Ponències/Comunicacions de congressos
http://hdl.handle.net/2117/3169
2024-03-28T18:47:28ZA new approach to the internal sizing of paper via biotechnological processes
http://hdl.handle.net/2117/19033
A new approach to the internal sizing of paper via biotechnological processes
García Ubasart, Jordi; Roncero Vivero, María Blanca; Vidal Lluciá, Teresa
This work deals with the study of a new biotechnological procedure, employing laccase in combination with hydrophobic compounds, for the biomodification of fibres and the internal sizing of paper. Cellulose fibres from eucalyptus kraft pulp, unbleached and TCF bleached, were incubated with laccase, in combination with a series of hydrophobes. Laccase treatments of cellulose fibres with lauryl gallate conferred the lowest level of water penetration in handsheets. It was observed that the hydrophobization of paper was not possible using the hidrophobe alone. The coupling of lauryl gallate onto cellulose fibres was firstly denoted by kappa number analysis, and further demonstrated by IR spectroscopy. The internal sizing of paper proved to be effective regardless the lignin content of eucalyptus fibres
2013-04-29T12:35:29ZGarcía Ubasart, JordiRoncero Vivero, María BlancaVidal Lluciá, TeresaThis work deals with the study of a new biotechnological procedure, employing laccase in combination with hydrophobic compounds, for the biomodification of fibres and the internal sizing of paper. Cellulose fibres from eucalyptus kraft pulp, unbleached and TCF bleached, were incubated with laccase, in combination with a series of hydrophobes. Laccase treatments of cellulose fibres with lauryl gallate conferred the lowest level of water penetration in handsheets. It was observed that the hydrophobization of paper was not possible using the hidrophobe alone. The coupling of lauryl gallate onto cellulose fibres was firstly denoted by kappa number analysis, and further demonstrated by IR spectroscopy. The internal sizing of paper proved to be effective regardless the lignin content of eucalyptus fibresEffect of the laccase mediator system on the fibre properties of TCF bleached kraft pulp
http://hdl.handle.net/2117/18998
Effect of the laccase mediator system on the fibre properties of TCF bleached kraft pulp
Cadena Chamorro, Edith Marleny; Cusola Aumedes, Oriol; Vidal Lluciá, Teresa; Torres López, Antonio Luis
The application of the laccase mediator system (L stage) to TCF bleached pulp from Eucalyptus globulus with a low residual lignin content provides useful information about its effect in the hexenuronic acids content, functional groups (carboxyl and carbonyl) and electrokinetic properties as ζ potential and surface charge. The use of laccase from Trametes villosa in combination with the mediator 1- hydroxybenzotriazole (HBT) produces an oxidation of the cellulose to carbonyl groups, and reduced the amount of carboxyl groups present in TCF pulp through partial removal of hexenuronic acids from it. This result can open up new prospects for increasing brightness stability. Additionally, the laccase mediator system modifies the surface charge and ζ potential of the fibre suspension for the removal de ionizables groups in TCF pulp. The reduction of the carboxyl content additionally alters the charge on fibre surfaces; this may be useful with a view to reducing pulp processing costs since a decreased content in ionizable groups can be expected to reduce consumption of cationic additives used in the production of paper. As regards electrokinetic properties, the laccase mediator system reduces the ζ potential of fibre suspensions by acting on carboxylic and hexenuronic acids. The biomodification of the chemical composition of TCF pulp by the laccase mediator system causes no substantial changes in the properties of the refined pulp (ºSR, %WRV); this indicates that the L treatment does not affect development of the primary effects of refining, and also that it may have a side effect on the fibre-water system by decreasing the proportion of ionizable groups and altering the electrokinetic properties of the pulp
