Preparation method of self-oil-spilling gel super-slip coating material for outdoor water mist collection

Abstract

The present invention discloses a method for preparing a self-overflowing oil gel super-lubricant coating material for outdoor water mist collection; the oil gel is prepared by swelling natural macromolecules such as carnauba wax and beeswax in food additive-grade lubricating oil such as ethyl oleate, and the solid content of the composite oil gel is adjusted to achieve the preparation of the self-overflowing oil gel super-lubricant coating material. The droplets have a small sliding angle on the super-lubricant coating, and the surface has the characteristics of self-cleaning, transparency, and water lubrication. The surface of the super-lubricant coating can quickly capture tiny droplets, expand droplets, and remove droplets, thereby having a high mist collection efficiency. The coating preparation method is simple, low-cost, easy to prepare on a large scale, and has broad application prospects.

Description

Technical Field

[0001] The invention relates to the technical field of preparation of super-slippery liquid surfaces, and in particular to a method for preparing a self-overflowing oil gel super-slippery liquid coating that can be used for outdoor water mist collection. Background Art

[0002] The preparation of super-slippery surface is inspired by the bionics of the lip of Nepenthes in nature. The surface of the lip of Nepenthes has a microscopic rough structure and lubricating liquid, which makes it very easy for microorganisms that stay on the lip to fall into the digestive system inside the mouth. Through bionic preparation, rough structures and lubrication mechanisms similar to the surface structure of the lip of Nepenthes can be designed on the substrate surface to achieve the preparation of super-slippery surface. Super-slippery surface has excellent water lubrication properties and is used in the fields of anti-icing, surface self-cleaning, droplet transport, etc.

[0003] In arid areas with large temperature differences between day and night, using super-lubricant surfaces to collect water mist is a low-cost method to obtain drinkable fresh water. However, existing super-lubricant coatings are mostly single-layer porous oil storage structures, which have insufficient oil retention stability and high operation and maintenance costs, making them difficult to apply to outdoor water mist collection. Summary of the invention

[0004] The purpose of the present invention is to solve the shortcomings of the above-mentioned background technology and provide a method for preparing an edible self-oiling super-lubricating liquid coating with simple process, short production cycle and low cost; the oil gel is prepared by swelling natural macromolecules such as carnauba wax and beeswax in food additive grade lubricating oil such as ethyl oleate, and the solid content of the composite oil gel is adjusted to achieve the preparation of the self-oiling gel super-lubricating liquid coating material. The droplets have a small sliding angle on the super-lubricating liquid coating, and the surface has the characteristics of self-cleaning, transparency, water lubrication, etc.

[0005] The technical solution of the present invention is: a method for preparing a self-spilling oil gel super-slip coating material for outdoor water mist collection, comprising the following steps:

[0006] A. Use a glass sheet as a substrate, ultrasonically clean it in acetone, ethanol, and deionized water in sequence, and dry it for later use;

[0007] B. adding beeswax to ethyl oleate in a mass ratio of beeswax to ethyl oleate of (4-5):100, heating and stirring until completely dissolved to obtain a beeswax / ethyl oleate mixed solution, then spin-coating the beeswax / ethyl oleate mixed solution on a substrate, and cooling to room temperature to obtain a lower layer of oil spill gel coating;

[0008] C. adding carnauba wax to ethyl oleate in a mass ratio of carnauba wax to ethyl oleate of (8-12):100, heating and stirring until completely dissolved to obtain a carnauba wax / ethyl oleate mixed solution, then adding deionized water and heating and stirring to synthesize an emulsion to obtain an upper porous oil gel emulsion;

[0009] D. Spin-coat the upper porous oil gel emulsion obtained in step C onto the lower oil spill oil gel coating obtained in step B, and then freeze-dry to obtain a self-oil spill gel super-lubricating liquid coating material of the upper porous oil gel and the lower oil spill oil gel.

[0010] Preferably, in step B, the beeswax and ethyl oleate are heated and stirred at a temperature of 60° C. to 70° C. for 30 min to 1 h.

[0011] Preferably, in step C, the temperature for heating and stirring the carnauba wax and ethyl oleate is 80° C. to 90° C. and the time is 2 h to 4 h.

[0012] Preferably, in step C, the temperature of adding deionized water and heating and stirring is 80° C. to 90° C. and the time is 10 to 30 minutes.

