A wear-resistant, photothermal, and hydrophobic microunit and its adhesion-controlled wear-resistant and anti-icing film

Abstract

The present invention relates to the field of micro-nano surface construction technology and surface interface anti-icing, and in particular to a wear-resistant photothermal hydrophobic microunit and a wear-resistant anti-icing film with controllable adhesion thereof. The raw materials of the wear-resistant photothermal hydrophobic microunit include 1 part of candle ash and 1-5 parts of diatomaceous earth by mass. The present invention provides a wear-resistant photothermal hydrophobic microunit with a simple raw material composition and hydrophobic ability and photothermal conversion ability. The present invention fills the lack of anti-icing technology in life scenes, with the anti-icing strategy of photothermal ability and super-hydrophobic properties as the main center, and develops a wear-resistant anti-icing film with controllable adhesive properties through a low-cost and environmentally friendly preparation process, thereby effectively solving the icing phenomenon on the surface of scenes such as car rearview mirrors and electric vehicle seats in daily life, and realizing the reuse of multiple surfaces of the film through the operations of pasting, peeling off, and transferring, while not affecting the normal use of the original surface.

Description

Technical Field

[0001] The invention relates to micro-nano surface construction technology and the field of surface interface anti-icing, and in particular to a wear-resistant photothermal hydrophobic microunit and a wear-resistant anti-icing film with controllable adhesion thereof. Background Art

[0002] Freezing is a very common natural phenomenon in low-temperature environments. It is a solid-liquid phase transition process in which liquid water is supercooled on a solid surface to form ice crystals and grow. Under different meteorological conditions, ice can form various forms such as snow and rime, creating a gorgeous and beautiful spectacle for nature. However, the accumulation of ice can also bring many inconveniences to human life and production, and even damage facilities and equipment and endanger life and health. For example, vehicle icing causes mechanical failures; road icing affects driving safety and increases the probability of traffic accidents; and ice on the surface of an aircraft may cause the aircraft's maneuverability and stability to decrease, threatening flight safety, causing significant losses or even catastrophic accidents. Therefore, establishing an effective anti-icing mechanism to achieve an efficient, environmentally friendly, and energy-saving anti-icing method has become an important scientific topic.

[0003] To solve the problem of surface icing, active anti-icing strategies oriented towards deicing are currently commonly used, mainly including mechanical deicing, thermal ice melting and chemical deicing. Active anti-icing mainly uses external energy input, which requires a lot of energy, and there is a risk of damaging existing facilities and lack of timeliness. Inspired by organisms with ice resistance in high-latitude areas, based on the mechanism of delaying ice formation and reducing ice adhesion, researchers have established a passive anti-icing strategy based on various bionic micro / nanostructure surfaces to resist ice formation. This strategy has the advantages of no energy consumption, no pollution, and effectiveness. However, it has been proven that it is impossible to completely eliminate surface icing by simply building surface micro / nanostructures. Summary of the invention

[0004] Based on the above content, the present invention provides a wear-resistant photothermal hydrophobic microunit and a wear-resistant anti-icing film with controllable adhesion thereof.

[0005] To achieve the above object, the present invention provides the following solutions:

[0006] One of the technical solutions of the present invention is a wear-resistant photothermal hydrophobic microunit, wherein the raw materials include 1 part of candle ash and 1-5 parts of diatomaceous earth by weight.

[0007] In some embodiments of the present invention, the median particle size of the diatomaceous earth is 20-50 μm.

[0008] The second technical solution of the present invention is a method for preparing the above-mentioned wear-resistant photothermal and hydrophobic microunits, which comprises adding candle ash into an organic solvent and dispersing the mixture evenly, adding diatomaceous earth and mixing the mixture evenly, and drying the mixture to obtain the wear-resistant photothermal and hydrophobic microunits.

[0009] The third technical solution of the present invention is the application of the above-mentioned wear-resistant photothermal hydrophobic microunit in the preparation of wear-resistant anti-icing film or passive anti-icing of vehicles or aircraft.

