Drying Colloids: Colloidal Warping

Achieving a defect-free surface for particulate coatings is a challenging design task, necessitating a thorough understanding of the material and its composition. Coatings formed through drying-induced processes are particularly susceptible to mechanical instability, including buckling and warping (see Fig. 1). In this project, we attempt to understand the phenomenon of warping in dried coatings using a model drying experimental set-up [sessile drop with colloids]. Our experimental results reveal a correlation between warping and local interparticle interactions. Our findings indicate that heightened colloidal attraction strengthens deposit rigidity, preempting warping.

Reference:

• Salinity induced stiffening of drying particulate film and dynamic warping, Hisay Lama, Ludovic Pauchard, Frédérique Giorgiutti-Dauphine, Sanjoy Khawas, Phys. Rev. Materials 7 (2), 025604 (2023).