Premium
Polymer encapsulation of fine particles by a supercritical antisolvent process
Author(s) -
Wang Yulu,
Pfeffer Robert,
Dave Rajesh,
Enick Robert
Publication year - 2005
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.10323
Subject(s) - polymer , supercritical fluid , chemical engineering , materials science , coating , particle size , acetone , micronization , supersaturation , microparticle , plga , nucleation , polymer chemistry , nanoparticle , chemistry , nanotechnology , composite material , organic chemistry , engineering
Coating and encapsulation of fine particles with polymer using a supercritical antisolvent (SAS) coating process was investigated in this research. Synthesized submicron silica particles were used as host particles and poly(lactide‐co‐glycolide) (PLGA), a biodegradable polymer used for controlled release of drugs, was chosen as the coating material. In the SAS coating process a suspension of silica particles in an acetone–polymer solution was sprayed through a capillary nozzle into supercritical (SC) CO 2 , which acts as an antisolvent for the acetone. A rapid mutual diffusion between the SC CO 2 and the acetone causes supersaturation of the polymer solution, leading to nucleation and precipitation of the polymer to encapsulate the silica particles. The operating parameters that have an effect on the coating process, such as polymer to particle weight ratio, polymer concentration, temperature, pressure, flow rate of polymer solution, and the addition of a SC CO 2 soluble surfactant, were systematically studied. It is shown that the polymer to silica ratio and the polymer concentration are critical for the successful encapsulation of silica particles with minimum agglomeration. © 2005 American Institute of Chemical Engineers AIChE J, 51: 440–455, 2005