Catarina M S S Neves | Universidade de Aveiro (original) (raw)

Papers by Catarina M S S Neves

Research paper thumbnail of Effect of the Methylation and N–H Acidic Group on the Physicochemical Properties of Imidazolium-Based Ionic Liquids

The Journal of Physical Chemistry, 2015

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Research paper thumbnail of Impact of Self-Aggregation on the Formation of Ionic-Liquid-Based Aqueous Biphasic Systems B

The Journal of Physical Chemistry, 2012

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Research paper thumbnail of 3. Aqueous biphasic systems formed by cholinium-based ionic liquids and mixtures of polymers

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

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Research paper thumbnail of Improved recovery of ionic liquids from contaminated aqueous streams using aluminium-based salts

RSC Advances, 2012

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Research paper thumbnail of Mutual Solubilities of Water and Hydrophobic Ionic Liquids

Journal of Physical Chemistry B, Oct 24, 2007

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Research paper thumbnail of Treatment of aqueous effluents contaminated with ionic liquids

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...

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Research paper thumbnail of 3. Aqueous biphasic systems formed by cholinium-based ionic liquids and mixtures of polymers

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

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Research paper thumbnail of Simultaneous Separation of Antioxidants and Carbohydrates From Food Wastes Using Aqueous Biphasic Systems Formed by Cholinium-Derived Ionic Liquids

Frontiers in Chemistry, 2019

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Research paper thumbnail of Solid + liquid equilibria and molecular structure studies of binary mixtures for nitrate ester’s stabilizers: Measurement and modeling

Thermochimica Acta, 2018

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Research paper thumbnail of Sustainable hydrophobic terpene-based eutectic solvents for the extraction and separation of metals

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.

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Research paper thumbnail of Binary Mixtures of Ionic Liquids in Aqueous Solution: Towards an Understanding of Their Salting-In/Salting-Out Phenomena

Journal of Solution Chemistry, 2018

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Research paper thumbnail of Effect of salts on the solubility of ionic liquids in water: experimental and electrolyte Perturbed-Chain Statistical Associating Fluid Theory

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...

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Research paper thumbnail of Improved recovery of ionic liquids from contaminated aqueous streams using aluminium-based salts

RSC Advances, 2012

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Research paper thumbnail of Composition and structural effects on the adsorption of ionic liquids onto activated carbon

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...

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Research paper thumbnail of Impact of Self-Aggregation on the Formation of Ionic-Liquid-Based Aqueous Biphasic Systems

The Journal of Physical Chemistry B, 2012

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Research paper thumbnail of Alkylimidazolium Based Ionic Liquids: Impact of Cation Symmetry on Their Nanoscale Structural Organization

The Journal of Physical Chemistry B, 2013

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Research paper thumbnail of Chameleonic Behavior of Ionic Liquids and Its Impact on the Estimation of Solubility Parameters

The Journal of Physical Chemistry B, 2011

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Research paper thumbnail of Mutual Solubilities of Water and Hydrophobic Ionic Liquids

The Journal of Physical Chemistry B, 2007

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Research paper thumbnail of Thermophysical properties of pure and water-saturated tetradecyltrihexylphosphonium-based ionic liquids

The Journal of Chemical Thermodynamics, 2011

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Research paper thumbnail of Thermophysical Characterization of Ionic Liquids Able To Dissolve Biomass

Journal of Chemical & Engineering Data, 2011

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Research paper thumbnail of Effect of the Methylation and N–H Acidic Group on the Physicochemical Properties of Imidazolium-Based Ionic Liquids

The Journal of Physical Chemistry, 2015

Bookmarks Related papers MentionsView impact

Research paper thumbnail of Impact of Self-Aggregation on the Formation of Ionic-Liquid-Based Aqueous Biphasic Systems B

The Journal of Physical Chemistry, 2012

Bookmarks Related papers MentionsView impact

Research paper thumbnail of 3. Aqueous biphasic systems formed by cholinium-based ionic liquids and mixtures of polymers

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

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Research paper thumbnail of Improved recovery of ionic liquids from contaminated aqueous streams using aluminium-based salts

RSC Advances, 2012

Bookmarks Related papers MentionsView impact

Research paper thumbnail of Mutual Solubilities of Water and Hydrophobic Ionic Liquids

Journal of Physical Chemistry B, Oct 24, 2007

Bookmarks Related papers MentionsView impact

Research paper thumbnail of Treatment of aqueous effluents contaminated with ionic liquids

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

Research paper thumbnail of 3. Aqueous biphasic systems formed by cholinium-based ionic liquids and mixtures of polymers

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

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Research paper thumbnail of Simultaneous Separation of Antioxidants and Carbohydrates From Food Wastes Using Aqueous Biphasic Systems Formed by Cholinium-Derived Ionic Liquids

Frontiers in Chemistry, 2019

Bookmarks Related papers MentionsView impact

Research paper thumbnail of Solid + liquid equilibria and molecular structure studies of binary mixtures for nitrate ester’s stabilizers: Measurement and modeling

Thermochimica Acta, 2018

Bookmarks Related papers MentionsView impact

Research paper thumbnail of Sustainable hydrophobic terpene-based eutectic solvents for the extraction and separation of metals

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

Research paper thumbnail of Binary Mixtures of Ionic Liquids in Aqueous Solution: Towards an Understanding of Their Salting-In/Salting-Out Phenomena

Journal of Solution Chemistry, 2018

Bookmarks Related papers MentionsView impact

Research paper thumbnail of Effect of salts on the solubility of ionic liquids in water: experimental and electrolyte Perturbed-Chain Statistical Associating Fluid Theory

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

Research paper thumbnail of Improved recovery of ionic liquids from contaminated aqueous streams using aluminium-based salts

RSC Advances, 2012

Bookmarks Related papers MentionsView impact

Research paper thumbnail of Composition and structural effects on the adsorption of ionic liquids onto activated carbon

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

Research paper thumbnail of Impact of Self-Aggregation on the Formation of Ionic-Liquid-Based Aqueous Biphasic Systems

The Journal of Physical Chemistry B, 2012

Bookmarks Related papers MentionsView impact

Research paper thumbnail of Alkylimidazolium Based Ionic Liquids: Impact of Cation Symmetry on Their Nanoscale Structural Organization

The Journal of Physical Chemistry B, 2013

Bookmarks Related papers MentionsView impact

Research paper thumbnail of Chameleonic Behavior of Ionic Liquids and Its Impact on the Estimation of Solubility Parameters

The Journal of Physical Chemistry B, 2011

Bookmarks Related papers MentionsView impact

Research paper thumbnail of Mutual Solubilities of Water and Hydrophobic Ionic Liquids

The Journal of Physical Chemistry B, 2007

Bookmarks Related papers MentionsView impact

Research paper thumbnail of Thermophysical properties of pure and water-saturated tetradecyltrihexylphosphonium-based ionic liquids

The Journal of Chemical Thermodynamics, 2011

Bookmarks Related papers MentionsView impact

Research paper thumbnail of Thermophysical Characterization of Ionic Liquids Able To Dissolve Biomass

Journal of Chemical & Engineering Data, 2011

Bookmarks Related papers MentionsView impact