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Different alkali deep eutectic solvents (DES), such as LiI:nEG, NaI:nEG, and KI:nEG, have been tested as electrolytes for dye sensitized solar cells (DSSCs). These DSSCs were prepared using pure DES or, alternatively, DES combined with different amounts of iodine (I2). The most important parameters, such as open circuit voltage (VOC), short circuit current density (JSC), fill factor (FF), and the overall conversion efficiency (η), were evaluated. Some DES seem to be promising candidates for DSSC applications, since they present higher VOC (up to 140 mV), similar FF values but less current density values, when compared with a reference electrolyte in the same experimental conditions. Additionally, electrochemical impedance spectroscopy (EIS) has been performed to elucidate the charge transfer and transport processes that occur in DSSCs. The values of different resistance (Ω·cm2) phenomena and recombination/relaxation time (s) for each process have been calculated. The best-performance was obtained for DES-based electrolyte, KI:EG (containing 0.5 mol% I2) showing an efficiency of 2.3%. The efficiency of this DES-based electrolyte is comparable to other literature systems, but the device stability is higher (only after seven months the performance of the device drop to 60%).
Hugo Cruz; Ana Pinto; Noémi Jordão; Luísa Neves; Luís Branco. Alkali Iodide Deep Eutectic Solvents as Alternative Electrolytes for Dye Sensitized Solar Cells. Sustainable Chemistry 2021, 2, 222 -236.
AMA StyleHugo Cruz, Ana Pinto, Noémi Jordão, Luísa Neves, Luís Branco. Alkali Iodide Deep Eutectic Solvents as Alternative Electrolytes for Dye Sensitized Solar Cells. Sustainable Chemistry. 2021; 2 (2):222-236.
Chicago/Turabian StyleHugo Cruz; Ana Pinto; Noémi Jordão; Luísa Neves; Luís Branco. 2021. "Alkali Iodide Deep Eutectic Solvents as Alternative Electrolytes for Dye Sensitized Solar Cells." Sustainable Chemistry 2, no. 2: 222-236.
This study seeks to render residues from banana plants into a useful byproduct with possible applications in wound dressings and food packaging. Films based on cellulose extracted from banana plant pseudostem and doped with phenolic compounds extracted from banana plant leaves were developed. The phenolic compounds were extracted using batch solid-liquid and Soxhlet methods, with different drying temperatures and periods of time. The total phenolic content and antioxidant activity were quantified. The optimum values were obtained using a three-day period batch-solid extraction at 40 °C (791.74 ± 43.75 mg/L). SEM analysis indicates that the pseudostem (PS) films have a porous structure, as opposed to hydroxyethyl cellulose (HEC) films which presented a homogeneous and dense surface. Mechanical properties confirmed the poor robustness of PS films. By contrast HEC films manifested improved tensile strength at low levels of water activity. FTIR spectroscopy reinforced the need to improve the cellulose extraction process, the success of lignin and hemicellulose removal, and the presence of phenolic compounds. XRD, TGA and contact angle analysis showed similar results for both films, with an amorphous structure, thermal stability and hydrophilic behavior.
Rosa Nascimento; Joana Monte; Mafalda Cadima; Vítor Alves; Luísa Neves. Rendering Banana Plant Residues into a Potentially Commercial Byproduct by Doping Cellulose Films with Phenolic Compounds. Polymers 2021, 13, 843 .
AMA StyleRosa Nascimento, Joana Monte, Mafalda Cadima, Vítor Alves, Luísa Neves. Rendering Banana Plant Residues into a Potentially Commercial Byproduct by Doping Cellulose Films with Phenolic Compounds. Polymers. 2021; 13 (5):843.
Chicago/Turabian StyleRosa Nascimento; Joana Monte; Mafalda Cadima; Vítor Alves; Luísa Neves. 2021. "Rendering Banana Plant Residues into a Potentially Commercial Byproduct by Doping Cellulose Films with Phenolic Compounds." Polymers 13, no. 5: 843.
Cynara cardunculus (cardoon) leaves are a rich source of bioactive compounds, such as cynaropicrin. In this work, ethanolic pulsed ultrasound assisted extraction (EtPUAE) derived extracts obtained from cardoon leaves were purified by membrane processing and the different fractions obtained were evaluated for their biological potential. A DuraMem® 200 membrane was selected for cynaropicrin recovery and removal of carbohydrates, in a diananofiltration mode. Diananofiltration (after 5 diavolumes) followed by nanofiltration allowed for a removal of 93.0% of glucose and 95.6% of fructose, with a cynaropicrin maximum loss of 13.9%. The fractionated extract revealed a higher biological activity, when tested with a BJ5-ta human normal fibroblast cell line. An integrated process is proposed, comprising an association of EtPUAE with a fractionation by diananofiltration, assuring a pay-back period of 4.58 years, assessed through an economic evaluation.
Teresa Brás; Daniela Rosa; Ana C. Gonçalves; Andreia C. Gomes; Carla Brazinha; Luísa A. Neves; Maria F. Duarte; João G. Crespo. Fractionation of Cynara cardunculus ethanolic extracts using diananofiltration. Separation and Purification Technology 2020, 256, 117856 .
AMA StyleTeresa Brás, Daniela Rosa, Ana C. Gonçalves, Andreia C. Gomes, Carla Brazinha, Luísa A. Neves, Maria F. Duarte, João G. Crespo. Fractionation of Cynara cardunculus ethanolic extracts using diananofiltration. Separation and Purification Technology. 2020; 256 ():117856.
