Angeles Blanco | Universidad Complutense de Madrid (original) (raw)
Papers by Angeles Blanco
Nanomaterials
To extend the application of cost-effective high-yield pulps in packaging, strength and barrier p... more To extend the application of cost-effective high-yield pulps in packaging, strength and barrier properties are improved by advanced-strength additives or by hot-pressing. The aim of this study is to assess the synergic effects between the two approaches by using nanocellulose as a bulk additive, and by hot-pressing technology. Due to the synergic effect, dry strength increases by 118% while individual improvements are 31% by nanocellulose and 92% by hot-pressing. This effect is higher for mechanical fibrillated cellulose. After hot-pressing, all papers retain more than 22% of their dry strength. Hot-pressing greatly increases the paper’s ability to withstand compressive forces applied in short periods of time by 84%, with a further 30% increase due to the synergic effect of the fibrillated nanocellulose. Hot-pressing and the fibrillated cellulose greatly decrease air permeability (80% and 68%, respectively) for refining pretreated samples, due to the increased fiber flexibility, whi...
Academia engineering, Mar 4, 2024
Tecnología Química, 2008
Cellulose, May 24, 2022
However, the ANN model, involving 4 inputs and 4 hidden neurons and calibrated on the basis of pi... more However, the ANN model, involving 4 inputs and 4 hidden neurons and calibrated on the basis of pine dataset, was accurate and robust enough to predict the aspect ratio of micro/nanofiber materials obtained from other cellulose sources including very different softwood and hardwood species such as Spruce, Eucalyptus and Aspen (R = 0.84). The neural network model was able to capture the nonlinearities involved in the data providing insight about the profile of the aspect ratio achieved with further homogenization during the fibrillation process.
Fermentation
Succinic acid (SA) is one of the main identified biomass-derived chemical building blocks. In thi... more Succinic acid (SA) is one of the main identified biomass-derived chemical building blocks. In this work we approach the study of its production by Actinobacillus succinogenes DSM 22257 from glucose, focusing on the development and application of a simple kinetic model capable of representing the evolution of the process over time for a great diversity of process variables key to the production of this platform bio-based chemical: initial biomass concentration, yeast extract concentration, agitation speed, and carbon dioxide flow rate. All these variables were studied experimentally, determining the values of key fermentation parameters: titer (23.8–39.7 g·L−1), yield (0.59–0.72 gSA·gglu−1), productivity (0.48–0.96 gSA·L−1·h−1), and selectivity (0.61–0.69 gSA·gglu−1). Even with this wide diversity of operational conditions, a non-structured and non-segregated kinetic model was suitable for fitting to experimental data with high accuracy, considering the values of the goodness-of-fit ...
Nanomaterials, Dec 19, 2022
Algal Research, 2017
Flocculation followed by settling is gaining momentum as a means to concentrate microalgal biomas... more Flocculation followed by settling is gaining momentum as a means to concentrate microalgal biomass due to the low investment and operation costs of the process. Microalgal flocculation can be further optimized by knowing the relationship between the hydrodynamic conditions applied in the process and the geometric properties of the flocs, namely characteristic size and fractal dimension, D f , given that settling rate is highly dependent on these two parameters. Current methods to characterize the geometry of flocs rely on estimating the 2D fractal dimension from microscopic images, which may result in inaccuracies caused by the overlapping or superimposition of aggregate structures prompted when the image of a 3D object is projected a on the plane, and due to the fact that the estimation performed is dependent on the orientation of the particle during image acquisition. The present paper describes a new procedure to estimate D f of Chlorella sorokiniana aggregates by correlating the 2D fractal dimension of the real aggregates microscopic images with the 2D fractal dimensions of computer generated flocs of prescribed 3D geometry. This procedure avoids the inaccuracies entailed with floc imaging and those due to the random orientation of the floc during image acquisition.
Pulp & paper Canada, 2000
... Titre du document / Document title. New system to predict deposits due to DCM destabilization... more ... Titre du document / Document title. New system to predict deposits due to DCM destabilization in paper mills. Auteur(s) / Author(s). BLANCO A. ; NEGRO C. ; MONTE M. Concepcion ; OTERO D. ; TIJERO J. ; Résumé / Abstract. ... Faire une nouvelle recherche Make a new search.
Antioxidants, 2020
Background: Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is causing profound heal... more Background: Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is causing profound health, economic, and social problems worldwide. Management of personal protective equipment (PPE) and its potential limited availability have created concerns about the increased risks for healthcare professionals at hospitals and nursing homes. Ozone is a powerful oxidant agent. The objectives of this study were to examine the effects of ozone treatment on PPE contaminated with SARS-CoV-2, and to explore whether relative humidity could modify those effects. Methods: PPE contaminated by heat-inactivated SARS-CoV-2 were treated with different ozone concentrations, exposure times, and relative humidity conditions. SARS-CoV-2 gene amplification was assessed by real-time polymerase chain reaction. Results: There was no amplification of SARS-CoV-2 in PPE after the following ozone exposures: 30 s at 10,000 ppm (20 g/m3), 5 min at 4000 ppm, and 10 min at 2000 ppm. At lower ozone concentrations, 4–...
Academia Engineering, Mar 4, 2024
Academia Engineering was launched in 2023 as an open access journal with the aim of contribution ... more Academia Engineering was launched in 2023 as an open access journal with the aim of contribution to the acceleration and advancement of engineering research. It is focused on sharing, inclusivity, and quality, following FAIR practices.As the Editor-in-Chief, I am honored to help a team of professionals dedicated to upholding the highest editorial standards and ensuring the continued relevance of the journal. Today, I am pleased to present the redefined journal scope, which emphasizes the importance of multidisciplinarity and interdisciplinarity as approaches for solving current global challenges, providing sustainable solutions, and improving overall societal well-being.
July 2007
Rheological properties of pulp suspensions play a very important role in the industry, mainly due... more Rheological properties of pulp suspensions play a very important role in the industry, mainly due to the consumption of energy for transporting pulp among the different parts of the paper mill. In this work, we determined the rheology of long- and short-fiber bleached kraft pulp suspensions by using a new rotational viscometer especially designed for their analysis. The experimental rheograms were adjusted to the Herschel-Bulkley model. We established the dependence of the rheological parameters on temperature, fiber length, and pulp consistency, to evaluate the relative influence of these factors and the corresponding interactions in the rheological parameters. In addition, we defined a mathematical model that enables the estimation of rheological parameters as a function of the different input factors. We validated this model with some preliminary experimental data.
Journal of Industrial Microbiology & Biotechnology, Jan 18, 2006
In this study, polysaccharide-producing bacteria were isolated from slimes collected from two Fin... more In this study, polysaccharide-producing bacteria were isolated from slimes collected from two Finnish and one Spanish paper mill and the exopolysaccharides (EPSs) produced by 18 isolates were characterised. Most of the isolates, selected on the bases of slimy colony morphology, were members of the family Enterobacteriaceae most frequently belonging to the genera Enterobacter and Klebsiella including Raoultella. All of the EPSs analysed showed the presence of charged groups in the form of uronic acid or pyruvate revealing the polyanionic nature of these polysaccharides. Further results of the carbohydrate analysis showed that the EPS produced by nine of the enterobacteria was colanic acid.
Cellulose Chemistry and Technology, 2005
An electrochemical treatment can be applied to remove lignin from the weak black liquor (WBL) fro... more An electrochemical treatment can be applied to remove lignin from the weak black liquor (WBL) from pulping plants, concomitantly with sodium salts' convertion into caustic soda, that can be reused in the pulping process or in other sequences, depending on the required. concentration. The electrolytic processing of kraft weak black liquor from a pulp mill, using straw as raw material, was studied at laboratory scale in a batch mode. The main problem found was anode's. high fouling, which was solved by using platinum wire anodes in combination with high current density through the anode and turbulent flow of the WBL in the anode compartment. To avoid anode's fouling, the velocity of the WBL in the cell was critical, while current density and temperature optimization were critical for the economical viability of the process.
