Catarina M S S Neves | Universidade de Aveiro (original) (raw)
Papers by Catarina M S S Neves
The Journal of Physical Chemistry, 2015
Bookmarks Related papers MentionsView impact
The Journal of Physical Chemistry, 2012
Bookmarks Related papers MentionsView impact
De Gruyter eBooks, May 20, 2019
In the past years, the relevance of introducing ionic liquids (ILs) has been shown as phase-formi... more In the past years, the relevance of introducing ionic liquids (ILs) has been shown as phase-forming components of aqueous biphasic systems (ABS), which allow the tailoring of polarity differences between the coexisting phases. Although investigations on the IL chemical structure and polymermolecularweight have been carried out, the use of mixtures of polymers can also be seen as a way of tailoring their two-phase formation ability and separation performance, which was not attempted earlier. In this work, we investigate novel ABS composed of cholinium-based ILs and mixtures of polymers, namely polyethylene glycol (PEG) of 400 and 2,000 g·mol-1, at differentmole fractions, as a way of tailoring the formation of ABS and their separation performance. The respective liquid-liquid phase diagrams were determined, and their ability to separate a set of alkaloids (caffeine, theophylline and theobromine) appraised. An increase on the PEG 2000mole fraction favors the formation of ABS. However, this does not follow a monotonous trend, where mole fractions of PEG 400 up to 0.3 do not display significant impact on the two-phase separation capability. Among the studied alkaloids, nicotine preferentially partitions to the IL-rich phase, while the remaining alkaloids majorly partition to the polymer-rich phase. Different selectivity patterns were verified, depending on the cholinium-based IL used and water content at the IL-rich phase. Overall, by using mixtures of polymers it is possible to decrease the viscosity of the coexisting phases and their toxicity impact, without losing their formation and separation capacities, by the addition of PEGs of lower molecular weight.publishe
Bookmarks Related papers MentionsView impact
RSC Advances, 2012
Bookmarks Related papers MentionsView impact
Journal of Physical Chemistry B, Oct 24, 2007
Bookmarks Related papers MentionsView impact
Ionic liquids are a class of solvents that, due to their unique properties, have been proposed in... more Ionic liquids are a class of solvents that, due to their unique properties, have been proposed in the past few years as alternatives to some hazardous volatile organic compounds. They are already used by industry, where it was possible to improve different processes by the incorporation of this kind of non-volatile and often liquid solvents. However, even if ionic liquids cannot contribute to air pollution, due to their negligible vapour pressures, they can be dispersed thorough aquatic streams thus contaminating the environment. Therefore, the main goals of this work are to study the mutual solubilities between water and different ionic liquids in order to infer on their environmental impact, and to propose effective methods to remove and, whenever possible, recover ionic liquids from aqueous media. The liquid-liquid phase behaviour of different ionic liquids and water was evaluated in the temperature range between (288.15 and 318.15) K. For higher melting temperature ionic liquids...
