An aqueous carbon nanotube and a preparation method and application thereof
By preparing hydrous carbon nanotubes and applying them to pot coatings, the problem of large temperature differences between the inner surface of the bottom and the inner surface of the pot wall was solved, achieving temperature uniformity and multifunctional properties of the coating.
Patent Information
- Application Number
- CN202311432818.6
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- Filing Date
- 2023-10-31
- Publication Date
- 2026-02-06
- Estimated Expiration
- 2043-10-31
AI Technical Summary
The large temperature difference between the inner surface of the bottom and the inner surface of the wall of a traditional wok leads to uneven heating of food and produces fumes that affect health.
By preparing hydrous carbon nanotubes, using ultrasonic pulverization to cut the carbon nanotubes into shorter pieces and filling them with water molecules, and controlling the degree of damage and the open state of the ports of the carbon nanotubes, a coating for the pot body is prepared to achieve uniform temperature on the inner surface of the pot bottom and the inner surface of the pot wall.
It achieves similar temperatures between the inner surface of the bottom of the wok and the inner surface of the wok wall, reducing the generation of oil fumes, and the coating is non-stick, corrosion-resistant and wear-resistant.
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Figure CN117466289B_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The present application relates to the technical field of nanomaterials, in particular to a water-containing carbon nanotube and a preparation method and application thereof. BACKGROUND
[0002] A traditional frying pan is composed of a pan body, a handle and a handle seat, wherein the pan body is divided into a bottom and a wall. When the frying pan is used for cooking, the bottom inner surface is extremely hot due to contacting the heat source, and the wall inner surface is relatively low due to being far away from the heat source, that is, the temperature difference between the bottom inner surface and the wall inner surface is extremely large, so the temperature of the entire inner surface of the pan body is uneven, which easily leads to the partial burning of food materials close to the bottom inner surface, accelerates the decomposition speed of oil in the food materials, and generates a large amount of oil fume, which is inhaled into the human lung through the nasal cavity and affects the health of the human body. Therefore, it is of great significance to develop a water-containing carbon nanotube for the bottom inner surface of the frying pan, which can make the temperature of the bottom inner surface close to that of the wall inner surface. SUMMARY
[0003] The primary object of the present application is to overcome the problem of the large temperature difference between the bottom inner surface and the wall inner surface of the frying pan in the prior art, and to provide a water-containing carbon nanotube.
[0004] Another object of the present application is to provide an application of the water-containing carbon nanotube in preparing a pan body coating.
[0005] Another object of the present application is to provide a pan body coating.
[0006] Another object of the present application is to provide a preparation method of the pan body coating.
[0007] Another object of the present application is to provide a pan body coating layer.
[0008] Another object of the present application is to provide an application of the pan body coating layer in preparing a frying pan.
[0009] Still another object of the present application is to provide a frying pan.
[0010] The above technical objects of the present application are achieved by the following technical solutions:
[0011] A water-containing carbon nanotube is prepared by the following preparation method:
[0012] S1. In a liquid environment, the carbon nanotubes (CNTs) are subjected to a short-cut treatment by an ultrasonic crushing method, and the liquid is removed to obtain carbon nanotubes with open ends;
[0013] S2. The carbon nanotubes with open ends are subjected to a water vapor bath, so that gaseous water molecules enter the carbon nanotubes, and then the gaseous water molecules are changed into liquid and / or solid water molecules by cooling, thereby obtaining the water-containing carbon nanotube.
[0014] The outer diameter (OD) of the carbon nanotube is ≤2nm; the ultrasonic frequency of the ultrasonic crushing method is 18-21kHz, the ultrasonic power is 100-1000W, and the ultrasonic vibration time is 100-1000s.
[0015] The water-containing carbon nanotube of the present application is filled with water molecules inside the carbon nanotube. Since the carbon nanotube has a small diameter and the size of the water molecules is about 0.4nm, the carbon nanotube with an outer diameter (OD) ≤2nm restricts the movement of the water molecules inside it, thereby increasing the freezing temperature of water and making it much higher than 0℃. This means that compared with pure water (liquid), the water (liquid and / or solid) in the water-containing carbon nanotube can absorb more heat to change phase (into gas), thereby having a better cooling effect.
