Application Of Supercritical Fluids Research Articles

Supercritical Fluid Applications in Advanced Materials Processing

ABSTRACTThe feasibility of using supercritical fluids to impregnate carbon/carbon composites with a ceramic precursor was successfully demonstrated. Improvements in mechanical properties and oxidation resistance were correlated with the distribution of silicon within the microstructure of the composites. In addition, supercritical fluids were also used to fractionate silicon carbide precursors and thereby control the physical properties and char yield.

超臨界流体の応用

The application of super critical fluids for wood chemistry is introduced in this paper. The general view over the application supercritical fluids for food andother industries is also mentioned.

Analysis of non-ionic surface active agents by supercritical fluid chromatography/mass spectrometry.

Application of supercritical fluid chromatography/mass spectrometry (SFC/MS) to the analysis of non-ionic surface active agents (NSAAs). The non-ionic surface active agents used as samples are R-O-(CH2CH2O)n-H, R-COO-(CH2CH2O)n-H, and R-N(CH2CH2OH)2. Polyethylene glycol-400 is also analyzed as a related compound. Their selected ion monitoring traces are shown together with some representative mass spectra. These NSAAs composed of many components are spearated and identified easily and rapidly by this SFC/MS system.

Étude de l'activité du sucralfate sur la motricité œsophagienne chez le sujet sain

An ideal extraction method should be swift, yield quantitative recovery without degradation, and the extracts should be easily separated from the solvent. The development and application of alternative green technology to replace conventional extraction methods with improved extraction efficiency and low environmental impact for the determination of natural bioactive compounds is therefore, highly important. Supercritical fluid technology offers features that overcome many limitations of conventional extraction methods.This review presents an analytical overview regarding the application of supercritical fluids in the extraction of bioactive compounds and their operative extraction conditions, along with the investigation of further improvements on the extraction efficiency and the applied techniques for the structural characterization and identification of such bioactive compounds.

Thermodynamic calculation of supercritical-fluid equilibria: New mixing rules for equations of state

Simple cubic equations of state with conventional mixing rules have played an important role in the calculation of phase equilibria and other thermodynamic properties of non-polar fluid mixtures. In the application of supercritical fluids to separation processes, volumetric as well as phase equilibrium properties are very important for rational process design. Heyen (1980) proposed a cubic equation of state which shows better accuracy in the calculation of volumetric properties, compared to the Peng-Robinson equation of state. In order to apply his equation to polar mixtures, Heyen recently proposed a density-independent mixing rule, but this does not obey the universally-observed quadratic mixing rule of the second virial coefficient in the low-density limit. This paper proposes a new density-dependent mixing rule for the Heyen equation of state. The Heyen equation of state with our new mixing rule appears to calculate the phase equilibria and the volumetric properties of CO 2-containing non-polar as well as polar mixtures with good accuracy.