[0010] A fourth technical solution of the present invention is a method for preparing a wear-resistant and anti-icing film with controllable adhesion, comprising the following steps:

[0011] After the polydimethylsiloxane (PDMS) precursor and the curing agent are uniformly mixed, a film is prepared by a template method, and a micro suction cup is constructed at the bottom of the film to obtain a film in a semi-molten state;

[0012] Spraying the mixed liquid onto the surface of the semi-molten film and solidifying it to obtain the wear-resistant and anti-icing film with controllable adhesion;

[0013] The mixed solution comprises the above-mentioned wear-resistant photothermal hydrophobic microunit, PDMS and an organic solvent;

[0014] The mass volume ratio of the wear-resistant photothermal hydrophobic microunit, PDMS and organic solvent is 1g:1g:100mL.

[0015] A fifth technical solution of the present invention is a wear-resistant and anti-icing film with controllable adhesion prepared by the above-mentioned preparation method.

[0016] A sixth technical solution of the present invention is the application of the above-mentioned wear-resistant anti-icing film with controllable adhesion in passive anti-icing of vehicles or aircraft.

[0017] The present invention discloses the following technical effects:

[0018] The invention provides a wear-resistant photothermal hydrophobic microunit, which has a simple raw material composition and has hydrophobic ability and photothermal conversion ability.

[0019] The preparation method of the wear-resistant photothermal hydrophobic microunit of the present invention is simple, the raw materials are easily available, and large-scale industrial preparation is easy.

[0020] The present invention fills the lack of anti-icing technology in life scenarios, takes the anti-icing strategy of photothermal capacity and super-hydrophobic properties as the main center, and develops a wear-resistant anti-icing film with controllable adhesive properties through a low-cost and environmentally friendly preparation process, thereby effectively solving the icing phenomenon on the surfaces of scenes such as car rearview mirrors and electric vehicle seats in daily life. The film can be reused between multiple surfaces through the operations of pasting, peeling and transferring, without affecting the normal use of the original surface. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0022] Figure 1 The present invention is a flow chart for preparing the wear-resistant and anti-icing film with controllable adhesive properties.

[0023] Figure 2 It is a schematic diagram of the technical effect of the wear-resistant and anti-icing film with controllable adhesion performance of the present invention.

[0024] Figure 3 This is a microstructure diagram of the wear-resistant photothermal and hydrophobic microunit prepared in Example 1 of the present invention. DETAILED DESCRIPTION

[0025] Various exemplary embodiments of the present invention will now be described in detail. This detailed description should not be considered as limiting the present invention, but should be understood as a more detailed description of certain aspects, features, and embodiments of the present invention.

[0026] It should be understood that the terms described in the present invention are only for describing a particular embodiment and are not intended to limit the present invention. In addition, for the numerical range in the present invention, it should be understood that each intermediate value between the upper and lower limits of the scope is also specifically disclosed. The intermediate value in any stated value or stated range, and each smaller range between any other stated value or intermediate value in the described range is also included in the present invention. The upper and lower limits of these smaller ranges can be independently included or excluded in the scope.

[0027] Unless otherwise indicated, all technical and scientific terms used herein have the same meanings as those generally understood by those skilled in the art. Although the present invention describes only preferred methods and materials, any methods and materials similar or equivalent to those described herein may also be used in the implementation or testing of the present invention. All documents mentioned in this specification are incorporated by reference to disclose and describe the methods and / or materials associated with the documents. In the event of a conflict with any incorporated document, the content of this specification shall prevail.

[0028] It will be apparent to those skilled in the art that various modifications and variations may be made to the specific embodiments of the present invention description without departing from the scope or spirit of the present invention. Other embodiments derived from the present invention description will be apparent to the skilled artisan. The present invention description and examples are exemplary only.

[0029] The words “include,” “including,” “have,” “contain,” etc. used in this document are open-ended terms, meaning including but not limited to.

