Effect of Non-Ionic Surface Active Agent on Wet Spherical Agglomeration

Abstract

In the present study the effects of non-ionic surface active agents added to suspending liquid on the wet spherical agglomeration process and the micromeritic properties of agglomerates were investigated. Sulfisomidine particles (100g) having a diameter of 73.3 or 79.3μm were dispersed in chloroform (2l) and were agglomerated with buffer solutions (pH 10.2, 50ml). The system was agitated by a turbine type agitator with 6 blades at 630rpm. Each of the six different surface active agents with HLB values in the range of 1.8 to 15.0 was added to the suspending liquid prior to starting the agglomeration. The length mean diameter of agglomerates and the geometric standard deviation decreased with increasing the concentration of surface active agent and attained approximately to the minimum at the critical micelle concentration. The above phenomena were enhanced as the HLB increased, especially in Tween 80 (HLB, 15). The agglomeration process was described as the first order kinetics. The kinetics parameters such as the rate constant, the population densities of flocculate and equilibrium agglomerate increased with increasing the concentration and the HLB of surface active agents. Finally the micromeritic properties of the agglomerate and the kinematic parameters could be correlated quantitatively with the one parameter, i.e. the interfacial tension between the bridging liquid and the suspending liquid, irrespective of the concentration and the HLB of surface active agents.