SCF technologies

Lynch [316] has recently critically reviewed the future development in analytical instrumental SCF technology. Modern instruments include manual and automated extractors that can handle large sample volumes (lOOmL for manual SFE and lOmL for automated SFE). From an experimental point of view, in using SFE attention should be paid to contamination from the seals of the SCF extractor. 

Supercritical fluid (SCF) technology presents a new and interesting route for particle formation, which avoids most of... 

In the last years supercritical fluid (SCF) technology has occupied a significant place in the high pressure chemical engineering. Due to their specific properties as liquid-like densities, gas-like viscosities and diffusivities intermediate between gas and liquid values, SCF have large potential in extraction and separation processes, polymer science and technology and in elaboration of new materials [1-4], In these last cases, to control the size of particles, we have to deal with the kinetics of their formation. ... 

Many contributors to this book belong to the Joint Association for the Advancement of SCF Technology (JAAST), a consortium established... 

With such major developments in the field of SCF technology, the objective of this chapter is to provide a critical overview of the solubility behavior of lipid components in SCCO2, which is fundamental for optimal process design as well as the unit operations of extraction, fractionation, and reactions using SCCO2 as applied to fats and oils processing. 

Currently, the SCF technology has a widespread utility ranging from food processing to pharmaceutical applications. The use of SCFs such as CO2 is proving to be environmentally benign and economical, with the added advantage of reduced residual solvents in food and pharmaceutical products. 

SCF technology can now be claimed as useful in producing particles ranging from 5 to 2000 nm. This patent covers a process that rapidly expands a solution of the compound and phospholipid surface modifiers in a liquefied gas into an aqueous medium, which contains the phospholipids. Expanding into an aqueous medium prevents particle agglomeration and particle growth, thereby producing particles of a narrow size distribution. 

Less than 5% of the SCF technology literature deals with chemical reactions, although this relatively new area is growing considerably because of applications such as oxidation of hazardous wastes in supercritical water. 

SCF technology has spread quickly from molecules such as naphthalene to more complex substances such as polymers, biomolecules, and surfactants. Supercritical fluids can be used to reduce the lower critical solution temperature of polymer solutions in order to remove polymers from liquid solvents(6.26 The technology has been extended to induce crystallization of other substances besides polymers from liquids, and has been named gas recrystallization(4). In other important applications, SCF carbon dioxide has been used to accomplish challenging fractionations of poly(ethylene glycols) selectively based on molecular weight as discussed in this symposium, and of other polymers(. ... 

Based on these results, we explored the possibility of using octanol as an amphiphilic cosolvent without the need for AOT. With the addition of octanol at a concentration of 0.5 M, it becomes possible to solubilize water at 0.05 M at only 80 bar. The Xmax is close to that of pure octanol, so that it is unlikely that water pools were formed. The cosolvent octanol could play an important role in SCF technology by increasing the solubilization of water. 

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