[0013] Preferably, in step C, the mass ratio of deionized water to the carnauba wax / ethyl oleate mixture is (7-9):1.

[0014] Preferably, in step D, the sample is freeze-dried at -10°C and 1.3 Pa for 2 h to 4 h.

[0015] Preferably, in step B and step D, ethyl oleate with a purity of ≥75wt% is used.

[0016] Preferably, in step B and step D, the spin coating speed is 2000-2500 r / min.

[0017] The present invention also provides a self-overflowing oil gel super-lubricant coating material for outdoor water mist collection, which is prepared according to the preparation method of the self-overflowing oil gel super-lubricant coating material for outdoor water mist collection described in any one of the above items.

[0018] The beneficial effects of the present invention are:

[0019] 1. By using a hierarchical design, a self-oil overflowing layer is added below the surface of the functional layer (porous oil gel layer), and the proportion of lubricating oil components is increased to improve the material's oil storage capacity and oil overflow capacity, which can achieve the effect of improving the material's stability and functional sustainability, and has great application prospects.

[0020] 2. The surface of the self-oil overflowing gel super-lubricant coating material prepared by the present invention has excellent liquid-repellent properties, and can quickly realize the gas-liquid conversion of water, the capture of tiny droplets, the expansion of water droplets, and the self-sliding collection of water droplets in outdoor day and night environments, thereby performing efficient outdoor water mist collection, and is suitable for various outdoor sports and outdoor survival.

[0021] 3. The coating is prepared using edible-grade raw materials, and no organic solvents are involved in the reaction process. The preparation of the coating has the advantages of simple and environmentally friendly methods, low cost, and easy large-scale application. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 The water collection efficiency test results of the self-leaking oil gel super slippery coating

[0023] Figure 2 Infrared spectrum of self-oil-leaking gel super-lubricant coating

[0024] Figure 3 The oil storage stability test results of the self-oil-leaking gel super-lubricant coating

[0025] Figure 4 The SEM images of the upper porous oil gel and the lower oil gel in the self-spilling oil gel super-lubricating liquid coating (measured after washing away ethyl oleate with n-hexane) DETAILED DESCRIPTION

[0026] In order to better understand the present invention, the content of the present invention is further illustrated below in conjunction with the examples, but the content of the present invention is not limited to the following examples. Those skilled in the art can make various changes or modifications to the present invention, and these equivalent forms are also within the scope of the claims listed in the application. The medicines used in the examples are all commercially available products unless otherwise specified, and the methods used are all conventional methods in the art unless otherwise specified.

[0027] Example 1

[0028] This embodiment provides a method for preparing a self-spilling oil gel super-slip coating material for outdoor water mist collection, the steps are as follows:

[0029] A. Experimental preparation: Cut the glass into 2 cm × 2 cm substrates, and ultrasonically clean them in acetone, ethanol, and deionized water in sequence, and then put them in an oven to dry for later use;

[0030] B. Preparation of lower oil spill oil gel: First, 4 g of beeswax was added to 110 ml of ethyl oleate (density 0.87 g / ml) with a purity of 75 wt%, and the mixed solution was heated at 60° C. and stirred for 30 min until it was completely dissolved to obtain a beeswax / ethyl oleate mixed solution, and then the beeswax / ethyl oleate mixed solution was spin-coated (spin-coating speed 2000 rpm, spin-coating time 1 min) on one side of the substrate, and cooled to room temperature to obtain a lower oil spill oil gel coating;

[0031] C. Preparation of the upper porous oil gel emulsion: First, 8 g of carnauba wax was added to 110 ml of ethyl oleate (density 0.87 g / ml) with a purity of 75 wt%, and the mixed solution was heated at 80° C. and stirred for 2 h until it was completely dissolved to obtain a carnauba wax / ethyl oleate mixed solution, and deionized water was added to the carnauba wax / ethyl oleate mixed solution, with a mass ratio of deionized water to the carnauba wax / ethyl oleate mixed solution of 7:1, and the mixture was heated at 80° C. and stirred for 10 min to synthesize an emulsion; and the upper porous oil gel emulsion was obtained;

[0032] D. Preparation of self-oil-spill gel super-lubricating liquid coating: The upper porous oil gel emulsion obtained in step C was spin-coated while hot (spin-coating speed 2000 rpm, spin-coating time 1 min) on the lower oil-spill oil gel coating obtained in step B, and then the sample was freeze-dried at -10°C, 1.3 Pa for 2 h. After drying, a self-oil-spill gel super-lubricating liquid coating with an upper porous oil gel and a lower oil-spill oil gel was obtained.

