TY - JOUR
T1 - Effect of solvent strength and operating pressure on the formation of submicrometer polymer particles in supercritical microjets
AU - Gokhale, Abhijit
AU - Khusid, Boris
AU - Dave, Rajesh N.
AU - Pfeffer, Robert
N1 - Funding Information:
We are grateful to Professor Edward Dreizin (NJIT) for critical reading and comments on an earlier version of this manuscript and Dr. Yueyang Shen (NJIT) for measuring the density and viscosity of PVP solutions. The work was supported by a grant from the New Jersey Commission of Science and Technology (Award # 01-2042-007-24).
PY - 2007/12
Y1 - 2007/12
N2 - 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.
AB - 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.
KW - Good and poor solvents
KW - Microjets
KW - Nanoparticles
KW - Polyvinylpyrrolidone
KW - Supercritical antisolvent
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U2 - 10.1016/j.supflu.2007.05.012
DO - 10.1016/j.supflu.2007.05.012
M3 - Article
AN - SCOPUS:34948895586
SN - 0896-8446
VL - 43
SP - 341
EP - 356
JO - Journal of Supercritical Fluids
JF - Journal of Supercritical Fluids
IS - 2
ER -