Cerium Oxide Ceramic Coatings for Heat Transfer
Solution Overview
Problem
There is a need for oxide ceramics that exhibit lower liquid wettability than conventional oxides, promote stable dropwise condensation, are stable at elevated temperatures, and have good mechanical properties, particularly for applications in heat transfer equipment where polymer films are not practical due to thermal resistance and durability issues.
Innovation Solution
A class of oxide ceramics comprising a primary oxide, such as cerium or hafnium, combined with a secondary oxide like lanthanum, praseodymium, or ytterbium, which are transparent to electromagnetic radiation and have a cubic crystal structure, providing enhanced wetting resistance and stability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If polymer films are applied to the surface to reduce film formation, then water wettability is reduced, but thermal resistance increases and adhesion/durability decreases
Solution Approach 1:
The patent changes the chemical composition parameters of the coating material by incorporating specific metal oxides (silica, alumina, titania) in controlled ratios to achieve low water wettability without relying on organic polymer films. This allows the surface to maintain hydrophobic properties while improving thermal conductivity and mechanical durability.
Solution Approach 2:
The patent creates a composite inorganic coating material combining multiple metal oxides (silica, alumina, titania) with complementary properties. This composite structure provides both low water wettability and superior thermal/m mechanical properties compared to single-material polymer coatings.
2Object-affected harmful factors
If polymer films are applied to the surface to reduce film formation, then water wettability is reduced, but thermal resistance increases
Solution Approach 1:
The patent changes the material composition from organic polymers to inorganic metal oxide coatings, fundamentally altering the thermal properties. The inorganic coating material has higher thermal conductivity and lower thermal resistance, allowing heat to pass through more effectively while maintaining water repellency.
Solution Approach 2:
The patent uses a composite inorganic coating system combining silica, alumina, and titania oxides, each contributing different thermal and surface properties. This composite structure achieves both low water wettability and acceptable thermal resistance, overcoming the limitations of polymer films.
3Temperature
If conventional oxide ceramics are used, then thermal stability is improved, but liquid wettability remains high
Solution Approach 1:
The patent modifies the surface chemical composition parameters of oxide ceramics by incorporating specific metal oxides (silica, alumina, titania) in controlled ratios and concentrations. This compositional adjustment changes the surface energy and wettability characteristics while preserving the bulk thermal stability of the ceramic material.
Solution Approach 2:
The patent creates a composite oxide ceramic coating combining multiple inorganic oxides with complementary properties. The silica provides thermal stability, while alumina and titania contribute to low surface energy and water repellency, achieving both thermal stability and low liquid wettability simultaneously.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
These materials demonstrate significantly lower water wettability, maintain stable dropwise condensation, and are transparent to UV, visible, or infrared radiation, making them suitable for heat transfer applications and other uses where resistance to liquid buildup is essential.
Implementation Method 1
The material comprises a primary oxide and a secondary oxide... These materials demonstrate significantly lower water wettability... promote stable dropwise condensation
Implementation Method 2
promote stable dropwise condensation... condensate forms as drops on the surface, which grow on the surface, coalesce with other drops, and are shed from the surface
Implementation Method 3
The material... is transparent to electromagnetic radiation of at least one type selected from the group consisting of ultraviolet radiation, visible light, and infrared radiation
Data Source
AI summary
Ceramic materials with relatively high resistance to wetting by various liquids, such as water, are presented, along with articles made with these materials, methods for making these articles and materials, and methods for protecting articles using coatings made from these materials. One embodiment is an article comprising a material that is transparent to electromagnetic radiation of at least one type selected from the group consisting of ultraviolet radiation, visible light, and infrared radiation. The material comprises a primary oxide and a secondary oxide. The primary oxide comprises cerium or hafnium. The secondary oxide comprises (i) praseodymium or ytterbium, and (ii) another cation selected from the group consisting of the rare earth elements, yttrium, and scandium.