Doctorat en Enginyeria Tèxtil i Papererahttp://hdl.handle.net/2117/1845822024-03-29T06:24:03Z2024-03-29T06:24:03ZIonic liquid, ultrasound-assisted synthesis of lignin nanoparticles for barrier-enhanced all-cellulose nanocomposite filmsAmini, ElaheValls Vidal, CristinaRoncero Vivero, María Blancahttp://hdl.handle.net/2117/3955082024-01-21T03:18:28Z2023-10-30T11:36:20ZIonic liquid, ultrasound-assisted synthesis of lignin nanoparticles for barrier-enhanced all-cellulose nanocomposite films
Amini, Elahe; Valls Vidal, Cristina; Roncero Vivero, María Blanca
The primary purpose of this work was to develop novel all-cellulose nanocomposite (ACNC) films by following a green approach that uses an ionic liquid as solvent and requires no additional reducing agents or stabilizers. In this way, biodegradable, UVblocking ACNC films were obtained by partially dissolving cellulose to entrap lignin nanoparticles (LNP) within. Lignin particles in proportions of 3–7 wt% were modified by sonication in an ionic liquid (IL) to obtain lignin-IL dispersions. The influence of the LNP-IL medium on the chemical, physical, and morphological properties of the resulting nanocomposites was examined, and the properties compared with those of an all-cellulose composite (ACC) film and untreated paper. The TEM technique revealed the formation of unevenly spherical LNPs as small as 5.133 ± 0.003 nm, and XRD spectroscopy a transition from cellulose I to II and an increase in the proportion of non-crystalline cellulose as a result of partial dissolution and regeneration. In addition, SEM images confirmed the deposition of LNPs onto the surface of the regenerated cellulose matrix. The incorporation of LNPs considerably enhanced the UV-blocking, oxygen and water-barrier, biodegradation, antioxidant and antibacterial properties of the films. Moreover, LNPs in proportions of 3 and 5 wt% increased tensile strength, and a proportion of 7 wt% allowed the films to block 97% of light at 280 nm and increased antioxidant activity by 68% relative to the control sample. Interestingly, a 7 wt% LNP content in the films decreased antibacterial activity against Staphylococcus aureus and Escherichia coli by about 42.85% and 63.88%, respectively. The new, multifunctional biocomposite films are suitable for various uses in cellulose-based food packaging
2023-10-30T11:36:20ZAmini, ElaheValls Vidal, CristinaRoncero Vivero, María BlancaThe primary purpose of this work was to develop novel all-cellulose nanocomposite (ACNC) films by following a green approach that uses an ionic liquid as solvent and requires no additional reducing agents or stabilizers. In this way, biodegradable, UVblocking ACNC films were obtained by partially dissolving cellulose to entrap lignin nanoparticles (LNP) within. Lignin particles in proportions of 3–7 wt% were modified by sonication in an ionic liquid (IL) to obtain lignin-IL dispersions. The influence of the LNP-IL medium on the chemical, physical, and morphological properties of the resulting nanocomposites was examined, and the properties compared with those of an all-cellulose composite (ACC) film and untreated paper. The TEM technique revealed the formation of unevenly spherical LNPs as small as 5.133 ± 0.003 nm, and XRD spectroscopy a transition from cellulose I to II and an increase in the proportion of non-crystalline cellulose as a result of partial dissolution and regeneration. In addition, SEM images confirmed the deposition of LNPs onto the surface of the regenerated cellulose matrix. The incorporation of LNPs considerably enhanced the UV-blocking, oxygen and water-barrier, biodegradation, antioxidant and antibacterial properties of the films. Moreover, LNPs in proportions of 3 and 5 wt% increased tensile strength, and a proportion of 7 wt% allowed the films to block 97% of light at 280 nm and increased antioxidant activity by 68% relative to the control sample. Interestingly, a 7 wt% LNP content in the films decreased antibacterial activity against Staphylococcus aureus and Escherichia coli by about 42.85% and 63.88%, respectively. The new, multifunctional biocomposite films are suitable for various uses in cellulose-based food packagingCharacterization of airborne particulate matter and its toxic and proarrhythmic effects: A case study in Aburrá Valley, ColombiaPalacio, Laura CarolinaDurango Giraldo, GeraldineZapata Hernandez, CamiloSanta González, GloriaUribe, DiegoSaiz Rodríguez, Francisco JavierBuitrago Sierra, RobisonTobón, Catalinahttp://hdl.handle.net/2117/3946612023-10-15T05:32:03Z2023-10-05T10:50:42ZCharacterization of airborne particulate matter and its toxic and proarrhythmic effects: A case study in Aburrá Valley, Colombia
Palacio, Laura Carolina; Durango Giraldo, Geraldine; Zapata Hernandez, Camilo; Santa González, Gloria; Uribe, Diego; Saiz Rodríguez, Francisco Javier; Buitrago Sierra, Robison; Tobón, Catalina
Particle matter (PM) is a complex mixture of particles suspended in the air, mainly caused by fuel combustion from vehicles and industry, and has been related to pulmonary and cardiovascular diseases. The Metropolitan Area of Aburrá Valley in Colombia is the second most populous urban agglomeration in the country and the third densest in the world, composed of ten municipalities. Examining the physicochemical properties of PM is crucial in comprehending its composition and its effects on human health, as it varies based on the socioeconomic dynamics specific to each city. This study characterized the PM collected from the north, south, and central zones to evaluate its chemical composition and morphology. Different elements such as silicon, carbon, aluminum, potassium, calcium, sodium, iron, magnesium, and copper and the presence of unburned fuel, motor oil, and silicon fibers were identified. In vitro and in silico studies were conducted to evaluate the toxicity of the PM, and it was found that the PM collected from the central zone had the greatest impact on cell viability and caused DNA damage. The in silico study demonstrated that PM has concentration-dependent proarrhythmic effects, reflected in an action potential duration shortening and an increased number of reentries, which may contribute to the development of cardiac arrhythmias. Overall, the results suggest that the size and chemical composition of ambient PM can induce toxicity and play an important role in the generation of arrhythmias
2023-10-05T10:50:42ZPalacio, Laura CarolinaDurango Giraldo, GeraldineZapata Hernandez, CamiloSanta González, GloriaUribe, DiegoSaiz Rodríguez, Francisco JavierBuitrago Sierra, RobisonTobón, CatalinaParticle matter (PM) is a complex mixture of particles suspended in the air, mainly caused by fuel combustion from vehicles and industry, and has been related to pulmonary and cardiovascular diseases. The Metropolitan Area of Aburrá Valley in Colombia is the second most populous urban agglomeration in the country and the third densest in the world, composed of ten municipalities. Examining the physicochemical properties of PM is crucial in comprehending its composition and its effects on human health, as it varies based on the socioeconomic dynamics specific to each city. This study characterized the PM collected from the north, south, and central zones to evaluate its chemical composition and morphology. Different elements such as silicon, carbon, aluminum, potassium, calcium, sodium, iron, magnesium, and copper and the presence of unburned fuel, motor oil, and silicon fibers were identified. In vitro and in silico studies were conducted to evaluate the toxicity of the PM, and it was found that the PM collected from the central zone had the greatest impact on cell viability and caused DNA damage. The in silico study demonstrated that PM has concentration-dependent proarrhythmic effects, reflected in an action potential duration shortening and an increased number of reentries, which may contribute to the development of cardiac arrhythmias. Overall, the results suggest that the size and chemical composition of ambient PM can induce toxicity and play an important role in the generation of arrhythmiasMaterials based on cellulose for e-commerce packagingEscursell Martínez, SilviaValls Vidal, CristinaLlorach-Massana, PereRoncero Vivero, María Blancahttp://hdl.handle.net/2117/3932602023-10-15T02:05:26Z2023-09-08T07:41:55ZMaterials based on cellulose for e-commerce packaging
Escursell Martínez, Silvia; Valls Vidal, Cristina; Llorach-Massana, Pere; Roncero Vivero, María Blanca
As a result of the pandemic and the new tax on the use of plastics in the EU, the consumption of cellulose has increased, especially for cardboard boxes as e-commerce packaging. Due to this high demand, the price of cellulose is rising considerably. It is also worth considering that in order to avoid problems with breakage during product mobility, overpackaging and the generation of more waste is a problem to be taken into account. Nature has shown us that it can optimise resources and energy, finding a balance between form, matter and function without generating waste, and building resilient, collaborative, creative and sensory models together. In fact, artists such as Leonardo da Vinci or naturalist as Ernst Haeckel already devoted themselves to observing and studying nature as a turning point