of FT-IR-ATR spectroscopy to evaluate the penetration of surface sizing agents into the paper structure / Paulo J. Ferreira in Industrial & engineering chemistry research, Vol. 48 N° 8 (Avril 2009) 

Public ISBD [article]  in Industrial & engineering chemistry research > Vol. 48 N° 8 (Avril 2009) . - pp. 3867–3872 Titre : Application of FT-IR-ATR spectroscopy to evaluate the penetration of surface sizing agents into the paper structure Type de document : texte imprimé Auteurs : Paulo J. Ferreira, Auteur ; José A. Gamelas, Auteur ; Isabel M. Moutinho, Auteur Année de publication : 2009 Article en page(s) : pp. 3867–3872 Note générale : Chemical engineering Langues : Anglais (eng) Mots-clés : Fourier  transform  infrared  spectroscopy  Paper  surface  sizing Résumé : It is widely recognized that the surface properties of paper depend on the fibrous matrix and the final surface treatment applied to the paper. Regarding chemical paper surface treatments, an important issue is the evaluation of the penetration of chemical compounds into the fibrous matrix, as the chemicals can potentially cause changes in the intrinsic properties of paper. The work presented here aimed to use Fourier transform infrared (FT-IR) spectroscopy to study paper surface sizing, namely, the penetration of the sizing chemicals into the paper structure. Two different surface sizing formulations were applied to paper produced from Eucalyptus globulus bleached pulp (reference paper): both contain 90% (w/w) cationic starch, but one contains 10% (w/w) poly(styrene-co-maleic anhydride) whereas the other contains 10% (w/w) poly(styrene-co-butyl acrylate). The surface-sized paper sheets were further manually delaminated, so that the top surfaces as well as the internal layers could be analyzed by FT-IR spectroscopy. A non-surface-sized sample was taken as the reference. From the spectroscopic results, it was possible to detect the presence of the copolymers on the paper top surfaces, despite the application of only small amounts of these chemicals in the surface sizing. However, the chemicals were not found in the layers closest to the surface (30−40 μm from the top), leading to the conclusion that the penetration of the sizing formulations into the fibrous matrix was insignificant (at least up to this distance). Infrared spectroscopy data also showed that the calcium carbonate added as a filler was always present at higher concentration in the analyzed inner layers than at the top surface, for the reference paper as well as the sized papers. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie801765c [article] Application of FT-IR-ATR spectroscopy to evaluate the penetration of surface sizing agents into the paper structure [texte imprimé] / Paulo J. Ferreira, Auteur ; José A. Gamelas, Auteur ; Isabel M. Moutinho, Auteur . - 2009 . - pp. 3867–3872. Chemical engineering Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 48 N° 8 (Avril 2009) . - pp. 3867–3872 Mots-clés : Fourier  transform  infrared  spectroscopy  Paper  surface  sizing Résumé : It is widely recognized that the surface properties of paper depend on the fibrous matrix and the final surface treatment applied to the paper. Regarding chemical paper surface treatments, an important issue is the evaluation of the penetration of chemical compounds into the fibrous matrix, as the chemicals can potentially cause changes in the intrinsic properties of paper. The work presented here aimed to use Fourier transform infrared (FT-IR) spectroscopy to study paper surface sizing, namely, the penetration of the sizing chemicals into the paper structure. Two different surface sizing formulations were applied to paper produced from Eucalyptus globulus bleached pulp (reference paper): both contain 90% (w/w) cationic starch, but one contains 10% (w/w) poly(styrene-co-maleic anhydride) whereas the other contains 10% (w/w) poly(styrene-co-butyl acrylate). The surface-sized paper sheets were further manually delaminated, so that the top surfaces as well as the internal layers could be analyzed by FT-IR spectroscopy. A non-surface-sized sample was taken as the reference. From the spectroscopic results, it was possible to detect the presence of the copolymers on the paper top surfaces, despite the application of only small amounts of these chemicals in the surface sizing. However, the chemicals were not found in the layers closest to the surface (30−40 μm from the top), leading to the conclusion that the penetration of the sizing formulations into the fibrous matrix was insignificant (at least up to this distance). Infrared spectroscopy data also showed that the calcium carbonate added as a filler was always present at higher concentration in the analyzed inner layers than at the top surface, for the reference paper as well as the sized papers. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie801765c

Modeling the turbulent flow of pulp suspensions / Carla A.F. Ventura in Industrial & engineering chemistry research, Vol. 50 N° 16 (Août 2011) 

Public ISBD [article]  in Industrial & engineering chemistry research > Vol. 50 N° 16 (Août 2011) . - pp. 9735-9742 Titre : Modeling the turbulent flow of pulp suspensions Type de document : texte imprimé Auteurs : Carla A.F. Ventura, Auteur ; Fernando A.P. Garcia, Auteur ; Paulo J. Ferreira, Auteur Année de publication : 2011 Article en page(s) : pp. 9735-9742 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Turbulent  flow  Modeling Résumé : Pulp fiber suspensions are complex systems because the components present singular and complex interactions between them. A mechanistic model for the turbulent flow regime of industrial pulp suspensions was developed on the basis of a CFD code, using the chemical engineering module of COMSOL Multiphysics software. The standard k-ε turbulence model, chosen to simulate turbulence, was tested and validated using four different industrial pulp suspensions previously characterized experimentally. The modeled pressure drop profiles agree very well with the experimental results obtained in a pilot rig. Therefore, the k-ε turbulence model for the simulation of pulp fiber suspension flows, associated with experimental rheological data, proved to be a prompt strategy to attain good prediction of pressure drop for fiber suspension flows. Moreover, the adjustment of the turbulence parameters confirmed previous studies, where it was concluded that the existence of particles, such as fibers, in a fluid flow induces a turbulence damping. DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=24425218 [article] Modeling the turbulent flow of pulp suspensions [texte imprimé] / Carla A.F. Ventura, Auteur ; Fernando A.P. Garcia, Auteur ; Paulo J. Ferreira, Auteur . - 2011 . - pp. 9735-9742. Chimie industrielle Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 50 N° 16 (Août 2011) . - pp. 9735-9742 Mots-clés : Turbulent  flow  Modeling Résumé : Pulp fiber suspensions are complex systems because the components present singular and complex interactions between them. A mechanistic model for the turbulent flow regime of industrial pulp suspensions was developed on the basis of a CFD code, using the chemical engineering module of COMSOL Multiphysics software. The standard k-ε turbulence model, chosen to simulate turbulence, was tested and validated using four different industrial pulp suspensions previously characterized experimentally. The modeled pressure drop profiles agree very well with the experimental results obtained in a pilot rig. Therefore, the k-ε turbulence model for the simulation of pulp fiber suspension flows, associated with experimental rheological data, proved to be a prompt strategy to attain good prediction of pressure drop for fiber suspension flows. Moreover, the adjustment of the turbulence parameters confirmed previous studies, where it was concluded that the existence of particles, such as fibers, in a fluid flow induces a turbulence damping. DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=24425218