A semi-empirical power-law model for the dip-coating of a substrate into a particle-containing, non-Newtonian, complex fluid system

Journal Article · 04 January 2019 · Ceramics International

DOI: https://doi.org/10.1016/j.ceramint.2018.12.154 · OSTI ID:1614197

Wang, Kaishi ^[1]; Bordia, Rajendra K.  ^[2]; Brush, Lucien N. ^[3]

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1. Aerospace Research Institute of Materials and Processing Technology, Beijing (China); DOE/OSTI
2. Clemson University, SC (United States)
3. University of Washington, Seattle, WA (United States)

The apparent viscosity of a particle suspension of ZrSi₂ particles, polyhydromethylsiloxane (PHMS) preceramic polymer and n-Octane solvent, used to process polymer-derived ceramic composite coatings, is shown by viscometric experiments to be shear-thinning. The suspension is dip-coated onto substrates and the measured entrained coating thickness, h₀, is observed to be a power-law function of U, the substrate extraction speed, as h₀ = 0.5051U^0.5. The experimentally observed semi-empirical model is directly compared to the results of a variety of theoretically derived Landau-Levich scaling laws and other models that have similar liquids and that include other effects. None of these cases predicts the scaling observed in these experiments. A correction factor is introduced to quantify the difference between the semi-empirical model with existing theoretical models. Possible explanations for the observed scaling behavior are presented.

• Research Organization: University of Washington, Seattle, WA (United States)
• Sponsoring Organization: USDOE; USDOE Office of Nuclear Energy (NE), Nuclear Energy University Program (NEUP)
• Grant/Contract Number: FE0023142
• OSTI ID: 1614197
• Journal Information: Ceramics International, Journal Name: Ceramics International Journal Issue: 6 Vol. 45; ISSN 0272-8842
• Publisher: ElsevierCopyright Statement
• Country of Publication: United States
• Language: English