Assessment of the kinetics of contact angle during the wetting of maltodextrin agglomerates

the wetting phenomenon of thick agglomerates was studied using tablets produced from 8 different fractions obtained from sieving of maltodextrin (de 15) powder. the fractions ranged in size from 38 to 150 μm. the tablets were produced by applying compression force equivalent to 2 tons by means of a hydraulic press. wetting kinetics was followed, after dep osition of a water dr oplet on the surface of the tablets, by m easuring the changes in contact angle. after an initial descent, the curve showed oscillations due to droplet recoiling phenomenon. surface texture was rougher for tablet than for the wetting mark as evaluated by fractal dimension of texture and angular second moment. no clear tendency of the eff ect of particle size on these parameters was observed.