[0030] Existing reports and measures on anti-icing are mostly aimed at industrial production and large-scale equipment and facilities, and few studies are oriented to daily life. In the winter in the north, people still use hot water, chisels and other methods to deal with common ice phenomena in daily life such as windows, electric vehicles, and cars, which causes great inconvenience to people's living and traveling. Therefore, it is of practical significance to develop a skin (film) anti-icing technology with controllable adhesion and apply it to life.

[0031] The present invention combines passive and active anti-icing strategies, and combines the photothermal anti-icing / removal surface with the synergistic effect of micro-nanostructure and solar thermal conversion. The surface can not only prevent ice accumulation on the surface by using its own surface properties such as super-hydrophobicity, but also achieve the purpose of deicing by absorbing sunlight energy to increase the surface temperature. As a clean energy that can be widely obtained, sunlight can also effectively alleviate the pressure from the environment and energy.

[0032] The first aspect of the present invention provides a wear-resistant photothermal hydrophobic microunit, wherein the raw materials include 1 part of candle ash and 1-5 parts of diatomaceous earth by weight.

[0033] In the present invention, diatomaceous earth plays the role of a micron framework and improves the wear resistance in the micro unit.

[0034] Candle soot plays a role in light-heat conversion and provides hydrophobicity.

[0035] Too little candle ash will reduce the surface hydrophobicity, while too much candle ash will reduce the wear resistance. Therefore, the present invention preferably limits the amount of candle ash added to the above parameters.

[0036] The wear-resistant photothermal and hydrophobic microunit of the present invention has hydrophobic ability and photothermal conversion ability.

[0037] In some embodiments of the present invention, the median particle size of the diatomaceous earth is 20-50 μm.

[0038] If the median particle size of diatomite is too large, the microstructure of the final film surface will be too large, reducing the hydrophobic stability of the film surface; if the median particle size of diatomite is too small, the amount of candle ash loaded will decrease, thereby affecting the hydrophobicity and photothermal conversion ability of the prepared film.

[0039] The second aspect of the present invention provides a method for preparing the above-mentioned wear-resistant photothermal and hydrophobic microunits, which comprises adding candle ash into an organic solvent and dispersing the mixture evenly, adding diatomaceous earth and mixing the mixture evenly, and drying the mixture to obtain the wear-resistant photothermal and hydrophobic microunits.

[0040] In some embodiments of the present invention, the organic solvent is ethanol; and the drying temperature is 70°C.

[0041] A third aspect of the present invention provides an application of the above-mentioned wear-resistant photothermal hydrophobic microunit in the preparation of a wear-resistant anti-icing film or passive anti-icing of vehicles or aircraft.

[0042] A fourth aspect of the present invention provides a method for preparing a wear-resistant and anti-icing film with controllable adhesion, comprising the following steps:

[0043] After the polydimethylsiloxane (PDMS) precursor and the curing agent are uniformly mixed, a film is prepared by a template method, and a micro suction cup is constructed at the bottom of the film to obtain a film in a semi-molten state;

[0044] Spraying the mixed liquid onto the surface of the semi-molten film and solidifying it to obtain the wear-resistant and anti-icing film with controllable adhesion;

[0045] The mixed solution comprises the above-mentioned wear-resistant photothermal hydrophobic microunit, PDMS and an organic solvent;

[0046] The mass volume ratio of the wear-resistant photothermal hydrophobic microunit, PDMS and organic solvent is 1g:1g:100mL.

[0047] In the present invention, if the amount of PDMS in the mixed liquid is too much, the PDMS will cover the surface nanostructure, lose its hydrophobicity and reduce the photothermal conversion performance. If the amount of PDMS is too little, the bonding force between the microunit and the film surface will be reduced. Therefore, the present invention preferably limits the amount of PDMS in the mixed liquid to the above parameters.

[0048] In some embodiments of the present invention, the mass ratio of the polydimethylsiloxane precursor to the curing agent is 10:1.

