Super-hydrophobic thermal management composite coating synthesized from modified spent bleaching clay and preparation method of super-hydrophobic thermal management composite coating

Abstract

The invention relates to a super-hydrophobic thermal management composite coating synthesized by modified spent bleaching clay and a preparation method thereof. The preparation method comprises the following steps: carbonizing a part of spent bleaching clay powder in a tubular furnace; carrying out air burning oxidation treatment on one part of spent bleaching clay powder in a tubular furnace; the method comprises the following steps: respectively adding two parts of spent bleaching clay powder into a mixed solution of hexadecyl trimethyl siloxane, tetraethyl silicate, ammonia water and ethanol, and carrying out hydrophobic treatment to obtain a dispersion liquid; sequentially centrifuging, washing and drying the dispersion liquid to obtain modified oxidized and carbonized spent bleaching clay powder; sequentially carrying out washing, drying and plasma treatment on the two surfaces of the substrate; mixing the oxidized and carbonized waste white clay powder with resin and a curing agent respectively, then adding the mixture into a solvent for stirring treatment, and preparing a spraying coating through ultrasonic oscillation treatment; the spraying paint is sprayed on the two faces of a prepared substrate respectively, and the modified spent bleaching clay synthesized super-hydrophobic thermal management composite coating is obtained after curing. The composite coating prepared by the method can obviously reduce the energy consumption in the aspects of heating and cooling.

Description

Technical Field

[0001] The invention belongs to the technical field of super-hydrophobic thermal management composite materials, and specifically relates to a super-hydrophobic thermal management composite coating synthesized from modified waste clay and a preparation method thereof. Background Art

[0002] Maintaining a relatively stable temperature plays a vital role in various industries, such as breeding and brewing. However, traditional temperature regulation mainly relies on air conditioning. Although room conditioning can effectively regulate temperature, it consumes a lot of energy. According to statistics, the energy consumption of indoor thermostats for heating and cooling accounts for about 20% of the world's total energy demand. At the same time, thermostats emit a large amount of carbon dioxide during operation, which has a very adverse impact on the environment. Therefore, it is crucial to develop energy-saving temperature regulation methods with minimal carbon footprint. In outdoor environments, heat mainly comes from solar radiation (λ≈0.25~2.5μm), which is also an important energy source for heating at present. Lack or excess of solar radiation usually leads to extreme outdoor environments. Rational use of solar radiation is an ideal strategy to achieve zero-energy outdoor thermal management. In addition, radiating heat to the cold outer space through the atmospheric long-wave infrared (LWIR) transmission window (λ≈8-13μm) is another key factor. Practice has shown that the heat transfer process can be controlled by adjusting the emissivity and transmittance; in recent years, radiation cooling technology using outer space (3K) as a cold source and solar heating technology using the sun (5800K) as a heat source have been proposed, which can effectively achieve passive cooling and heating without additional energy consumption.

[0003] Due to the optical properties of thermal management materials, maintaining a clean surface plays an important role in their performance. Manual maintenance will consume a lot of manpower, financial resources and material resources. Therefore, in recent years, it has been proposed to prepare new materials with self-cleaning functions such as super-hydrophobicity and super-slippery composite thermal management functions to achieve the purpose of durable thermal management materials. Summary of the invention

[0004] In view of the problems existing in the above-mentioned prior art, the present invention provides a modified waste clay synthesized super-hydrophobic thermal management composite coating and a preparation method thereof. The composite coating prepared by this method can significantly reduce the energy consumption in heating and cooling, and greatly reduce the cost of manpower maintenance.