2013-04-26T09:16:28ZCadena Chamorro, Edith MarlenyCusola Aumedes, OriolVidal Lluciá, TeresaTorres López, Antonio LuisThe application of the laccase mediator system (L stage) to TCF bleached pulp from Eucalyptus globulus with a low residual lignin content provides useful information about its effect in the hexenuronic acids content, functional groups (carboxyl and carbonyl) and electrokinetic properties as ζ potential and surface charge. The use of laccase from Trametes villosa in combination with the mediator 1- hydroxybenzotriazole (HBT) produces an oxidation of the cellulose to carbonyl groups, and reduced the amount of carboxyl groups present in TCF pulp through partial removal of hexenuronic acids from it. This result can open up new prospects for increasing brightness stability. Additionally, the laccase mediator system modifies the surface charge and ζ potential of the fibre suspension for the removal de ionizables groups in TCF pulp. The reduction of the carboxyl content additionally alters the charge on fibre surfaces; this may be useful with a view to reducing pulp processing costs since a decreased content in ionizable groups can be expected to reduce consumption of cationic additives used in the production of paper. As regards electrokinetic properties, the laccase mediator system reduces the ζ potential of fibre suspensions by acting on carboxylic and hexenuronic acids. The biomodification of the chemical composition of TCF pulp by the laccase mediator system causes no substantial changes in the properties of the refined pulp (ºSR, %WRV); this indicates that the L treatment does not affect development of the primary effects of refining, and also that it may have a side effect on the fibre-water system by decreasing the proportion of ionizable groups and altering the electrokinetic properties of the pulpBleached dissolving pulps applying laccase treatments
http://hdl.handle.net/2117/17489
Bleached dissolving pulps applying laccase treatments
Quintana, Elisabet; Valls Vidal, Cristina; Roncero Vivero, María Blanca
A biobleaching sequence, using a laccase enzyme (Trametes Villosa) in combination with different mediators, was applied to softwood dissolving cellulose in order to study its bleaching efficiency and its potential in terms of kappa number, ISO brightness and viscosity. The tested mediators were classified as synthetic compounds such as HBT (1-hydroxybenzotriazole) and VA (violuric acid), and as natural compounds such as SA (syringaldehyde) and pCA (p-coumaric acid). The influence of the enzymatic stage in the bleaching sequence was compared with a control treatment and also with a conventional alkaline hydrogen peroxide stage. The contribution of L (laccasemediator) stage on the effluent properties is important for evaluating and minimizing its environmental impact. Therefore, effluent properties (COD, colour, residual enzyme activity and toxicity) were determined. Laccase-VA system showed the most promising results in reducing kappa number and increasing brightness without detriment to viscosity
2013-01-23T10:51:06ZQuintana, ElisabetValls Vidal, CristinaRoncero Vivero, María BlancaA biobleaching sequence, using a laccase enzyme (Trametes Villosa) in combination with different mediators, was applied to softwood dissolving cellulose in order to study its bleaching efficiency and its potential in terms of kappa number, ISO brightness and viscosity. The tested mediators were classified as synthetic compounds such as HBT (1-hydroxybenzotriazole) and VA (violuric acid), and as natural compounds such as SA (syringaldehyde) and pCA (p-coumaric acid). The influence of the enzymatic stage in the bleaching sequence was compared with a control treatment and also with a conventional alkaline hydrogen peroxide stage. The contribution of L (laccasemediator) stage on the effluent properties is important for evaluating and minimizing its environmental impact. Therefore, effluent properties (COD, colour, residual enzyme activity and toxicity) were determined. Laccase-VA system showed the most promising results in reducing kappa number and increasing brightness without detriment to viscosityLaccase-TEMPO oxidation of sisal pulp for improving paper strength properties: influence of the operating conditions
http://hdl.handle.net/2117/17345
Laccase-TEMPO oxidation of sisal pulp for improving paper strength properties: influence of the operating conditions
Aracri, Elisabetta; Valls Vidal, Cristina; Vidal Lluciá, Teresa
The oxidation of a low lignin content sisal pulp by laccase-TEMPO system has been investigated and evaluated as potential approach for improving the paper strength properties. TEMPO mediated oxidation was found to cause the formation of aldehyde and carboxyl groups in proportions dependent on the particular reaction conditons. The treatment was performed in acetate buffer pH 5 at room temperature and the influence of process variables (viz laccase dose, TEMPO dose and reaction time)on the properties of the pulp and the resulting handsheets was assessed by using a three-variable sequential statistical plan. The increase of aldehyde groups was found to be closely aligned with enhanced wet strength which was ascribed to the formation of inter-fibre convalent bonding through hemiacetal linkages