in their designs and paintings. Focusing on materials, scientists such as Lynn Margulis, Janine Benyus or Stefano Mancuso have demonstrated the variety and different reproduction processes in natural ecosystems, as well as the interdependent relationship between them. And even new methodologies go beyond sustainability, and there is already talk of regenerative culture and systemic design. In other words, achieving transformative innovation through a more holistic vision and in collaboration with different entities. Following these considerations, our approach is to apply these natural systems to e-commerce packaging, obtaining a greater variety of biomaterials. For this reason we present different proposals for materials based on cellulose, one of the most abundant and renewable biopolymers on earth. We will also analyse the differences between cellulose extracted from vegetable fibre and cellulose generated from bacteria. Their properties provide us with flexibility, strength, toughness, among others, and allow us to rethink the different production processes to adapt them to each type of product and avoid generating overpackaging
2023-09-08T07:41:55ZEscursell Martínez, SilviaValls Vidal, CristinaLlorach-Massana, PereRoncero Vivero, María BlancaAs a result of the pandemic and the new tax on the use of plastics in the EU, the consumption of cellulose has increased, especially for cardboard boxes as e-commerce packaging. Due to this high demand, the price of cellulose is rising considerably. It is also worth considering that in order to avoid problems with breakage during product mobility, overpackaging and the generation of more waste is a problem to be taken into account. Nature has shown us that it can optimise resources and energy, finding a balance between form, matter and function without generating waste, and building resilient, collaborative, creative and sensory models together. In fact, artists such as Leonardo da Vinci or naturalist as Ernst Haeckel already devoted themselves to observing and studying nature as a turning point in their designs and paintings. Focusing on materials, scientists such as Lynn Margulis, Janine Benyus or Stefano Mancuso have demonstrated the variety and different reproduction processes in natural ecosystems, as well as the interdependent relationship between them. And even new methodologies go beyond sustainability, and there is already talk of regenerative culture and systemic design. In other words, achieving transformative innovation through a more holistic vision and in collaboration with different entities. Following these considerations, our approach is to apply these natural systems to e-commerce packaging, obtaining a greater variety of biomaterials. For this reason we present different proposals for materials based on cellulose, one of the most abundant and renewable biopolymers on earth. We will also analyse the differences between cellulose extracted from vegetable fibre and cellulose generated from bacteria. Their properties provide us with flexibility, strength, toughness, among others, and allow us to rethink the different production processes to adapt them to each type of product and avoid generating overpackagingDesign and characterization of reversible thermodynamic SMPU-based fabrics with improved comfort propertiesGonzález Bertran, JuditArdanuy Raso, MònicaGonzalez Colominas, MartaRodriguez, RosaJovancic, Petarhttp://hdl.handle.net/2117/3857862024-03-10T08:14:45Z2023-03-30T09:59:17ZDesign and characterization of reversible thermodynamic SMPU-based fabrics with improved comfort properties
González Bertran, Judit; Ardanuy Raso, Mònica; Gonzalez Colominas, Marta; Rodriguez, Rosa; Jovancic, Petar
In recent years, great efforts have been made to research and develop advanced thermodynamic textiles that can change their thermal behavior in response to external stimuli. More specifically, shape memory alloys and shape memory polymer coatings have used for thermal comfort applications. However, the use of shape memory polymers in the form of filament yarns integrated in the fabrics has not yet reported. These fabrics have some advantages related to versatility in shape design. The aim of this study was to develop woven SMPU-based fabrics with reversible thermodynamic properties induced by weft SMPU filament yarns interlaced into polyester (PES) fabrics. To this end, PES woven fabrics with different ratios of weft SMPU filament yarns (PES/SMPU 1:0; 3:1; 1:1; 1: 3, and 0:1) were developed and their thermodynamic properties (thermal resistance, water vapor resistance, and permeability index), shape memory effect, and mechanical