Results
- Showing results for:
- Reset all filters
Search results
-
Journal articleAbouelela AR, Hallett JP, 2021,
Hazardous Creosote Wood Valorization via Fractionation and Enzymatic Saccharification Coupled with Simultaneous Extraction of the Embedded Polycyclic Aromatic Hydrocarbons Using Protic Ionic Liquid Media
, ACS SUSTAINABLE CHEMISTRY & ENGINEERING, Vol: 9, Pages: 704-716, ISSN: 2168-0485- Author Web Link
- Cite
- Citations: 17
-
Journal articleShmool TA, Martin LK, Clarke CJ, et al., 2021,
Exploring conformational preferences of proteins: ionic liquid effects on the energy landscape of avidin
, Chemical Science, Vol: 12, Pages: 196-209, ISSN: 2041-6520In this work we experimentally investigate solvent and temperature induced conformational transitions of proteins and examine the role of ion–protein interactions in determining the conformational preferences of avidin, a homotetrameric glycoprotein, in choline-based ionic liquid (IL) solutions. Avidin was modified by surface cationisation and the addition of anionic surfactants, and the structural, thermal, and conformational stabilities of native and modified avidin were examined using dynamic light scattering, differential scanning calorimetry, and thermogravimetric analysis experiments. The protein-surfactant nanoconjugates showed higher thermostability behaviour compared to unmodified avidin, demonstrating distinct conformational ensembles. Small-angle X-ray scattering data showed that with increasing IL concentration, avidin became more compact, interpreted in the context of molecular confinement. To experimentally determine the detailed effects of IL on the energy landscape of avidin, differential scanning fluorimetry and variable temperature circular dichroism spectroscopy were performed. We show that different IL solutions can influence avidin conformation and thermal stability, and we provide insight into the effects of ILs on the folding pathways and thermodynamics of proteins. To further study the effects of ILs on avidin binding and correlate thermostability with conformational heterogeneity, we conducted a binding study. We found the ILs examined inhibited ligand binding in native avidin while enhancing binding in the modified protein, indicating ILs can influence the conformational stability of the distinct proteins differently. Significantly, this work presents a systematic strategy to explore protein conformational space and experimentally detect and characterise ‘invisible’ rare conformations using ILs.
-
Book chapterBaaqel H, Hallett JP, Guillén-Gosálbez G, et al., 2021,
Uncertainty analysis in life-cycle assessment of early-stage processes and products: a case study in dialkyl-imidazolium ionic liquids
, Computer Aided Chemical Engineering, Pages: 785-790This paper presents a methodology for combining foreground and background uncertainty in the life-cycle assessment (LCA) of processes and products at a low technology-readiness level. We compare the LCA of two ionic liquids, 1-butyl-3-methyl-imidazoliumtetrafluoroborate [bmim][BF<inf>4</inf>] and 1-butyl-3-methyl-imidazolium hexafluorophosphate [bmim][PF<inf>6</inf>]. The nominal scenario predicts that [bmim][BF<inf>4</inf>] generates lower end-point environmental impacts than [bmim][PF<inf>6</inf>]. However, the uncertainty ranges around these nominal predictions overlap significantly, with [bmim][BF<inf>4</inf>] causing higher impacts than those of [bmim][PF<inf>6</inf>] in up to 30% of the uncertainty scenarios. On top of this, accounting for uncertainty in the foreground data more than doubles the estimated impact ranges in several damage categories. This case study, therefore, demonstrates the need for combining foreground and background data uncertainty for more reliable life-cycle assessments.
-
Journal articleNakasu PYS, Pin TC, Hallett JP, et al., 2021,
In-depth process parameter investigation into a protic ionic liquid pretreatment for 2G ethanol production
, Renewable Energy, Vol: 172, Pages: 816-828, ISSN: 0960-1481Protic ionic liquids (PILs) are promising pretreatment agents that can efficiently deconstruct lignocellulosic biomass for 2G ethanol production. PIL synthesis is less costly than that of aprotic imidazolium-based ILs thereby reducing the final ethanol price. However, a more comprehensive investigation is still necessary in order to better understand how PILs affect biomass during pretreatment. An investigation of process parameters was carried out for pretreatment of sugarcane bagasse using the PIL monoethanolammonium acetate, [MEA]OAc], focussing on main pretreatment parameters — time, temperature, solids loading, and water content. Optimal conditions were found to be 2 h, 150 °C, 15 wt% solids loading and 20 wt% water content. Lignin solubilization of almost 60 wt% was achieved with no carbohydrate losses, leading to 78.6% and 49% of cellulose and hemicellulose yields during saccharification. The addition of hemicellulases increased the hemicelluloses yield in saccharification to up to 66% with a high enzyme loading, 5.8 wt%. Ethanol, isopropanol, isoamyl alcohol and water were tested as anti-solvents; none of which led to higher sugar yields or modified recovered lignin structures, as confirmed by spectroscopic methods. Lignin analysis revealed the presence of S, G and H moieties, low degree of condensation, and a potential to produce aromatic compounds that could add value to the biorefinery.
