Skip to main content
Self-Assembly of Colloidal Particles from Evaporating Droplets: Role of DLVO Interactions and Proposition of a Phase Diagram
Langmuir (2010)
  • Rajneesh Bhardwaj, Columbia University
  • Xiaohua Fang, Columbia University
  • Ponisseril Somasundaran, Columbia University
  • Daniel Attinger, Columbia University
The shape of deposits obtained from drying drops containing colloidal particles matters for technologies such as inkjet printing, microelectronics, and bioassay manufacturing. In this work, the formation of deposits during the drying of nanoliter drops containing colloidal particles is investigated experimentally with microscopy and profilometry, and theoretically with an in-house finite-element code. The system studied involves aqueous drops containing titania nanoparticles evaporating on a glass substrate. Deposit shapes from spotted drops at different pH values are measured using a laser profilometer. Our results show that the pH of the solution influences the dried deposit pattern, which can be ring-like or more uniform. The transition between these patterns is explained by considering how DLVO interactions such as the electrostatic and van der Waals forces modify the particle deposition process. Also, a phase diagram is proposed to describe how the shape of a colloidal deposit results from the competition among three flow patterns: a radial flow driven by evaporation at the wetting line, a Marangoni recirculating flow driven by surface tension gradients, and the transport of particles toward the substrate driven by DLVO interactions. This phase diagram explains three types of deposits commonly observed experimentally, such as a peripheral ring, a small central bump, or a uniform layer. Simulations and experiments are found in very good agreement.
  • DVLO interaction,
  • microscopy,
  • profilmoetry
Publication Date
March 25, 2010
Publisher Statement
Reprinted with permission from Langmuir, 2010, 26 (11), pp 7833–7842, DOI: 10.1021/la9047227. Copyright 2010 American Chemical Society.
Citation Information
Rajneesh Bhardwaj, Xiaohua Fang, Ponisseril Somasundaran and Daniel Attinger. "Self-Assembly of Colloidal Particles from Evaporating Droplets: Role of DLVO Interactions and Proposition of a Phase Diagram" Langmuir Vol. 26 Iss. 11 (2010)
Available at: