Superhydrophobic Rare Earth Oxide (REO) Coatings via Solution Precursor Plasma Spray (SPPS)

- Pengyun Xu

SPPS is a plasma spray process which uses solution precursors of the desired coating material as feedstocks, instead of powder in the conventional plasma spray process. SPPS allows control of splats in the micron/nanometer size and is capable of depositing finely-structured coatings.


The current research has the following four goals:

(1) Fabrication of superhydrophobic REO coatings via solution precursor atmospheric plasma spray (SPAPS) process;

(2) Developing a novel solution precursor vacuum plasma spray (SPVPS) process to fabricate superhydrophobic coatings;

(3) Investigating the basis of the hydrophobicity of REOs and the reversible wettability of the coatings;

(4) Tailoring the wettability of the coatings via different deposition processes and pre-/post-deposition treatments.

The SPPS process provides new insights into fabricating superhydrophobic ceramic coatings on a large scale, quickly, and efficiently, in contrast to many multi-step synthetic methods using polymeric organic materials. The superhydrophobic ceramic coatings have many interesting features including self-cleaning, anti-icing, anti-fouling, etc.

Some findings regarding the current research are reported as follows. A novel SPVPS process is developed for the first time by combining solution precursor plasma spray and vacuum plasma spray. The feasibility, capability, and potentials of using the new technique to fabricate dense and superhydrophobic ceramic coatings are explored. Superhydrophobic ytterbium coatings with columnar hierarchical structures are fabricated via the SPAPS and SPVPS processes. The reversible wetting behavior of the coatings are investigated which indicates that the hydrocarbon adsorption and desorption play decisive roles in the reversible wettability of REOs. Coatings with different microstructures, wettability and mechanical properties in terms of the desired requirements are deposited via tailoring the surface structures.