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| IV. - CHEMICAL EXTRACTION |

IONIC LIQUIDS

ABOUT

  • are salts composed of an organic cation and member of different organic and inorganic amions that meet at temperatures below 100 °C
  • difficult to dissolve - covalent and noncovalent interactions

An ionic liquid (IL) is a salt in the liquid state. In some contexts, the term has been restricted to salts whose melting point is below some arbitrary temperature, such as 100 °C (212 °F). While ordinary liquids such as water and gasoline are predominantly made of electrically neutral molecules, ionic liquids are largely made of ions. These substances are variously called liquid electrolytes, ionic melts, ionic fluids, fused salts, liquid salts, or ionic glasses.

a. Melting point c. d. e.
High thermal stability < 100 °C Negligible vapor pressure High viscosity High solubility in water

  • Ionic liquids have many potential applications. They are powerful solvents and can be used as electrolytes. Salts that are liquid at near-ambient temperature are important for electric battery applications, and have been considered as sealants due to their very low vapor pressure.

  • Any salt that melts without decomposing or vaporizing usually yields an ionic liquid. Sodium chloride (NaCl), for example, melts at 801 °C (1,474 °F) into a liquid that consists largely of sodium cations (Na+) and chloride anions (Cl−). Conversely, when an ionic liquid is cooled, it often forms an ionic solid—which may be either crystalline or glassy.

SOURCE

  • Introduction to Ionic Liquids

  • New green solvents - this process needs to be carried out under nitrogen, requires a precise temperature control, the raw material needs to be added in small portions to the hot liquid, and the obtained keratin is not water soluble.

  • Process:

SOURCE

  • A second life for low-grade wool through formation of all-keratin composites in cystine reducing calcium chloride–water–ethanol solution, Christa Fitz-Binder, Tung Pham and Thomas Bechtold, 2019, DOI 10.1002/jctb.6151, wileyonlinelibrary.com
  • Keratin-based Biomaterials and Bioproducts, Narendra Reddy, 2017, ISBN: 978-1-91024-287-2, http://www.polymer-books.com

TYPES OF ILs CHEMICALS

  • Room-temperature ILs
  • Task-specific ILs
  • Polyionic liquids
  • Supported IL membranes - include composites of ILs supported on metal–organic frameworks

SOURCE

Separating organic compounds

Organic compounds

- [BMIM]+.Cl–
- [BMIM]+.Cl–
- [BMIM]+.Br–
- [AMIM]+.Cl–
- 1-Butyl-3-methylimidazolium tetrafluoroborate
- 1-Butyl-3-methylimidazolium hexafluorophosphate
- [BMIM]+.Br– : 1-Butyl-3-methylimidazolium bromide

TYPES

UREA

also known as carbamide, is an organic compound with chemical formula CH₄N₂O. It is a colorless, odorless solid, highly soluble in water, and practically non-toxic. Urea is widely used in fertilizers as a source of nitrogen (N) and is an important raw material for the chemical industry.

Chemical formula Melting point Molar mass Density Systematic name Appearance Solubility in water
CH₄N₂O 182 °C 76,12 g/mol 1.32 g/cm³ thiokarbonyldiamid white solid 545 g/L (at 25 °C)

THIOUREA

is an organosulfur compound with the formula CH₄N₂S. Thiourea is a reagent in organic synthesis. It is mainly consumed as a precursor to thiourea dioxide, which is a common reducing agent in textile processing.

Chemical formula Melting point Molar mass Density Appearance Solubility in water
CH₄N₂S 133 - 135 °C 76,12 g/mol 1,4 g/cm³ white solid 142 g/l (25 °C)
  • Difference:

    Urea and thiourea are organic compounds having a carbon atom bonded to two amine groups. The key difference between urea and thiourea is that urea does not contain sulfur atoms, whereas thiourea contains sulfur atoms.

SOURCE

CONCLUSION

  • The research seeks to use ILs during the extraction process although for its high price and unavailability it has not been possible.
Last update: 2022-05-24