[0005] In order to achieve the above object, the present invention provides a method for preparing a super-hydrophobic thermal management composite coating synthesized from modified waste clay, comprising the following steps:

[0006] Step 1: placing the waste clay in a ball mill for ball milling to obtain waste clay powder, and then evenly dividing the waste clay powder into two parts;

[0007] Step 2: Carbonizing a portion of the waste clay powder in a tube furnace to obtain carbonized waste clay powder;

[0008] Step 3: performing an air-burning oxidation treatment on a portion of the waste clay powder in a tube furnace to obtain an oxidized waste clay powder;

[0009] Step 4: adding the waste clay powders in step 2 and step 3 to a mixed solution of hexadecyltrimethylsiloxane, tetraethyl silicate, ammonia water and ethanol for hydrophobic treatment to obtain a dispersion;

[0010] Step 5: centrifuging, washing and drying the dispersion in sequence to obtain modified oxidized waste clay powder and carbonized waste clay powder respectively;

[0011] Step 6: Washing, drying, and plasma treating both sides of the substrate in sequence;

[0012] Step 7: mixing the oxidized waste clay powder and the carbonized waste clay powder with a resin and a curing agent respectively, adding them into a solvent for stirring, and preparing a spray coating by ultrasonic oscillation treatment;

[0013] Step 8: Use a spray gun to spray the spray coating on both sides of the prepared substrate, and after curing, obtain a modified waste clay synthetic super-hydrophobic thermal management composite coating.

[0014] As a preference, during the ball milling process in step 1, the rotation speed of the ball mill is 400 r / min and the ball milling time is 6 h.

[0015] As a preference, during the carbonization process in step 2, the temperature of the tube furnace is 600° C., the carbonization time is 5 hours, and at the same time, during the carbonization process, argon gas is filled into the tube furnace to form a protective atmosphere.

[0016] As a preference, during the oxidation treatment in step three, the temperature of the tube furnace is 500° C., the oxidation time is 5 hours, and at the same time, during the oxidation treatment, no inert gas is filled into the tube furnace.

[0017] Preferably, during the hydrophobic treatment in step 4, the mass fraction of hexadecyltrimethylsiloxane in the mixed solution is 3-5wt%, the mass fraction of tetraethyl silicate is 3-7wt%, and the mass fraction of ammonia water is 20-26wt%.

[0018] As a preference, during the centrifugal treatment process in step five, the centrifuge speed is 8000 r / min, the centrifugal time is 5 min, and at the same time, the centrifugal treatment process and the washing treatment are repeated for multiple cycles, with the number of cycles being 3 to 5 times.

[0019] As a preference, in the plasma treatment process in step six, the power of the plasma treatment is 50 to 150 W, and the treatment time is 30 to 35 min.

[0020] As a preferred embodiment, in step seven, the resin includes one or more of epoxy resin, polyimide resin, polyamide-imide or phenolic resin; the curing agent includes one or more of methylhexahydrophthalic anhydride, polyetheramine or polydiimide; the ratio of the resin to the curing agent is 1:1; and the solvent is a mixed solution of ethyl acetate and ethanol in a ratio of 2:3.

[0021] As a preferred embodiment, when spraying in step eight, the spray gun pressure is 20-25 MPa, and the vertical distance between the spray gun outlet and the substrate is 18-20 cm; the mass fraction of the resin in the super-hydrophobic thermal management composite coating is 30%-40%, the curing temperature is 110-130°C, the curing pressure is 0.5-1 MPa, and the curing time is 1-2 h.

[0022] The present invention also provides a modified waste clay synthesized super-hydrophobic thermal management composite coating, which is prepared by a preparation method of a modified waste clay synthesized super-hydrophobic thermal management composite coating.

