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In the name of God

In the name of God. Particle design using supercritical fluids. Supervisor : Dr. Ghaziaskar By: M. Amirabadi. content. Presentation of Supercritical Fluids Reasons of using Supercritical Fluids Processes of Supercritical Fluid producing micro and nano-particles

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In the name of God

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  1. In the name of God Particle design using supercritical fluids Supervisor : Dr. Ghaziaskar By: M. Amirabadi

  2. content • Presentation of Supercritical Fluids • Reasons of using Supercritical Fluids • Processes of Supercritical Fluid producing micro and nano-particles • Applications of these processes • Conclusion • References

  3. Supercritical fluid A substance At temperatures and pressures above its critical temperature and pressure ( its critical point ) is called a supercritical fluid.

  4. Why are we using supercritical fluids ?

  5. Properties of some supercritical fluids

  6. Why is CO2 the most commonly used solvent ? • It is easy to attain critical conditions of CO2 • Inexpensive • Nontoxic • Non-flamable • Providing CO2 in high purity is easy

  7. Particle design insupercritical media

  8. advantages of particle design using supercritical technology to conventional methods Supercritical technology • Produces very small particles (micro & nano) • Produces narrow particle size distribution (PSD) • Separation of fluid from particles is done easily • Reduces wastes

  9. Supercritical fluid methods for particle design • RESS (Rapid Expansion of Supercritical Solutions) • SAS/GAS (Supercritical fluid Anti-Solvent • PGSS (Particles from Gas-Saturated Solutions (or Suspensions) • DELOS (Depressurization of an Expanded Liquid Solution)

  10. RESS (Rapid expansion of Supercritical Solutions)

  11. Morphology of particles • Material structure Crystalline or amorphose Composite or pure • RESS parameters Temperature Pressure drop Distance of impact of the jet against the surface Dimensions of the atomization vessel Nozzle geometry

  12. Advantages of RESS • Producing solvent free products • With no residual trace of solvent , particles are suitable for therapeutic scopes • It can be used for heat labile drugs because of low critical temperature • It needs simple equipment and it is cheap • Produced particles requires no post processing

  13. Key limitations of RESS • substrate should be soluble in CO2 • Co-solvent can be used for insoluble substrates but elimination of co-solvent is not easy and cheap

  14. Liquid anti-solvent process • There are two liquid solvents (A&B) • Solvents are miscible • Solute is soluble in A &not soluble in B • Addition of B to the solution of solute in A causes precipitation of solute in microparticle

  15. Supercritical fluid anti-solvent • Solute is dissolved in a solvent • Solute is not soluble in supercritical fluid • Supercritical fluid (anti-solvent) is introduced in solvent • Supercritical fluid expands the solution and decreases solvent power • Solute precipitates in the form of micro or nano particle

  16. Advantages of supercritical fluid antisolvent to liquid antisolvent • Separation of antisolvent is easy • SAS is faster because of high diffusion rate of supercritical fluid • SAS can produce smaller particles • In SAS particle size distribution is possible

  17. The solute is recrystallized in 3 ways • SAS/GAS (supercritical anti-solvent or gas anti-solvent) • ASES (aerosol solvent extraction system) • SEDS (solution enhanced dispersion by supercritical fluid)

  18. SAS/GAS (Supercritical Anti-Solvent)

  19. ASES (Aerosol Solvent Extraction System )

  20. SEDS (Solution Enhanced Dispersion by Supercritical Fluids )

  21. Experiments are carried out in three scales • Laboratorial scale • Pilot scale • Plant scale

  22. Supercritical antisolvent fractionation of Propolis in pilot scale • Propolis has applications in medicine ,hygiene and beauty

  23. Components of propolis Flavonoids Essential oil Separation with extraction Separation with SAS • High molecular mass components

  24. Schematic of pilot scale propolis extraction/fractionation plant

  25. Crystal formation of BaCl2 and NH4Cl using a supercritical fluid antisolvent • SAS process has been used to produce crystals of BaCl2 and NH4Cl from solutions of dimethyl sulfoxide (DMSO)

  26. Parameters that affect on crystallization of BaCl2 & NH4Cl • Injection rate of CO2 • Initial chloride concentration in DMSO • Temperature

  27. Instruments used for determining particle properties • Morphology Scanning electron microscope (SEM) • Composition Energy dispersive X-Ray spectrometer (EDS) • Internal structure X-Ray diffractometer (XRD) • Particle size Image size of SEM photomicrographs

  28. Crystal habit of BaCl2 • Slow injection rate of CO2 Cubic shaped crystals (Equant habit) • Rapid injection rate of CO2 Needle-like crystals (Acicular habit) The variation in crystal habit result from the alteration of the relative growth rate of crystal faces

  29. Crystal habit of NH4CL • Slow injection rate of CO2 Equant • Rapid injection rate of CO2tabular

  30. Internal structure of BaCl2 • Unprocessed particles (Orthorhombic space lattice) • Processed particles (Hexagonal space lattice)

  31. Internal structure of NH4Cl • Unprocessed particles (Cubic) • Processed particles (Cubic) • Cubic space lattic is the only possible crystal system for NH4Cl

  32. Crystal size & composition • Crystal size • The slower injection rate of CO2 ,the larger crystal size • Crystal composition • Composition of crystals did not changed after processing by CO2

  33. Separation of BaCl2 & NH4Cl mixtures in DMSO • The SAS process enables the separation of multicomponent mixtures if the nucleation of each component occurs at different pressures

  34. SAS has used in following applications • Explosives and propellants • Polymers and biopolymers • Pharmaceutical principles • Coloring matter, catalysts, superconductors and inorganic compounds

  35. Explosives and propellants • Small particles of these compound improves the combustion process • Attainment of the highest energy from the detonation depends on particle size

  36. Polymers and biopolymers Polymer microspheres can be used as: • Stationary phases in chromatography • Adsorbents • Catalyst supports • Drug delivery system

  37. Pharmaceutical principles • Increasing bio-availability of poorly-soluble molecules • Designing formulations for sustained-release • Substitution of injection delivery by less invasive methods, like pulmonary delivery

  38. Coloring matter, catalysts, superconductors and inorganic compounds • Color strength is enhanced if dying matter is in the form of micro particles • Catalysts in the form of nanoparticles have excellent activity because of large surface areas

  39. RESS & SAS • Regarding the materials RESS & SAS are complementary • RESSCompound is soluble in CO2 • SAS Compound is insoluble in CO2

  40. Conclusion

  41. Rapid expansion of supercritical fluid (RESS) • CO2 is reached to the desired pressure and temperature • In extraction unit solute(s) is dissolved in CO2 • In precipitation unit solution is depressurized • Solubility of CO2 is decreased and solute(s) precipitates in the form of very small particle or fibers and films

  42. SAS/GAS(supercritical anti-solvent) • In this method a batch of solution is expanded by mixing with supercritical fluid

  43. ASES (aerosol solvent extraction system) • This method involves spraying the solution through an atomization nozzle as fine droplets into compressed carbon dioxide

  44. SEDS (solution enhanced dispersion by supercritical fluids) • In this method a nozzle with tow coaxial passages allows to introduce the supercritical fluid and a solution of active substance(s) into the vessel

  45. Steps of fractionation of Propolis • CO2 is supplied from cylinders. • Solution of Propolis in Ethanol is in storage tank1. • Propolis solution and CO2 are mixed before precipitation chamber EX1. • In EX1 the Propolis solution becomes supersaturate and high molecular mass components precipitate . • CO2 and Propolis solution will furture face two pressure drop. • In SV1 flavonoids precipitate. • In SV3 essential oil and ethanol precipitate.

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