CN110791125A

CN110791125A - Preparation method of super-hydrophobic anti-icing material

Info

Publication number: CN110791125A
Application number: CN201810869309.2A
Authority: CN
Inventors: 杨林翔; 熊党生; 张璇; 吴玉林; 佟威
Original assignee: Nanjing University of Science and Technology
Current assignee: Nanjing University of Science and Technology
Priority date: 2018-08-02
Filing date: 2018-08-02
Publication date: 2020-02-14

Abstract

The invention discloses a preparation method of a super-hydrophobic anti-icing material. The method comprises the steps of firstly polishing a base material by using sand paper, then immersing the base material into a mixed solution of hydrochloric acid and 30% hydrogen peroxide for etching to form a micro-nano structure, immersing the micro-nano structure into a suspension of nano ZnO particles and cellulose for sedimentation, then immersing the micro-nano structure into an organic solution of PDMS, taking out the micro-nano structure and curing the micro-nano structure to obtain the super-hydrophobic anti-icing material. The invention has low cost, simple process and wide applicable matrix material, and the prepared super-hydrophobic anti-icing material has good anti-icing and self-cleaning capabilities and is suitable for mechanical anti-icing in low-temperature and high-humidity environment.

Description

Preparation method of super-hydrophobic anti-icing material

Technical Field

The invention relates to a preparation method of a super-hydrophobic anti-icing material, belonging to the field of materials.

Background

The super-hydrophobic material is a material with a surface static water contact angle larger than 150 degrees and a rolling angle smaller than 10 degrees, water drops cannot well infiltrate on the surface of the super-hydrophobic material and keep spherical rolling, and the super-hydrophobic property is presented macroscopically. Researches show that the super-hydrophobic surface can delay the icing time, reduce the ice coating amount and reduce the adhesion of ice blocks to the solid surface. In recent years, the preparation of superhydrophobic surfaces has been a hot spot in material research, and the surfaces with superhydrophobic properties need to satisfy one of the following conditions: firstly, the surface of the substrate needs to have a certain rough structure; secondly, the substrate has lower surface energy.

The existing preparation method of the super-hydrophobic surface mainly comprises a sol-gel method, a photoetching method, a chemical corrosion method, a chemical vapor deposition method, a template method and the like. These methods, although different in terms of preparation principles and processes, generally follow one principle: i.e. a combination of interface roughness and low surface energy. The commonly used low surface energy materials mainly refer to fluorine-containing and silicon-containing polymers, such as Polytetrafluoroethylene (PTFE), fluorosilanes and the like, and the materials can show good hydrophobic and ice-repellent performance, antifouling performance and self-lubricating performance. Wang et al enhanced SiO nanoparticles with FAS₂The hydrophobicity of the particles is realized, and a super-hydrophobic interface with a static water contact angle of 163 degrees is prepared, but the method has the problems of complexity, time consumption, complex equipment, expensive raw materials, high cost and the like, and the large-scale manufacture of the super-hydrophobic surface is difficult (Peng Wang, et al]Journal of materials Chemistry A,2016,4(20): 7869-. Although the defects can be well overcome by the simple brushing and spraying method, the micro-nano structure of the prepared super-hydrophobic surface is easy to damage, so that the super-hydrophobicity is lost.

In addition, the presence of the roughness helps to further increase the contact angle of the hydrophobic coating, reduce the contact area between the water droplet and the substrate, and reduce the adhesion between the two, wherein the contained air can form a thermal insulating layer, reduce the heat transfer rate and thus delay the icing time, and if the substrate is slightly tilted, the droplet can leave the surface of the material before icing, so that no ice coating can accumulate on the substrate. Hydrophobic silicon oxide nano-particles are coated on the surface of a base material to construct a micron-nano composite structure, so that a compact super-hydrophobic surface with small roughness can be formed. However, the superhydrophobic surface formed by this method has problems that it is easy to be detached and self-anti-icing is difficult to be achieved in a low-temperature and high-humidity environment (CN 105694715A).

Disclosure of Invention

The invention aims to provide a simple and easy preparation method of a super-hydrophobic anti-icing material.

The technical solution for realizing the purpose of the invention is as follows:

the preparation method of the super-hydrophobic anti-icing material comprises the following specific steps:

(1) pretreatment of the substrate: polishing a base material by using sand paper, immersing the base material into a mixed solution of hydrochloric acid and 30% hydrogen peroxide for etching for 3-5 min, and cleaning and drying by using water and ethanol;

(2) preparing a nano-particle suspension: dispersing 100-300 nm ZnO nanoparticles in a hexane solution of stearic acid, and mixing the ZnO nanoparticles and a thickening agent according to a mass ratio of 10: 1-20: 1 adding thickening agent cellulose, and stirring at room temperature to form uniform suspension;

(3) preparation of PDMS solution: dissolving a Polydimethylsiloxane (PDMS) prepolymer and a curing agent in an organic solvent according to a proportion, and stirring to obtain a uniform solution;

(4) preparing a super-hydrophobic surface: and (3) immersing the etched base material into the suspension obtained in the step (2), standing for 3-5 min, taking out, drying at room temperature, immersing into the solution obtained in the step (3), standing for 40-50 s, taking out the base material, and curing to obtain the super-hydrophobic anti-icing material.

Preferably, in step (1), the substrate is a metal alloy such as iron and aluminum alloy, or an organic polymer material such as epoxy resin.

Preferably, in the step (1), the volume ratio of the concentrated hydrochloric acid to the 30% hydrogen peroxide solution in the mixed solution of hydrochloric acid and hydrogen peroxide is 10: 3.

preferably, in the step (2), the concentration of the hexane solution of stearic acid is 0.02-0.05 mol/L.