[0016] When the inner surface coating of the bottom of the wok to which the water-containing carbon nanotube is added is heated, the water (liquid and / or solid) inside the carbon nanotube will absorb a large amount of heat and change phase (into gas), thereby reducing the temperature of the inner surface coating of the bottom. At this time, the inner surface coating of the wall of the wok will not have a temperature drop since no water-containing carbon nanotube is added, so that the inner surface of the bottom and the inner surface of the wall of the wok have similar temperatures when the wok is used.
[0017] In addition, since the diameter (outer diameter) of the carbon nanotube is very small, the movement of the water molecules inside the carbon nanotube is greatly restricted, and after the gaseous water molecules inside the carbon nanotube are changed into liquid and / or solid water molecules by cooling, the movement of the water molecules is further restricted, making it difficult for the water molecules to escape from the water-containing carbon nanotube.
[0018] In the present application, when the carbon nanotubes (CNTs) are subjected to short-cut treatment by using the ultrasonic crushing method, the transient cavitation effect formed by the collapse and rupture of the ultrasonic cavitation bubbles is used to make the high-intensity pressure and heat released by the cavitation bubbles directly impact the carbon nanotubes, so that the carbon nanotubes are broken along the length direction, the length of the carbon nanotubes is shortened, the number of the carbon nanotubes is increased, and the ports of the carbon nanotubes are opened at the same time. Then, gaseous water molecules are filled into the carbon nanotubes with opened ports by using a water vapor bath, and the gaseous water molecules are changed into liquid and / or solid water molecules by cooling, thereby obtaining the water-containing carbon nanotubes.
[0019] In the present application, specific ultrasonic frequency, ultrasonic power and ultrasonic vibration time are used to control the damage degree, length and opening state of the ports of the carbon nanotubes after short-cut treatment, thereby improving the effect of the water-containing carbon nanotubes on reducing the temperature of the inner surface coating of the bottom of the wok, and achieving the purpose that the inner surface of the bottom (with water-containing carbon nanotubes) and the inner surface of the wall (without water-containing carbon nanotubes) of the wok have similar temperatures when the wok is used.
[0020] Specifically, when the ultrasonic frequency, ultrasonic power or ultrasonic vibration time is insufficient, although the damage degree of the carbon nanotubes is small, the effect of the carbon nanotubes broken along the length direction is poor, the length of the carbon nanotubes is too long, and the port of the carbon nanotubes is not completely opened, which are all not conducive to filling water molecules into the carbon nanotubes, reduce the effect of the water-containing carbon nanotubes on reducing the temperature of the coating layer on the inner surface of the bottom of the wok, and are not conducive to achieving the purpose that the inner surface of the bottom and the inner surface of the wall of the wok are close in temperature during use. When the ultrasonic frequency, ultrasonic power or ultrasonic vibration time is excessive, although the port of the carbon nanotubes is completely opened, the damage degree of the carbon nanotubes is too large, and the length of the carbon nanotubes is too short, the carbon nanotubes are severely damaged, and the pore size is large, which is conducive to filling water molecules into the carbon nanotubes, but the carbon nanotubes cannot accommodate and bind water molecules, which is not conducive to forming water-containing carbon nanotubes, reduces the effect of the water-containing carbon nanotubes on reducing the temperature of the coating layer on the inner surface of the bottom of the wok, and is not conducive to achieving the purpose that the inner surface of the bottom and the inner surface of the wall of the wok are close in temperature during use.
[0021] Specifically, the ultrasonic frequency of the ultrasonic crushing method is 20 kHz, the ultrasonic power is 500 W, and the ultrasonic vibration time is 800 s.
[0022] Specifically, the outer diameter (OD) of the carbon nanotubes is 1-2 nm.
[0023] The carbon nanotubes of the present application can be obtained by self-preparation using conventional methods in the art, or can be obtained by commercial purchase.
[0024] Specifically, the carbon nanotubes are single-walled carbon nanotubes and / or multi-walled carbon nanotubes.
[0025] In the present application, single-walled carbon nanotubes have only one layer of carbon nanotube wall; multi-walled carbon nanotubes contain at least two layers of carbon nanotube wall, such as double-walled carbon nanotubes and the like.
[0026] Specifically, the liquid in step S1 is one or more of water, ethanol or polyvinyl alcohol; wherein the ethanol can be anhydrous ethanol, or a solution of ethanol and water mixed in any ratio.
[0027] Specifically, the removal of the liquid in step S1 is achieved by heating to evaporate the liquid.