performance were evaluated and compared to the 100% PES reference fabric. All the SMPU-based fabrics developed were classified as extremely breathable (water vapor resistance <6 m2 Pa/W) and thermally comfortable (water vapor permeability index <0.3). The fabrics integrating the SMPU filament yarns reacted dynamically to the temperature stimuli over and below Tg, whereas the 100% PES fabric showed passive thermodynamic behavior. This dynamism led to an improvement in thermal protection against an increase in ambient temperature, reaching values of 13.18 mK m2 /W in thermal resistance (PES/SMPU 0:1), while also maintaining good moisture management properties, reaching values of 5.19 m2 Pa/W in water vapor resistance (PES/SMPU 0:1)
2023-03-30T09:59:17ZGonzález Bertran, JuditArdanuy Raso, MònicaGonzalez Colominas, MartaRodriguez, RosaJovancic, PetarIn recent years, great efforts have been made to research and develop advanced thermodynamic textiles that can change their thermal behavior in response to external stimuli. More specifically, shape memory alloys and shape memory polymer coatings have used for thermal comfort applications. However, the use of shape memory polymers in the form of filament yarns integrated in the fabrics has not yet reported. These fabrics have some advantages related to versatility in shape design. The aim of this study was to develop woven SMPU-based fabrics with reversible thermodynamic properties induced by weft SMPU filament yarns interlaced into polyester (PES) fabrics. To this end, PES woven fabrics with different ratios of weft SMPU filament yarns (PES/SMPU 1:0; 3:1; 1:1; 1: 3, and 0:1) were developed and their thermodynamic properties (thermal resistance, water vapor resistance, and permeability index), shape memory effect, and mechanical performance were evaluated and compared to the 100% PES reference fabric. All the SMPU-based fabrics developed were classified as extremely breathable (water vapor resistance <6 m2 Pa/W) and thermally comfortable (water vapor permeability index <0.3). The fabrics integrating the SMPU filament yarns reacted dynamically to the temperature stimuli over and below Tg, whereas the 100% PES fabric showed passive thermodynamic behavior. This dynamism led to an improvement in thermal protection against an increase in ambient temperature, reaching values of 13.18 mK m2 /W in thermal resistance (PES/SMPU 0:1), while also maintaining good moisture management properties, reaching values of 5.19 m2 Pa/W in water vapor resistance (PES/SMPU 0:1)Transformation of a waste from the paper industry into a nanocellulosic materialHuete Matute, NoemiCusola Aumedes, OriolRoncero Vivero, María Blancahttp://hdl.handle.net/2117/3824132023-09-24T03:00:37Z2023-02-07T10:22:00ZTransformation of a waste from the paper industry into a nanocellulosic material
Huete Matute, Noemi; Cusola Aumedes, Oriol; Roncero Vivero, María Blanca
The constant search for productive improvements in the paper industry and the growing awareness of society about the problems derived from the use of fossil-based materials, are pushing the research efforts towards the development of renewable alternatives. On the one hand, several studies reported on lignocellulosic biomass as a sustainable alternative due to its high renewability, abundance, biodegradability, and low cost. On the other hand, the sludge produced during water treatments in a paper industry is a common residue which is usually discarded but can still contain high amounts of lignocellulosic material. The present study explores the revalorization of an industrial by-product coming from the water-treatment operations in a paper mill. The residue is used to obtain a nanocellulosic biomaterial, using cellulase-assisted enzymatic treatments in combination with mechanical processes. The results show that enzymatic treatments improve the processing of fibrillar nanocellulose (NCF), with an increase in the hydrophobic behavior of the NFC, giving rise to transparent films with reduced whiteness, in contrast to those which were simply refined. However, the obtained films showed a reduced tensile resistance. The enzymatic action prior to refining improves the obtaining of smaller fibres and increases the percentage of fines. Thus, a more homogeneous film formation is obtained, compared to a later enzymatic action. Several films with an increasing NFC content were produced and analyzed. Results indicate that an increasing NFC content rises the film density, air barrier, transparency, and water permeability and decreases whiteness and tensile strength. The study demonstrates that it is technically possible to use a waste from a paper wastewater treatment plant to produce NFC