Preferably, in the step (3), the concentration of the PDMS prepolymer is 1g/mL organic solvent.

Preferably, in step (3), the organic solvent is selected from tetrahydrofuran or hexane.

Preferably, in the step (4), the drying time at room temperature is 12-15 min.

Preferably, in the step (4), the curing is performed for 1-2 hours at 60-120 ℃ and then for 1-2 hours at 100-120 ℃.

Compared with the prior art, the invention has the following remarkable advantages:

1) the preparation method is simple, and the processing process is simple and easy to implement;

2) the prepared super-hydrophobic anti-icing material can effectively delay the icing speed in a low-temperature high-humidity environment, and can be widely applied to mechanical anti-icing in the low-temperature high-humidity environment.

Drawings

FIG. 1 is a graph showing the results of the static water contact angle test of the superhydrophobic anti-icing material of example 1.

FIG. 2 is a graph of the results of the static water contact angle test of the superhydrophobic anti-icing material of example 2.

FIG. 3 shows the results of the anti-icing test of the super-hydrophobic anti-icing material under the environment of low temperature (-20 deg.C) and high humidity (environment humidity 80% + -10%).

Detailed Description

The present invention will be described in more detail with reference to the following examples and the accompanying drawings.

Example 1

(1) Pretreatment of the substrate: polishing an epoxy resin substrate by using sand paper, and then immersing the substrate into a solution of 10: 3, reacting the mixture with 30 percent hydrogen peroxide solution for 5min, taking out the base material, washing the base material with deionized water and ethanol, and drying the base material by blowing.

(2) Preparing a nano-particle suspension: adding 0.142g of stearic acid into 15mL of n-hexane solution, stirring to obtain a uniform solution, dispersing 2g of hydrophobic ZnO nanoparticles into the solution, stirring at room temperature for 30min, adding 0.1g of cellulose, and continuing stirring for 10 min.

(3) Preparation of PDMS solution: 1g of PDMS prepolymer and 0.1g of curing agent were dissolved in 50mL of Tetrahydrofuran (THF), and the mixture was stirred for 10 min.

(4) Preparing a super-hydrophobic surface: and (3) immersing the etched epoxy resin substrate into the suspension obtained in the step (2) for 3min, taking out, drying at normal temperature for 15min, immersing into the PDMS solution obtained in the step (3), taking out after 45s, curing at 60 ℃ for 2h, and drying at 100 ℃ for 1h to obtain the super-hydrophobic anti-icing material.

As shown in fig. 1, the contact angle of the surface of the prepared superhydrophobic anti-icing material is 151 °.

Example 2

(1) Pretreatment of the substrate: grinding a 6061 aluminum alloy substrate by using sand paper, and then immersing the substrate into 10: 3, reacting for 3min in a concentrated hydrochloric acid and hydrogen peroxide solution, taking out the base material, washing with deionized water and ethanol, and drying.

As shown in fig. 2, the contact angle of the prepared superhydrophobic anti-icing material is 154 °.

FIG. 3 shows the results of the anti-icing test of the super-hydrophobic anti-icing material in a low-temperature and high-humidity environment. The white substrate was the substrate prepared with the superhydrophobic anti-icing material (denoted as substrate a) and the control was pretreated only (denoted as substrate B), starting with no ice coating on both substrates. After 28min, the surface of the substrate A began to freeze, while the surface of the substrate B had completely frozen. Compared with the icing time of the two substrates in the same low-temperature high-humidity environment, the prepared super-hydrophobic anti-icing material can effectively delay the icing time.

Comparative example 1

This comparative example is essentially the same as example 2, the only difference being that the mass ratio of ZnO nanoparticles to thickener is 8: 1.

because the ratio of ZnO nanoparticles to thickener is less than 10: 1, the obtained suspension has poor ductility, cannot obtain a uniform coating, and has obviously poor hydrophobic effect.

Comparative example 2

This comparative example is essentially the same as example 1, except that the mass ratio of ZnO nanoparticles to thickener is 30: 1.

since the ratio of ZnO nanoparticles to thickener is greater than 20: 1, the concentration of the obtained suspension is low, so that super-hydrophobic ZnO particles are difficult to deposit on the surface of a base material, and the hydrophobic effect is obviously poor.

Claims

1. The preparation method of the super-hydrophobic anti-icing material is characterized by comprising the following specific steps of:

(3) preparation of PDMS solution: dissolving a PDMS prepolymer and a curing agent in an organic solvent according to a proportion, and stirring to obtain a uniform solution;

2. The method according to claim 1, wherein in the step (1), the substrate is a metal alloy or an organic polymer material.

3. The method according to claim 1, wherein in the step (1), the volume ratio of the concentrated hydrochloric acid to the 30% hydrogen peroxide solution in the mixed solution of hydrochloric acid and hydrogen peroxide is 10: 3.

4. the method according to claim 1, wherein the concentration of the hexane solution of stearic acid in the step (2) is 0.02 to 0.05 mol/L.

5. The method according to claim 1, wherein in the step (3), the concentration of the PDMS precursor is 1g/mL of the organic solvent.

6. The method according to claim 1, wherein in the step (3), the organic solvent is selected from tetrahydrofuran and hexane.

7. The preparation method according to claim 1, wherein in the step (4), the drying time at room temperature is 12-15 min.

8. The preparation method according to claim 1, wherein in the step (4), the curing is performed at 60-120 ℃ for 1-2 h, and then at 100-120 ℃ for 1-2 h.