[0028] Specifically, the specific operation of removing the liquid in step S1 is to heat the carbon nanotubes to 150-200℃ under an inert gas atmosphere, and keep the temperature for 20-50 min.
[0029] Any inert gas commonly used in the art can be used in the present application, such as nitrogen and the like.
[0030] Specifically, the time of the water vapor bath in step S2 is ≥1 h.
[0031] Specifically, the cooling in step S2 refers to placing the carbon nanotubes in an environment with a temperature of ≤0℃.
[0032] Further, the cooling in step S2 refers to placing the carbon nanotubes in an environment with a temperature of -20 to -30℃.
[0033] The application of the above water-containing carbon nanotubes in preparing a pot coating should also be within the protection scope of the present application.
[0034] A pot coating, by weight, comprises the following components:
[0035] 8-12 parts of aluminum sol, 8-12 parts of silicon sol, 15-25 parts of siloxane, 2-6 parts of iron black, 15-25 parts of ethanol, and 0.1-0.5 parts of water-containing carbon nanotubes.
[0036] The pot coating of the present application not only can reduce the temperature of the inner surface coating of the bottom of a frying pan, and achieve the purpose that the inner surface of the bottom and the inner surface of the wall of the frying pan have similar temperatures during use, but also the coating prepared by the pot coating has good non-stick performance, corrosion resistance and wear resistance.
[0037] The ethanol has high polarity and low boiling point. When added to the pot coating, the ethanol will volatilize and generate a large amount of gas during sol-gel and heating drying, thereby promoting the generation of a large amount of small circular pores, forming a coating with a micron-sized pore structure. The circular pores on the coating can effectively insulate heat, and also can absorb moisture. When the coating is heated, the moisture in the pores of the coating evaporates and is released slowly, producing the Leidenfrost effect, so that the water molecules rapidly spread on the surface of the coating to form a water film heat insulation layer, which can well isolate the food and the frying pan, prevent the food from sticking to the bottom of the frying pan, and achieve the purpose of improving the non-stick performance of the coating.
[0038] Due to the presence of ethanol, the coating prepared by the pot coating has high porosity and porous network structure, which reduces the strength and toughness of the coating, and makes the corrosion resistance and wear resistance of the coating worse. The pot coating of the present application uses aluminum sol and silicon sol to make the coating contain Al2O3 and SiO2, which improves the strength and toughness of the coating, thereby ensuring that the prepared coating has sufficient corrosion resistance and wear resistance. The siloxane can provide an organic network structure for other inorganic components in the pot coating, so that the prepared coating has a certain toughness. The iron black acts as a bonding agent and a light shielding agent in the coating prepared by the pot coating. The compactness of the coating can improve the corrosion resistance, wear resistance and bonding force of the coating, and on the other hand, can greatly reduce the heat conduction effect caused by infrared thermal radiation.
[0039] Specifically, the pot coating includes the following components in parts by weight: 9-11 parts of aluminum sol, 9-11 parts of silica sol, 18-22 parts of siloxane, 3-5 parts of iron black, 18-22 parts of ethanol, and 0.2-0.4 parts of water-containing carbon nanotubes.
[0040] Specifically, the siloxane is one or more of methyltrimethoxysilane (MTM), tetraethoxysilane (TEOS), or methyltriethoxysilane (MTES).
[0041] Specifically, the iron black can be in the form of pure magnetite or in the form of magnetite mainly containing other impurities (without affecting the performance of the coating), such as manganese oxide.
[0042] A method for preparing a pot coating includes the following steps:
[0043] Mixing the components in the pot coating described above, thereby obtaining the pot coating.
[0044] A pot coating is prepared by the following process: spraying a pot coating, calcining, thereby obtaining the pot coating.
[0045] Specifically, the calcination temperature is 150-200℃.
[0046] Specifically, the calcination time is 10-30 min.
[0047] The application of the pot coating described above in the preparation of a wok should also be within the protection scope of the present application.
[0048] A wok includes a pot body made of a metal base, and the inner surface of the bottom of the pot body has the pot coating described above.
[0049] Specifically, the inner surface of the wall of the pot body has a hydrophobic coating.
[0050] The hydrophobic coating on the inner surface of the wall of the wok can achieve the effect of non-stick of food materials due to its hydrophobic property.
[0051] Further, the hydrophobic coating is prepared by the following process: spraying a hydrophobic coating, calcining, thereby obtaining the pot coating.