[0049] In some embodiments of the present invention, the diameter of the micro suction cup is 1 mm-5 mm; the spraying conditions are: spraying pressure 0.2 MPa, spraying distance 15 cm, and spraying thickness 200 μm. Spraying thickness that is too thin will lead to a decrease in the photothermal conversion ability. Spraying that is too thick will affect the flexibility of the film.

[0050] The invention constructs a micro suction cup with a diameter of 1 mm to 5 mm at the bottom of the PDMS film so that the micro suction cup has a controllable adhesion ability and is used for anti-icing.

[0051] In some specific embodiments of the present invention, the micro-suction cup can be made by a specific mold; the mold is composed of a cylindrical array with a controllable radius (3mm-5mm), a controllable height (0.2mm-0.6mm), a controllable spacing (1mm-4mm), and an arrangement (quadrilateral and hexagonal). The adhesion of the film is controlled by adjusting the radius, depth and spacing of the micro-suction cup, and the adhesion on the glass is about 3.2kpa-8.1kpa, and the adhesion on the stainless steel surface is 1.7kpa-4.5kpa.

[0052] In some embodiments of the present invention, the organic solvent is hexane.

[0053] A fifth aspect of the present invention provides a wear-resistant and anti-icing film with controllable adhesion prepared by the above-mentioned preparation method.

[0054] A sixth aspect of the present invention provides an application of the above-mentioned wear-resistant and anti-icing film with controllable adhesion in passive anti-icing of vehicles or aircraft.

[0055] Unless otherwise specified, the raw materials and reagents used in the examples of the present invention can be obtained through commercial sources.

[0056] The candle ash used in the embodiments of the present invention is made from white candles purchased on the market. Specifically, when the candle is burning stably, a glass sheet is placed in the candle flame so that the candle is not fully burned and black ash is generated on the glass sheet. Finally, the black ash is scraped off the glass sheet and collected to obtain the candle ash.

[0057] The technical solutions provided by the present invention are described in detail below in conjunction with the embodiments, but they should not be construed as limiting the protection scope of the present invention.

[0058] Example 1

[0059] (1) Preparation of wear-resistant photothermal and hydrophobic microunits: 1 g of candle ash was added to 50 mL of ethanol, stirred thoroughly and then ultrasonically treated for 1 hour to make it evenly dispersed. Then, 3 g of diatomaceous earth (median particle size 25 μm) was added to the uniform dispersion and mechanically stirred for 12 hours. Then, black powder (i.e., wear-resistant photothermal and hydrophobic microunits) was obtained after vacuum drying at 70°C.

[0060] (2) Preparation of wear-resistant and anti-icing film: Mix the PDMS precursor and curing agent in a mass ratio of 10:1, and evacuate for 1 hour to remove bubbles. Pour the degassed PDMS into a mold with a surface structure to prepare a film, and prepare micro-suction cups on the surface of the film. The mold used is composed of a cylindrical array with a controllable radius (3mm-5mm), controllable height (0.2mm-0.6mm), controllable spacing (1mm-4mm), and arrangement (quadrilateral and hexagonal). The adhesion of the film is controlled by adjusting the radius of the micro-suction cup to 4mm, the depth to 0.6mm, and the spacing to 2mm. Specifically, the adhesion on the glass is about 8.1kPa, and the adhesion on the stainless steel surface is 4.5kPa (enabling the film to be easily attached and removed on a variety of surfaces). Then, at 60°C, a uniform mixture of 0.5g of wear-resistant photothermal and hydrophobic microunits, 0.5g of PDMS, and 50mL of hexane was sprayed onto the semi-molten PDMS film to enhance the bonding force between the wear-resistant photothermal and hydrophobic microunits and the film. The spraying pressure was 0.2Mpa, the spraying distance was 15cm, and the spraying thickness was 200μm. After that, the film was demolded after the PDMS was completely cured to obtain a wear-resistant and anti-icing film with controllable adhesion.

[0061] The hydrophobic property of the wear-resistant photothermal hydrophobic microunit prepared in this embodiment is characterized by a contact angle of about 160° through a contact angle meter.