[0023] The present invention provides a kind of modified waste clay synthetic super hydrophobic thermal management composite coating and preparation method thereof, in the preparation process, first waste clay powder is carbonized, oxidized, on the one hand can significantly improve its uniformity of distribution in solvent, and then can significantly improve its dispersion performance in spray coating.On the other hand, waste clay can make it obtain extremely high absorbance and reflectivity respectively in sunlight band after carbonization and oxidation treatment, and then can obtain waste clay powder of high reflectivity and absorbance, for the functionalization of waste clay lays a good foundation.Material self-cleaning function can be further given by hydrophobic treatment, and hydrophobically modified waste clay can have excellent mechanical properties, while having a larger specific surface area, it is helpful to form a synergistically enhanced effect with the friction and wear performance of super hydrophobic thermal management coating. By hydrolyzing and condensing hexadecane trimethylsiloxane (HDTMS) and tetraethyl orthosilicate (TEOS), low surface energy polysiloxane (POS) was modified on the surface of carbonized and oxidized waste clay, and then the modified powder and epoxy resin (EP) were used as the main raw materials. The two powders were sprayed on both sides of the substrate through a spraying process to prepare a super-hydrophobic thermal management composite coating. The composite coating prepared in this way has excellent super-hydrophobic properties, good chemical stability and self-cleaning properties on both sides. At the same time, the white cooling surface can provide a good cooling effect due to its ultra-high reflectivity in the solar band and extremely high emissivity in the infrared band, while the high absorbance of the black heating surface in the solar band provides the coating with considerable heating capacity.

[0024] The composite coating prepared by this method can significantly reduce energy consumption in heating and cooling, and greatly reduce the cost of human maintenance. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 The scanning electron microscope images of the waste clay before and after carbonization and oxidation modification in the present invention;

[0026] Figure 2 This is a scanning electron microscope image of the hydrophobically modified oxidized and carbonized waste clay in the present invention;

[0027] Figure 3 is a scanning electron microscope image of the super-hydrophobic thermal management coating of the present invention;

[0028] Figure 4 Measured temperature curves of the super-hydrophobic thermal management coating in different seasons;

[0029] Figure 5 These are images of different liquids on the surface of the super-hydrophobic thermal management coating in the present invention.

[0030] Figure 6 The contact angle and sliding angle of different liquids on the surface of the super-hydrophobic thermal management coating in the present invention. DETAILED DESCRIPTION

[0031] The present invention will be further described below.

[0032] like Figures 1 to 6 As shown, the present invention provides a method for preparing a super-hydrophobic thermal management composite coating synthesized from modified waste clay, comprising the following steps:

[0033] Step 1: placing the waste clay in a ball mill for ball milling to obtain waste clay powder, and then evenly dividing the waste clay powder into two parts;

[0034] Step 2: Carbonizing a portion of the waste clay powder in a tube furnace to obtain carbonized waste clay powder;

[0035] Step 3: performing an air-burning oxidation treatment on a portion of the waste clay powder in a tube furnace to obtain an oxidized waste clay powder;

[0036] Step 4: adding the waste clay powders in step 2 and step 3 to a mixed solution of hexadecyltrimethylsiloxane, tetraethyl silicate, ammonia water and ethanol for hydrophobic treatment to obtain a dispersion;

[0037] Step 5: centrifuging, washing and drying the dispersion in sequence to obtain modified oxidized waste clay powder and carbonized waste clay powder respectively;

[0038] Step 6: Washing, drying, and plasma treating both sides of the substrate in sequence;

[0039] Step 7: mixing the oxidized waste clay powder and the carbonized waste clay powder with a resin and a curing agent respectively, adding them into a solvent for stirring, and preparing a spray coating by ultrasonic oscillation treatment;

[0040] Step 8: Use a spray gun to spray the spray coating on both sides of the prepared substrate, and after curing, obtain a modified waste clay synthetic super-hydrophobic thermal management composite coating.

[0041] As a preference, during the ball milling process in step 1, the rotation speed of the ball mill is 400 r / min and the ball milling time is 6 h.

[0042] As a preference, during the carbonization process in step 2, the temperature of the tube furnace is 600° C., the carbonization time is 5 hours, and at the same time, during the carbonization process, argon gas is filled into the tube furnace to form a protective atmosphere.

[0043] As a preference, during the oxidation treatment in step three, the temperature of the tube furnace is 500° C., the oxidation time is 5 hours, and at the same time, during the oxidation treatment, no inert gas is filled into the tube furnace.