[0033] Example 2

[0034] This embodiment provides a method for preparing a self-spilling oil gel super-slip coating material for outdoor water mist collection, the steps are as follows:

[0035] A. Experimental preparation: Cut the glass into 2 cm × 2 cm substrates, and ultrasonically clean them in acetone, ethanol, and deionized water in sequence, and then put them in an oven to dry for later use;

[0036] B. Preparation of lower layer oil spill oil gel: First, 4.2 g of beeswax was added to 115 ml of ethyl oleate (density 0.87 g / ml) with a purity of 75 wt%, and the mixed solution was heated at 62° C. and stirred for 35 min until it was completely dissolved to obtain a beeswax / ethyl oleate mixed solution, and then the beeswax / ethyl oleate mixed solution was spin-coated (spin-coating speed 2000 rpm, spin-coating time 1 min) on the substrate surface and cooled to room temperature to obtain a lower layer oil spill oil gel coating;

[0037] C. Preparation of the upper porous oil gel emulsion: First, 8.2 g of carnauba wax was added to 115 ml of ethyl oleate (density 0.87 g / ml) with a purity of 75 wt%, and the mixed solution was heated at 82° C. and stirred for 2.5 h until it was completely dissolved to obtain a carnauba wax / ethyl oleate mixed solution, and deionized water was added to the carnauba wax / ethyl oleate mixed solution, with a mass ratio of deionized water to the carnauba wax / ethyl oleate mixed solution of 7.2:1, and the mixture was heated at 80° C. and stirred for 15 min to synthesize an emulsion; and the upper porous oil gel emulsion was obtained;

[0038] D. Preparation of self-oil-spill gel super-lubricating liquid coating: The upper porous oil gel emulsion obtained in step C was spin-coated while hot (spin-coating speed 2000 rpm, spin-coating time 1 min) on the lower oil-spill oil gel coating obtained in step B, and then the sample was freeze-dried at -10°C, 1.3 Pa for 2.5 h. After drying, a self-oil-spill gel super-lubricating liquid coating with an upper porous oil gel and a lower oil-spill oil gel was obtained.

[0039] Example 3

[0040] This embodiment provides a method for preparing a self-spilling oil gel super-slip coating material for outdoor water mist collection, the steps are as follows:

[0041] A. Experimental preparation: Cut the glass into 2 cm × 2 cm substrates, and ultrasonically clean them in acetone, ethanol, and deionized water in sequence, and then put them in an oven to dry for later use;

[0042] B. Preparation of lower layer oil spill oil gel: First, 4.5 g of beeswax was added to 120 ml of ethyl oleate (density 0.87 g / ml) with a purity of 75 wt%, and the mixed solution was heated at 64° C. and stirred for 40 min until it was completely dissolved to obtain a beeswax / ethyl oleate mixed solution, and then the beeswax / ethyl oleate mixed solution was spin-coated (spin-coating speed 2000 rpm, spin-coating time 1 min) on the substrate surface and cooled to room temperature to obtain a lower layer oil spill oil gel coating;

[0043] C. Preparation of the upper porous oil gel emulsion: First, 8.5 g of carnauba wax was added to 120 ml of ethyl oleate (density 0.87 g / ml) with a purity of 75 wt%, and the mixed solution was heated at 84° C. and stirred for 2.5 h until it was completely dissolved to obtain a carnauba wax / ethyl oleate mixed solution, and deionized water was added to the carnauba wax / ethyl oleate mixed solution, with a mass ratio of deionized water to the carnauba wax / ethyl oleate mixed solution of 7.4:1, and the mixture was heated at 85° C. and stirred for 20 min to synthesize an emulsion; and an upper porous oil gel emulsion was obtained;

[0044] D. Preparation of self-oil-spill gel super-lubricating liquid coating: The upper porous oil gel emulsion obtained in step C was spin-coated while hot (spin-coating speed 2000 rpm, spin-coating time 1 min) on the lower oil-spill oil gel coating obtained in step B, and then the sample was freeze-dried at -10°C, 1.3 Pa for 2.5 h. After drying, a self-oil-spill gel super-lubricating liquid coating with an upper porous oil gel and a lower oil-spill oil gel was obtained.

