Drying of colloidal suspension drops : pattern formation and mechanical deformation
Name
1191838754-MIT.pdf
Size
37.13 MB
Format
Adobe PDF
Checksum (MD5)
ce62366d135c955bd56c0bee88278506
Author(s)
Lilin, Paul.
Advisor(s)
Irmgard Bischofberger.
Date Issued
2020
Publisher
Massachusetts Institute of Technology
Abstract
The drying of drops of colloidal suspensions on a hydrophilic substrate leads to the formation of a close-packed solid particle deposit. The initial volume fraction of particles sets the shape and size of this deposit, from a ring at the edge of the drop to a solid film covering the initial wetted area. We show that this deposit remains saturated with water and we explain the propagation of the solidification front by considering the evaporative flux and mass conservation. As the deposit forms, tensile drying stresses generate regularly spaced radial cracks. The crack patterns define four different regimes which we relate to experimental measurements of the deposit shape. The radial cracks separate the deposit into a multitude of petals. Due to the negative water pressure inside the pores of the deposit, these petals bend upwards creating mesmerizing forms reminiscent of blooming flowers.
Description
Thesis: S.M., Massachusetts Institute of Technology, Department of Mechanical Engineering, May, 2020
Cataloged from the official PDF of thesis.
Includes bibliographical references (pages 119-122).
Subjects
Mechanical Engineering.
MIT Department
Massachusetts Institute of Technology. Department of Mechanical Engineering
Terms of Use
MIT theses may be protected by copyright. Please reuse MIT thesis content according to the MIT Libraries Permissions Policy, which is available through the URL provided.
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