Home > News > Superhydrophobic materials come out! Both superhydrophobicity and mechanical stability will be widely used in the future

Superhydrophobic materials come out! Both superhydrophobicity and mechanical stability will be widely used in the future

wallpapers News 2020-06-19
Why can water spiders walk on water? Why does the lotus leaf "sludge without staining"? Why won't the butterfly's wings get wet? These are related to the superhydrophobicity of the surface of the "body" of animals and plants.
 
Inspired by the above natural phenomena, people gradually grasp the secret of the material's hydrophobicity-it has excellent repulsion to water, water droplets keep a spherical shape on its surface, and it is easy to roll. The water droplets can also take away the surface of the material Dust to achieve a cleaning effect.
 
However, the surface structure of superhydrophobic materials prepared by people in the past is very fragile and difficult to achieve full application. How to coat the surface of superhydrophobic materials with strong "armor" without affecting its hydrophobic performance has become the direction of efforts of researchers in this field. They can solve the critical problem of insufficient mechanical stability of superhydrophobic surfaces by "wearing" superhydrophobic covers with micro-structured "armor" with excellent mechanical stability.
 
Superhydrophobicity vs. mechanical stability
 
In recent years, due to their unique physical properties, superhydrophobic materials derived from animal and plant bionics have shown great application potential in fields such as surface self-cleaning, biological antifouling, waterproof, and anti-icing, fluid drag reduction, and heat and mass transfer.
 
It is understood that the superhydrophobicity of superhydrophobic materials can be attributed to the micro/nano-rough structure that can trap air and hold up droplets. Not resistant to abrasion will also cause the underlying material to be exposed, and the local chemical properties of the surface will change, making it from hydrophobic to hydrophilic.
 
 
According to previous scientific research, it is believed that the mechanical stability and superhydrophobicity of the material surface are two characteristics that cannot be achieved simultaneously. This is because the micro/nano rough structure is to increase the hydrophobicity by reducing the contact area of ​​the material with water, which also causes the micro/nanostructure to withstand a higher local pressure, which is more susceptible to wear. This means that in the conventional superhydrophobic materials, the two characteristics of superhydrophobicity and mechanical stability will inevitably lead to a decrease in the performance of the other side when the return of one side is improved.
 
To achieve a double superposition of the mechanical stability and superhydrophobic performance of the same material surface, it is necessary to install "armor" on the surface of superhydrophobic materials with weaker mechanical properties.
 
On the one hand, to achieve mechanical stability requires geometric design on a more substantial structural scale; on the other hand, to ensure good superhydrophobicity, structural optimization is needed for the nanoscale. Scientists split the superhydrophobicity and mechanical stability into two different fundamental scales through the "decoupling mechanism." They optimized the design separately, and then combined them to let the microstructures that provide mechanical stability play the role of "armor." To prevent the structure with superhydrophobicity from being worn.
 
The microstructure is to achieve micron or even more macro-scale levels. This structure is more wear-resistant and durable, and can provide mechanical stability to protect nanomaterials from wear; the protected nanostructures mainly assume superhydrophobicity. In this way, the microstructure "armor" prepared by optimizing the design can well protect the superhydrophobic nanomaterial from abrasion, thereby constructing an "armored" superhydrophobic surface.
 
In the course of the experiment, the researchers obtained microstructural design principles by combining the infiltration theory and mechanical mechanics analysis, and at the same time used micro-processing techniques such as photolithography, cold/hot pressing to prepare the armor structure on silicon wafers, ceramics, metals, and glass The surface of the universal substrate is combined with superhydrophobic nanomaterials to construct an "armored" superhydrophobic surface with excellent mechanical stability.
 
Researchers have applied this new superhydrophobic material surface to solar cell cover plates. Self-cleaning technology can skillfully use rain or mist droplets to eliminate dust and other pollution, maintain the efficient energy conversion of solar cells for a long time, and save the new water resources and labor costs necessary for the traditional cleaning process.
 
The team found that the new superhydrophobic material also has comprehensive properties such as resistance to chemical corrosion and thermal degradation, resistance to high-speed jet impact, and resistance to condensation failure. The new content also achieves high light transmittance of the armored glass surface, which will also create conditions for application in self-cleaning vehicle glass and architectural glass curtain walls.

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