Chicago/Turabian StyleTeresa Brás; Daniela Rosa; Ana C. Gonçalves; Andreia C. Gomes; Carla Brazinha; Luísa A. Neves; Maria F. Duarte; João G. Crespo. 2020. "Fractionation of Cynara cardunculus ethanolic extracts using diananofiltration." Separation and Purification Technology 256, no. : 117856.
The development of natural based, effective and protective wound dressings associated to local treatment applied on chronic wounds, represents a major challenge nowadays. In this work chitosan-based films were prepared with different concentrations of ethanolic ultrasound assisted extracts from Cynara cardunculus leaves (EtPUAE). The physico-chemical film properties revealed that extract incorporation influences the volumetric swelling capacity and mechanical properties of the films, leading to materials with a lower fluid absorption capacity and more fragile. However, no impact was detected on the thermal properties of the films, as well as on their dense structure characterized by Scanning Electronic Microscopy (SEM) analysis. Biological screening of chitosan-based films show that chitosan with a 1% (w/w) and a 5% (w/w) EtPUAE loading did not induce cytotoxicity on normal human skin fibroblasts (Bj5-ta cell line), mainly attributed to cynaropicrin (extract key active compound) present in the film below its IC50 value. Nevertheless, chitosan-based films with 5% (w/w) EtPUAE presented an interesting anti-inflammatory activity. Bj5-ta cells stimulated with liposaccharides (LPS), presented a reduction of 86% on IL-6 cytokine levels, after exposure to chitosan with 5% EtPUAE film extract. The results obtained in this study open up the possibility of successfully using chitosan films doped with EtPUAE for development of chronic wound dressings, with the advantage of using naturally-sourced materials with anti-inflammatory activity.
Teresa Brás; Daniela Rosa; Ana C. Gonçalves; Andreia C. Gomes; Vítor D. Alves; João G. Crespo; Maria F. Duarte; Luísa A. Neves. Development of bioactive films based on chitosan and Cynara cardunculus leaves extracts for wound dressings. International Journal of Biological Macromolecules 2020, 163, 1707 -1718.
AMA StyleTeresa Brás, Daniela Rosa, Ana C. Gonçalves, Andreia C. Gomes, Vítor D. Alves, João G. Crespo, Maria F. Duarte, Luísa A. Neves. Development of bioactive films based on chitosan and Cynara cardunculus leaves extracts for wound dressings. International Journal of Biological Macromolecules. 2020; 163 ():1707-1718.
Chicago/Turabian StyleTeresa Brás; Daniela Rosa; Ana C. Gonçalves; Andreia C. Gomes; Vítor D. Alves; João G. Crespo; Maria F. Duarte; Luísa A. Neves. 2020. "Development of bioactive films based on chitosan and Cynara cardunculus leaves extracts for wound dressings." International Journal of Biological Macromolecules 163, no. : 1707-1718.
Deep eutectic mixtures (DES) have been proposed in the last years as viable and more sustainable solvents, in a myriad of applications. CO2 capture or adsorption is one of those possible applications, where DES can act as an alternative to the amine-based solvents that are currently being used in carbon capture and sequestration (CCS) processes. In this work, different choline chloride DES were prepared, and CO2 solubility and diffusivity coefficients were measured. The DES were immobilized in a PTFE porous support, and the pure gas permeability of 3 different gases (N2, CO2 and CH4) was assessed, as well as DES supported liquid membranes ideal selectivity. An enzyme that is able to convert CO2 into bicarbonate was also added to the DES and DES supported membranes, in order to increase the transport towards CO2. The tested DES show solubility values in line with the ones reported in literature for related DES family and ionic liquids. Solubility and diffusivity of CO2 showed the best results in the DES composed of choline chloride and urea, showing even higher values when the enzyme was dispersed. The supported liquid membranes show higher permeability towards CO2, especially in DES with choline chloride and urea. The membrane containing this DES also showed high selectivity for CO2/CH4, with values above the Robeson upper bound. This proves that DES supported membranes are a viable strategy for CO2 adsorption/sequestration and that the prepared membranes may have applications in gas separation processes, particularly in the separation of CO2 from CH4, as in the case of natural gas streams treatment or biogas.
Rita Craveiro; Luísa A. Neves; Ana Rita C. Duarte; Alexandre Paiva. Supported liquid membranes based on deep eutectic solvents for gas separation processes. Separation and Purification Technology 2020, 254, 117593 .
AMA StyleRita Craveiro, Luísa A. Neves, Ana Rita C. Duarte, Alexandre Paiva. Supported liquid membranes based on deep eutectic solvents for gas separation processes. Separation and Purification Technology. 2020; 254 ():117593.
Chicago/Turabian StyleRita Craveiro; Luísa A. Neves; Ana Rita C. Duarte; Alexandre Paiva. 2020. "Supported liquid membranes based on deep eutectic solvents for gas separation processes." Separation and Purification Technology 254, no. : 117593.