2023-02-07T10:22:00ZHuete Matute, NoemiCusola Aumedes, OriolRoncero Vivero, María BlancaThe constant search for productive improvements in the paper industry and the growing awareness of society about the problems derived from the use of fossil-based materials, are pushing the research efforts towards the development of renewable alternatives. On the one hand, several studies reported on lignocellulosic biomass as a sustainable alternative due to its high renewability, abundance, biodegradability, and low cost. On the other hand, the sludge produced during water treatments in a paper industry is a common residue which is usually discarded but can still contain high amounts of lignocellulosic material. The present study explores the revalorization of an industrial by-product coming from the water-treatment operations in a paper mill. The residue is used to obtain a nanocellulosic biomaterial, using cellulase-assisted enzymatic treatments in combination with mechanical processes. The results show that enzymatic treatments improve the processing of fibrillar nanocellulose (NCF), with an increase in the hydrophobic behavior of the NFC, giving rise to transparent films with reduced whiteness, in contrast to those which were simply refined. However, the obtained films showed a reduced tensile resistance. The enzymatic action prior to refining improves the obtaining of smaller fibres and increases the percentage of fines. Thus, a more homogeneous film formation is obtained, compared to a later enzymatic action. Several films with an increasing NFC content were produced and analyzed. Results indicate that an increasing NFC content rises the film density, air barrier, transparency, and water permeability and decreases whiteness and tensile strength. The study demonstrates that it is technically possible to use a waste from a paper wastewater treatment plant to produce NFCNatural additives to enhance the barrier properties of nanocellulose filmsFernández Santos, JuliaValls Vidal, CristinaCusola Aumedes, OriolRoncero Vivero, María Blancahttp://hdl.handle.net/2117/3815292023-10-22T06:28:34Z2023-01-31T12:10:07ZNatural additives to enhance the barrier properties of nanocellulose films
Fernández Santos, Julia; Valls Vidal, Cristina; Cusola Aumedes, Oriol; Roncero Vivero, María Blanca
Finding alternatives to fossil-based materials is one of the most important challenges of our time. Since cellulose is the most abundant natural polymer on the planet, its use to solve this challenge would be ideal. In the present work, cellulose nanocrystals (CNC) were mixed with different plasticizers to obtain films with improved properties. To this aim, a first study was conducted in order to find the optimal amounts of plasticizer which maximize the compatibility with nanocellulose. The studied additives were Sorbitol (Sor), Glycerol (Gly), Maltitol (Mal), Xylitol (Xyl), Mannitol (Man), Gellan gum (Gg), and Ethylene glycol (Eg). The addition of these plasticizers to the CNC matrix was expected to improve the film flexibility and workability, which is one of the major limitations of this polymer. The selected plasticizers show similar structure to nanocellulose, with free hydroxyl groups which allow compatibility with nanocellulose, resulting in homogeneous films. The films with different amounts of additives were characterized in terms of barrier properties, crystallinity, SFE (surface free energy), and biodegradability. The barrier properties of the films were analyzed in terms of air, oil, water, water vapor and oxygen permeabilities. Results show that all additives decreased air and water permeance, to a greater or lesser extent. CNC films with Mal, Sor, and Xyl had a better oxygen barrier than the control, showing a total oxygen resistance at RH below 60%. About WVTR at moderate (50%) and drastic (90%) humidity, Mal and Gg showed values below the control. Films containing Mal provided the best barrier properties to oxygen and water vapor transmission. The interaction of the films with other compounds (liquids or adhesives) was observed through SFE. In relation to biodegradability, all the additives increased the biodegradability of CNC-based films when subjected to a biodegradability test under controlled composting conditions. These biodegradability results are relevant in terms of the environmental impact of the films, especially if the films are intended to provide a sustainable alternative to traditional food packaging materials