[0044] Preferably, during the hydrophobic treatment in step 4, the mass fraction of hexadecyltrimethylsiloxane (HDTMS) in the mixed solution is 3-5wt%, the mass fraction of tetraethyl silicate (TEOS) is 3-7wt%, and the mass fraction of ammonia water is 20-26wt%.

[0045] As a preference, during the centrifugal treatment process in step five, the centrifuge speed is 8000 r / min, the centrifugal time is 5 min, and at the same time, the centrifugal treatment process and the washing treatment are repeated for multiple cycles, with the number of cycles being 3 to 5 times.

[0046] As a preference, in the plasma treatment process in step six, the power of the plasma treatment is 50 to 150 W, and the treatment time is 30 to 35 min.

[0047] As a preferred embodiment, in step seven, the resin includes one or more of epoxy resin, polyimide resin, polyamide-imide or phenolic resin; the curing agent includes one or more of methylhexahydrophthalic anhydride, polyetheramine or polydiimide; the ratio of the resin to the curing agent is 1:1; and the solvent is a mixed solution of ethyl acetate and ethanol in a ratio of 2:3.

[0048] As a preferred embodiment, when spraying in step eight, the spray gun pressure is 20-25 MPa, and the vertical distance between the spray gun outlet and the substrate is 18-20 cm; the mass fraction of the resin in the super-hydrophobic thermal management composite coating is 30%-40%, the curing temperature is 110-130°C, the curing pressure is 0.5-1 MPa, and the curing time is 1-2 h.

[0049] The present invention also provides a modified waste clay synthesized super-hydrophobic thermal management composite coating, which is prepared by a preparation method of a modified waste clay synthesized super-hydrophobic thermal management composite coating.

[0050] In order to further elaborate the present invention, the present invention is described below by way of embodiments:

[0051] Embodiment 1:

[0052] 1. Place 10g of waste clay in a ball mill for ball milling. The ball mill speed is set to 400r / min and the ball milling time is 12h;

[0053] 2. 5 g of waste clay powder was carbonized in a tube furnace. The temperature of the tube furnace was set to 600 ° C. The carbonization time was 5 h. Argon was introduced to form a protective atmosphere.

[0054] 3. 5 g of waste clay powder was oxidized in a tube furnace. The temperature of the tube furnace was set to 500° C., the carbonization time was 5 h, and no inert gas was introduced.

[0055] 4. Add 0.5 g of hexadecane trimethylsiloxane, 0.5 g of tetraethyl silicate, 4 g of ammonia water and 20 ml of ethanol to 1 g of the waste clay after oxidation treatment and carbonization treatment respectively; then place the obtained mixed solution in an oil bath pot, set the temperature to 60°C, the speed to 3000 r / min, and the reaction time to 5 h;

[0056] 5. The dispersion after the reaction is completed is centrifuged, washed and dried, wherein the speed of the centrifuge is set to 8000r / min, the centrifugal time is 5min, and ethanol is used for washing, wherein the centrifugal treatment and the washing treatment are cyclically performed for three times, and then dried in an oven at 60°C to obtain hydrophobically modified oxidized and carbonized waste clay powder;

[0057] 6. Wash, dry and plasma treat the substrate. Use an ultrasonic cleaner to wash it. Dry it in an oven and then plasma treat it. The power of the plasma treatment is 100W and the time is 30min.

[0058] 7. 1 g of the modified oxidized and carbonized waste clay was mixed with 0.8 g of epoxy resin, 0.8 g of methyl hexahydrophthalic anhydride curing agent and 10 ml of a mixed solution of ethyl acetate and ethanol, respectively, and the coating was obtained after stirring and ultrasonic circulation for three times;

[0059] 8. Spray the coating on both sides of the prepared substrate respectively. The spray gun pressure is 20 MPa and the nozzle is 20 cm away from the substrate. Then, cure it to obtain a super hydrophobic thermal management coating. The curing temperature is 120°C, the pressure is 1 MPa, and the curing time is 2 hours.

[0060] Embodiment 2:

[0061] 1. Mill 10 g of waste clay in a ball mill at a speed of 400 r / min for 6 h;

[0062] 2. 5 g of waste clay powder was carbonized in a tube furnace. The temperature of the tube furnace was set to 600 ° C. The carbonization time was 5 h. Argon was introduced to form a protective atmosphere.

[0063] 3. 5 g of waste clay powder was oxidized in a tube furnace. The temperature of the tube furnace was set to 500° C., the carbonization time was 5 h, and no inert gas was introduced.

[0064] 4. Add 0.5 g hexadecane trimethylsiloxane, 1 g tetraethyl silicate, 4 g ammonia water and 20 ml ethanol to 1 g of waste clay after oxidation treatment and carbonization treatment respectively; then place the obtained mixed solution in an oil bath pot, set the temperature to 60 ° C, the speed to 3000 r / min, and the reaction time to 5 h;

[0065] 5. The dispersion after the reaction is completed is centrifuged, washed and dried, wherein the speed of the centrifuge is set to 8000r / min, the centrifugal time is 5min, and ethanol is used for washing, wherein the centrifugal treatment and the washing treatment are cyclically performed for three times, and then dried in an oven at 60°C to obtain hydrophobically modified oxidized and carbonized waste clay powder;

[0066] 6. Wash, dry and plasma treat the substrate. Wash with an ultrasonic cleaner, dry in an oven and then plasma treat with a power of 50 W for 30 min.

[0067] 7. 1 g of the modified oxidized and carbonized waste clay was mixed with 0.8 g of epoxy resin, 0.8 g of methyl hexahydrophthalic anhydride curing agent and 10 ml of a mixed solution of ethyl acetate and ethanol, respectively, and the coating was obtained after stirring and ultrasonic circulation for three times;

[0068] 8. Spray the coating on both sides of the prepared substrate, with a spray gun pressure of 20 MPa and a nozzle distance of 20 cm from the substrate; then cure to obtain a super hydrophobic thermal management coating, with a curing temperature of 120°C, a pressure of 1 MPa, and a curing time of 2 h;

[0069] Embodiment 3:

[0070] 1. Place 10g of waste clay in a ball mill for ball milling. The ball mill speed is set to 400r / min and the ball milling time is 6h;

[0071] 2. 5 g of waste clay powder was carbonized in a tube furnace. The temperature of the tube furnace was set to 600 ° C. The carbonization time was 5 h. Argon was introduced to form a protective atmosphere.

[0072] 3. 5 g of waste clay powder was oxidized in a tube furnace. The temperature of the tube furnace was set to 500° C., the carbonization time was 5 h, and no inert gas was introduced.

[0073] 4. Add 0.5g hexadecanetrimethylsiloxane, 2g tetraethyl silicate, 4g ammonia water and 20ml ethanol to 1g of the waste clay after oxidation treatment and carbonization treatment respectively; then place the obtained mixed solution in an oil bath pot, set the temperature to 60°C, the speed to 3000r / min, and the reaction time to 5h;

[0074] 5. The dispersion after the reaction is completed is centrifuged, washed and dried, wherein the speed of the centrifuge is set to 8000r / min, the centrifugal time is 5min, and ethanol is used for washing, wherein the centrifugal treatment and the washing treatment are cyclically performed for three times, and then dried in an oven at 60°C to obtain hydrophobically modified oxidized and carbonized waste clay powder;

[0075] 6. Wash, dry and plasma treat the substrate. Wash with an ultrasonic cleaner, dry in an oven and then plasma treat with a power of 100 W for 35 min.

[0076] 7. 1 g of the modified oxidized and carbonized waste clay was mixed with 0.8 g of epoxy resin, 0.8 g of methyl hexahydrophthalic anhydride curing agent and 10 ml of a mixed solution of ethyl acetate and ethanol, respectively, and the coating was obtained after stirring and ultrasonic circulation for three times;

[0077] 8. Spray the coating on both sides of the prepared substrate respectively. The spray gun pressure is 20 MPa and the nozzle is 18 cm away from the substrate. Then, cure it to obtain a super hydrophobic thermal management coating. The curing temperature is 120°C, the pressure is 0.7 MPa, and the curing time is 2 hours.