This work explores the novelty of dissolving chitin-glucan complex (CGC), from two fungal strains, Komagataella pastoris (CGCP) and Aspergillus niger (CGCKZ) (KiOnutrime-CG™), using biocompatible ionic liquids (ILs). Three cholinium-based ILs were tested, choline acetate, choline propionate and choline hexanoate. Although all tested ILs resulted in the dissolution of the co-polymer at a concentration of 5 % (w/w), distinct polymeric structures, films or gels, were obtained from CGCP and CGCKZ, respectively. CGCP films were dense, flexible and elastic, with high swelling capacity (> 200 %). The IL anion alkyl chain length influenced the polymeric structures’ properties, namely, the CGCP films elongation at break and swelling degree. CGCKZ resulted in weak gels. For both polymeric structures, exposure to the ILs under the dissolution conditions caused significant changes in the co-polymers’ chemical structure, namely, reduction of their glucan moiety and reduction of the degree of acetylation, thus yielding chitosan-glucan complexes (ChGC) enriched in glucosamine (53.4 ± 0.3–60.8 ± 0.3 %).
Inês C. Ferreira; Diana Araújo; Pierre Voisin; Vítor D. Alves; Andreia A. Rosatella; Carlos A.M. Afonso; Filomena Freitas; Luísa A. Neves. Chitin-glucan complex – Based biopolymeric structures using biocompatible ionic liquids. Carbohydrate Polymers 2020, 247, 116679 .
AMA StyleInês C. Ferreira, Diana Araújo, Pierre Voisin, Vítor D. Alves, Andreia A. Rosatella, Carlos A.M. Afonso, Filomena Freitas, Luísa A. Neves. Chitin-glucan complex – Based biopolymeric structures using biocompatible ionic liquids. Carbohydrate Polymers. 2020; 247 ():116679.
Chicago/Turabian StyleInês C. Ferreira; Diana Araújo; Pierre Voisin; Vítor D. Alves; Andreia A. Rosatella; Carlos A.M. Afonso; Filomena Freitas; Luísa A. Neves. 2020. "Chitin-glucan complex – Based biopolymeric structures using biocompatible ionic liquids." Carbohydrate Polymers 247, no. : 116679.
Deep eutectic solvents (DES) composed of lithium, sodium, or potassium iodide salts in suitable combination with ethylene glycol (EG), glycerol (Gly), or polyethylene glycol (PEG) have been developed. All prepared DES were characterized by thermal analysis (DSC and TGA) and its complex conductivity (σ*) and impedance (Z*) frequency were evaluated through dielectric relaxation spectroscopy (DRS). Two- and three-electrode electrochemical studies of all DES have been performed. All DES avoid crystallization, exhibiting conductivity values in a range from 10–4 to 10–2 S cm–1 at room temperature and electrochemical windows higher than 1 V (on the order of 3–4 V), fulfilling the usual suitability criteria for utilization in electrochromic devices (ECD). The most promissory DES as electrolytes were tested for ECD. Being suitable candidates for further application in batteries.
Hugo Cruz; Noemi Jordao; Ana Lucia Pinto; Madalena Dionisio; Luisa A. Neves; Luis C. Branco. Alkaline Iodide-Based Deep Eutectic Solvents for Electrochemical Applications. ACS Sustainable Chemistry & Engineering 2020, 1 .
AMA StyleHugo Cruz, Noemi Jordao, Ana Lucia Pinto, Madalena Dionisio, Luisa A. Neves, Luis C. Branco. Alkaline Iodide-Based Deep Eutectic Solvents for Electrochemical Applications. ACS Sustainable Chemistry & Engineering. 2020; ():1.
Chicago/Turabian StyleHugo Cruz; Noemi Jordao; Ana Lucia Pinto; Madalena Dionisio; Luisa A. Neves; Luis C. Branco. 2020. "Alkaline Iodide-Based Deep Eutectic Solvents for Electrochemical Applications." ACS Sustainable Chemistry & Engineering , no. : 1.
The unprecedently high CO2 levels in the atmosphere evoke the urgent need for development of technologies for mitigation of its emissions. Among the alternatives, the biocatalytic route has been claimed as one of the most promising. In the present work, the carbonic anhydrase from bovine erythrocytes (BCA) was employed as a model enzyme for structural studies in an aqueous phase at alkaline pH, which is typical of large-scale absorption processes under operation. Circular dichroism (CD) analysis revealed a high enzymatic stability at pH 10 with a prominent decrease of the melting temperature above this value. The CO2 absorption capacity of the aqueous solutions were assessed by online monitoring of pressure decay in a stainless-steel cell, which indicated a better performance at pH 10 with a kinetic rate increase of up to 43%, as compared to non-biocatalytic conditions. Even low enzyme concentrations (0.2 mg g−1) proved to be sufficient to improve the overall CO2 capture process performance. The enzyme-enhanced approach of CO2 capture presents a high potential and should be further studied.
Aline M. De Castro; Elisabete Ferreira; Carla Portugal; Luisa A. Neves; João G. Crespo. Biocatalytic CO2 Absorption and Structural Studies of Carbonic Anhydrase under Industrially-Relevant Conditions. International Journal of Molecular Sciences 2020, 21, 2918 .
AMA StyleAline M. De Castro, Elisabete Ferreira, Carla Portugal, Luisa A. Neves, João G. Crespo. Biocatalytic CO2 Absorption and Structural Studies of Carbonic Anhydrase under Industrially-Relevant Conditions. International Journal of Molecular Sciences. 2020; 21 (8):2918.
Chicago/Turabian StyleAline M. De Castro; Elisabete Ferreira; Carla Portugal; Luisa A. Neves; João G. Crespo. 2020. "Biocatalytic CO2 Absorption and Structural Studies of Carbonic Anhydrase under Industrially-Relevant Conditions." International Journal of Molecular Sciences 21, no. 8: 2918.
