Research project
Low power non cavitational ultrasound control of nucleation processes
- Start date: 1 January 2020
- End date: Ongoing
- Funder: Diamond Light Source/RAL/SM38430, SM34844, SM31212, EPSRC 113224
- Partners and collaborators: Dr Arwen Tyler, Prof Michael Rappolt, Dr Amin Sadeghpour, Prof Ken Lewtas, Andy Price
- Primary investigator: Professor Megan Povey
- External co-investigators: Ken Lewtas and Andy Price
- Postgraduate students: Marjorie Ladd Parada
Low power (non-cavitational) ultrasound can be used to control crystal nucleation in undercooled melts and saturated solutions. Crystallisation is a crucial step in all processing industries – pharma, agrichemicals, food, fine chemicals, polymers etc. Our technique is game changing, permitting unrivalled precise control over crystallisation processes. Our work at the Diamond Light Source aims to fully understand the physical processes underpinning our technology.
Publications and outputs
Povey, M. J., et al. (2023). "“Sounding” out crystal nuclei—A mathematical-physical and experimental investigation." Journal of Chemical Physics 158(17).
We outline techniques for the control and measurement of the nucleation of crystalline materials. Small angle x-ray scattering/wide angle x-ray scattering x-ray diffraction measurements are presented that demonstrate the impact of low power, continuous, non-cavitational ultrasound on the nucleation and crystallization of a wax—n-eicosane dissolved in a heptane/toluene solvent. A mathematical-physical approach based on the rectification of heat and mass transport by such a low power oscillating pressure field is outlined, and it is suggested that this approach be combined with dissipative particle dynamics computational modeling to develop a predictive method capable of modeling the impact of low power oscillating pressure fields (acoustics and ultrasonics) on a wide range of nucleating systems. Combining the ultrasound pitch and catch speed of sound measurements with low power harmonically oscillating pressure fields to monitor and control nucleation presents the prospect of entirely new industrially significant methods of process control in crystallization. It also offers new insights into nucleation processes in general. However, for the acoustic control technique to be widely applied , further theoretical and modeling work will be necessary since, at present, we are unable to predict the precise effect of low power ultrasound in any given situation.
Changing how and when materials crystallise - - Diamond Light Source