[0052] Further, the hydrophobic coating includes the following components in parts by weight:
[0053] 8-12 parts of aluminum sol, 8-12 parts of silica sol, 15-25 parts of siloxane, and 2-6 parts of iron black.
[0054] Further, the calcination temperature is 150-200℃.
[0055] Further, the metal matrix is one or more of an aluminum alloy matrix, a copper alloy matrix, a tinplate matrix, a Q235 steel matrix, a stainless steel matrix, or a titanium alloy matrix.
[0056] The present application has the following advantages:
[0057] The present application has the following advantages:
[0058] The present application has the following advantages: BRIEF DESCRIPTION OF DRAWINGS
[0059] Figure 1 The present application has the following advantages:
[0060] Figure 2 The present application has the following advantages:
[0061] Figure 3 The present application has the following advantages:
[0062] Figure 4 The present application has the following advantages:
[0063] Figure 5 The present application has the following advantages:
[0064] Figure 6 The present application has the following advantages:
[0065] Figure 7 The present application has the following advantages:
[0066] Figure 8 SEM topography and energy spectrum analysis of the hydrophobic coating of Example 1.
[0067] Figure 9 Contact angle diagram of the hydrophobic coating of Example 1.
[0068] Figure 10 XRD diagram of the hydrophobic coating of Example 1.
[0069] Figure 11 Longitudinal section microscope topography diagram of the hydrophobic coating of Example 1.
[0070] Figure 12 Anodic polarization curve diagram of the pot coating of Example 1.
[0071] Figure 13 Anodic polarization curve diagram of the hydrophobic coating of Example 1. DETAILED DESCRIPTION
[0072] The application will be further described in conjunction with the examples. These examples are only used to illustrate the application and not used to limit the scope of the application. The experimental methods in the following example embodiments are not specified, which are usually according to the conventional conditions in the art or according to the suggested conditions of the manufacturers; the raw materials, reagents and the like used, if not specially specified, are the raw materials and reagents which can be obtained from the conventional market and the like by commercial ways. Any non-essential changes and substitutions made by the person skilled in the art on the basis of the application all belong to the scope of the application claimed.
[0073] In the various embodiments and comparative examples of the application:
[0074] The carbon nanotube 1# is single-walled carbon nanotube, with an outer diameter (OD) of 1-2 nm, from Shanghai Maikelin Biochemical Technology Co., Ltd., S835718;
[0075] The carbon nanotube 2# is single-walled carbon nanotube, with an outer diameter (OD) <2 nm, from Shanghai Maikelin Biochemical Technology Co., Ltd., C822927;
[0076] The siloxane is methyltrimethoxysilane (MTMS);
[0077] The iron black is in the form of mainly ferriferrous oxide and containing other impurity (manganese oxide) components.
[0078] Example 1
[0079] This embodiment provides a water-containing carbon nanotube, which is prepared by the following preparation method:
[0080] S1. In anhydrous ethanol environment, the carbon nanotubes 1# (CNTs) are shortened by ultrasonic crushing method, then the carbon nanotubes 1# are heated to 150℃ under nitrogen atmosphere for 30 min to remove anhydrous ethanol, and the carbon nanotubes 1# with open ends are obtained;
[0081] S2. The carbon nanotubes 1# with open ends are placed in a water vapor bath for 2 h, so that gaseous water molecules enter the carbon nanotubes, then the carbon nanotubes are sealed with a bag and quickly placed in an environment with a temperature of -25℃, so that the gaseous water molecules are changed into liquid and / or solid water molecules by cooling, and the water-containing carbon nanotubes are obtained;
[0082] The ultrasonic frequency of the ultrasonic crushing method is 20 kHz, the ultrasonic power is 500 W, and the ultrasonic vibration time is 800 s.
