Adsorption-stress relationship in drying of silica/PVA suspensions

In this study, we investigated drying process of silica/PVA suspensions. After measuring the amount of polymer adsorption and the stress evolution of a film during drying process, we could find a quantitative relationship between polymer adsorption and stress development, for silica/PVA suspensions of different pH and mixing time. For all the suspensions of different pH, both the amount of polymer adsorption (Γ) and the plateau stress of dry film (σ(p)) could be scaled onto a single master curve as a function of mixing time (t(m)). The scaling of mixing time for both Γ and σ(p) could be performed by the same scale factor, which implies that there is a one to one correlation between adsorption and stress. This correlation implies that we can control the microstructure and performance of dry film by adjusting the amount of polymer adsorption. The origin of adsorption kinetics of silica/PVA suspension was also discussed in terms of saponification of acetate groups in PVA, which facilitates hydrogen bonding between silica and PVA.