Bookmarks Related papers MentionsView impact
Ionic Liquids, 2019
In the past years, the relevance of introducing ionic liquids (ILs) has been shown as phase-formi... more In the past years, the relevance of introducing ionic liquids (ILs) has been shown as phase-forming components of aqueous biphasic systems (ABS), which allow the tailoring of polarity differences between the coexisting phases. Although investigations on the IL chemical structure and polymermolecularweight have been carried out, the use of mixtures of polymers can also be seen as a way of tailoring their two-phase formation ability and separation performance, which was not attempted earlier. In this work, we investigate novel ABS composed of cholinium-based ILs and mixtures of polymers, namely polyethylene glycol (PEG) of 400 and 2,000 g·mol-1, at differentmole fractions, as a way of tailoring the formation of ABS and their separation performance. The respective liquid-liquid phase diagrams were determined, and their ability to separate a set of alkaloids (caffeine, theophylline and theobromine) appraised. An increase on the PEG 2000mole fraction favors the formation of ABS. However, this does not follow a monotonous trend, where mole fractions of PEG 400 up to 0.3 do not display significant impact on the two-phase separation capability. Among the studied alkaloids, nicotine preferentially partitions to the IL-rich phase, while the remaining alkaloids majorly partition to the polymer-rich phase. Different selectivity patterns were verified, depending on the cholinium-based IL used and water content at the IL-rich phase. Overall, by using mixtures of polymers it is possible to decrease the viscosity of the coexisting phases and their toxicity impact, without losing their formation and separation capacities, by the addition of PEGs of lower molecular weight.publishe
Bookmarks Related papers MentionsView impact
Frontiers in Chemistry, 2019
Bookmarks Related papers MentionsView impact
Thermochimica Acta, 2018
Bookmarks Related papers MentionsView impact
Chemical Communications, 2018
Sustainable hydrophobic eutectic solvents, composed of low-priced and biodegradable terpenes and ... more Sustainable hydrophobic eutectic solvents, composed of low-priced and biodegradable terpenes and fatty acids, were used for the extraction and separation of Cu(ii) from other transition metals in mildly acidic solutions.
Bookmarks Related papers MentionsView impact
Journal of Solution Chemistry, 2018
Bookmarks Related papers MentionsView impact
Physical chemistry chemical physics : PCCP, Jan 25, 2015
Due to scarce available experimental data, as well as due to the absence of predictive models, th... more Due to scarce available experimental data, as well as due to the absence of predictive models, the influence of salts on the solubility of ionic liquids (ILs) in water is still poorly understood. To this end, this work addresses the solubility of the IL 1-butyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide ([C4C1im][NTf2]), at 298.15 K and 0.1 MPa, in aqueous salt solutions (from 0.1 to 1.5 mol kg(-1)). At salt molalities higher than 0.2 mol kg(-1), all salts caused salting-out of [C4C1im][NTf2] from aqueous solution with their strength decreasing in the following order: Al2(SO4)3 > ZnSO4 > K3C6H5O7 > KNaC4H4O6 > K3PO4 > Mg(CH3CO2)2 > K2HPO4 > MgSO4 > KH2PO4 > KCH3CO2. Some of these salts lead however to the salting-in of [C4C1im][NTf2] in aqueous medium at salt molalities lower than 0.2 mol kg(-1). To attempt the development of a model able to describe the salt effects, comprising both the salting-in and salting-out phenomena observed, the electro...
Bookmarks Related papers MentionsView impact
RSC Advances, 2012
Bookmarks Related papers MentionsView impact
Environmental science. Processes & impacts, 2013
The applications and variety of ionic liquids (ILs) have increased during the last few years, and... more The applications and variety of ionic liquids (ILs) have increased during the last few years, and their use at a large scale will require their removal/recovery from wastewater streams. Adsorption on activated carbons (ACs) has been recently proposed for this aim and this work presents a systematic analysis of the influence of the IL chemical structures (cation side chain, head group, anion type and the presence of functional groups) on their adsorption onto commercial AC from water solution. Here, the adsorption of 21 new ILs, which include imidazolium-, pyridinium-, pyrrolidinium-, piperidinium-, phosphonium- and ammonium-based cations and different hydrophobic and hydrophilic anions, has been experimentally measured. This contribution allows an expansion of the range of IL compounds studied in previous works, and permits a better understanding of the influence of the IL structures through the adsorption on AC. In addition, the COSMO-RS method was used to analyze the measured adso...