2023-01-31T12:10:07ZFernández Santos, JuliaValls Vidal, CristinaCusola Aumedes, OriolRoncero Vivero, María BlancaFinding alternatives to fossil-based materials is one of the most important challenges of our time. Since cellulose is the most abundant natural polymer on the planet, its use to solve this challenge would be ideal. In the present work, cellulose nanocrystals (CNC) were mixed with different plasticizers to obtain films with improved properties. To this aim, a first study was conducted in order to find the optimal amounts of plasticizer which maximize the compatibility with nanocellulose. The studied additives were Sorbitol (Sor), Glycerol (Gly), Maltitol (Mal), Xylitol (Xyl), Mannitol (Man), Gellan gum (Gg), and Ethylene glycol (Eg). The addition of these plasticizers to the CNC matrix was expected to improve the film flexibility and workability, which is one of the major limitations of this polymer. The selected plasticizers show similar structure to nanocellulose, with free hydroxyl groups which allow compatibility with nanocellulose, resulting in homogeneous films. The films with different amounts of additives were characterized in terms of barrier properties, crystallinity, SFE (surface free energy), and biodegradability. The barrier properties of the films were analyzed in terms of air, oil, water, water vapor and oxygen permeabilities. Results show that all additives decreased air and water permeance, to a greater or lesser extent. CNC films with Mal, Sor, and Xyl had a better oxygen barrier than the control, showing a total oxygen resistance at RH below 60%. About WVTR at moderate (50%) and drastic (90%) humidity, Mal and Gg showed values below the control. Films containing Mal provided the best barrier properties to oxygen and water vapor transmission. The interaction of the films with other compounds (liquids or adhesives) was observed through SFE. In relation to biodegradability, all the additives increased the biodegradability of CNC-based films when subjected to a biodegradability test under controlled composting conditions. These biodegradability results are relevant in terms of the environmental impact of the films, especially if the films are intended to provide a sustainable alternative to traditional food packaging materialsIonic liquid/ZnO assisted preparation of high barrier cellulose nanocomposite films by in situ ring-opening polymerization of lactide monomersAmini, ElaheValls Vidal, CristinaYousefi, HosseinRoncero Vivero, María Blancahttp://hdl.handle.net/2117/3804052024-01-21T05:54:51Z2023-01-13T13:52:01ZIonic liquid/ZnO assisted preparation of high barrier cellulose nanocomposite films by in situ ring-opening polymerization of lactide monomers
Amini, Elahe; Valls Vidal, Cristina; Yousefi, Hossein; Roncero Vivero, María Blanca
Cellulose-based composites have aroused increasing interest as potential replacements for fossil fuel-based plastics. In this work, transparent cellulose-grafted-PLA nanocomposite films were prepared by grafting polylactide (PLA) onto cellulose. PLA was synthesized by in situ ring opening polymerization from a regenerated cellulose matrix, using zinc oxide nanoparticles (ZnONPs) in 1-ethyl-3-methylimidazolium acetate (EmimAc) as solvent. A facile route was devised to modify the starting material (cellulose paper) by partial dissolution and regeneration that used an ionic liquid (IL) as a smart nanowelding agent to assemble nanometric cellulose structures. The influence of the proportion of ZnONPs (1–5 wt%) and L-lactide (LA) monomers (10–70 wt%) used on the properties of the resulting nanocomposite films was examined by comparison with an all-cellulose composite (ACC) and pure cellulose paper. Incorporating ZnONPs and PLA was found to enhance the mechanical, barrier and optical properties of the films. The maximum tensile strength and best barrier properties were those of a film obtained from 5%ZnONPs and 70%LA. FTIR spectra confirmed a new form of interaction between PLA and the regenerated cellulose matrix. Also, XRD spectra revealed a transition from cellulose I to II and an increase in the proportion of noncrystalline cellulose through partial dissolution and regeneration. Although the surface morphology of the nanocomposite films was influenced by the presence of ZnONPs and PLA chains, their color and chemical structure were not. The transparent cellulose-grafted-PLA nanocomposite films obtained are highly promising as packaging materials