[0045] Example 4

[0046] This embodiment provides a method for preparing a self-spilling oil gel super-slip coating material for outdoor water mist collection, the steps are as follows:

[0047] A. Experimental preparation: Cut the glass into 2 cm × 2 cm substrates, and ultrasonically clean them in acetone, ethanol, and deionized water in sequence, and then put them in an oven to dry for later use;

[0048] B. Preparation of lower oil spill oil gel: First, 4.6 g of beeswax was added to 125 ml of ethyl oleate (density 0.87 g / ml) with a purity of 75 wt%, and the mixed solution was heated at 65° C. and stirred for 40 min until it was completely dissolved to obtain a beeswax / ethyl oleate mixed solution, and then the beeswax / ethyl oleate mixed solution was spin-coated (spin-coating speed 2000 rpm, spin-coating time 1 min) on the substrate surface and cooled to room temperature to obtain a lower oil spill oil gel coating;

[0049] C. Preparation of the upper porous oil gel emulsion: First, 8.7 g of carnauba wax was added to 125 ml of ethyl oleate (density 0.87 g / ml) with a purity of 75 wt%, and the mixed solution was heated at 85° C. and stirred for 3 h until it was completely dissolved to obtain a carnauba wax / ethyl oleate mixed solution, and deionized water was added to the carnauba wax / ethyl oleate mixed solution, with the mass ratio of deionized water to the carnauba wax / ethyl oleate mixed solution being 7.6:1, and the mixture was heated at 85° C. and stirred for 20 min to synthesize an emulsion; and the upper porous oil gel emulsion was obtained;

[0050] D. Preparation of self-oil-spill gel super-lubricating liquid coating: The upper porous oil gel emulsion obtained in step C was spin-coated while hot (spin-coating speed 2000 rpm, spin-coating time 1 min) on the lower oil-spill oil gel coating obtained in step B, and then the sample was freeze-dried for 3 h at -10°C and 1.3 Pa. After drying, a self-oil-spill gel super-lubricating liquid coating with an upper porous oil gel and a lower oil-spill oil gel was obtained.

[0051] Example 5

[0052] This embodiment provides a method for preparing a self-spilling oil gel super-slip coating material for outdoor water mist collection, the steps are as follows:

[0053] A. Experimental preparation: Cut the glass into 2 cm × 2 cm substrates, and ultrasonically clean them in acetone, ethanol, and deionized water in sequence, and then put them in an oven to dry for later use;

[0054] B. Preparation of lower oil spill oil gel: First, 4.8 g of beeswax was added to 125 ml of ethyl oleate (density 0.87 g / ml) with a purity of 75 wt%, and the mixed solution was heated at 68° C. and stirred for 50 min until it was completely dissolved to obtain a beeswax / ethyl oleate mixed solution, and then the beeswax / ethyl oleate mixed solution was spin-coated (spin-coating speed 2000 rpm, spin-coating time 1 min) on the substrate surface and cooled to room temperature to obtain a lower oil spill oil gel coating;

[0055] C. Preparation of the upper porous oil gel emulsion: First, 8.8 g of carnauba wax was added to 125 ml of ethyl oleate (density 0.87 g / ml) with a purity of 75 wt%, and the mixed solution was heated at 88° C. and stirred for 3 h until it was completely dissolved to obtain a carnauba wax / ethyl oleate mixed solution, deionized water was added to the carnauba wax / ethyl oleate mixed solution, and the mass ratio of deionized water to the carnauba wax / ethyl oleate mixed solution was 7.8:1, and the mixture was heated at 90° C. and stirred for 25 min to synthesize an emulsion; the upper porous oil gel emulsion was obtained;

[0056] D. Preparation of self-oil-spill gel super-lubricating liquid coating: The upper porous oil gel emulsion obtained in step C was spin-coated while hot (spin-coating speed 2000 rpm, spin-coating time 1 min) on the lower oil-spill oil gel coating obtained in step B, and then the sample was freeze-dried for 3 h at -10°C and 1.3 Pa. After drying, a self-oil-spill gel super-lubricating liquid coating with an upper porous oil gel and a lower oil-spill oil gel was obtained.

