Solidification and Ordering during Directional Drying of a Colloidal Dispersion

详细信息    查看全文

• 作者：Lucas Goehring ; William J. Clegg ; Alexander F. Routh
• 刊名：Langmuir
• 出版年：2010
• 出版时间：June 15, 2010
• 年：2010
• 卷：26
• 期：12
• 页码：9269-9275
• 全文大小：864K
• 年卷期：v.26,no.12(June 15, 2010)
• ISSN：1520-5827

文摘

During drying, colloidal dispersions undergo processes such as solidification, cracking, and the draining of interstitial pores. Here we show that the solidification of polystyrene and silica dispersions, during directional drying, occurs in two separate stages. These correspond to the initial ordering and subsequent aggregation of the colloidal particles. Transitions between these stages are observed as changes in transparency and color that propagate as distinct fronts along the drying layer. The dynamics of these fronts are shown to arise from a balance between compressive capillary forces and the electrostatic and van der Waals forces described by DLVO theory. This suggests a simple method by which the maximum interparticle repulsion between particles can be measured through the optical inspection of the dynamics of a drying dispersion, under a microscope.