[0062] The anti-icing performance verification of the wear-resistant and anti-icing film with controllable adhesion prepared in this embodiment was carried out in a cold room at -20°C, and it was able to delay the freezing of 20 microliters of droplets dripping on the surface of the film for more than 500 seconds, and at the same time, thaw the 20 microliters of frozen droplets within 400 seconds under the irradiation of 1 sunlight. The wear resistance test was performed by fixing a film with a length and width of 1.5 cm under a 100g weight and rubbing it back and forth on the surface of 1000 mesh sandpaper. The wear resistance was manifested as the contact angle was still close to 150° when the friction distance reached 300 cm. The adhesion performance was measured by a tensile gauge, by adhering a film with a length and width of 3 cm to the glass surface, and using a tensile gauge to linearly stretch it in the vertical direction until the film detached from the glass surface. The maximum value recorded by the tensile gauge was the adhesion force.

[0063] Comparative Example 1

[0064] The only difference from Example 1 is that the addition of candle ash is omitted in step (1); the remaining steps and parameters are the same as those in Example 1.

[0065] The hydrophobic property of the wear-resistant photothermal hydrophobic microunit prepared in this comparative example was characterized by a contact angle measuring instrument, and the contact angle was about 15°.

[0066] The anti-icing performance verification method of the controllable adhesion wear-resistant anti-icing film prepared in this comparative example was carried out in a -20°C cold room in the same manner as in Example 1. A 20 microliter droplet dropped on the surface of the film froze within 30 seconds, and the frozen droplet could not be thawed under the irradiation of 1 sunlight.

[0067] The embodiments described above are only descriptions of the preferred modes of the present invention, and are not intended to limit the scope of the present invention. Without departing from the design spirit of the present invention, various modifications and improvements made to the technical solutions of the present invention by ordinary technicians in this field should all fall within the protection scope determined by the claims of the present invention.

Claims

1. A wear-resistant photothermal hydrophobic microunit, characterized in that: The composition is composed of 1 part of candle ash and 1-5 parts of diatomaceous earth by weight; The median particle size of the diatomaceous earth is 20-50 μm; The preparation method of the wear-resistant photothermal hydrophobic microunit comprises the following steps: adding candle ash into ethanol and dispersing it evenly, adding diatomaceous earth and mixing it evenly, and drying it at 70° C. to obtain the wear-resistant photothermal hydrophobic microunit.

2. Use of the wear-resistant photothermal hydrophobic microunit as claimed in claim 1 in passive ice protection for vehicles or aircraft, or in the preparation of wear-resistant ice-proof films.

3. A method for preparing a wear-resistant and anti-icing film with controllable adhesion, characterized in that: The following steps are involved: After the polydimethylsiloxane precursor and the curing agent are uniformly mixed, a film is prepared by using a template method, and a micro-suction cup is constructed at the bottom of the film to obtain a film in a semi-molten state; Spraying the mixed liquid onto the surface of the semi-molten film and solidifying it to obtain the wear-resistant and anti-icing film with controllable adhesion; The mixed liquid comprises the wear-resistant photothermal hydrophobic microunit according to claim 1, polydimethylsiloxane and an organic solvent; The mass volume ratio of the wear-resistant photothermal hydrophobic microunit, polydimethylsiloxane and organic solvent is 1g:1g:100mL.

4. The method for preparing the wear-resistant and anti-icing film with controllable adhesion according to claim 3, characterized in that: The diameter of the micro suction cup is 1 mm-5 mm; the spraying conditions are: spraying temperature 60° C., spraying pressure 0.2 MPa, spraying distance 15 cm, spraying thickness 200 μm; and the organic solvent is hexane.

5. A wear-resistant and anti-icing film with controllable adhesion prepared according to the preparation method of claim 3 or 4.

6. Use of the wear-resistant anti-icing film with controllable adhesion as claimed in claim 5 in passive anti-icing of vehicles or aircraft.

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