Interfacial Chemical Properties of Powder and Spherical Agglomeration in Liquid

Abstract

The wet spherical agglomeration technique with a small amount of bridging liquid which preferentially wets solid particles, is one of the accepted method to agglomerate the particles dispersed in liquid. In the present study, the effects of addition of ethanol and surface active agent to the suspension on the agglomeration behavior of sulfisomidine dispersed in chloroform were investigated. Addition of a suitable amount of ethanol, say 100ml, slightly increased the agglomerate size compared with the case without addition. When the ethanol was added more than this amount, the agglomerate size decreased significantly. While, the agglomeration did not occur absolutely when ionic surfactant was added.
The contact angles of bridging liquid on solid particles in the same system as the agglomeration process were measured as a function of surfactant concentration and the methodology, i. e. sessile drop, hanging drop and Wilhelmy method. The contact angles obtained by the sessile drop method were reasonably correlated with the agglomerate size, which decreased with increasing the contact angle. The correlation of agglomerate size with both parameters of the interfacial tension between the bridging liquid and the dispersing medium and the contact angle were described linearly by equation (11) as seen in Fig. 6.