[0083] A pot body coating, calculated by weight parts, comprises the following components:
[0084] Aluminum sol 10 parts, silica sol 10 parts, siloxane 20 parts, iron black 4 parts, ethanol 20 parts, water-containing carbon nanotubes 0.3 parts;
[0085] A preparation method of a pot body coating, comprising the following steps:
[0086] Mixing each part of the above pot body coating, placing it in a magnetic stirrer for constant temperature stirring for 2 h, and setting the temperature to 50℃, and the pot body coating is obtained;
[0087] A frying pan, comprising a pot body made of a metal base, as shown in Figure 1 The inner surface of the pot bottom of the pot body has a pot body coating, and the inner surface of the pot wall of the pot body has a hydrophobic coating; the pot body coating is formed on the inner surface of the pot bottom by spraying the above pot body coating on the inner surface of the pot bottom, and the hydrophobic coating is formed on the inner surface of the pot wall by spraying the hydrophobic coating on the inner surface of the pot wall, standing for 4 h, and then placing it in a furnace for calcination at 160℃ for 30 min;
[0088] The hydrophobic coating, calculated by weight parts, comprises the following components:
[0089] Aluminum sol 10 parts, silica sol 10 parts, siloxane 20 parts, iron black 4 parts;
[0090] The metal base is an aluminum alloy base.
[0091] Examples 2-7 and Comparative Examples 1-3
[0092] Examples 2-7 and Comparative Examples 1-3 provide different water-containing carbon nanotubes, pot body coatings, pot body coatings, and frying pans, which differ from Example 1 in that the ultrasonic frequency, ultrasonic power, and ultrasonic vibration time of the ultrasonic crushing method are different, and the rest are consistent with Example 1, as shown below:
[0093] Table 1 Parameters of ultrasonic pulverization method of Examples 1-7 and Comparative Examples 1-3
[0094]
[0095] Example 8
[0096] This example provides a water-containing carbon nanotube, a pot body paint, a pot body coating, and a frying pan, which differs from Example 1 in that the type of carbon nanotube is different, carbon nanotube 2# is used instead of carbon nanotube 1#, and the rest is consistent with Example 1.
[0097] Example 9
[0098] This example provides a water-containing carbon nanotube, a pot body paint, a pot body coating, and a frying pan, which differs from Example 1 in that the amount of each component of the pot body paint and the hydrophobic paint is different, and the rest is consistent with Example 1, which is shown as follows:
[0099] A pot body paint, calculated by weight parts, includes the following components:
[0100] 8 parts of aluminum sol, 8 parts of silica sol, 15 parts of siloxane, 2 parts of iron black, 15 parts of ethanol, and 0.1 parts of water-containing carbon nanotube;
[0101] The hydrophobic paint, calculated by weight parts, includes the following components:
[0102] 8 parts of aluminum sol, 8 parts of silica sol, 15 parts of siloxane, and 2 parts of iron black.
[0103] Example 10
[0104] This example provides a water-containing carbon nanotube, a pot body paint, a pot body coating, and a frying pan, which differs from Example 1 in that the amount of each component of the pot body paint and the hydrophobic paint is different, and the rest is consistent with Example 1, which is shown as follows:
[0105] A pot body paint, calculated by weight parts, includes the following components:
[0106] 12 parts of aluminum sol, 12 parts of silica sol, 25 parts of siloxane, 6 parts of iron black, 25 parts of ethanol, and 0.5 parts of water-containing carbon nanotube;
[0107] The hydrophobic paint, calculated by weight parts, includes the following components:
[0108] 12 parts of aluminum sol, 12 parts of silica sol, 25 parts of siloxane, and 6 parts of iron black.
[0109] Example 11
[0110] The embodiment provides an aqueous carbon nanotube, a wok coating, a wok coating layer and a wok, which are different from those in the embodiment 1 in that the wok coating and the hydrophobic coating do not contain iron black, and the rest are the same as those in the embodiment 1.
[0111] Embodiment 12
[0112] The embodiment provides an aqueous carbon nanotube, a wok coating, a wok coating layer and a wok, which are different from those in the embodiment 1 in that the wok coating does not contain ethanol, and the rest are the same as those in the embodiment 1.
[0113] Comparative Example 4
[0114] The comparative example provides a wok coating, a wok coating layer and a wok, which are different from those in the embodiment 1 in that the aqueous carbon nanotube is not prepared, that is, the wok coating does not contain the aqueous carbon nanotube, and the rest are the same as those in the embodiment 1.
[0115] Comparative Example 5
[0116] The comparative example provides an aqueous carbon nanotube, a wok coating, a wok coating layer and a wok, which are different from those in the embodiment 1 in that, in the preparation process of the aqueous carbon nanotube, the carbon nanotube is not subjected to the shortening treatment of step S1, and the rest are the same as those in the embodiment 1.
[0117] Comparative Example 6
[0118] The comparative example provides an aqueous carbon nanotube, a wok coating, a wok coating layer and a wok, which are different from those in the embodiment 1 in that, in the preparation process of the aqueous carbon nanotube, the water vapor bath of step S2 is not performed, and the rest are the same as those in the embodiment 1.