International Journal of Biological Macromolecules, Sep 1, 2023
International Journal of Biological Macromolecules, Apr 1, 2022
Current knowledge on the properties of different types of cellulose nanofibers (CNFs) is fragment... more Current knowledge on the properties of different types of cellulose nanofibers (CNFs) is fragmented. Properties variation is very extensive, depending on raw materials, effectiveness of the treatments to extract the cellulose fraction from the lignocellulosic biomass, pretreatments to facilitate cellulose fibrillation and final mechanical process to separate the microfibrils. Literature offers multiple parameters to characterize the CNFs prepared by different routes. However, there is a lack of an extensive guide to compare the CNFs. In this study, we perform a critical comparison of rheological, compositional, and morphological features of CNFs, produced from the most representative types of woody plants, hardwood and softwood, using different types and intensities of pretreatments, including enzymatic, chemical and mechanical ones, and varying the severity of mechanical treatment focusing on the relationship between macroscopic and microscopic parameters. This structured information will be exceedingly useful to select the most appropriate CNF for a certain application based on the most relevant parameters in each case.
Latin American Applied Research, Mar 29, 2020
−− Nanocellulose (NC) and its wide applications have attracted high attention due to its desirabl... more −− Nanocellulose (NC) and its wide applications have attracted high attention due to its desirable properties such as high surface area, extraordinary mechanical properties, high reactivity and easy modification of NC surface due to the presence of primary hydroxyl groups. NC also presents several environmental benefits, including high potential availability because its production is coming from natural sources, renewability and nontoxicity. This paper briefly summarizes some of the activities of the research group "Cellulose, Paper and Water Advanced Treatments" from Complutense University of Madrid that were presented in CAIQ 2019, including the main types of NC, the production processes and their characterization. Additionally, the most promising NC applications are described such as for paper and board, for wastewater treatment, food and cement-based materials. Moreover, a market perspective of NC is also presented.
1st International Conference on Environmental, Industrial and Applied Microbiology, BioMicroWorld 2005, 2005
Applied Catalysis B: Environmental, 2019
This paper shows that incorporation of Cu inhibits the anatase to rutile phase transition at temp... more This paper shows that incorporation of Cu inhibits the anatase to rutile phase transition at temperatures above 500°C. The control sample, with 0% Cu contained 34.3% anatase at 600°C and transitioned to 100% rutile by 650°C. All copper doped samples maintained 100% anatase up to 600°C. With 2% Cu doping, anatase fully transformed to rutile at 650°C, at higher Cu contents of 4% & 8% mixed phased samples, with 27.3% anatase and 74.3% anatase respectively, are present at 650°C. All samples had fully transformed to rutile by 700°C. 0%, 4% and 8% Cu were evaluated for photocatalytic degradation of 1, 4 dioxane. Without any catalyst, 15.8% of the 1,4 dioxane degraded upon irradiation with light for 4 h. Cu doped TiO 2 shows poor photocatalytic degradation ability compared to the control samples. Density functional theory (DFT) studies of Cu-doped rutile and anatase show formation of charge compensating oxygen vacancies and a Cu 2+ oxidation state. Reduction of Cu 2+ to Cu + and Ti 4+ to Ti 3+ was detected by XPS after being calcined to 650-700°C. This reduction was also shown in DFT studies. Cu 3d states are present in the valence to conduction band energy gap upon doping. We suggest that the poor photocatalytic activity of Cu-doped TiO 2 , despite the high anatase content, arises from the charge recombination at defect sites that result from incorporation of copper into TiO 2 .
International journal of biological macromolecules, Jan 20, 2017
In the present work, lignocellulosic micro/nanofibers (LCMNF) were produced from pine sawdust. Fo... more In the present work, lignocellulosic micro/nanofibers (LCMNF) were produced from pine sawdust. For that, pine sawdust was submitted to alkali treatment and subsequent bleaching stages, tailoring its chemical composition with the purpose of obtaining effective LCMNF. The obtained LCMNF were characterized and incorporated to recycled cardboard boxes with the purpose of producing recycled paper. The obtained results showed that it was possible to obtain LCMNF with the same reinforcing potential than those cellulose nanofibers (CNF) prepared by oxidative or other chemical methods In fact, the obtained papers increased the breaking length of recycled cardboard from 3338m to 5347m, being a value significantly higher than the requirements to produce paper bags. Overall, the studied strategies could allow a significant reduction of paper basis weight, with the consequent material saving and, thus, contribution to the environment.