2023-01-13T13:52:01ZAmini, ElaheValls Vidal, CristinaYousefi, HosseinRoncero Vivero, María BlancaCellulose-based composites have aroused increasing interest as potential replacements for fossil fuel-based plastics. In this work, transparent cellulose-grafted-PLA nanocomposite films were prepared by grafting polylactide (PLA) onto cellulose. PLA was synthesized by in situ ring opening polymerization from a regenerated cellulose matrix, using zinc oxide nanoparticles (ZnONPs) in 1-ethyl-3-methylimidazolium acetate (EmimAc) as solvent. A facile route was devised to modify the starting material (cellulose paper) by partial dissolution and regeneration that used an ionic liquid (IL) as a smart nanowelding agent to assemble nanometric cellulose structures. The influence of the proportion of ZnONPs (1–5 wt%) and L-lactide (LA) monomers (10–70 wt%) used on the properties of the resulting nanocomposite films was examined by comparison with an all-cellulose composite (ACC) and pure cellulose paper. Incorporating ZnONPs and PLA was found to enhance the mechanical, barrier and optical properties of the films. The maximum tensile strength and best barrier properties were those of a film obtained from 5%ZnONPs and 70%LA. FTIR spectra confirmed a new form of interaction between PLA and the regenerated cellulose matrix. Also, XRD spectra revealed a transition from cellulose I to II and an increase in the proportion of noncrystalline cellulose through partial dissolution and regeneration. Although the surface morphology of the nanocomposite films was influenced by the presence of ZnONPs and PLA chains, their color and chemical structure were not. The transparent cellulose-grafted-PLA nanocomposite films obtained are highly promising as packaging materialsMaterials and manufacturing methods for EWOD devices: current status and sustainability challengesCaro Pérez, OriolCasals Terré, JasminaRoncero Vivero, María Blancahttp://hdl.handle.net/2117/3767882023-10-08T12:42:43Z2022-11-18T14:32:05ZMaterials and manufacturing methods for EWOD devices: current status and sustainability challenges
Caro Pérez, Oriol; Casals Terré, Jasmina; Roncero Vivero, María Blanca
Electrowetting-on-dielectric (EWOD) devices have proven to be effective tools for precise microfluidic manipulation or in liquid lenses that surpass conventional solid lenses in versatility. However, the fabrication of these devices presents many challenges, such as their scalability or the growing concern on their environmental impact due to materials used in their fabrication. This review provides a comprehensive analysis of the materials currently used in the fabrication of EWOD devices and the characteristics they must meet. In addition, a discussion of future challenges in the fabrication of EWOD devices is presented, in particular the environmental problems presented by some of the materials currently in use.
2022-11-18T14:32:05ZCaro Pérez, OriolCasals Terré, JasminaRoncero Vivero, María BlancaElectrowetting-on-dielectric (EWOD) devices have proven to be effective tools for precise microfluidic manipulation or in liquid lenses that surpass conventional solid lenses in versatility. However, the fabrication of these devices presents many challenges, such as their scalability or the growing concern on their environmental impact due to materials used in their fabrication. This review provides a comprehensive analysis of the materials currently used in the fabrication of EWOD devices and the characteristics they must meet. In addition, a discussion of future challenges in the fabrication of EWOD devices is presented, in particular the environmental problems presented by some of the materials currently in use.Cellulose acetate films from chemo-enzymatic dissolving pulpsQuintana, ElisabetAgo, MarikoValls Vidal, CristinaFernández Santos, JuliaRoncero Vivero, María BlancaRojas, Orlando J.http://hdl.handle.net/2117/3754802023-10-22T07:57:26Z2022-11-03T12:18:34ZCellulose acetate films from chemo-enzymatic dissolving pulps
Quintana, Elisabet; Ago, Mariko; Valls Vidal, Cristina; Fernández Santos, Julia; Roncero Vivero, María Blanca; Rojas, Orlando J.
The purpose of this work is to obtain dissolving cellulose fibers that are suitable for the manufacturing of cellulose derivatives. Therefore, the combination of enzymatic and chemical treatments during the bleaching stage (lignin removal) and purification stage (hemicellulose removal) is proposed. The obtained dissolving cellulose was submitted to acetylation reactions, and then acetate films were prepared as an example of end product. Assessing the quality of acetate films, it was concluded that dissolving cellulose fibers had good properties and fulfilled the quality requirements. These satisfactory results were compared with acetate films obtained under same acetylation conditions, but the dissolving cellulose fibers used as a raw material came from a conventional and industrial process.
