Centrifugal ultrafiltration for determination of filter cake properties of colloids

The article is devoted to the application of analytical centrifugation for the measurement and analysis of centrifugal ultrafiltration kinetics. The model of centrifugal ultrafiltration of colloids accounting for the cake formation, compression and possible decompression is proposed. The method for the determination of filter cake properties (pressure dependency of specific cake resistance) from the results of batch centrifugal ultrafiltration experiment is presented. The method was tested for the determination of filterability of model samples: aqueous solutions of protein (bovine serum albumin) and nanoparticle suspension (Laponite RD). The pressure dependency of specific cake resistance was determined in the range of 10−500 kPa from the results of centrifugal ultrafiltration experiments at different centrifugal rotation speeds. The obtained values of specific resistance were in good correspondence with those measured in a series of reference constant pressure dead-end filtration tests.