Bookmarks Related papers MentionsView impact
The Journal of Physical Chemistry B, 2012
Bookmarks Related papers MentionsView impact
The Journal of Physical Chemistry B, 2013
Bookmarks Related papers MentionsView impact
The Journal of Physical Chemistry B, 2011
Bookmarks Related papers MentionsView impact
The Journal of Physical Chemistry B, 2007
Bookmarks Related papers MentionsView impact
The Journal of Chemical Thermodynamics, 2011
Bookmarks Related papers MentionsView impact
Journal of Chemical & Engineering Data, 2011
Bookmarks Related papers MentionsView impact
The Journal of Physical Chemistry, 2015
Bookmarks Related papers MentionsView impact
The Journal of Physical Chemistry, 2012
Bookmarks Related papers MentionsView impact
De Gruyter eBooks, May 20, 2019
In the past years, the relevance of introducing ionic liquids (ILs) has been shown as phase-formi... more In the past years, the relevance of introducing ionic liquids (ILs) has been shown as phase-forming components of aqueous biphasic systems (ABS), which allow the tailoring of polarity differences between the coexisting phases. Although investigations on the IL chemical structure and polymermolecularweight have been carried out, the use of mixtures of polymers can also be seen as a way of tailoring their two-phase formation ability and separation performance, which was not attempted earlier. In this work, we investigate novel ABS composed of cholinium-based ILs and mixtures of polymers, namely polyethylene glycol (PEG) of 400 and 2,000 g·mol-1, at differentmole fractions, as a way of tailoring the formation of ABS and their separation performance. The respective liquid-liquid phase diagrams were determined, and their ability to separate a set of alkaloids (caffeine, theophylline and theobromine) appraised. An increase on the PEG 2000mole fraction favors the formation of ABS. However, this does not follow a monotonous trend, where mole fractions of PEG 400 up to 0.3 do not display significant impact on the two-phase separation capability. Among the studied alkaloids, nicotine preferentially partitions to the IL-rich phase, while the remaining alkaloids majorly partition to the polymer-rich phase. Different selectivity patterns were verified, depending on the cholinium-based IL used and water content at the IL-rich phase. Overall, by using mixtures of polymers it is possible to decrease the viscosity of the coexisting phases and their toxicity impact, without losing their formation and separation capacities, by the addition of PEGs of lower molecular weight.publishe
Bookmarks Related papers MentionsView impact
RSC Advances, 2012
Bookmarks Related papers MentionsView impact
Journal of Physical Chemistry B, Oct 24, 2007
Bookmarks Related papers MentionsView impact
Ionic liquids are a class of solvents that, due to their unique properties, have been proposed in... more Ionic liquids are a class of solvents that, due to their unique properties, have been proposed in the past few years as alternatives to some hazardous volatile organic compounds. They are already used by industry, where it was possible to improve different processes by the incorporation of this kind of non-volatile and often liquid solvents. However, even if ionic liquids cannot contribute to air pollution, due to their negligible vapour pressures, they can be dispersed thorough aquatic streams thus contaminating the environment. Therefore, the main goals of this work are to study the mutual solubilities between water and different ionic liquids in order to infer on their environmental impact, and to propose effective methods to remove and, whenever possible, recover ionic liquids from aqueous media. The liquid-liquid phase behaviour of different ionic liquids and water was evaluated in the temperature range between (288.15 and 318.15) K. For higher melting temperature ionic liquids...
Bookmarks Related papers MentionsView impact
Ionic Liquids, 2019
In the past years, the relevance of introducing ionic liquids (ILs) has been shown as phase-formi... more In the past years, the relevance of introducing ionic liquids (ILs) has been shown as phase-forming components of aqueous biphasic systems (ABS), which allow the tailoring of polarity differences between the coexisting phases. Although investigations on the IL chemical structure and polymermolecularweight have been carried out, the use of mixtures of polymers can also be seen as a way of tailoring their two-phase formation ability and separation performance, which was not attempted earlier. In this work, we investigate novel ABS composed of cholinium-based ILs and mixtures of polymers, namely polyethylene glycol (PEG) of 400 and 2,000 g·mol-1, at differentmole fractions, as a way of tailoring the formation of ABS and their separation performance. The respective liquid-liquid phase diagrams were determined, and their ability to separate a set of alkaloids (caffeine, theophylline and theobromine) appraised. An increase on the PEG 2000mole fraction favors the formation of ABS. However, this does not follow a monotonous trend, where mole fractions of PEG 400 up to 0.3 do not display significant impact on the two-phase separation capability. Among the studied alkaloids, nicotine preferentially partitions to the IL-rich phase, while the remaining alkaloids majorly partition to the polymer-rich phase. Different selectivity patterns were verified, depending on the cholinium-based IL used and water content at the IL-rich phase. Overall, by using mixtures of polymers it is possible to decrease the viscosity of the coexisting phases and their toxicity impact, without losing their formation and separation capacities, by the addition of PEGs of lower molecular weight.publishe
Bookmarks Related papers MentionsView impact
Frontiers in Chemistry, 2019
Bookmarks Related papers MentionsView impact
Thermochimica Acta, 2018
Bookmarks Related papers MentionsView impact
Chemical Communications, 2018
Sustainable hydrophobic eutectic solvents, composed of low-priced and biodegradable terpenes and ... more Sustainable hydrophobic eutectic solvents, composed of low-priced and biodegradable terpenes and fatty acids, were used for the extraction and separation of Cu(ii) from other transition metals in mildly acidic solutions.
