Robust, transparent, superhydrophobic coatings using novel hydrophobic/hydrophilic dual-sized silica particles

Authors

Xiaoxiao Zhao, Center for BioModular Multiscale Systems for Precision Medicine, Department of Mechanical & Industrial Engineering, Louisiana State University, Baton Rouge, LA 70803, United States.
Daniel S. Park, Center for BioModular Multiscale Systems for Precision Medicine, Department of Mechanical & Industrial Engineering, Louisiana State University, Baton Rouge, LA 70803, United States.
Junseo Choi, Center for BioModular Multiscale Systems for Precision Medicine, Department of Mechanical & Industrial Engineering, Louisiana State University, Baton Rouge, LA 70803, United States.
Sunggook Park, Center for BioModular Multiscale Systems for Precision Medicine, Department of Mechanical & Industrial Engineering, Louisiana State University, Baton Rouge, LA 70803, United States.
Steven A. Soper, Departments of Chemistry and Mechanical Engineering, University of Kansas, Lawrence, KS 66045, United States.
Michael C. Murphy, Center for BioModular Multiscale Systems for Precision Medicine, Department of Mechanical & Industrial Engineering, Louisiana State University, Baton Rouge, LA 70803, United States. Electronic address: murphy@lsu.edu.

Document Type

Article

Publication Date

8-15-2020

Abstract

HYPOTHESIS: The superhydrophobic lotus leaf has dual-scale surface structures, that is, nano-bumps on micro-mountains. Large hydrophilic particles, due to its high surface energy and weight, have high affility to substrates and tend to precipitate at the bottom of coating films. Small hydrophobic particles, due to its low surface energy and weight, tends to sit on the top of coating films and form porous structures. To mimic the lotus leaf surface, it may be possible to develop dual-sized particle films, in which small particles are decorated on large particles. EXPERIMENTS: A one-step spin coating of a mixture of dual-sized silica particles (55/200 nm) was used. Epoxy resin was added to improve the adhesion of particle films. The single-sized and dual-sized particle films were compared. The mechanical robustness of particle films was tested by tape peeling and droplet impact. FINDINGS: The novel combination of hydrophobic silica (55 nm) and hydrophilic silica (200 nm) is essential in creating the hierarchical structures. By combining the strong adhesion of hydrophilic silica (bottom of coating film) to polymer substrates and porous structures of hydrophobic silica (top of coating film), we first time report a one-step and versatile approach to create uniform, transparent, robust, and superhydrophobic surface.

Publication Source (Journal or Book title)

Journal of colloid and interface science

First Page

347

Last Page

354

Recommended Citation

Zhao, X., Park, D. S., Choi, J., Park, S., Soper, S. A., & Murphy, M. C. (2020). Robust, transparent, superhydrophobic coatings using novel hydrophobic/hydrophilic dual-sized silica particles. Journal of colloid and interface science, 574, 347-354. https://doi.org/10.1016/j.jcis.2020.04.065