Studies of phase transitions in fluids, oils and fats by DSC and ultrasound spectroscopy

The use of acoustic techniques as Process Analytical Technology (PAT) tools is relatively low compared to their electromagnetic counterparts, with buffer rod techniques having especially scarce use. Some work has been completed using acoustic techniques to monitor crystallisation and mostly consists of pulse echo techniques. Use of acoustic techniques as PAT is mostly limited to single frequency transducers and using the most basic acoustic parameters to gain information on the process. This thesis aims to fill this gap in knowledge through the use of both a buffer rod and broadband transducers for the acoustic/ultrasound monitoring of crystallisation processes. Current PAT, many of which are based on electromagnetic waves, have a range of limitations including an inability to accurately measure opaque solutions. Low powered acoustic techniques are relatively underutilised for studying phase transitions despite providing unique information – speed of sound and adiabatic compressibility of the system studied. Low power (