in thf tetrahydrofuran the internal diameter of the inner nozzle passage through which the co 2 was introduced was 1 6 mm that of the outer passage through which the target solution was introduced 2 5 mm the nozzle outlet diameter was 0 2 mm in example d2 an assembly of the type illustrated in fig3 to 5 with a nozzle outlet separation u201c d u201d of 4 mm was used to introduce the same reagents the co 2 was introduced through the inner passage of the nozzle used in example d1 the outer nozzle passage was not used all other operating conditions were the same for both experiments within the particle formation vessel the temperature was 309 k 36 u00b0 c and the pressure was 80 bar the target solution concentration was 5 w v and its flow rate 1 ml min the co 2 flow rate was 200 g min and its inlet temperature 356 k 83 u00b0 c sems for the products of examples d1 and d2 are shown in fig1 and 14 respectively their aerosizer u2122 particle size distributions are shown in fig1 a and 15b and 16 a and 16 b respectively d2 showing a significantly smaller particle size and a better distribution than d1 it was also found that the fluid.