In this study, conditions for ultrasound assisted extraction (UAE) of cynaropicrin from Cynara cardunculus leaves by assessing the effect of pulsed mode and different duty cycles were optimized. Pulse mode presented a reduction of 45 % on energy consumption/ g cynaropicrin extracted, comparatively to continuous mode, and a duty cycle of 25 % presented the highest kinetic rate between the duty cycles under study, with a lower number of pulse repetitions necessary to reach a steady state conditions. The extraction methodology was further optimized by response surface methodology (RSM), using a Box-Bhenken design with 3 factors (solid/liquid ratio, amplitude and temperature), and 3 levels for correlation of independent variables with the extraction yield (mg of cynaropicrin/g dry weight) and cynaropicrin concentration (mg cynaropicrin /g extract). Experimental results were fitted to a second order polynomial model, using multiple regression and analysis of variance to determine the fitness of the model. Optimal conditions were found for a solid/liquid ratio of 1/27, amplitude of 67 % and temperature of 44 °C, with a predicted value of 23.99 mg/g DW and 192.23 mg/g extract for extraction yield and cynaropicrin concentration, respectively. The predicted values fit the experimental ones, with a 95 % confidence level showing the accuracy of the model. The results obtained suggest the applicability of the UAE optimization methodologies described, for cynaropicrin extraction from Cynara cardunculus leaves, illustrating its potential application on biotechnological and agro food industries.
Teresa Brás; Ana F.C. Paulino; Luísa A. Neves; João Crespo; Maria F. Duarte. Ultrasound assisted extraction of cynaropicrin from Cynara cardunculus leaves: Optimization using the response surface methodology and the effect of pulse mode. Industrial Crops and Products 2020, 150, 112395 .
AMA StyleTeresa Brás, Ana F.C. Paulino, Luísa A. Neves, João Crespo, Maria F. Duarte. Ultrasound assisted extraction of cynaropicrin from Cynara cardunculus leaves: Optimization using the response surface methodology and the effect of pulse mode. Industrial Crops and Products. 2020; 150 ():112395.
Chicago/Turabian StyleTeresa Brás; Ana F.C. Paulino; Luísa A. Neves; João Crespo; Maria F. Duarte. 2020. "Ultrasound assisted extraction of cynaropicrin from Cynara cardunculus leaves: Optimization using the response surface methodology and the effect of pulse mode." Industrial Crops and Products 150, no. : 112395.
The co-culture of Cupriavidus necator DSM 428 and Pseudomonas citronellolis NRRL B-2504 was performed using apple pulp waste from the fruit processing industry as the sole carbon source to produce poly(3-hydroxybutyrate), P(3HB) and medium-chain length PHA, mcl-PHA, respectively. The polymers accumulated by both strains were extracted from the co-culture’s biomass, resulting in a natural blend that was composed of around 48 wt% P(3HB) and 52 wt% mcl-PHA, with an average molecular weight of 4.3 × 105 Da and a polydispersity index of 2.2. Two melting temperatures (Tm) were observed for the blend, 52 and 174 °C, which correspond to the Tm of the mcl-PHA and P(3HB), respectively. P(3HB)/mcl-PHA blend films prepared by the solvent evaporation method had permeabilities to oxygen and carbon dioxide of 2.6 and 32 Barrer, respectively. The films were flexible and easily deformed, as demonstrated by their tensile strength at break of 1.47 ± 0.07 MPa, with a deformation of 338 ± 19% until breaking, associated with a Young modulus of 5.42 ± 1.02 MPa. This study demonstrates for the first time the feasibility of using the co-culture of C. necator and P. citronellolis strains to obtain a natural blend of P(3HB)/mcl-PHA that can be processed into films suitable for applications ranging from commodity packaging products to high-value biomaterials.
Ana Teresa Rebocho; João R. Pereira; Luísa A. Neves; Vítor D. Alves; Chantal Sevrin; Christian Grandfils; Filomena Freitas; Maria A. M. Reis. Preparation and Characterization of Films Based on a Natural P(3HB)/mcl-PHA Blend Obtained through the Co-culture of Cupriavidus Necator and Pseudomonas Citronellolis in Apple Pulp Waste. Bioengineering 2020, 7, 34 .
AMA StyleAna Teresa Rebocho, João R. Pereira, Luísa A. Neves, Vítor D. Alves, Chantal Sevrin, Christian Grandfils, Filomena Freitas, Maria A. M. Reis. Preparation and Characterization of Films Based on a Natural P(3HB)/mcl-PHA Blend Obtained through the Co-culture of Cupriavidus Necator and Pseudomonas Citronellolis in Apple Pulp Waste. Bioengineering. 2020; 7 (2):34.
Chicago/Turabian StyleAna Teresa Rebocho; João R. Pereira; Luísa A. Neves; Vítor D. Alves; Chantal Sevrin; Christian Grandfils; Filomena Freitas; Maria A. M. Reis. 2020. "Preparation and Characterization of Films Based on a Natural P(3HB)/mcl-PHA Blend Obtained through the Co-culture of Cupriavidus Necator and Pseudomonas Citronellolis in Apple Pulp Waste." Bioengineering 7, no. 2: 34.