[0057] Example 6

[0058] This embodiment provides a method for preparing a self-spilling oil gel super-slip coating material for outdoor water mist collection, the steps are as follows:

[0059] A. Experimental preparation: Cut the glass into 2 cm × 2 cm substrates, and ultrasonically clean them in acetone, ethanol, and deionized water in sequence, and then put them in an oven to dry for later use;

[0060] B. Preparation of lower oil spill oil gel: First, 5 g of beeswax was added to 130 ml of ethyl oleate (density 0.87 g / ml) with a purity of 75 wt%, and the mixed solution was heated at 70° C. and stirred for 1 h until it was completely dissolved to obtain a beeswax / ethyl oleate mixed solution, and then the beeswax / ethyl oleate mixed solution was spin-coated (spin-coating speed 2000 rpm, spin-coating time 1 min) on the substrate surface and cooled to room temperature to obtain a lower oil spill oil gel coating;

[0061] C. Preparation of the upper porous oil gel emulsion: First, 9.2 g of carnauba wax was added to 130 ml of ethyl oleate (density 0.87 g / ml) with a purity of 75 wt%, and the mixed solution was heated at 90° C. and stirred for 4 h until it was completely dissolved to obtain a carnauba wax / ethyl oleate mixed solution, and deionized water was added to the carnauba wax / ethyl oleate mixed solution, with the mass ratio of deionized water to the carnauba wax / ethyl oleate mixed solution being 8:1, and the mixture was heated at 90° C. and stirred for 30 min to synthesize an emulsion; and the upper porous oil gel emulsion was obtained;

[0062] D. Preparation of self-oil-spill gel super-lubricating liquid coating: The upper porous oil gel emulsion obtained in step C was spin-coated while hot (spin-coating speed 2000 rpm, spin-coating time 1 min) on the lower oil-spill oil gel coating obtained in step B, and then the sample was freeze-dried at -10°C, 1.3 Pa for 4 h. After drying, a self-oil-spill gel super-lubricating liquid coating with an upper porous oil gel and a lower oil-spill oil gel was obtained.

[0063] Comparative Example

[0064] The preparation method of this comparative example refers to Progress in Organic Coatings 162 (2022) 106590, and the specific steps are as follows: 0.2 g of beeswax and 1.8 g of sunflower oil are mixed and heated to 80 degrees to obtain a hot melt liquid, which is then spin-coated (2000 rpm, 1 min) on a substrate treated in the same manner as step A of this embodiment, and a super-lubricant coating is obtained after cooling.

[0065] Performance Testing

[0066] Figure 1 The test conditions are as follows: a 5 g / h water vapor mist source is placed 5 cm away from the sample, and a water mist collection test is performed on the self-oil spill coating prepared in Example 1, the super slippery liquid coating prepared in the comparative example, the glass substrate treated in step A in Example 1, and the upper layer of oil gel prepared by directly spin coating the upper layer of porous oil gel emulsion on the substrate in step C of Example 1. Figure 1 It can be seen that the collection effect of the original glass substrate is the worst. The super-lubricant coating prepared in the comparative example and the upper layer of oil gel prepared by directly spin-coating the upper porous oil gel emulsion on the substrate in step C of Example 1 are not as good as the self-oiling coating of the present invention after 2 hours, because the collection efficiency decreases due to the loss of the oil layer.

[0067] Figure 2 This is the FTIR infrared spectrum test of the super-slip coating made from the oil spill gel in Example 1. The upper curve is the infrared spectrum of the lower layer of the oil spill gel, and the lower curve is the infrared spectrum of the upper layer of the porous oil gel. Figure 2 It can be seen that the coating material prepared in the present invention is an organic material composed of pure natural long-chain natural macromolecules.

[0068] Figure 3 The shear resistance test of the super slippery liquid coating obtained from oil spill gel in Example 1 was carried out in a sizing machine at different speeds. Figure 3 It can be seen that the sample has basically no change in mass at a rotation speed of 1000-7000rpm, and the sliding angle (WSA) is less than 15 degrees. It has the advantages of no loss of lubricating oil and no change in surface wettability.

