CN-122011470-A - Directional bouncing anti-icing surface based on asymmetric superhydrophobic structure and preparation method thereof

CN122011470ACN 122011470 ACN122011470 ACN 122011470ACN-122011470-A

Abstract

The invention discloses a directional bouncing anti-icing surface based on an asymmetric superhydrophobic structure and a preparation method thereof, and belongs to the technical field of functional material surfaces and anti-icing. The directional bouncing ice-proof surface based on the asymmetric superhydrophobic structure comprises an asymmetric structure array with a specific shape and a low surface energy coating covered on the surface of the asymmetric structure array, wherein the asymmetric structure array is composed of a plurality of micron-level or millimeter-level columnar structure units, the top ends of the columnar structure units are provided with asymmetric inclined geometric surfaces, the asymmetric inclined geometric surfaces of the top ends of the columnar structure units are provided with consistent inclined directions, the surface of the columnar structure units is provided with a micro-nano composite rough structure, and the surface of the columnar structure units is modified with the low surface energy coating, so that the directional bouncing ice-proof surface based on the asymmetric superhydrophobic structure has the overall superhydrophobic characteristic. The invention realizes an actively oriented anti-icing mechanism.

Inventors

NING YUZHEN
SU LIYING
LIU KESONG
ZHAO ZHIHONG
HAN JIANDONG
LIU ZEYE
CHEN ZHUO

Assignees

北京航空航天大学

Dates

Publication Date: 20260512
Application Date: 20260330

Claims (10)

1. The directional bouncing anti-icing surface based on the asymmetric superhydrophobic structure is characterized by comprising an asymmetric structure array with a specific shape and a low surface energy coating covered on the surface of the asymmetric structure array; the surface of the columnar structure unit is constructed with a micro-nano composite coarse structure, and the surface of the columnar structure unit is modified with the low-surface energy coating, so that the whole directional bouncing ice-preventing surface based on the asymmetric superhydrophobic structure has superhydrophobic characteristic; The asymmetric micro-nano composite rough structure of the structural array and the columnar structural unit and the low surface energy coating act together, so that asymmetric interfacial force and Laplacian pressure difference are generated when the directional bouncing anti-icing surface based on the asymmetric super-hydrophobic structure is contacted with the liquid drops, and the liquid drops are driven to be ejected from the directional bouncing anti-icing surface based on the asymmetric super-hydrophobic structure directionally and rapidly.
2. The directional bouncing ice preventing surface based on an asymmetric superhydrophobic structure according to claim 1, wherein an inclination angle of an asymmetric inclined geometrical plane of a top end of the columnar structural unit is 1 ° to 89 °.
3. The directional bouncing ice preventing surface based on an asymmetric superhydrophobic structure according to claim 1, wherein a pitch between adjacent columnar structural units is 0.5 to 10 times a cross-sectional feature size.
4. The directional bouncing ice preventing surface based on an asymmetric superhydrophobic structure according to claim 1, wherein a cross-sectional feature size of the columnar structural unit is 5 μm to 2mm, and a height of the columnar structural unit is 10 μm to 5mm.
5. The directional bouncing anti-icing surface based on an asymmetric superhydrophobic structure according to claim 1, wherein the micro-nano composite coarse structure is formed by performing organic solvent cleaning and ultraviolet post-curing treatment on photo-curing resin forming a columnar structure unit, so as to form submicron or nanometer coarse morphology on the surface of the columnar structure unit in situ.
6. The directional bouncing anti-icing surface based on an asymmetric superhydrophobic structure according to claim 1, wherein the low surface energy coating is selected from any one of (a) an organic-inorganic hybrid coating formed by blending polydimethylsiloxane and hydrophobic silica nanoparticles, (b) a silica nanoparticle layer formed by dispersing hydrophobic silica nanoparticles in ethanol solution and spraying and drying, and (c) a fluorosilane monolayer formed by chemical vapor deposition or solution self-assembly.
7. A method for preparing an oriented bouncing ice-preventing surface based on an asymmetric superhydrophobic structure according to any one of claims 1 to 6, comprising the steps of: S1, adopting a surface projection photocuring additive manufacturing technology, taking photocuring resin as a material, and curing and forming layer by layer to obtain an asymmetric initial structure array; S2, cleaning the asymmetric initial structure array obtained in the step S1 by using an organic solvent to dissolve and remove resin with incompletely cured surface, roughening the surface of the resin, and then performing ultraviolet post-curing treatment to form the micro-nano composite rough structure on the surface of the structure to obtain an asymmetric structure array; S3, preparing a low surface energy coating on the surface of the asymmetric structure array obtained in the step S2, and performing thermal curing treatment on the coating to obtain the directional bouncing anti-icing surface based on the asymmetric superhydrophobic structure.
8. The method for preparing an ice-resistant surface for directional bouncing based on an asymmetric superhydrophobic structure according to claim 7, wherein in the step S1, the parameters of the surface projection photocuring additive manufacturing process comprise exposure light intensity per unit area of 1-100 mW/cm 2 , single-layer exposure time of 0.5-30 seconds, and thickness of a printing layer of 10-500 μm.
9. The method for preparing the directional bouncing anti-icing surface based on the asymmetric superhydrophobic structure according to claim 7, wherein the organic solvent used for cleaning in the step S2 is ethanol, isopropanol or acetone, the cleaning mode in the step S2 comprises dipping cleaning or ultrasonic auxiliary cleaning, the cleaning time is 1-30 minutes, and the ultraviolet post-curing treatment time in the step S2 is 1-60 minutes; The heat curing treatment of the coating in step S3 is specifically heating at 30 to 100 ℃ for 10 to 120 minutes.
10. Use of the directional bouncing ice-repellent surface based on an asymmetric superhydrophobic structure according to any of claims 1-6 for anti-icing and enhanced heat transfer in low Wen Chipian heat exchangers, aerospace devices, wind turbine blades or electric power transmission devices.