2013-01-14T14:38:05ZAracri, ElisabettaValls Vidal, CristinaVidal Lluciá, TeresaThe oxidation of a low lignin content sisal pulp by laccase-TEMPO system has been investigated and evaluated as potential approach for improving the paper strength properties. TEMPO mediated oxidation was found to cause the formation of aldehyde and carboxyl groups in proportions dependent on the particular reaction conditons. The treatment was performed in acetate buffer pH 5 at room temperature and the influence of process variables (viz laccase dose, TEMPO dose and reaction time)on the properties of the pulp and the resulting handsheets was assessed by using a three-variable sequential statistical plan. The increase of aldehyde groups was found to be closely aligned with enhanced wet strength which was ascribed to the formation of inter-fibre convalent bonding through hemiacetal linkagesNanofibrillated cellulose as reinforcement for high performance cement mortar composites
http://hdl.handle.net/2117/16480
Nanofibrillated cellulose as reinforcement for high performance cement mortar composites
Ardanuy Raso, Mònica; Claramunt Blanes, Josep; Parés Sabatés, Ferran; Aracri, Elisabetta; Vidal Lluciá, Teresa
In this work, the preparation and characterization of new cement mortars reinforced with nanofibrillated cellulose fibres has been carried out. The effect of the fibre fibrillation degree on the mechanical performance of the obtained composites is presented and analyzed, taking into account the reinforcement final size depending on the intensity of the mechanical treatment applied. On the one hand, conventional pulps have been obtained by subjecting sisal fibres to a soft mechanical treatment and, on the other hand, nanofibrillated cellulose pulps have been prepared by the application of a high intensity refining process. These pulps were incorporated and homogenously dispersed in cement mortars, and subsequently, the resulting pastes were cured for 28 days. The mechanical performance of the different composites was determined by flexure tests
2012-09-13T09:11:54ZArdanuy Raso, MònicaClaramunt Blanes, JosepParés Sabatés, FerranAracri, ElisabettaVidal Lluciá, TeresaIn this work, the preparation and characterization of new cement mortars reinforced with nanofibrillated cellulose fibres has been carried out. The effect of the fibre fibrillation degree on the mechanical performance of the obtained composites is presented and analyzed, taking into account the reinforcement final size depending on the intensity of the mechanical treatment applied. On the one hand, conventional pulps have been obtained by subjecting sisal fibres to a soft mechanical treatment and, on the other hand, nanofibrillated cellulose pulps have been prepared by the application of a high intensity refining process. These pulps were incorporated and homogenously dispersed in cement mortars, and subsequently, the resulting pastes were cured for 28 days. The mechanical performance of the different composites was determined by flexure testsPaper functionalization by means of enzymatic surface treatments using hydrophobic compounds and lignosulfonates
http://hdl.handle.net/2117/16451
Paper functionalization by means of enzymatic surface treatments using hydrophobic compounds and lignosulfonates
Cusola Aumedes, Oriol; García Ubasart, Jordi; Valls Vidal, Cristina; Vidal Lluciá, Teresa; Roncero Vivero, María Blanca
In the present work an innovative method for achieving enzymatic surface functionalization on finished paper sheets is presented. A commercial filter paper was surface sized with laccase derived from Trametes Villosa, Lauryl Gallate (LG) as hydrophobic compound, and soluble lignin. Moreover, this study shows the positive influence of sulfonated lignin (SL) acting as a dispersant improving the surface distribution of the LG along the paper sheet. The hydrophobic behavior of obtained sheets is comparable to the commercial ones. Hydrophobicity was measured by the water absorption test, and the variation in the contact angle through time was monitorized by a contact angle goniometer. Hydrophobized paper absorption was compared with Teflon® in order to determine the evaporated and absorbed water amounts from the paper surface. The treatment time, was also studied
