Study of buckling behavior of drying colloidal droplet

Abstract

Stability behaviour of drying colloidal droplet for fast drying condition (Pe > 1) is investigated according to theory of shallow shell. To capture the local buckling behaviour of colloidal droplet, a small segment from full spherical shape is considered for modelling through shallow shell theory. Theorical studies are carried out considering two different segments, for first case square segment is considered assuming segment to be pin jointed with rest of the shell structure and for second case circular segment is considered assuming segment to be clamped with rest of the shell structure. The closed form relation for lower critical buckling pressure and critical relation between droplet radius and particle size as well in terms of shell parameter such as particle size, particle packing volume fraction, particle coordination number and elastic properties of particles are formulated. Theoretical outcome of the study compared with experimental data. The relations for size of the dent and dent amplitude in terms of colloid particle size are also obtained. The results presented here could help in altering the morphology of drying droplet in numerous applications of spray drying process.