Iongel-based CO2 separation membranes were prepared by fast (< 1 min) UV-initiated polymerization of poly(ethylene glycol) diacrylate (PEGDA) in the presence of different ionic liquids (ILs) with the [C2mim]+ cation and anions such as [TFSI]−, [FSI]−, [C(CN)3]− and [B(CN)4]−. The four ILs were completely miscible with the non-ionic PEGDA network. Transparent and free-standing iongels containing between 60 and 90 %wt of IL were obtained and characterized by diverse techniques (FTIR, TGA, DSC, DMTA, SEM, CO2 solubility and pure gas permeability). The thermal and mechanical stability of the iongels, as well as CO2 solubility, were found to be strictly dependent on the IL content and the anion’s nature. The TGA results indicated that the iongels mostly follow the thermal profile of the respective neat ILs. The DMTA analysis revealed that the iongels based on fluorinated anions have higher storage modulus than those of cyano-functionalized anions. Conversely, the PEGDA–C(CN)3 iongels presented the highest CO2 solubility values ranging from 72 to 80 mmol/g. Single CO2 permeabilities of 583 ± 29 Barrer and ideal CO2/N2 selectivities of 66 ± 3 were obtained with the PEGDA–70 C(CN)3 iongel membrane. This work demonstrates that the combination of PEGDA with high contents of the best performing ILs is a promising and simple strategy, opening up new possibilities in the design of high-performance iongel membranes for CO2 separation.
Ana P. S. Martins; Asier Fdz De Añastro; Jorge L. Olmedo-Martínez; Ana R. Nabais; Luísa A. Neves; David Mecerreyes; Liliana C. Tomé. Influence of Anion Structure on Thermal, Mechanical and CO2 Solubility Properties of UV-Cross-Linked Poly(ethylene glycol) Diacrylate Iongels. Membranes 2020, 10, 46 .
AMA StyleAna P. S. Martins, Asier Fdz De Añastro, Jorge L. Olmedo-Martínez, Ana R. Nabais, Luísa A. Neves, David Mecerreyes, Liliana C. Tomé. Influence of Anion Structure on Thermal, Mechanical and CO2 Solubility Properties of UV-Cross-Linked Poly(ethylene glycol) Diacrylate Iongels. Membranes. 2020; 10 (3):46.
Chicago/Turabian StyleAna P. S. Martins; Asier Fdz De Añastro; Jorge L. Olmedo-Martínez; Ana R. Nabais; Luísa A. Neves; David Mecerreyes; Liliana C. Tomé. 2020. "Influence of Anion Structure on Thermal, Mechanical and CO2 Solubility Properties of UV-Cross-Linked Poly(ethylene glycol) Diacrylate Iongels." Membranes 10, no. 3: 46.
Ana Teresa Rebocho; Filomena Freitas; Joao Ricardo Pereira; Luisa Alexandra Neves; Vitor Delgado Alves; Chantal Sevrin; Christian Grandfils; Maria A Reis. Production of Medium-Chain Length Polyhydroxyalkanoates by Pseudomonas citronellolis Grown in Apple Pulp Waste. 2020, 1 .
AMA StyleAna Teresa Rebocho, Filomena Freitas, Joao Ricardo Pereira, Luisa Alexandra Neves, Vitor Delgado Alves, Chantal Sevrin, Christian Grandfils, Maria A Reis. Production of Medium-Chain Length Polyhydroxyalkanoates by Pseudomonas citronellolis Grown in Apple Pulp Waste. . 2020; ():1.
Chicago/Turabian StyleAna Teresa Rebocho; Filomena Freitas; Joao Ricardo Pereira; Luisa Alexandra Neves; Vitor Delgado Alves; Chantal Sevrin; Christian Grandfils; Maria A Reis. 2020. "Production of Medium-Chain Length Polyhydroxyalkanoates by Pseudomonas citronellolis Grown in Apple Pulp Waste." , no. : 1.
Chitin, chitosan and their complexes with β‐glucan (chitin–glucan complex, CGC, and chitosan–glucan complex, ChGC) are value‐added polysaccharides extracted from the cell‐walls of many fungi. Commercial chitin and its deacetylated form, chitosan, are currently obtained from marine waste material, mostly animal sources (crustaceans and marine invertebrates), through harsh chemical procedures that have low reproducibility due to the variability of the composition of the sources and their seasonal character. These disadvantages are overcome by using fungi as sources of chitinous polymers. The extraction of chitin/chitosan from fungi cell‐walls has the great advantage of yielding products with stable composition and properties, using simpler procedures, with the added benefit of also generating CGC and ChGC, two copolymers that combine the proven properties of chitin/chitosan with those of β‐glucans. Over the last decades, fungal chitinous polymers have been the focus of extensive research that included optimization of the cultivation conditions of a wide range of species and the development of optimized extraction, purification and characterization techniques, as well as the demonstration of the biopolymers' biological properties, which include immunomodulatory, anticancer, antioxidant and antimicrobial activity. Given these properties, several attempts were made to develop applications for them in areas ranging from biomedicine and pharmaceuticals to food and agriculture. Despite their wide range of proven functional properties that include the ability to form different polymeric structures, as well as biological activity, fungal chitinous biopolymers are still underexplored. Nevertheless, these biopolymers hold great potential for development into valuable products or applications that are surely worth further investigation. © 2019 Society of Chemical Industry
Diana Araújo; Inês Ferreira; Cristiana A. V. Torres; Luísa Neves; Filomena Freitas. Chitinous polymers: extraction from fungal sources, characterization and processing towards value‐added applications. Journal of Chemical Technology & Biotechnology 2019, 95, 1277 -1289.