2012-09-07T10:20:41ZCusola Aumedes, OriolGarcía Ubasart, JordiValls Vidal, CristinaVidal Lluciá, TeresaRoncero Vivero, María BlancaIn the present work an innovative method for achieving enzymatic surface functionalization on finished paper sheets is presented. A commercial filter paper was surface sized with laccase derived from Trametes Villosa, Lauryl Gallate (LG) as hydrophobic compound, and soluble lignin. Moreover, this study shows the positive influence of sulfonated lignin (SL) acting as a dispersant improving the surface distribution of the LG along the paper sheet. The hydrophobic behavior of obtained sheets is comparable to the commercial ones. Hydrophobicity was measured by the water absorption test, and the variation in the contact angle through time was monitorized by a contact angle goniometer. Hydrophobized paper absorption was compared with Teflon® in order to determine the evaporated and absorbed water amounts from the paper surface. The treatment time, was also studiedStudy of the effects on bast and core flax fibres of laccase + mediator/phenol treatments
http://hdl.handle.net/2117/15301
Study of the effects on bast and core flax fibres of laccase + mediator/phenol treatments
Fillat Latorre, Amanda; Roncero Vivero, María Blanca; Vidal Lluciá, Teresa
2012-02-22T10:48:58ZFillat Latorre, AmandaRoncero Vivero, María BlancaVidal Lluciá, TeresaUsing biotechnology for paper functionalisation: flax fibers with antimicrobial properties
http://hdl.handle.net/2117/15298
Using biotechnology for paper functionalisation: flax fibers with antimicrobial properties
Fillat Latorre, Amanda; Gallardo Román, Óscar; Vidal Lluciá, Teresa; Pastor Blasco, Francisco I. Javier; Díaz, Pilar; Roncero Vivero, María Blanca
Unbleached flax fibres were treated with laccase from Pycnoporus cinnabarinus and low molecular weight phenols (syringaldehyde –SA, acetosyringone –AS- and p-coumaric acid –PCA-) to biomodify lignocellulosic fibres in order to confer them antibacterial properties. After the enzymatic treatment, PCA, SA and AS produced an increase in kappa number (lignin estimation), which is due to a partial covalent binding of the phenoxy radicals on pulp. To take advantage of the tendency of these natural phenols to couple to fibres, a standard method to determine bacterial growing inhibition was carried out. Antimicrobial properties of the pulps were tested on S. aureus, P. aeruginosa and K. pneumonia. Treated pulps produced a greater reduction in viable organisms than the laccase control after the same contact time, in some cases nearly total organism elimination was seen. Optical properties of treated papers were also measured in order to evaluate the possible coloration obtained. These results suggest that these low molecular weight phenols are covalently bounded to the flax fibres by the laccase and can act as antimicrobial agents.
2012-02-22T09:40:28ZFillat Latorre, AmandaGallardo Román, ÓscarVidal Lluciá, TeresaPastor Blasco, Francisco I. JavierDíaz, PilarRoncero Vivero, María BlancaUnbleached flax fibres were treated with laccase from Pycnoporus cinnabarinus and low molecular weight phenols (syringaldehyde –SA, acetosyringone –AS- and p-coumaric acid –PCA-) to biomodify lignocellulosic fibres in order to confer them antibacterial properties. After the enzymatic treatment, PCA, SA and AS produced an increase in kappa number (lignin estimation), which is due to a partial covalent binding of the phenoxy radicals on pulp. To take advantage of the tendency of these natural phenols to couple to fibres, a standard method to determine bacterial growing inhibition was carried out. Antimicrobial properties of the pulps were tested on S. aureus, P. aeruginosa and K. pneumonia. Treated pulps produced a greater reduction in viable organisms than the laccase control after the same contact time, in some cases nearly total organism elimination was seen. Optical properties of treated papers were also measured in order to evaluate the possible coloration obtained. These results suggest that these low molecular weight phenols are covalently bounded to the flax fibres by the laccase and can act as antimicrobial agents.Enzymatic treatments of paper surface using laccase, hydrophobic compounds and lignin
http://hdl.handle.net/2117/13311
Enzymatic treatments of paper surface using laccase, hydrophobic compounds and lignin
Cusola Aumedes, Oriol; Roncero Vivero, María Blanca; García Ubasart, Jordi; Valls Vidal, Cristina
This study demonstrates the potential of applying surface enzymatic treatments on finished paper sheets to improve their physical characteristics. Research studies have recently reported that is possible to internally size paper using enzymatic treatments, applied in mass. In the present work an innovative method for achieving enzymatic surface sizing on finished paper sheets is presented. A commercial filter paper and handmade eucalyptus sheets were surface sized with laccase derived from Trametes Villosa, Lauryl Gallate (LG) as hydrophobic compound, and soluble lignin. Moreover, this study shows the positive influence of sulfonated lignin since it acts as a dispersant, improving the homogeneous distribution of the LG along the paper sheet.