-
Journal articleMalaret F, Hallett J, Campbell KS, 2020,
Oxidative ionothermal synthesis for micro and macro Zn-based materials
, MATERIALS ADVANCES, Vol: 1, Pages: 3597-3604- Author Web Link
- Cite
- Citations: 4
-
Journal articleClarke CJ, Richardson ND, Firth AEJ, et al., 2020,
Thermolysis of Organofluoroborate Ionic Liquids to NHC-Organofluoroborates
, ACS SUSTAINABLE CHEMISTRY & ENGINEERING, Vol: 8, Pages: 16386-16390, ISSN: 2168-0485- Cite
- Citations: 4
-
Journal articleSkoronski E, Fernandes M, Malaret FJ, et al., 2020,
Use of phosphonium ionic liquids for highly efficient extraction of phenolic compounds from water
, Separation and Purification Technology, Vol: 248, Pages: 1-8, ISSN: 1383-5866Ionic liquids (ILs) are undergoing development as extractants for phenolic compounds from wastewater due to their outstanding properties. Although many ILs have been considered, the use of phosphonium-based ILs has thus far been neglected, despite advantages in viscosity and low water solubility. This work details the application of phosphonium-based ILs for the liquid–liquid extraction of phenolic compounds from water. The selected target contaminants, phenol and 2,4-dichlorophenol, were extracted using two ILs composed of trihexyltetradecylphosphonium cations with decanoate or bis(2,4,4-trymetylpentyl)phosphinate anions. The effect of volume ratio, time of contact, pH, temperature and (inorganic) salt concentration on the extraction efficiency were examined. Additionally, the ILs used in this study were characterised in terms of water solubility and solvatochromic polarity. These ILs are less soluble in water than the others reported in the literature, and even at a volume ratio (water: ionic liquid) of 135, the IL can extract more than 99% and 89% of 2,4-dichlorophenol and phenol, respectively, in just 10 min, with the best extraction performance at lower temperatures and pH lower than the pKa of these phenolic compounds. Overall, these ILs demonstrate high potential for phenol extraction and can be considered as a powerful alternative for wastewater treatment.
-
Journal articleAbouelela AR, Tan S-Y, Kelsall GH, et al., 2020,
Toward a Circular Economy: Decontamination and Valorization of Postconsumer Waste Wood Using the ionoSolv Process
, ACS SUSTAINABLE CHEMISTRY & ENGINEERING, Vol: 8, Pages: 14441-14461, ISSN: 2168-0485- Author Web Link
- Cite
- Citations: 27
-
Journal articleGreen SP, Wheelhouse KM, Payne AD, et al., 2020,
On the Use of Differential Scanning Calorimetry for Thermal Hazard Assessment of New Chemistry: Avoiding Explosive Mistakes
, Angewandte Chemie, Vol: 132, Pages: 15930-15934, ISSN: 0044-8249© 2020 Wiley-VCH GmbH Differential scanning calorimetry (DSC) is increasingly used as evidence to support a favourable safety profile of novel chemistry, or to highlight the need for caution. DSC enables preliminary assessment of the thermal hazards of a potentially energetic compound. However, unlike other standard characterisation methods, which have well defined formats for reporting data, the current reporting of DSC results for thermal hazard assessment has shown concerning trends. Around half of all results in 2019 did not include experimental details required to replicate the procedure. Furthermore, analysis for thermal hazard assessment is often only conducted in unsealed crucibles, which could lead to misleading results and dangerously incorrect conclusions. We highlight the specific issues with DSC analysis of hazardous compounds currently in the organic chemistry literature and provide simple “best practice” guidelines which will give chemists confidence in reported DSC results and the conclusions drawn from them.
-
Journal articleGreen SP, Wheelhouse KM, Payne AD, et al., 2020,
On the Use of Differential Scanning Calorimetry for Thermal Hazard Assessment of New Chemistry: Avoiding Explosive Mistakes
, Angewandte Chemie International Edition, Vol: 59, Pages: 15798-15802, ISSN: 1433-7851<jats:title>Abstract</jats:title><jats:p>Differential scanning calorimetry (DSC) is increasingly used as evidence to support a favourable safety profile of novel chemistry, or to highlight the need for caution. DSC enables preliminary assessment of the thermal hazards of a potentially energetic compound. However, unlike other standard characterisation methods, which have well defined formats for reporting data, the current reporting of DSC results for thermal hazard assessment has shown concerning trends. Around half of all results in 2019 did not include experimental details required to replicate the procedure. Furthermore, analysis for thermal hazard assessment is often only conducted in unsealed crucibles, which could lead to misleading results and dangerously incorrect conclusions. We highlight the specific issues with DSC analysis of hazardous compounds currently in the organic chemistry literature and provide simple “best practice” guidelines which will give chemists confidence in reported DSC results and the conclusions drawn from them.</jats:p>
This data is extracted from the Web of Science and reproduced under a licence from Thomson Reuters. You may not copy or re-distribute this data in whole or in part without the written consent of the Science business of Thomson Reuters.