2022-11-03T12:18:34ZQuintana, ElisabetAgo, MarikoValls Vidal, CristinaFernández Santos, JuliaRoncero Vivero, María BlancaRojas, Orlando J.The purpose of this work is to obtain dissolving cellulose fibers that are suitable for the manufacturing of cellulose derivatives. Therefore, the combination of enzymatic and chemical treatments during the bleaching stage (lignin removal) and purification stage (hemicellulose removal) is proposed. The obtained dissolving cellulose was submitted to acetylation reactions, and then acetate films were prepared as an example of end product. Assessing the quality of acetate films, it was concluded that dissolving cellulose fibers had good properties and fulfilled the quality requirements. These satisfactory results were compared with acetate films obtained under same acetylation conditions, but the dissolving cellulose fibers used as a raw material came from a conventional and industrial process.Direct synthesis of HKUST-1 onto cotton fabrics and propertiesLobo da Costa, BrianAtaide Rosa, Isadora Letícia AparecidaHipólito Silvio, VitóriaWu, QiuyueBlock Samulewski, RafaelPereria Scacchetti, Fabio AlexandreMoises, Murillo PereiraLis Arias, Manuel JoséMaesta Bezerra, Fabriciohttp://hdl.handle.net/2117/3744442023-02-19T02:12:49Z2022-10-14T11:42:08ZDirect synthesis of HKUST-1 onto cotton fabrics and properties
Lobo da Costa, Brian; Ataide Rosa, Isadora Letícia Aparecida; Hipólito Silvio, Vitória; Wu, Qiuyue; Block Samulewski, Rafael; Pereria Scacchetti, Fabio Alexandre; Moises, Murillo Pereira; Lis Arias, Manuel José; Maesta Bezerra, Fabricio
Metal-organic frameworks are crystalline nanostructures formed by a metal interspersed by an organic binder. These metal-organic materials are examples of nanomaterials applied to textile material in search of new functionalized textiles. Cotton is a cellulosic fiber of great commercial importance, and has good absorption capacity and breathability; however, due to these characteristics, it is susceptible to the development of microorganisms on its surface. This work aims to analyze how the direct synthesis of HKUST-1 in cotton fabric modifies the chemical and physical properties. The material obtained was characterized by scanning electron microscopy to obtain its morphology, by spectrophotometry CIE L*a*b* to verify the color change, by a biological test to verify its resistance to microorganisms and, finally, by a unidirectional traction test to verify the change in its mechanical resistance. Thereby, it was possible to observe the formation of MOFs with the morphology of nanorods, and also, with regard to HKUST-1 in the cotton fabric, when applied, an elimination percentage higher than 99% was observed for both bacteria, E. coli and S. aureus. The presence of MOF was detected even after washing, however, the loss of 75% in the mechanical resistance of the material makes its potential for textile finishing unworkable.
2022-10-14T11:42:08ZLobo da Costa, BrianAtaide Rosa, Isadora Letícia AparecidaHipólito Silvio, VitóriaWu, QiuyueBlock Samulewski, RafaelPereria Scacchetti, Fabio AlexandreMoises, Murillo PereiraLis Arias, Manuel JoséMaesta Bezerra, FabricioMetal-organic frameworks are crystalline nanostructures formed by a metal interspersed by an organic binder. These metal-organic materials are examples of nanomaterials applied to textile material in search of new functionalized textiles. Cotton is a cellulosic fiber of great commercial importance, and has good absorption capacity and breathability; however, due to these characteristics, it is susceptible to the development of microorganisms on its surface. This work aims to analyze how the direct synthesis of HKUST-1 in cotton fabric modifies the chemical and physical properties. The material obtained was characterized by scanning electron microscopy to obtain its morphology, by spectrophotometry CIE L*a*b* to verify the color change, by a biological test to verify its resistance to microorganisms and, finally, by a unidirectional traction test to verify the change in its mechanical resistance. Thereby, it was possible to observe the formation of MOFs with the morphology of nanorods, and also, with regard to HKUST-1 in the cotton fabric, when applied, an elimination percentage higher than 99% was observed for both bacteria, E. coli and S. aureus. The presence of MOF was detected even after washing, however, the loss of 75% in the mechanical resistance of the material makes its potential for textile finishing unworkable.