Desiccation of a clay film: Cracking versus peeling

• Published in: The European physical journal. E, Soft matter and biological physics Vol. 27; no. 4; pp. 391 - 395
• Main Authors: Sadhukhan, S., Prehl, J., Blaudeck, P., Hoffmann, K. H., Dutta, T., Tarafdar, S.
• Format: Journal Article
• Language: English
• Published: Berlin/Heidelberg Springer-Verlag 01.12.2008; EDP Sciences
• Subjects: Biological and Medical Physics; Biophysics; Chemistry; Complex Fluids and Microfluidics; Complex Systems; Exact sciences and technology; General and physical chemistry; Nanotechnology; Physics; Physics and Astronomy; Polymer Sciences; Regular Article; Soft and Granular Matter; Surface physical chemistry; Surfaces and Interfaces; Thin Films; 62.20.mt Cracks; 45.70.Qj Pattern formation; 61.43.Bn Structural modeling: serial-addition models, computer simulation; Clay; Square lattice; Phase diagram; Film; Roughness; Adhesion; Layer thickness; Chemical reduction; Substrate; Penetration; Simulation; Models; Drying
• ISSN: 1292-8941; 1292-895X
• DOI: 10.1140/epje/i2008-10401-9

We report a simulation study on competition between cracking and peeling, in a layer of clay on desiccation and how this is affected by the rate of drying , as well as the roughness of the substrate. The system is based on a simple 2-dimensional spring model. A vertical section through the layer with finite thickness is represented by a rectangular array of nodes connected by linear springs on a square lattice. The effect of reduction of the natural length of the springs, which mimics the drying is studied. Varying the strength of adhesion between sample and substrate and the rate of penetration of the drying front produces an interesting phase diagram, showing cross-over from peeling to cracking behavior. Changes in the number and width of cracks on varying the layer thickness is observed to reproduce experimental reports.