AMA StyleDiana Araújo, Inês Ferreira, Cristiana A. V. Torres, Luísa Neves, Filomena Freitas. Chitinous polymers: extraction from fungal sources, characterization and processing towards value‐added applications. Journal of Chemical Technology & Biotechnology. 2019; 95 (5):1277-1289.
Chicago/Turabian StyleDiana Araújo; Inês Ferreira; Cristiana A. V. Torres; Luísa Neves; Filomena Freitas. 2019. "Chitinous polymers: extraction from fungal sources, characterization and processing towards value‐added applications." Journal of Chemical Technology & Biotechnology 95, no. 5: 1277-1289.
Bearing in mind that Metal Organic Frameworks (MOFs) have remarkable CO2 adsorption selectivity and Mixed Matrix Membranes (MMMs) have been identified as potential solution for advancing the current state of the art of membrane separation technology, this work investigates the effect of combining a MOF, with high adsorption properties towards CO2 when compared to CH4 (MOF-5), with a blend of poly(ionic liquid)/ionic liquid (PIL/IL) for biogas upgrading. The blend system consisted of a pyrrolidinium-based PIL, poly([Pyr11][Tf2N]), and a free imidazolium-based IL, [C2mim][BETI]. The MOF-5 was incorporated at different loadings (10, 20, 30 wt%), and MMMs were prepared by solvent evaporation and characterized by diverse techniques (FTIR, SEM, TGA, puncture tests and single gas transport). The results showed that the free IL is miscible with the PIL, while MOF-5 particles were uniformly dispersed into the PIL/IL matrix. The formed PIL/IL/MOF-5 membranes revealed suitable thermal stability (Tonset up to 656 K) for biogas upgrading processes, but a loss of mechanical stability was found after the incorporation of MOF-5, and thus more rigid and fragile membranes were obtained. At 30 wt% of MOF-5 loading the CO2 permeability increased 133% when compared to that of the pristine PIL/IL membrane, mainly due to the adsorption capacity of the MOF, as well as its porous structure. The presence of a porous structure may also be the reason why the ideal selectivity decreases by 88% for the MMM with the highest loading. It was possible to demonstrate the relevance of studying different components within the polymeric matrix in order to assess not only thermal, mechanical and chemical properties, but also gas transport response.
Adriana M. Sampaio; Ana Rita Nabais; Liliana C. Tomé; Luísa A. Neves. Impact of MOF-5 on Pyrrolidinium-Based Poly(ionic liquid)/Ionic Liquid Membranes for Biogas Upgrading. Industrial & Engineering Chemistry Research 2019, 59, 308 -317.
AMA StyleAdriana M. Sampaio, Ana Rita Nabais, Liliana C. Tomé, Luísa A. Neves. Impact of MOF-5 on Pyrrolidinium-Based Poly(ionic liquid)/Ionic Liquid Membranes for Biogas Upgrading. Industrial & Engineering Chemistry Research. 2019; 59 (1):308-317.
Chicago/Turabian StyleAdriana M. Sampaio; Ana Rita Nabais; Liliana C. Tomé; Luísa A. Neves. 2019. "Impact of MOF-5 on Pyrrolidinium-Based Poly(ionic liquid)/Ionic Liquid Membranes for Biogas Upgrading." Industrial & Engineering Chemistry Research 59, no. 1: 308-317.
Conventional extraction technologies to recover sesquiterpene lactones, relay on long extraction periods, with high temperatures, and use of organic solvents, often leading to degradation of target compounds. Within the present study, the effect of environmentally friendly, and economically viable methodologies, namely ultrasound assisted extraction, using biocompatible solvents, upon cynaropicrin, a sesquiterpene lactone found in Cynara cardunculus leaves was evaluated. Hansen solubility parameters, cynaropicrin extraction yield and energy consumption were evaluated. The ultrasound assisted extraction, using ethanol, showed to be the best cynaropicrin extraction methodology, leading to a reduction of 99% of extraction time (7 h to 5 min), a 30% increase of the cynaropicrin extraction yield (40.32–55.00 mg/g Dry Weight), and a 97% reduction of energy consumption (1.160–0.027 kWh/gcynaropicrin), compared to Soxhlet extraction. The results obtained from this study may be easily transposed to other sesquiterpene lactones extraction processes, with industrial relevance, as an alternative to conventional extraction methodologies.
Teresa Brás; Luísa A. Neves; João Crespo; Maria F. Duarte. Effect of extraction methodologies and solvent selection upon cynaropicrin extraction from Cynara cardunculus leaves. Separation and Purification Technology 2019, 236, 116283 .
AMA StyleTeresa Brás, Luísa A. Neves, João Crespo, Maria F. Duarte. Effect of extraction methodologies and solvent selection upon cynaropicrin extraction from Cynara cardunculus leaves. Separation and Purification Technology. 2019; 236 ():116283.
Chicago/Turabian StyleTeresa Brás; Luísa A. Neves; João Crespo; Maria F. Duarte. 2019. "Effect of extraction methodologies and solvent selection upon cynaropicrin extraction from Cynara cardunculus leaves." Separation and Purification Technology 236, no. : 116283.