Nanomaterials
To extend the application of cost-effective high-yield pulps in packaging, strength and barrier p... more To extend the application of cost-effective high-yield pulps in packaging, strength and barrier properties are improved by advanced-strength additives or by hot-pressing. The aim of this study is to assess the synergic effects between the two approaches by using nanocellulose as a bulk additive, and by hot-pressing technology. Due to the synergic effect, dry strength increases by 118% while individual improvements are 31% by nanocellulose and 92% by hot-pressing. This effect is higher for mechanical fibrillated cellulose. After hot-pressing, all papers retain more than 22% of their dry strength. Hot-pressing greatly increases the paper’s ability to withstand compressive forces applied in short periods of time by 84%, with a further 30% increase due to the synergic effect of the fibrillated nanocellulose. Hot-pressing and the fibrillated cellulose greatly decrease air permeability (80% and 68%, respectively) for refining pretreated samples, due to the increased fiber flexibility, whi...
Academia engineering, Mar 4, 2024
Tecnología Química, 2008
Cellulose, May 24, 2022
However, the ANN model, involving 4 inputs and 4 hidden neurons and calibrated on the basis of pi... more However, the ANN model, involving 4 inputs and 4 hidden neurons and calibrated on the basis of pine dataset, was accurate and robust enough to predict the aspect ratio of micro/nanofiber materials obtained from other cellulose sources including very different softwood and hardwood species such as Spruce, Eucalyptus and Aspen (R = 0.84). The neural network model was able to capture the nonlinearities involved in the data providing insight about the profile of the aspect ratio achieved with further homogenization during the fibrillation process.
Fermentation
Succinic acid (SA) is one of the main identified biomass-derived chemical building blocks. In thi... more Succinic acid (SA) is one of the main identified biomass-derived chemical building blocks. In this work we approach the study of its production by Actinobacillus succinogenes DSM 22257 from glucose, focusing on the development and application of a simple kinetic model capable of representing the evolution of the process over time for a great diversity of process variables key to the production of this platform bio-based chemical: initial biomass concentration, yeast extract concentration, agitation speed, and carbon dioxide flow rate. All these variables were studied experimentally, determining the values of key fermentation parameters: titer (23.8–39.7 g·L−1), yield (0.59–0.72 gSA·gglu−1), productivity (0.48–0.96 gSA·L−1·h−1), and selectivity (0.61–0.69 gSA·gglu−1). Even with this wide diversity of operational conditions, a non-structured and non-segregated kinetic model was suitable for fitting to experimental data with high accuracy, considering the values of the goodness-of-fit ...
Nanomaterials, Dec 19, 2022
Algal Research, 2017
Flocculation followed by settling is gaining momentum as a means to concentrate microalgal biomas... more Flocculation followed by settling is gaining momentum as a means to concentrate microalgal biomass due to the low investment and operation costs of the process. Microalgal flocculation can be further optimized by knowing the relationship between the hydrodynamic conditions applied in the process and the geometric properties of the flocs, namely characteristic size and fractal dimension, D f , given that settling rate is highly dependent on these two parameters. Current methods to characterize the geometry of flocs rely on estimating the 2D fractal dimension from microscopic images, which may result in inaccuracies caused by the overlapping or superimposition of aggregate structures prompted when the image of a 3D object is projected a on the plane, and due to the fact that the estimation performed is dependent on the orientation of the particle during image acquisition. The present paper describes a new procedure to estimate D f of Chlorella sorokiniana aggregates by correlating the 2D fractal dimension of the real aggregates microscopic images with the 2D fractal dimensions of computer generated flocs of prescribed 3D geometry. This procedure avoids the inaccuracies entailed with floc imaging and those due to the random orientation of the floc during image acquisition.
Pulp & paper Canada, 2000
... Titre du document / Document title. New system to predict deposits due to DCM destabilization... more ... Titre du document / Document title. New system to predict deposits due to DCM destabilization in paper mills. Auteur(s) / Author(s). BLANCO A. ; NEGRO C. ; MONTE M. Concepcion ; OTERO D. ; TIJERO J. ; Résumé / Abstract. ... Faire une nouvelle recherche Make a new search.