Description

Directional bouncing anti-icing surface based on asymmetric superhydrophobic structure and preparation method thereof Technical Field The invention belongs to the technical field of functional material surfaces and anti-icing, and particularly relates to a directional bouncing anti-icing surface based on an asymmetric superhydrophobic structure and a preparation method thereof. Background Surface icing is a common problem jeopardizing several critical areas. In the aerospace field, the icing of wings or sensors (such as airspeed tubes) can destroy aerodynamic profiles, resulting in loss of lift and failure of control, which has historically been one of the key factors in causing flight accidents. In the fields of power transmission and distribution and new energy, the tower can collapse due to icing of a power transmission line, large-scale power failure can be caused, pneumatic efficiency of the wind driven generator can be suddenly reduced due to icing of the wind driven generator blade, and the power generation loss can reach 50% at most. In the field of low-temperature refrigeration and heat exchange, the frosting of the evaporator can reduce the heat transfer efficiency by 50-75%, and greatly increase the energy consumption. The mainstream deicing technology (such as electrothermal deicing, anti-icing liquid spraying, mechanical deicing and the like) applied in the current engineering belongs to an active strategy, and has the defects of high energy consumption, low efficiency, dependence on complex systems or influence on the environment and the like. The passive anti-icing technology aims at physically inhibiting nucleation and adhesion of ice crystals through the special design of the material surface, and has the advantages of energy conservation and environmental protection. Inspired by the nature, the bionic super-hydrophobic surface is widely focused as a passive anti-icing strategy with low energy consumption. The basic principle is that a micro-nano coarse structure is constructed and a low-surface energy substance is modified, so that a stable air cushion (Cassie-Baxter state) is formed at a solid-liquid interface, the actual contact area is obviously reduced, the heat transfer is delayed, the ice nucleus formation energy barrier is increased, and finally the icing delay and the ice adhesion strength are reduced. Research shows that the superhydrophobic surface with specific micron-sized structure (such as columnar and conical) can effectively prolong the icing time. More importantly, a "pancake bounce" may occur when a droplet impinges on such a surface, shortening its solid-liquid contact time to the order of milliseconds, which can theoretically be shorter than the nucleation time of a supercooled droplet, providing a key opportunity to prevent the droplet from freezing. However, the anti-icing performance of the existing superhydrophobic surface has the fundamental limitation that firstly, the bouncing behavior direction of liquid drops is completely random, the liquid drops after bouncing off are very easy to fall back to the original surface again or be combined with other liquid drops, so that the liquid drops are retained in a local area to create opportunities for ice nucleus growth, and secondly, on the horizontal or small-inclination-angle surface, the liquid drop removal is seriously dependent on gravity, and the efficiency is low. Therefore, how to actively control the bouncing direction of the liquid drop so that the liquid drop is quickly and directionally separated from the surface is a core challenge of breaking through the bottleneck of the conventional passive anti-icing technology and realizing source prevention and control. Disclosure of Invention The invention aims to overcome the defects of random removal direction and low efficiency of the prior superhydrophobic surface liquid drops, provides an oriented bouncing anti-icing surface based on an asymmetric superhydrophobic structure and a preparation method thereof, the directional bouncing anti-icing surface can induce liquid drops to generate rapid directional bouncing or deviation, so that the detention time and collision probability of the liquid drops on the low-temperature surface are greatly reduced, and the anti-icing mechanism upgrading from 'deferring icing' to 'actively preventing the liquid drops from detention' is realized. In order to achieve the above purpose, the invention adopts the following technical scheme: an oriented bouncing anti-icing surface based on an asymmetric superhydrophobic structure comprises an asymmetric structure array with a specific morphology and a low surface energy coating covered on the surface of the asymmetric structure array; the surface of the columnar structure unit is constructed with a micro-nano composite coarse structure, and the surface of the columnar structure unit is modified with the low-surface energy coating, so that the whole directional bouncing ice-preventing s