Stainless steel super-hydrophobic and super-hydrophilic surface and preparation method and application thereof

Abstract

The invention discloses a stainless steel super-hydrophobic and super-hydrophilic surface. Multiple sub arrays are distributed on the surface of stainless steel. Multiple super-hydrophobic areas and multiple super-hydrophilic areas in each sub array are arranged alternately in wedge shapes or triangular shapes. Super-hydrophilic gathering areas are districted among the sub arrays. The super-hydrophobic surface is excellent in super-hydrophobic performance; liquid drops are quite small in adhesion and can fall off quite easily; the super-hydrophilic areas can adsorb the liquid drops, the liquiddrops at the top ends of the wedge shapes or the triangular shapes can be driven by the plus force generated by the wedge shapes or the triangular shapes to move automatically and rapidly toward thebottoms of the wedge shapes or the triangular shapes; the super-hydrophobic areas which are alternate with the super-hydrophilic areas can repel oriented output of the liquid drops; the super-hydrophilic areas and the super-hydrophobic areas achieve the synergistic effect, so that the condensed small liquid drops are continuously gathered to a hydrophilic gathering area, and high-concentration self-drive water collection is achieved; falling of the liquid drops is accelerated, and thus, the condensation heat transfer efficiency is improved. The invention further provides a preparation method and application of the stainless steel super-hydrophobic and super-hydrophilic surface.

Description

technical field [0001] The invention relates to the technical field of surface modification of metal substrates, in particular to a superhydrophobic-superhydrophilic surface of stainless steel and a preparation method and application thereof. Background technique [0002] In many important applications, such as heat transfer, seawater desalination, water harvesting, etc., the condensation of water vapor is a very important process. On a solid surface, the condensation process includes droplet condensation and film condensation, and the condensation method depends on the wettability of the condensation surface. Droplet condensation can greatly improve the efficiency of heat transfer. Studies have shown that compared with film condensation, the heat transfer efficiency of droplet condensation can be increased by more than 10 times. [0003] Condensing equipment is a device used to promote condensation, which mainly uses the principle of heat exchange to cool and condense stea...

AI Technical Summary

Problems solved by technology

For example: Patent CN201710134468 discloses a method of laser selective melting of metal nanoparticles solution additively manufacturing hydrophobic surfaces in an air environment. The improved method requires chemical assistance, and the spread of metal nanoparticles is difficult to uniform, resulting in unstable laser cladding quality. The processing efficiency is not high; the patent CN201710017934 discloses laser preparation of metal biomimetic super-hydrophobic surfaces. After the sample is laser-treated once, the plane is rotated 90° and then processed for the second time, which is similar to grid processing. The rotation in the processing step is not rigorous, making the sample There is no uniform standard

However, the super-hydrophobic surface prepared by the above methods can only prevent the condensation of droplets on the surface, but cannot make the condensed droplets leave the surface quickly, which has very limited improvement in the condensation efficiency of condensation equipment.

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