Acoustic and photoacoustic measurements in supercritical fluids; a new approach to determining the critical point of mixtures

The application of a shear mode piezoelectric sensor to monitoring the high-pressure phase behaviour of asymmetric binary systems

“…Over the past few years, our research group has developed non-visual methods for studying high-pressure vapour-liquid equilibria using a variety of different sensor [37][38][39][40][41]. In particular, we have reported [42] that a shear-mode piezoelectric sensor can be used to measure the bubble-, dew-, and critical-point of binary mixtures.…”

Ultraviolet and Light Absorption Spectrometry

“…1996 deal of interest in the areas of multiple-wavelength, derivative, and flow injection techniques. A new area of development is spectrophotometry with supercritical fluids with papers describing methods for detecting the presence of contaminants in a flowing stream of supercritical fluid (34), a system for temperature and pressure control of an ultraviolet detector for supercritical fluid chromatography (35), and a method of making acoustic and photoacoustic measurements in supercritical fluids (36). Metals.…”

Detecting phase transitions in supercritical mixtures: an enabling tool for greener chemical reactions

“…CO 2 , C 2 H 6 , CF 3 CH 2 F) to as complex as six-component mixtures (CO 2 + H 2 + CO + propene + iso-and n-butyraldehyde; Popov et al 1994;Kordikowski & Poliakoff 1998;Ke et al 2001a;Oag et al 2004). Among these systems, the binary mixtures provide a fundamental understanding of the behaviour of mixed supercritical solvents (e.g.…”

“…Our measurements have been carried out in static cells (Popov et al 1994;Kordikowski et al 1996aKordikowski et al , 1997, the key components of which are two identical ultrasonic transducers placed in parallel (figure 2a): the first feeding a sound wave into the fluid and the second acting as a 'microphone' to convert the sound wave into electric signals. We measure the transit time (Dt) of the sound wave, which is inversely proportional to the speed of sound.…”