This preparative scale supercritical fluid extraction (SFE) system using carbon dioxide is equipped with a pump and back-pressure regulator to enable delivery of up to 150 ml/min of CO2, and is also equipped with a 1 liter extraction vessel.

Schematic Flow Diagram of System

1. CO2
2. Modifier or washing solution
3. CO2 Large volume solvent delivery pump (PU-2150; Max.150 mL/min)
4. Modifier delivery pump
5. Stop valve
6. Safety valve
7. Pre-heating coil
8. Extraction vessel (1000 mL)
9. Temperature control jacket
10. Temperature meter
11. Back pressure valve
12. 6-way switching valve
13. Pressure meter
14. Fraction vessel
15. Back pressure valve
16. Temperature controller

Perfluoropolyether (PFPE) is a lubricant widely used in many aerospace, vacuum, electronic and semiconductor applications due to its excellent chemical and tribological properties. It is typically used for friction reducing films on hard disks. In order to obtain a greater amount of functional PFPE, supercritical carbon dioxide extraction systems can refine and separate wide molecular weight distribution PFPE mixtures into a higher performance PFPE with a narrower molecular weight distribution.

GPC chromatograms of PFPE fractions (Z DOL-2000, Polydispersity: 1.78) extracted by this system

Average molecular weight and polydispersity (Mw/Mn) of PFPE fractions extracted by this system.

The table outlines various PFPE fractions with narrow molecular weight distributions based on items such as polydispersity, 1.18 to 1.28.