[0119] Comparative Example 7
[0120] The comparative example provides an aqueous carbon nanotube, a wok coating, a wok coating layer and a wok, which are different from those in the embodiment 1 in that, in the preparation process of the aqueous carbon nanotube, only the water vapor bath of step S2 is performed, and the rest are the same as those in the embodiment 1.
[0121] Sample characterization
[0122] The wok coating of each embodiment and comparative example is characterized as follows:
[0123] (1) The micro-morphology and energy spectrum element content of the wok coating and the hydrophobic coating of each embodiment and comparative example are analyzed by using a SIGMA500 type tungsten filament scanning electron microscope;
[0124] (2) The wok coating and the hydrophobic coating of each embodiment are analyzed by using a laser confocal scanning microscope;
[0125] (3) The pot body coating and hydrophobic coating of each embodiment were analyzed using a contact angle measuring instrument;
[0126] (4) The phase composition and roughness of the pot body coating and hydrophobic coating of each embodiment and comparative example were analyzed using a D8 ADVANCE X-ray diffraction analyzer.
[0127] Figure 2 The images show the scanning electron microscope (SEM) morphology and energy dispersive spectroscopy (EDS) analysis of the coating on the pot body in Example 1. From... Figure 2 It can be seen that the surface of the pot coating in Example 1 has uniformly distributed circular pores and depressions with a diameter of 20-100 μm. This is because during the preparation of the pot coating, the evaporation of ethanol generates a large amount of gas, which promotes the formation of a large number of tiny circular pores, forming a pore structure with a micron size. The energy dispersive spectroscopy (EDS) analysis results show that the pot coating is mainly composed of Si, Al, Fe, Mn, C, and O. Among them, Si comes from siloxanes and silica sols, Al comes from aluminum sols, Fe and Mn come from iron black, and C in the coating comes from the residual components of siloxanes and ethanol and hydrous carbon nanotubes.
[0128] Figure 3 This is a laser confocal scanning microscope image of the coating on the pot body in Example 1. From... Figure 3 It can be seen that the roughness Ra of the pot body coating in Example 1 is 8.15 μm.
[0129] Figure 4 This is a contact angle diagram of the pot body coating in Example 1. From... Figure 4 It can be seen that the left contact angle of the pot body coating in Example 1 is 21.4°, the right contact angle is 16.4°, and the average is 18.9°, that is, the pot body coating in Example 1 is a hydrophilic coating.
[0130] Figure 5 The image shows the XRD pattern of the pot body coating in Example 1. Figure 5 It is known that the phase composition of the pot coating in Example 1 contains SiO2, Al2SiO5, Al2(SiO4)O, Al2(SiO4)(OH)2, Fe3O4, and MnO(OH). Among them, SiO2 is formed by dehydration of silica sol, and Al2SiO5 and Al2(SiO4)O are formed by chemical bonding between O-Si-O or Si-O-Si groups formed by the condensation polymerization of siloxanes and aluminum sol. Al2(SiO4)(OH)2 is an oligomer formed by siloxane alcohol (Si-OH) formed by the hydrolysis of siloxanes and Al2O3 in aluminum sol.
[0131] Figure 6 This is a longitudinal section microscope image of the coating on the pot body in Example 1. From... Figure 6It can be seen that the longitudinal section of the pot body coating of Example 1 is dense and free of holes near the aluminum alloy substrate, the bonding interface between the aluminum alloy substrate and the pot body coating has no cracks or peeling, the pot body coating is in a continuous distribution form, and the coating thickness is in the range of 80-100 μm. Although the surface of the pot body coating has relatively large circular holes, it does not affect the bonding force between the pot body coating and the aluminum alloy substrate, nor does it reduce the corrosion resistance of the pot bottom coating.
[0132] Figure 7 The scanning electron microscope morphology of the pot body coating of Example 11-12 and Comparative Examples 4-6 is shown in Figure A, which is the scanning electron microscope morphology of the pot body coating of Example 11, Figure B is the scanning electron microscope morphology of the pot body coating of Example 12, Figure C is the scanning electron microscope morphology of the pot body coating of Comparative Example 4, Figure D is the scanning electron microscope morphology of the pot body coating of Comparative Example 5, and Figure E is the scanning electron microscope morphology of the pot body coating of Comparative Example 6. From Figure 7 It can be seen that the pot body coating of Example 11 without iron black has cracks and irregularly shaped holes, because iron black can be used as a reinforcing body for the pot body coating to improve the mechanical properties of the pot body coating, and when iron black is absent, the mechanical properties of the pot body coating are poor, so cracks and irregularly shaped holes appear; the pot body coating of Example 12 without ethanol has very few circular holes and dimples.