Antioxidants, 2020
Background: Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is causing profound heal... more Background: Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is causing profound health, economic, and social problems worldwide. Management of personal protective equipment (PPE) and its potential limited availability have created concerns about the increased risks for healthcare professionals at hospitals and nursing homes. Ozone is a powerful oxidant agent. The objectives of this study were to examine the effects of ozone treatment on PPE contaminated with SARS-CoV-2, and to explore whether relative humidity could modify those effects. Methods: PPE contaminated by heat-inactivated SARS-CoV-2 were treated with different ozone concentrations, exposure times, and relative humidity conditions. SARS-CoV-2 gene amplification was assessed by real-time polymerase chain reaction. Results: There was no amplification of SARS-CoV-2 in PPE after the following ozone exposures: 30 s at 10,000 ppm (20 g/m3), 5 min at 4000 ppm, and 10 min at 2000 ppm. At lower ozone concentrations, 4–...
Academia Engineering, Mar 4, 2024
Academia Engineering was launched in 2023 as an open access journal with the aim of contribution ... more Academia Engineering was launched in 2023 as an open access journal with the aim of contribution to the acceleration and advancement of engineering research. It is focused on sharing, inclusivity, and quality, following FAIR practices.As the Editor-in-Chief, I am honored to help a team of professionals dedicated to upholding the highest editorial standards and ensuring the continued relevance of the journal. Today, I am pleased to present the redefined journal scope, which emphasizes the importance of multidisciplinarity and interdisciplinarity as approaches for solving current global challenges, providing sustainable solutions, and improving overall societal well-being.
July 2007
Rheological properties of pulp suspensions play a very important role in the industry, mainly due... more Rheological properties of pulp suspensions play a very important role in the industry, mainly due to the consumption of energy for transporting pulp among the different parts of the paper mill. In this work, we determined the rheology of long- and short-fiber bleached kraft pulp suspensions by using a new rotational viscometer especially designed for their analysis. The experimental rheograms were adjusted to the Herschel-Bulkley model. We established the dependence of the rheological parameters on temperature, fiber length, and pulp consistency, to evaluate the relative influence of these factors and the corresponding interactions in the rheological parameters. In addition, we defined a mathematical model that enables the estimation of rheological parameters as a function of the different input factors. We validated this model with some preliminary experimental data.
Journal of Industrial Microbiology & Biotechnology, Jan 18, 2006
In this study, polysaccharide-producing bacteria were isolated from slimes collected from two Fin... more In this study, polysaccharide-producing bacteria were isolated from slimes collected from two Finnish and one Spanish paper mill and the exopolysaccharides (EPSs) produced by 18 isolates were characterised. Most of the isolates, selected on the bases of slimy colony morphology, were members of the family Enterobacteriaceae most frequently belonging to the genera Enterobacter and Klebsiella including Raoultella. All of the EPSs analysed showed the presence of charged groups in the form of uronic acid or pyruvate revealing the polyanionic nature of these polysaccharides. Further results of the carbohydrate analysis showed that the EPS produced by nine of the enterobacteria was colanic acid.
Cellulose Chemistry and Technology, 2005
An electrochemical treatment can be applied to remove lignin from the weak black liquor (WBL) fro... more An electrochemical treatment can be applied to remove lignin from the weak black liquor (WBL) from pulping plants, concomitantly with sodium salts' convertion into caustic soda, that can be reused in the pulping process or in other sequences, depending on the required. concentration. The electrolytic processing of kraft weak black liquor from a pulp mill, using straw as raw material, was studied at laboratory scale in a batch mode. The main problem found was anode's. high fouling, which was solved by using platinum wire anodes in combination with high current density through the anode and turbulent flow of the WBL in the anode compartment. To avoid anode's fouling, the velocity of the WBL in the cell was critical, while current density and temperature optimization were critical for the economical viability of the process.