Poly(ionic liquid)s (PIL) have emerged as a class of versatile polyelectrolites, that can be used to prepare new materials able to achieve superior performances compared to conventional polymers. The combination of PILs with ionic liquids (ILs) may serve as a suitable matrix for the preparation of membranes for gas separation. In this work, mixed matrix membranes (MMMs) combining a pyrrolidinium-based PIL, an IL and three highly CO2-selective metal organic frameworks (MOFs) were prepared. The different MOFs (MIL-53(Al), Cu3(BTC)2 and ZIF-8) were used as fillers, aiming to maximize the membranes performance towards the purification of syngas. The influence of different MOFs and loadings (0, 10, 20 and 30 wt.%) on the thermal and mechanical stabilities of the membranes and their performance in terms of CO2 permeability and CO2/H2 ideal selectivity was assessed. The compatibility between the materials was confirmed by SEM-EDS and FTIR spectroscopy. The prepared MMMs revealed to be thermally stable within the temperature range of the syngas stream, with a loss of mechanical stability upon the MOF incorporation. The increasing MOF content in the MMMs, resulted in an improvement of both CO2 permeability and CO2/H2 ideal selectivity. Among the three MOFs studied, membranes based on ZIF-8 showed the highest permeabilities (up to 97.2 barrer), while membranes based on MIL-53(Al) showed the highest improvement in selectivity (up to 13.3). Remarkably, all permeation results surpass the upper bound limit for the CO2/H2 separation, showing the membranes potential for the desired gas separation.
Ana Nabais; Ana P. S. Martins; Vítor D. Alves; João Crespo; Isabel M. Marrucho; Liliana C. Tomé; Luísa A. Neves. Poly(ionic liquid)-based engineered mixed matrix membranes for CO2/H2 separation. Separation and Purification Technology 2019, 222, 168 -176.
AMA StyleAna Nabais, Ana P. S. Martins, Vítor D. Alves, João Crespo, Isabel M. Marrucho, Liliana C. Tomé, Luísa A. Neves. Poly(ionic liquid)-based engineered mixed matrix membranes for CO2/H2 separation. Separation and Purification Technology. 2019; 222 ():168-176.
Chicago/Turabian StyleAna Nabais; Ana P. S. Martins; Vítor D. Alves; João Crespo; Isabel M. Marrucho; Liliana C. Tomé; Luísa A. Neves. 2019. "Poly(ionic liquid)-based engineered mixed matrix membranes for CO2/H2 separation." Separation and Purification Technology 222, no. : 168-176.
The efficient separation of gases has industrial, economic, and environmental importance. Here, we report the improvement in gas separation performance of a polyimide-based matrix (Matrimid®5218) filled with a Cu-based metal organic framework [MOF, Cu3(BTC)2] with two different ionic liquids (ILs) confined within the pores. The chosen ILs are commonly used in gas solubilization, 1-ethyl-3-methylimidazolium tetrafluoroborate ([EMIM][BF4]) and 1-Ethyl-3-methylimidazolium trifluoromethanesulfonate ([EMIM][OTf]), and the incorporation of the [EMIM][BF4]@Cu-BTC and [EMIM][OTf]@Cu-BTC composites in Matrimid®5218 proved to be an efficient strategy to improve the permeability and selectivity toward CO2/N2 and CO2/CH4 mixtures.
Bernardo Monteiro; Ana R. Nabais; Maria H. Casimiro; Ana P. S. Martins; Rute O. Francisco; Luísa A. Neves; Cláudia C. L. Pereira. Impact on CO2/N2 and CO2/CH4 Separation Performance Using Cu-BTC with Supported Ionic Liquids-Based Mixed Matrix Membranes. Membranes 2018, 8, 93 .
AMA StyleBernardo Monteiro, Ana R. Nabais, Maria H. Casimiro, Ana P. S. Martins, Rute O. Francisco, Luísa A. Neves, Cláudia C. L. Pereira. Impact on CO2/N2 and CO2/CH4 Separation Performance Using Cu-BTC with Supported Ionic Liquids-Based Mixed Matrix Membranes. Membranes. 2018; 8 (4):93.
Chicago/Turabian StyleBernardo Monteiro; Ana R. Nabais; Maria H. Casimiro; Ana P. S. Martins; Rute O. Francisco; Luísa A. Neves; Cláudia C. L. Pereira. 2018. "Impact on CO2/N2 and CO2/CH4 Separation Performance Using Cu-BTC with Supported Ionic Liquids-Based Mixed Matrix Membranes." Membranes 8, no. 4: 93.
Pseudomonas chlororaphis subsp. aurantiaca (DSM 19603) was grown on crude glycerol from biodiesel production to produce a medium-chain-length polyhydroxyalkanoate (mcl-PHA), composed of 3-hydroxydodecanoate (43 ± 1.8 mol%), 3-hydroxydecanoate (29 ± 3.1 mol%), 3-hydroxytetradecanoate (12 ± 0.4 mol%), 3-hydroxyoctanoate (10 ± 1.5 mol%) and 3-hydroxyhexanoate (6 ± 0.3 mol%). The biopolymer had an average molecular weight of 1.1 × 105 Da, with a polydispersity index of 1.5, and was semi-crystalline, as shown by its crystallinity index of 37 ± 0.2%. It had low melting (44 °C) and glass transition (−48 °C) temperatures, and was thermally stable up to 285 °C. The biopolymer films were elastic and translucid, were hydrophobic and presented relatively high permeability to oxygen and carbon dioxide. The films demonstrated to have good adhesion properties towards porcine skin and human skin. The tension (61.1 ± 20.6 kPa) and shear (12.7 ± 2.14 kPa) bond strength of the mcl-PHA for porcine skin suggest its potential as a biomaterial for the development of novel natural adhesives for wound closure or wound dressings.
