Author
Heather D. Willauer
Other affiliations: University of Alabama, Naval Air Systems Command
Bio: Heather D. Willauer is an academic researcher from United States Naval Research Laboratory. The author has contributed to research in topics: Catalysis & Aqueous solution. The author has an hindex of 27, co-authored 75 publications receiving 8697 citations. Previous affiliations of Heather D. Willauer include University of Alabama & Naval Air Systems Command.
Topics: Catalysis, Aqueous solution, Diesel fuel, Biodiesel, Ionic liquid
Papers published on a yearly basis
Papers
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TL;DR: A series of hydrophilic and hydrophobic 1-alkyl-3-methylimidazolium room temperature ionic liquids (RTILs) have been prepared and characterized to determine how water content, density, viscosity, surface tension, melting point, and thermal stability are affected by changes in alkyl chain length and anion.
3,469 citations
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TL;DR: The partitioning of simple substituted-benzene derivatives between water and the room temperature ionic liquid, butylmethylimidazolium hexafluorophosphate, is based on the solutes' charged state or relative hydrophobicity as discussed by the authors.
2,058 citations
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TL;DR: Hydrophilic ionic liquids can be salted-out and concentrated from aqueous solution upon addition of kosmotropic salts forming aqueously biphasic systems as illustrated by the phase behavior of mixtures of 1-butyl-3-methylimidazolium chloride and K3PO4.
Abstract: Hydrophilic ionic liquids can be salted-out and concentrated from aqueous solution upon addition of kosmotropic salts forming aqueous biphasic systems as illustrated by the phase behavior of mixtures of 1-butyl-3-methylimidazolium chloride ([C4mim]Cl) and K3PO4.
960 citations
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TL;DR: In this article, the role of both the promoter and support play on the catalysts' activity is reviewed, and the role that both the promoters and support plays on the catalyst's activity is discussed.
Abstract: The impact that anthropogenic CO2 is having on the environment has been thoroughly documented over the last 20 years. Many different technologies have been proposed to reduce its impact on global warming such as geological sequestration. However, an interesting and attractive alternative would be the recycling of the gas into energy-rich molecules. Iron rather than cobalt catalysts, based on the Fischer–Tropsch technology, have shown the greatest promise in converting CO2 to value-added hydrocarbons. The addition of co-catalysts is, however, essential to fine tune the product distribution to the more desired alkene products. The role that both the promoter and support play on the catalyst's activity is reviewed.
351 citations
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TL;DR: Partition coefficients, as values of log P, between two room-temperature ionic liquids and between water and an aqueous biphasic system have been correlated with Abraham's solute descriptors to yield linear free energy relationships.
Abstract: Partition coefficients, as values of log P, between water and two room-temperature ionic liquids and between water and an aqueous biphasic system have been correlated with Abraham's solute descriptors to yield linear free energy relationships that can be used to predict further values of log P, to ascertain the solute properties that lead to increased or decreased log P values, and to characterize the partition systems It is shown that, in all three of the systems, an increase in solute hydrogen-bond basicity leads to a decrease in log P and an increase in solute volume leads to an increase in log P For the two ionic liquid systems, an increase in solute hydrogen-bond acidity similarly decreases log P, but for the aqueous biphasic system, solute hydrogen-bond acidity has no effect on log P These effects are rather smaller than those observed in traditional water−solvent systems However, the ionic liquids appear to have an increased affinity for polyaromatic hydrocarbons as compared to traditional orga
188 citations
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TL;DR: There are indications that switching from a normal organic solvent to an ionic liquid can lead to novel and unusual chemical reactivity, which opens up a wide field for future investigations into this new class of solvents in catalytic applications.
Abstract: Ionic liquids are salts that are liquid at low temperature (<100 degrees C) which represent a new class of solvents with nonmolecular, ionic character. Even though the first representative has been known since 1914, ionic liquids have only been investigated as solvents for transition metal catalysis in the past ten years. Publications to date show that replacing an organic solvent by an ionic liquid can lead to remarkable improvements in well-known processes. Ionic liquids form biphasic systems with many organic product mixtures. This gives rise to the possibility of a multiphase reaction procedure with easy isolation and recovery of homogeneous catalysts. In addition, ionic liquids have practically no vapor pressure which facilitates product separation by distillation. There are also indications that switching from a normal organic solvent to an ionic liquid can lead to novel and unusual chemical reactivity. This opens up a wide field for future investigations into this new class of solvents in catalytic applications.
5,387 citations
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TL;DR: In this paper, the authors demonstrate that cellulose can be dissolved without activation or pretreatment in, and regenerated from, 1-butyl-3-methylimidazolium chloride and other hydrophilic ionic liquids.
Abstract: We report here initial results that demonstrate that cellulose can be dissolved without activation or pretreatment in, and regenerated from, 1-butyl-3-methylimidazolium chloride and other hydrophilic ionic liquids. This may enable the application of ionic liquids as alternatives to environmentally undesirable solvents currently used for dissolution of this important bioresource.
4,276 citations
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TL;DR: Rogers and Seddon as discussed by the authors reviewed recent progress on developing new ionic liquid solvents for use in chemical synthesis, catalysis, fuel cells, and other applications.
Abstract: Ionic liquids are composed entirely of ions. Because of the wide range of possible binary and ternary ionic liquids, they offer a potentially wide range of solvent properties. In their Perspective,
Rogers and Seddon
review recent progress on developing new ionic liquid solvents for use in chemical synthesis, catalysis, fuel cells, and other applications. Ionic liquids are considered advantageous not only because of their versatility but also for their "green" credentials, although it is important to remember that not all ionic liquids are environmentally benign. One industrial process has been reported, and others may not be far behind. The authors conclude that in the next decade, ionic liquids are likely to replace conventional solvents in many applications.
3,687 citations
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TL;DR: A series of hydrophilic and hydrophobic 1-alkyl-3-methylimidazolium room temperature ionic liquids (RTILs) have been prepared and characterized to determine how water content, density, viscosity, surface tension, melting point, and thermal stability are affected by changes in alkyl chain length and anion.
3,469 citations
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TL;DR: It is shown that the conductivity and viscosity of these liquids is controlled by ion mobility and the availability of voids of suitable dimensions, and this is consistent with the fluidity of other ionic liquids and molten salts.
Abstract: Deep Eutectic Solvents (DES) can be formed between a variety of quaternary ammonium salts and carboxylic acids. The physical properties are significantly affected by the structure of the carboxylic acid but the phase behavior of the mixtures can be simply modeled by taking account of the mole fraction of carboxylic acid in the mixture. The physical properties such as viscosity, conductivity, and surface tension of these DES are similar to ambient temperature ionic liquids and insight into the cause of these properties is gained using hole-theory. It is shown that the conductivity and viscosity of these liquids is controlled by ion mobility and the availability of voids of suitable dimensions, and this is consistent with the fluidity of other ionic liquids and molten salts. The DES are also shown to be good solvents for metal oxides, which could have potential application for metal extraction.
2,904 citations