[0069] Figure 4 This is the SEM image of the oil spill gel super slip coating obtained in Example 1 after the lubricating oil is washed away. Figure 4It can be seen that the porous structure of the upper porous oil gel is conducive to surface oil retention and hydrophobicity, and the lower oil spill oil gel is a loose lamellar structure, which is conducive to the storage of a large amount of lubricating oil and the upward supply of lubricating oil. Therefore, it can be concluded that the product prepared by the present invention has the advantages of high long-term water mist collection efficiency, pollution-free and non-toxic materials and raw materials and preparation process, self-oil spillage and self-supply performance, strong surface hydrophobic stability, etc.

[0070] As can be seen from the above, the present invention prepares a surface coating material for the lip of a pitcher plant from a bionic perspective. The present invention includes the steps of preparing a lower layer of oil-overflowing oil gel, preparing an upper layer of porous oil gel emulsion, and preparing a self-overflowing oil gel super-slip coating. The super-slip coating has excellent liquid-repellent properties, and the water sliding angle is less than 15 degrees. Due to the hierarchical structure design, the lower layer of oil-overflowing oil gel has an oil supply function, and the upper layer of porous oil gel has a porous oil absorption function, thereby forming a stable self-overflowing oil gel super-slip coating. The surface can quickly realize the gas-liquid conversion of water, the capture of tiny droplets, the expansion of water droplets, and the self-sliding collection of water droplets in outdoor day and night environments, thereby performing efficient outdoor water mist collection. And because the coating preparation uses edible-grade raw materials, and no organic solvents are involved in the reaction process, the preparation of the coating has the advantages of simple and environmentally friendly methods, low cost, and easy large-scale application.

[0071] Finally, it should be noted that the above content is only used to illustrate the technical solution of the present invention, rather than to limit the scope of protection of the present invention. Simple modifications or equivalent substitutions of the technical solution of the present invention by ordinary technicians in this field do not deviate from the essence and scope of the technical solution of the present invention.

Claims

1. A method for preparing a self-spilling oil gel super-slip coating material for outdoor water mist collection, characterized in that: The following steps are involved: A. Use a glass sheet as a substrate, ultrasonically clean it in acetone, ethanol, and deionized water in sequence, and dry it for later use; B. adding beeswax to ethyl oleate in a mass ratio of beeswax to ethyl oleate of (4-5):100, heating and stirring until completely dissolved, the heating and stirring temperature is 60°C-70°C, and the time is 30min-1h to obtain a beeswax / ethyl oleate mixed solution, then spin-coating the beeswax / ethyl oleate mixed solution on a substrate, and cooling to room temperature to obtain a lower layer of oil spill gel coating; C. adding carnauba wax to ethyl oleate in a mass ratio of carnauba wax to ethyl oleate of (8-12):100, heating and stirring until completely dissolved, heating and stirring at a temperature of 80°C-90°C for 2h-4h, to obtain a carnauba wax / ethyl oleate mixed solution; then adding deionized water and heating and stirring to synthesize an emulsion, heating and stirring at a temperature of 80°C-90°C for 10-30min, and the mass ratio of deionized water to carnauba wax / ethyl oleate mixed solution of (7-9):1, to obtain an upper porous oil gel emulsion; D. Spin-coat the upper porous oil gel emulsion obtained in step C onto the lower oil spill oil gel coating obtained in step B, and then freeze-dry to obtain a self-oil spill gel super-lubricating liquid coating material of the upper porous oil gel and the lower oil spill oil gel.

2. The method for preparing the self-overflowing oil gel super-slip coating material for outdoor water mist collection according to claim 1, characterized in that: In step D, the sample is freeze-dried at -10°C and 1.3 Pa for 2 h to 4 h.

3. The method for preparing the self-overflowing oil gel super-slip coating material for outdoor water mist collection according to claim 1, characterized in that: In both step B and step D, ethyl oleate with a purity of ≥75wt% is used.

4. The method for preparing the self-overflowing oil gel super-lubricant coating material for outdoor water mist collection according to claim 1, characterized in that: In step B and step D, the spin coating speed is 2000-2500 r / min.

5. A self-spilling oil gel super-slip coating material for outdoor water mist collection, characterized in that: The self-oil-spilling gel super-lubricant coating material for outdoor water mist collection is prepared according to the preparation method of any one of claims 1 to 4.

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