Nanoparticle antisolvent precipitation

Matteucci, M. E., Hotze, M. A., Johnston, K. P., and Williams, III. R. O. (2006), Drug nanoparticles by antisolvent precipitation Mixing energy versus surfactant stabilization, Langmuir, 22, 8951-8959. 

Reverchon, R. Review supercritical antisolvent precipitation of micro- and nanoparticles. J. Supercrit. Eluids 1999, 75 (1), 1-21. 

Reverchon E, Della Porta G. Production of antibiotic micro- and nanoparticles by supercritical antisolvent precipitation. Powder Technol 1999 106 23-29. 

Reverchon E. Supercritical antisolvent precipitation of micro-and nanoparticles. J Supercrit Fluids 1999 15 1-21. 

Reverchon, E., De Marco, L, Torino, E. (2007). Nanoparticles production by supercritical antisolvent precipitation A general interpretation. The Journal of Supercritical Fluids, 43, 126-138. 

Microparticles can be produced by a simple technique that consists of spraying a polymer, e.g., PLLA, solution in dichloromethane (or dimethylsulfoxide), through a nozzle into a reactor filled with supercritical carbon dioxide (Reverchon et al, 2000). This process is known as supercritical antisolvent precipitation (SAS). The experimental parameters have a limited influence on the particle size (1-4 /im). A modified version of the process, known as the SAS-EM process, allows nanoparticles of a controlled size (30-50 nm) to be produced (Chattopadhay et al., 2002). In order to restrict the use of an organic solvent. Pack and co-workers fed the SAS reactor with a solution of PLLA prepared by homogeneous ring-opening polymerisation in supercritical HCFC-22 (Pack et al, 2003a). 

Reverchon E, Della Porta G, Di TroUo A, Supercritical antisolvent precipitation of nanoparticles of superconductor precursors , Ind Eng Chem Res, 1998 37(3) 952—... 

FIG. 20 22 Schematic of supercritical antisolvent with enhanced mass-transfer process to produce nanoparticles of controllable size. R, precipitation chamber SCF pump, supply of supercritical COg I, inline filter H, ultrasonic horn P, pump for drug solution G, pressure gauge. 

Jarmer, D.J. Lengsfeld, C.S. Randolph, T.W. Manipulation of particle size distribution of poly(-lactic acid) nanoparticles with a jet-swirl nozzle during precipitation with a compressed antisolvent. J. Supercrit. Fluids 2003, 27 (3), 317-336. 

Gallagher PM, Coffey MP, Krukonis VJ, Klasutis N. Gas anti-solvent recrystallization new process to recrystallize compounds insoluble in supercritical fluids. In Johnston KP, Penniger JML, eds. Supercritical Fluid Science and Technology. Washington, DC American Chemical Society, 1989 334-354. Dixon D, Johnston KP, Bodmeier R. Polymeric materials formed by precipitation with a compressed fluid antisolvent. AIChE J 1993 39 127-136. Chattopadhyay P, Gupta RB. Production of griseofulvin nanoparticles using supercritical CO2 antisolvent with enhanced mass transfer. Int J Pharm 2001 228 19-31. 

Muhrer G, Mazzotti M. Precipitation of lysoz5une nanoparticles from dimethyl sulfoxide using carbon dioxide as antisolvent. Biotechnol Prog2003 19 549-556. 

In this paper, we present a novel synthesis of TiOi support by precipitation using supercritical CO2 as an antisolvent. We found that supercritical treated supports can remarkablely enhance the catalytic activity of gold nanoparticles for low temperature CO oxidation. 

The bottom-up technique refers to synthesis based on atom-by-atom or molecule-by-molecule arrangement in a controlled manner, which is regulated by thermodynamic means (Keck et al. 2008). The process takes place through controlled chemical reactions, either gas or liquid phase, resulting in nucleatiOT and growth of nanoparticles. Bottom-up techniques (like supercritical fluid antisolvent techniques, precipitation methods etc.) create heavily clustered masses of particles that do not break up on reconstitution (Shrivastava 2008 Mishra et al. 2010). 

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