Aeolotropic super-hydrophobic surface of aluminum material and preparation method of aeolotropic super-hydrophobic surface

Abstract

The invention relates to a preparation technology for an aeolotropic super-hydrophobic surface of an aluminum material. According to the preparation technology, directional coarse grinding and directional fine grinding are conducted on the aluminum material successively through a scouring pad, abrasive paper, a steel brush and other hard rough materials; after being put to lye, the aluminum material is descaled, activated, and further roughened; and a multilevel micro-nano composite structure can be constructed through subsequent weak alkaline boiling water soaking treatment, and after the multilevel micro-nano composite structure is subjected to fluoroalkylsilane chemical modification, the aeolotropic super-hydrophobic surface can be obtained. In the direction of directional grinding, an aluminum sheet has the super-hydrophobicity, the contacting angle is larger than 150 degrees, the rolling angle is smaller than 10 degrees, and the contact is in a Cassie compound state; in the direction perpendicular to the grinding direction, the contacting angle is invariant, but the rolling angle is among 10-20 degrees, so that a water drop moves more easily in the parallel direction of a stripe / groove formed during grinding. The aeolotropic super-hydrophobic surface has wide application prospects in the fields of directional condensation water collecting, dropwise condensation heat transferring and directional defrosting deicing as well as microfluid, biomedical equipment and the like.

Description

technical field [0001] The invention relates to a preparation technology of anisotropic super-hydrophobic surface of aluminum material. Background technique [0002] The special micro-nano composite structure in organisms can endow it with special surface characteristics, typically the surface of plant leaves with "lotus leaf effect" (such as lotus leaves, etc.) Hydrophobic properties. The special anisotropic micro-nano structures in organisms have some special wetting properties endowed by these structures. Rice leaves, for example, have an anisotropic hierarchical structure and exhibit superhydrophobicity. The arrangement of micropapillae on the surface of rice leaves is anisotropic, and the quasi-one-dimensional arrangement direction of these micropapillae is parallel to the edge of the leaf. Therefore, the rice leaf surface exhibits anisotropic wettability, and water droplets can easily roll along the direction parallel to the leaf edge, thereby guiding the flow of ra...

AI Technical Summary

Problems solved by technology

Although existing technologies can achieve differential wettability, they generally only have hydrophobicity, or cannot have superhydrophobicity in both directions. At least in one direction, the rolling angle of water droplets is greater than 10°, making it difficult to roll. , and often contact with the surface in a Wenzel wet state, with strong adhesion, which is very unfavorable for the application of this surface in directional condensation water collection, droplet condensation heat transfer and directional defrosting and deicing, because these fields not only require water droplet movement There is anisotropy, and it is also required to be in Cassie complex contact in all directions, with small adhesion for easy desorption

Images