[0133] Figure 8 The scanning electron microscope morphology and energy spectrum analysis of the hydrophobic coating of Example 1 are shown in Figure A and Figure B. From Figure 8 It can be seen that the hydrophobic coating of Example 1 has no obvious circular holes and dimples due to the absence of ethanol, and from the energy spectrum analysis structure, it can be seen that the main components of the hydrophobic coating of Example 1 are consistent with those of the pot body coating of Example 1, except that the content of each component is different, in particular, the content of C in the hydrophobic coating has decreased significantly, because ethanol and water-containing carbon nanotubes are not added in the preparation process of the hydrophobic coating.
[0134] Figure 9 The contact angle diagram of the hydrophobic coating of Example 1 is shown in Figure A. From Figure 9 It can be seen that the left contact angle of the hydrophobic coating of Example 1 is 119.6°, the right contact angle is 129.3°, and the average is 124.45°.
[0135] Figure 10 The XRD diagram of the hydrophobic coating of Example 1 is shown in Figure A. From Figure 10 It can be seen that the phase composition of the hydrophobic coating of Example 1 contains SiO2, Al2SiO5, Al2(SiO4)O, Al2(SiO4)(OH)2, Fe3O4 and MnO(OH), which is consistent with the phase composition of the pot body coating of Example 1, except that the content of each phase is different, mainly in that the diffraction peak intensity of each phase is different.
[0136] Figure 11 A longitudinal sectional microscope topography of the hydrophobic coating of Example 1 is shown in Figure 1. It can be seen that the hydrophobic coating of Example 1 has no cracks or peeling phenomenon at the interface with the aluminum alloy substrate, and the hydrophobic coating is in a continuous distribution form, and the coating thickness is in the range of 80-100 μm. Figure 11
[0137] In addition, the pot body coating and the hydrophobic coating of Examples 2-10 have similar phenomena to the pot body coating and the hydrophobic coating of Example 1.
[0138] Performance test
[0139] The pot body coating and the hydrophobic coating of each example and the comparative example were subjected to temperature test, and the thickness, roughness, contact angle, wear resistance, corrosion resistance, adhesion and thermal conductivity of the pot body coating and the hydrophobic coating of each example and the comparative example were measured, wherein:
[0140] Temperature test: The woks prepared from each example and each comparative example were simulated for their actual use, no object was placed inside the pot body, a gas stove was heated for 1 min, five-point sampling method was adopted to test the pot body coating of five points on the inner surface of the bottom of the pot by infrared temperature measuring instrument (Xima AR892 high temperature temperature measuring instrument), and the average value was taken as the temperature of the pot body coating; equidistant sampling method was adopted to test the hydrophobic coating of five points on the inner surface of the pot wall by infrared temperature measuring instrument (Xima AR892 high temperature temperature measuring instrument), and the average value was taken as the temperature of the hydrophobic coating;
[0141] Roughness measurement: laser confocal scanning microscope was adopted for measurement;
[0142] Contact angle measurement: contact angle measuring instrument was adopted for measurement, and the average value of the left and right contact angles was taken as the contact angle size of each coating;
[0143] Wear resistance test: wear resistance tester was adopted to test the wear resistance of each coating, with Scotch-Brite as the friction head, the Scotch-Brite was replaced every 500 times of friction of the wear resistance tester, and the wear resistance of the coating was represented by the number of friction times when the coating was worn out to expose the aluminum alloy substrate, and the greater the number of friction times, the better the wear resistance of the coating;
[0144] Corrosion resistance test: each coating was placed in a 5% citric acid solution, and IM6 electrochemical workstation three-electrode method was adopted to determine the anodic polarization curve of each coating in the citric acid solution, and the open circuit potential and breakdown potential were analyzed, and the breakdown point was used to represent the corrosion resistance of each coating, and the greater the breakdown potential, the better the corrosion resistance of the coating;
[0145] Bonding force (adhesion force) measurement: the bonding force between each coating and the aluminum alloy substrate is measured by using WS-2005 automatic scratch technology, that is, the bonding force between each coating and the aluminum alloy substrate is the adhesion force of each coating;
[0146] Thermal conductivity measurement: the thermal conductivity of each coating is measured by using LFA-467 flash laser method thermal conductivity instrument, and the smaller the thermal conductivity, the better the heat insulation effect.
