In this paper we compare the efficiency of a Microfluidizer to a high pressure valve homogeniser (HPH)
for the production of oil continuous emulsions by investigating the effect of pressure, number of passes,
phase viscosities and salt addition on droplet size. The results obtained show that the Microfluidizer and
HPH have similar emulsification efficiency, giving droplets of 60 nm diameter at a pressure of 50 MPa.
By increasing the pressure to 100 MPa the droplet diameter was reduced by 10 nm in both devices.
Increasing the number of passes in the HPH caused an increase in droplet size probably as a consequence
of the temperature increase from multiple passes causing an increase in coalescence. Changing the
viscosity ratio from 0.001 to 1 resulted in a minimal change in droplet size indicating that the flow is
elongational when break-up occurs rather than turbulent as expected.