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Supercritical fluids act as a new medium for the generation of novel crystalline forms of APIs (Active Pharmaceutical Ingredients) named as pharmaceutical cocrystals. Supercritical fluid technology offers a new platform that allows a single-step generation of particles that are difficult or even impossible to obtain by traditional techniques.
Non ideal compressible fluid dynamics (NICFD), or non ideal gas dynamics, is a branch of fluid mechanics studying the dynamic behavior of fluids not obeying ideal-gas thermodynamics. It is for example the case of dense vapors , supercritical flows and compressible two-phase flows .
In thermodynamics, the Frenkel line is a proposed boundary on the phase diagram of a supercritical fluid, separating regions of qualitatively different behavior. [1] Fluids on opposite sides of the line have been described as "liquidlike" or "gaslike", and exhibit different behaviors in terms of oscillation, excitation modes, and diffusion.
Supercritical fluid chromatography (SFC) [1] is a form of normal phase chromatography that uses a supercritical fluid such as carbon dioxide as the mobile phase. [2] [3] It is used for the analysis and purification of low to moderate molecular weight, thermally labile molecules and can also be used for the separation of chiral compounds.
The supercritical solvent is passed into a vessel at lower pressure than the extraction vessel. The density, and hence dissolving power, of supercritical fluids varies sharply with pressure, and hence the solubility in the lower density CO 2 is much lower, and the material precipitates for collection. It is possible to fractionate the dissolved ...
For example, “a fluid is considered to be ‘supercritical’ when its temperature and pressure exceed the temperature and pressure at the critical point”. In the studies of supercritical extraction, however, “supercritical fluid” is applied for a narrow temperature region of 1-1.2 T c {\displaystyle T_{c}} or T c {\displaystyle T_{c ...
The supercritical fluid is then added as an antisolvent, which decreases the solubility of the system. As a result, particles of small diameter are formed. [8] There are various submethods to SAS which differ in the method of introduction of the supercritical fluid into the organic solution. [12]
However, different criteria still allow to distinguish liquid-like and more gas-like states of a supercritical fluid. These criteria result in different boundaries in the pT plane. These lines emanate either from the critical point, or from the liquid–vapor boundary (boiling curve) somewhat below the critical point.