Effect of solvent strength and operating pressure on the formation of submicrometer polymer particles in supercritical microjets

Abhijit Gokhale, Boris Khusid, Rajesh N. Dave, Robert Pfeffer

Research output: Contribution to journalArticlepeer-review

49 Scopus citations

Abstract

A supercritical antisolvent (SAS) process is described which utilizes a mixture of thermodynamically good and poor polymer solvents and micronozzles. Experiments were conducted on polyvinylpyrrolidone (PVP) solutions in a mixture of dichloromethane (DCM) (a good solvent) and acetone (a poor solvent). Decreasing the nozzle diameter and the fluid velocity were shown to favor the disintegration of supercritical jets into drops. Mass transport of CO2 into, and solvents out of, the falling supercritical drops, rather than mass transport during jet breakup, are found to control the particle formation. Varying the acetone content of the solvent, the nozzle diameter and the jet velocity are demonstrated to provide an efficient method to decrease the particle diameter to several tens of nanometers and smooth their surface irregularities. The proposed method is expected to be applicable to a wide variety of polymers.

Original languageEnglish (US)
Pages (from-to)341-356
Number of pages16
JournalJournal of Supercritical Fluids
Volume43
Issue number2
DOIs
StatePublished - Dec 2007

All Science Journal Classification (ASJC) codes

  • Chemical Engineering(all)
  • Condensed Matter Physics
  • Physical and Theoretical Chemistry

Keywords

  • Good and poor solvents
  • Microjets
  • Nanoparticles
  • Polyvinylpyrrolidone
  • Supercritical antisolvent

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