Location of Repository

Characterisation and Applications of CO2-Expanded Solvents.

By Reena Mistry

Abstract

The use of CO2 as an alternative to traditional organic solvents has been an extensive area of research over the last several decades with research focusing mainly on supercritical applications. Gas eXpanded Liquids (GXLs) combine the advantages of liquid CO2 and co-solvents. Much like its supercritical counterpart, the solvent power of GXLs can be tuned by varying the liquid phase concentration as a function of pressure. Determination of solvent-solute interactions is key to the understanding of solvent properties in liquids and expanded solvents.\ud Spectroscopic measurements of a range of binary mixtures of organic solvent with carbon dioxide have been recorded to calculate solvatochromic parameters for gas expanded liquids. Data obtained for gas expanded solvents showed a significant change in local polarity upon addition of CO2, modifying the properties of traditional organic solvents. Protic solvents were found to behave anomalously to conventional aprotic solvents.\ud Density, relative permittivity, and CO2 solubility at 25 °C and 50 bar pressure for a range of CO2-expanded solvents are reported for the first time. The dissolution of CO2 into liquid organic solvents to generate expanded liquids has resulted in significant changes in bulk solvent properties. Collation of relative permittivity data and solvatochromism data of the expanded liquids has given an insight into the structural changes occurring in the local and bulk regions of the solvent, resulting in the occurrence of preferential solvation. Variation in these solvent properties are understood by the determination of molar free volumes which was correlated with the Hildebrand solubility parameter showing that the expansion of molecular solvents is controlled by the thermodynamics of cavity formation.\ud A range of applications have been probed using gas expanded liquids as replacement solvents. One of the most prominent advantages of GXLs for chemical synthesis is their adjustable solvating power. Areas such as biphasic chemistry, selective reactions, solubility, and phase behaviour studies have been explored. It was found that in each application the CO2 expanded solvent had a varied ‘role’

Publisher: University of Leicester
Year: 2008
OAI identifier: oai:lra.le.ac.uk:2381/4111

Suggested articles

Preview

Citations

  1. (1989). Acs Symposium Series, doi
  2. (1960). Acta Chemica Scandinavica, doi
  3. (1984). American Institute of Chemical Engineers,
  4. (1987). Analytical Chemistry, doi
  5. (1978). Angewandte ChemieInternational Edition in English, doi
  6. (2005). Applied Catalysis, A: General, doi
  7. (1998). Berichte Der Bunsen-Gesellschaft-Physical Chemistry Chemical Physics,
  8. (2003). Bioresource Technology, doi
  9. (1993). Biotechnology and Bioengineering, doi
  10. (2003). Carbon Dioxide Recovery and Utilization, doi
  11. (2003). Catalysis Reviews - Science and Engineering, doi
  12. (1999). Catalysis Today, doi
  13. (2000). Chapters three and four have shown the simplistic nature of GXLs by determining their physical parameters, however, initial studies of phase behaviour
  14. (2001). Chemical & Engineering News, doi
  15. (2003). Chemical Communications, doi
  16. (1981). Chemical Engineering Science, doi
  17. (1997). Chemical Engineers'
  18. (1973). Chemical Reviews, doi
  19. (1999). Chemical Society Reviews, doi
  20. (1999). Chemical synthesis using supercritical fluids, doi
  21. (2007). Chemie Ingenieur Technik, doi
  22. (2004). Chemistry in Alternative Reaction Media, doi
  23. (2002). Clean Solvents, doi
  24. (2001). Coordination Chemistry Reviews, doi
  25. (1999). Dry Cleaning Methods and Carbon-Dioxide-Based Compositions,
  26. (2000). Dry Cleaning system Using Densified Carbon Dioxide and a Silicone Surfactant Adjunct. doi
  27. (2002). Dyes and Pigments, doi
  28. (2003). Energy Conversion and Management, doi
  29. (2002). Energy Sources, doi
  30. (2005). Fluid Phase Equilibria, doi
  31. (2004). Gongye Cuihua,
  32. (2006). Journal of Catalysis, doi
  33. (2000). Journal of Supercritical Fluids, doi
  34. (1990). Liebigs Annalen Der Chemie, doi
  35. (1997). Liebigs Annalen-Recueil, doi
  36. (1995). Liebigs Annalen, doi
  37. (2007). Molecular Simulation, doi
  38. (2005). Multiphase Homogeneous Catalysis, doi
  39. (1986). Organic Solvents:
  40. (1991). Perfum Flavor,
  41. (1994). PGSS (Particles from Gas saturated Solutions) a new process for powder generation, in:
  42. (1994). Phase-transfer catalysis : fundamentals, applications, and industrial perspectives, doi
  43. (1922). Physical Reviews, doi
  44. (1993). Pure and Applied Chemistry, doi
  45. (2000). Renewable & Sustainable Energy Reviews, doi
  46. (1998). Review of Scientific Instruments, doi
  47. (2003). Solvents and Solvent effects doi
  48. (1989). Spectrochimica Acta Part A - Molecular and Biomolecular Spectroscopy, doi
  49. (1963). Tables of Dipole Moments, doi
  50. (1976). The Influence of Mass and Heat Transfer on the Performance of Heterogeneous Catalysts doi
  51. (2006). Topics in Catalysis, doi
  52. (1983). Transactions of the Asae, doi
  53. (2003). Yuki Gosei Kagaku Kyokaishi,
  54. (1906). Zeitschrift fur Physikalische Chemie doi
  55. (1996). Zhurnal Fizicheskoi Khimii,

To submit an update or takedown request for this paper, please submit an Update/Correction/Removal Request.