International Journal of Biological Macromolecules, Sep 1, 2023
International Journal of Biological Macromolecules, Apr 1, 2022
Current knowledge on the properties of different types of cellulose nanofibers (CNFs) is fragment... more Current knowledge on the properties of different types of cellulose nanofibers (CNFs) is fragmented. Properties variation is very extensive, depending on raw materials, effectiveness of the treatments to extract the cellulose fraction from the lignocellulosic biomass, pretreatments to facilitate cellulose fibrillation and final mechanical process to separate the microfibrils. Literature offers multiple parameters to characterize the CNFs prepared by different routes. However, there is a lack of an extensive guide to compare the CNFs. In this study, we perform a critical comparison of rheological, compositional, and morphological features of CNFs, produced from the most representative types of woody plants, hardwood and softwood, using different types and intensities of pretreatments, including enzymatic, chemical and mechanical ones, and varying the severity of mechanical treatment focusing on the relationship between macroscopic and microscopic parameters. This structured information will be exceedingly useful to select the most appropriate CNF for a certain application based on the most relevant parameters in each case.
Latin American Applied Research, Mar 29, 2020
−− Nanocellulose (NC) and its wide applications have attracted high attention due to its desirabl... more −− Nanocellulose (NC) and its wide applications have attracted high attention due to its desirable properties such as high surface area, extraordinary mechanical properties, high reactivity and easy modification of NC surface due to the presence of primary hydroxyl groups. NC also presents several environmental benefits, including high potential availability because its production is coming from natural sources, renewability and nontoxicity. This paper briefly summarizes some of the activities of the research group "Cellulose, Paper and Water Advanced Treatments" from Complutense University of Madrid that were presented in CAIQ 2019, including the main types of NC, the production processes and their characterization. Additionally, the most promising NC applications are described such as for paper and board, for wastewater treatment, food and cement-based materials. Moreover, a market perspective of NC is also presented.
1st International Conference on Environmental, Industrial and Applied Microbiology, BioMicroWorld 2005, 2005
Applied Catalysis B: Environmental, 2019
This paper shows that incorporation of Cu inhibits the anatase to rutile phase transition at temp... more This paper shows that incorporation of Cu inhibits the anatase to rutile phase transition at temperatures above 500°C. The control sample, with 0% Cu contained 34.3% anatase at 600°C and transitioned to 100% rutile by 650°C. All copper doped samples maintained 100% anatase up to 600°C. With 2% Cu doping, anatase fully transformed to rutile at 650°C, at higher Cu contents of 4% & 8% mixed phased samples, with 27.3% anatase and 74.3% anatase respectively, are present at 650°C. All samples had fully transformed to rutile by 700°C. 0%, 4% and 8% Cu were evaluated for photocatalytic degradation of 1, 4 dioxane. Without any catalyst, 15.8% of the 1,4 dioxane degraded upon irradiation with light for 4 h. Cu doped TiO 2 shows poor photocatalytic degradation ability compared to the control samples. Density functional theory (DFT) studies of Cu-doped rutile and anatase show formation of charge compensating oxygen vacancies and a Cu 2+ oxidation state. Reduction of Cu 2+ to Cu + and Ti 4+ to Ti 3+ was detected by XPS after being calcined to 650-700°C. This reduction was also shown in DFT studies. Cu 3d states are present in the valence to conduction band energy gap upon doping. We suggest that the poor photocatalytic activity of Cu-doped TiO 2 , despite the high anatase content, arises from the charge recombination at defect sites that result from incorporation of copper into TiO 2 .
International journal of biological macromolecules, Jan 20, 2017
In the present work, lignocellulosic micro/nanofibers (LCMNF) were produced from pine sawdust. Fo... more In the present work, lignocellulosic micro/nanofibers (LCMNF) were produced from pine sawdust. For that, pine sawdust was submitted to alkali treatment and subsequent bleaching stages, tailoring its chemical composition with the purpose of obtaining effective LCMNF. The obtained LCMNF were characterized and incorporated to recycled cardboard boxes with the purpose of producing recycled paper. The obtained results showed that it was possible to obtain LCMNF with the same reinforcing potential than those cellulose nanofibers (CNF) prepared by oxidative or other chemical methods In fact, the obtained papers increased the breaking length of recycled cardboard from 3338m to 5347m, being a value significantly higher than the requirements to produce paper bags. Overall, the studied strategies could allow a significant reduction of paper basis weight, with the consequent material saving and, thus, contribution to the environment.