2011-09-23T09:30:55ZCusola Aumedes, OriolRoncero Vivero, María BlancaGarcía Ubasart, JordiValls Vidal, CristinaThis study demonstrates the potential of applying surface enzymatic treatments on finished paper sheets to improve their physical characteristics. Research studies have recently reported that is possible to internally size paper using enzymatic treatments, applied in mass. In the present work an innovative method for achieving enzymatic surface sizing on finished paper sheets is presented. A commercial filter paper and handmade eucalyptus sheets were surface sized with laccase derived from Trametes Villosa, Lauryl Gallate (LG) as hydrophobic compound, and soluble lignin. Moreover, this study shows the positive influence of sulfonated lignin since it acts as a dispersant, improving the homogeneous distribution of the LG along the paper sheet.Efecto del grado de fibrilación sobre las propiedades mecánicas de morteros de cemento reforzados con fibras vegetales
http://hdl.handle.net/2117/13022
Efecto del grado de fibrilación sobre las propiedades mecánicas de morteros de cemento reforzados con fibras vegetales
Ardanuy Raso, Mònica; Claramunt Blanes, Josep; Arévalo Peces, Raquel; García Hortal, José Antonio
En este trabajo se han llevado a cabo la preparación y caracterización de nuevos compuestos a base de morteros de cemento reforzados con fibras celulósicas nanofibriladas. El efecto del grado de fibrilación de las fibras sobre las propiedades mecánicas de los composites resultantes se presenta y analiza en base al tamaño final del refuerzo obtenido según la intensidad del tratamiento mecánico aplicado. Para ello se ha partido de fibras de sisal que han sido sometidas a un pulpeado mecánico suave para obtener las pulpas convencionales y a un pulpeado mecánico muy intenso para obtener celulosa nanofibrilada. Las pastas obtenidas han sido incorporadas y dispersadas homogéneamente en morteros de cemento, para posteriormente curar los compuestos durante 28 días. Finalmente se han determinado las propiedades mecánicas de los compuestos con ensayos de flexión. Los resultados indican como las fibras con un alto grado de fibrilación conducen a compuestos con un mayor módulo y resistencia comparados con los obtenidos con las fibras que únicamente han sido sometidas a un pulpeado mecánico suave.
2011-07-21T07:54:14ZArdanuy Raso, MònicaClaramunt Blanes, JosepArévalo Peces, RaquelGarcía Hortal, José AntonioEn este trabajo se han llevado a cabo la preparación y caracterización de nuevos compuestos a base de morteros de cemento reforzados con fibras celulósicas nanofibriladas. El efecto del grado de fibrilación de las fibras sobre las propiedades mecánicas de los composites resultantes se presenta y analiza en base al tamaño final del refuerzo obtenido según la intensidad del tratamiento mecánico aplicado. Para ello se ha partido de fibras de sisal que han sido sometidas a un pulpeado mecánico suave para obtener las pulpas convencionales y a un pulpeado mecánico muy intenso para obtener celulosa nanofibrilada. Las pastas obtenidas han sido incorporadas y dispersadas homogéneamente en morteros de cemento, para posteriormente curar los compuestos durante 28 días. Finalmente se han determinado las propiedades mecánicas de los compuestos con ensayos de flexión. Los resultados indican como las fibras con un alto grado de fibrilación conducen a compuestos con un mayor módulo y resistencia comparados con los obtenidos con las fibras que únicamente han sido sometidas a un pulpeado mecánico suave.