Adsorption‐mediated nonlinearity of critical cracking thickness in drying nanoparticle–polymer suspensions. Issue 5 (13th February 2021)

• Record Type: Journal Article
• Authors: Yamamura, Masato
• Is Part Of: AIChE journal. Volume 67:Issue 5(2021)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2021-02-13
• Subjects: critical cracking thickness -- drying -- polymer adsorption -- stress -- suspension; Chemical engineering -- Periodicals; Génie chimique -- Périodiques; 660.28
• DOI: 10.1002/aic.17229
• Languages: English
• ISSNs: 0001-1541

Abstract

Abstract: We examine the critical cracking thicknesses of as‐dried colloidal TiO2 suspensions containing water‐soluble polymeric additives, above which cracks spontaneously propagate. In contrast to common observations, the critical cracking thickness increases in a nonlinear, stepwise manner as increasing the concentration of the polymeric additive in the suspension. The critical thickness diverges when the polymer content increases above a certain threshold. We demonstrate that the first and second critical cracking thickness increments are attributable to the onset of polymer adsorption and a subsequent transition in the conformations of the adsorbing polymer chains, respectively. The critical thickness profiles with respect to normalized polymer adsorption amounts at different particle diameters converged into a single master curve. These results illustrate nontrivial evaporation processes in which the various roles of polymeric additives delay cracking into thicker films.