Bookmarks Related papers MentionsView impact
Journal of Solution Chemistry, 2018
Bookmarks Related papers MentionsView impact
Physical chemistry chemical physics : PCCP, Jan 25, 2015
Due to scarce available experimental data, as well as due to the absence of predictive models, th... more Due to scarce available experimental data, as well as due to the absence of predictive models, the influence of salts on the solubility of ionic liquids (ILs) in water is still poorly understood. To this end, this work addresses the solubility of the IL 1-butyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide ([C4C1im][NTf2]), at 298.15 K and 0.1 MPa, in aqueous salt solutions (from 0.1 to 1.5 mol kg(-1)). At salt molalities higher than 0.2 mol kg(-1), all salts caused salting-out of [C4C1im][NTf2] from aqueous solution with their strength decreasing in the following order: Al2(SO4)3 > ZnSO4 > K3C6H5O7 > KNaC4H4O6 > K3PO4 > Mg(CH3CO2)2 > K2HPO4 > MgSO4 > KH2PO4 > KCH3CO2. Some of these salts lead however to the salting-in of [C4C1im][NTf2] in aqueous medium at salt molalities lower than 0.2 mol kg(-1). To attempt the development of a model able to describe the salt effects, comprising both the salting-in and salting-out phenomena observed, the electro...
Bookmarks Related papers MentionsView impact
RSC Advances, 2012
Bookmarks Related papers MentionsView impact
Environmental science. Processes & impacts, 2013
The applications and variety of ionic liquids (ILs) have increased during the last few years, and... more The applications and variety of ionic liquids (ILs) have increased during the last few years, and their use at a large scale will require their removal/recovery from wastewater streams. Adsorption on activated carbons (ACs) has been recently proposed for this aim and this work presents a systematic analysis of the influence of the IL chemical structures (cation side chain, head group, anion type and the presence of functional groups) on their adsorption onto commercial AC from water solution. Here, the adsorption of 21 new ILs, which include imidazolium-, pyridinium-, pyrrolidinium-, piperidinium-, phosphonium- and ammonium-based cations and different hydrophobic and hydrophilic anions, has been experimentally measured. This contribution allows an expansion of the range of IL compounds studied in previous works, and permits a better understanding of the influence of the IL structures through the adsorption on AC. In addition, the COSMO-RS method was used to analyze the measured adso...
Bookmarks Related papers MentionsView impact
The Journal of Physical Chemistry B, 2012
Bookmarks Related papers MentionsView impact
The Journal of Physical Chemistry B, 2013
Bookmarks Related papers MentionsView impact
The Journal of Physical Chemistry B, 2011
Bookmarks Related papers MentionsView impact
The Journal of Physical Chemistry B, 2007
Bookmarks Related papers MentionsView impact
The Journal of Chemical Thermodynamics, 2011
Bookmarks Related papers MentionsView impact
Journal of Chemical & Engineering Data, 2011
Bookmarks Related papers MentionsView impact