João Ricardo Pereira; Diana Filipa Araújo; Ana C. Marques; Luísa A. Neves; Christian Grandfils; Chantal Sevrin; Vitor Delgado Alves; Elvira Fortunato; Maria A.M. Reis; Filomena Freitas. Demonstration of the adhesive properties of the medium-chain-length polyhydroxyalkanoate produced by Pseudomonas chlororaphis subsp. aurantiaca from glycerol. International Journal of Biological Macromolecules 2018, 122, 1144 -1151.
AMA StyleJoão Ricardo Pereira, Diana Filipa Araújo, Ana C. Marques, Luísa A. Neves, Christian Grandfils, Chantal Sevrin, Vitor Delgado Alves, Elvira Fortunato, Maria A.M. Reis, Filomena Freitas. Demonstration of the adhesive properties of the medium-chain-length polyhydroxyalkanoate produced by Pseudomonas chlororaphis subsp. aurantiaca from glycerol. International Journal of Biological Macromolecules. 2018; 122 ():1144-1151.
Chicago/Turabian StyleJoão Ricardo Pereira; Diana Filipa Araújo; Ana C. Marques; Luísa A. Neves; Christian Grandfils; Chantal Sevrin; Vitor Delgado Alves; Elvira Fortunato; Maria A.M. Reis; Filomena Freitas. 2018. "Demonstration of the adhesive properties of the medium-chain-length polyhydroxyalkanoate produced by Pseudomonas chlororaphis subsp. aurantiaca from glycerol." International Journal of Biological Macromolecules 122, no. : 1144-1151.
The incorporation of a Metal-Organic Framework (MOF), Fe(BTC), into a polymeric membrane was assessed for CO2/N2 gas separation. The adsorptive and filler properties of the MOF in the Mixed Matrix Membranes (MMMs) produced were investigated as a strategy to separate CO2 from N2 and contribute to reduce CO2 emissions. Therefore, Fe(BTC) was firstly characterized by single-component adsorption equilibria measurements of CO2 and N2, to evaluate the MOF performance as an adsorbent for CO2/N2 separation and its adsorption role in the MMMs performance. Fe(BTC) was then incorporated in Matrimid®5218 at different loading percentages, and the MMMs produced were characterized by distinct techniques (SEM, TGA, puncture tests and contact angle essays). Finally, pure gas permeation experiments were carried out for CO2 and N2 at 303 K, 323 K and 353 K, to evaluate the temperature impact on both gas permeability and CO2/N2 ideal selectivity. The results show that an increase in CO2 permeability and CO2/N2 ideal selectivity can be advantageously achieved, especially at the higher operating temperature of 353 K. At these conditions, the Robeson upper-bound is surpassed, which is a clear indication of the high potential of using Matrimid®5218/Fe(BTC) MMMs in post-combustion streams at high-temperatures.
Ana Nabais; Rui Ribeiro; José Mota; Vitor Delgado Alves; Isabel A.A.C. Esteves; Luísa A. Neves. CO 2 /N 2 gas separation using Fe(BTC)-based mixed matrix membranes: A view on the adsorptive and filler properties of metal-organic frameworks. Separation and Purification Technology 2018, 202, 174 -184.
AMA StyleAna Nabais, Rui Ribeiro, José Mota, Vitor Delgado Alves, Isabel A.A.C. Esteves, Luísa A. Neves. CO 2 /N 2 gas separation using Fe(BTC)-based mixed matrix membranes: A view on the adsorptive and filler properties of metal-organic frameworks. Separation and Purification Technology. 2018; 202 ():174-184.
Chicago/Turabian StyleAna Nabais; Rui Ribeiro; José Mota; Vitor Delgado Alves; Isabel A.A.C. Esteves; Luísa A. Neves. 2018. "CO 2 /N 2 gas separation using Fe(BTC)-based mixed matrix membranes: A view on the adsorptive and filler properties of metal-organic frameworks." Separation and Purification Technology 202, no. : 174-184.
Magdalena Malankowska; Charles Martins; H.S. Rho; L.A. Neves; R.M. Tiggelaar; João Crespo; M.P. Pina; R. Mallada; H. Gardeniers; I.M. Coelhoso. Microfluidic devices as gas – Ionic liquid membrane contactors for CO2 removal from anaesthesia gases. Journal of Membrane Science 2018, 545, 107 -115.
AMA StyleMagdalena Malankowska, Charles Martins, H.S. Rho, L.A. Neves, R.M. Tiggelaar, João Crespo, M.P. Pina, R. Mallada, H. Gardeniers, I.M. Coelhoso. Microfluidic devices as gas – Ionic liquid membrane contactors for CO2 removal from anaesthesia gases. Journal of Membrane Science. 2018; 545 ():107-115.
Chicago/Turabian StyleMagdalena Malankowska; Charles Martins; H.S. Rho; L.A. Neves; R.M. Tiggelaar; João Crespo; M.P. Pina; R. Mallada; H. Gardeniers; I.M. Coelhoso. 2018. "Microfluidic devices as gas – Ionic liquid membrane contactors for CO2 removal from anaesthesia gases." Journal of Membrane Science 545, no. : 107-115.