[0147] The experimental results are shown in the following table:
[0148] Table 3 Temperature test results of examples 1-12 and comparative examples 1-7
[0149]
[0150]
[0151] From table 3, it can be seen that only when the outer diameter (OD) of the carbon nanotube is ≤2nm, the ultrasonic frequency of the ultrasonic crushing method is 18-21kHz, the ultrasonic power is 100-1000W, and the ultrasonic vibration time is 100-1000s, the water-containing carbon nanotube can effectively reduce the temperature of the inner surface coating of the bottom of the frying pan, and achieve the purpose that the inner surface temperature of the bottom and the inner surface temperature of the wall of the frying pan are similar when the frying pan is used.
[0152] Table 4 Performance test results of the pot coating of examples 1-12 and comparative examples 1-7
[0153]
[0154]
[0155] Figure 12 The anodic polarization curve of the pot coating of example 1 is shown in the figure.
[0156] From table 4 and Figure 12 It can be seen that the pot coating prepared by using the water-containing carbon nanotube has good corrosion resistance and wear resistance, and the open circuit potential of the pot coating of example 1 is-0.226V and the breakdown potential is 1.66V.
[0157] Table 5 Performance test results of the hydrophobic coating of examples 1-12 and comparative examples 1-7
[0158]
[0159]
[0160] Figure 13 The anodic polarization curve of the hydrophobic coating of example 1 is shown in the figure.
[0161] From Table 5 and Figure 13 It can be seen that the hydrophobic coatings of each of the examples and the comparative example all have good hydrophobic effect, also have strong adhesion, and the open circuit potential of the hydrophobic coating of Example 1 is -0.598 V, and the breakdown potential is 1.18 V.
[0162] Obviously, the above embodiments of the present application are only examples for clearly illustrating the present application, and are not intended to limit the implementation manners of the present application. Based on the above description, other different forms of changes or variations can be made by those skilled in the art. Here, it is not necessary and also impossible to enumerate all the implementation manners. Any modification, equivalent replacement and improvement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the claims of the present application.
Claims
1. A coating for a pot body, characterized in that, Based on parts by weight, it includes the following components: 8-12 parts aluminum sol, 8-12 parts silica sol, 15-25 parts siloxane, 2-6 parts iron black, 15-25 parts ethanol, and 0.1-0.5 parts hydrated carbon nanotubes; The hydrous carbon nanotubes were prepared by the following method: S1. In a liquid environment, carbon nanotubes are chopped using ultrasonic pulverization and the liquid is removed to obtain carbon nanotubes with open ends. S2. The carbon nanotube with the open end is subjected to a water vapor bath to allow gaseous water molecules to enter the carbon nanotube. Then, the temperature is lowered to change the gaseous water molecules into liquid and / or solid water molecules, thus obtaining a water-containing carbon nanotube. The outer diameter of the carbon nanotubes is 1~2nm; the ultrasonic frequency of the ultrasonic pulverization method is 18~21kHz, the ultrasonic power is 100~1000W, and the ultrasonic vibration time is 100~1000s.
2. The pot body coating according to claim 1, characterized in that, The ultrasonic pulverization method uses an ultrasonic frequency of 20kHz, an ultrasonic power of 500W, and an ultrasonic vibration time of 800s.
3. The pot coating according to claim 1, characterized in that, The carbon nanotubes are single-walled carbon nanotubes and / or multi-walled carbon nanotubes.
4. A method for preparing a coating for a pot body, characterized in that, Includes the following steps: The pot body coating is obtained by mixing the various parts of the pot body coating according to any one of claims 1 to 3.
5. A pot body coating, prepared by the following process: spraying the pot body coating of any one of claims 1 to 3, and calcining to obtain the pot body coating.
6. The application of the pot body coating of claim 5 in the preparation of a wok.
7. A wok, characterized in that, The pot body includes a metal substrate, and the inner surface of the bottom of the pot body has the pot body coating as described in claim 5.
8. The wok according to claim 7, characterized in that, The inner surface of the pot wall has a hydrophobic coating.