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Improved PCA process for the production of nano‐ and microparticles of polymers
Author(s) -
Pérez Y.,
Wubbolts F. E.,
Witkamp G. J.,
Jansens P. J.,
de Loos Th.W.
Publication year - 2004
Publication title -
aiche journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.958
H-Index - 167
eISSN - 1547-5905
pISSN - 0001-1541
DOI - 10.1002/aic.10210
Subject(s) - miscibility , polymer , chemical engineering , solvent , dispersity , particle size , precipitation , nanometre , stripping (fiber) , particle (ecology) , nano , penetration (warfare) , chemistry , spinodal decomposition , mixing (physics) , phase (matter) , materials science , polymer chemistry , organic chemistry , composite material , physics , oceanography , operations research , quantum mechanics , meteorology , engineering , geology
The system dextran‐DMSO‐CO 2 has been chosen as a model system to study the fundamentals of the precipitation of biodegradable polymers, using the precipitation with a compressed antisolvent (PCA) process. At conditions of completely miscibility between the organic solvent (DMSO) and CO 2 , it is proposed that the formation of droplets in the system is not the consequence of atomization of the DMSO solution, but rather the result of the occurrence of a liquid‐liquid phase split when the DMSO‐solution and CO 2 are intimately mixed. Penetration of CO 2 into the droplets and stripping of DMSO induces the solidification of these droplets. A new device was designed to separate the three steps involved in the process: mixing of CO 2 and solution, liquid‐ liquid phase split, and stripping of the solvent. This new device eliminates agglomeration of particles, and yields reproducible results. The particle size can be easily manipulated over a size range from several nanometers to tenths of microns by changes in the operating conditions. The influence of these operating conditions (pressure, temperature, polymer concentration, and solution/CO 2 composition ratio) on particle morphology has been studied. © 2004 American Institute of Chemical Engineers AIChE J, 50: 2408–2417, 2004