[0078] Embodiment 4:

[0079] 1. Place 10g of waste clay in a ball mill for ball milling. The ball mill speed is set to 400r / min and the ball milling time is 6h;

[0080] 2. 5 g of waste clay powder was carbonized in a tube furnace. The temperature of the tube furnace was set to 600 ° C. The carbonization time was 5 h. Argon was introduced to form a protective atmosphere.

[0081] 3. 5 g of waste clay powder was oxidized in a tube furnace. The temperature of the tube furnace was set to 500° C., the carbonization time was 5 h, and no inert gas was introduced.

[0082] 4. Add 0.5 g of hexadecane trimethylsiloxane, 0.5 g of tetraethyl silicate, 4 g of ammonia water and 20 ml of ethanol to 1 g of the waste clay after oxidation treatment and carbonization treatment respectively; then place the obtained mixed solution in an oil bath pot, set the temperature to 60°C, the speed to 3000 r / min, and the reaction time to 5 h;

[0083] 5. The dispersion after the reaction is completed is centrifuged, washed and dried, wherein the speed of the centrifuge is set to 8000r / min, the centrifugal time is 5min, and ethanol is used for washing, wherein the centrifugal treatment and the washing treatment are cyclically performed for three times, and then dried in an oven at 60°C to obtain hydrophobically modified oxidized and carbonized waste clay powder;

[0084] 6. Wash, dry and plasma treat the substrate. Use an ultrasonic cleaner to wash it. Dry it in an oven and then plasma treat it. The power of the plasma treatment is 100W and the time is 30min.

[0085] 7. 1 g of the modified oxidized and carbonized waste clay was mixed with 0.8 g of epoxy resin, 0.8 g of polyetheramine curing agent, and 10 ml of ethyl acetate and ethanol, respectively, and stirred and ultrasonically cycled three times to obtain a coating;

[0086] 8. Spray the coating on both sides of the prepared substrate, with a spray gun pressure of 20 MPa and a nozzle distance of 20 cm from the substrate; then cure to obtain a super hydrophobic thermal management coating, with a curing temperature of 120°C, a pressure of 1 MPa, and a curing time of 2 h;

[0087] Embodiment 5:

[0088] 1. Mill 10 g of waste clay in a ball mill. The speed of the ball mill is set to 400 r / min and the milling time is 12 h.

[0089] 2. 5 g of waste clay powder was carbonized in a tube furnace. The temperature of the tube furnace was set to 600 ° C. The carbonization time was 5 h. Argon was introduced to form a protective atmosphere.

[0090] 3. 5 g of waste clay powder was oxidized in a tube furnace. The temperature of the tube furnace was set to 500° C., the carbonization time was 5 h, and no inert gas was introduced.

[0091] 4. Add 0.5 g of hexadecane trimethylsiloxane, 0.5 g of tetraethyl silicate, 4 g of ammonia water and 20 ml of ethanol to 1 g of the waste clay after oxidation treatment and carbonization treatment respectively; then place the obtained mixed solution in an oil bath pot, set the temperature to 60°C, the speed to 3000 r / min, and the reaction time to 5 h;

[0092] 5. The dispersion after the reaction is completed is centrifuged, washed and dried, wherein the speed of the centrifuge is set to 8000r / min, the centrifugal time is 5min, and ethanol is used for washing, wherein the centrifugal treatment and the washing treatment are cyclically performed for three times, and then dried in an oven at 60°C to obtain hydrophobically modified oxidized and carbonized waste clay powder;

[0093] 6. Wash, dry and plasma treat the substrate. Use an ultrasonic cleaner to wash it. Dry it in an oven and then plasma treat it. The power of the plasma treatment is 100W and the time is 30min.

[0094] 7. 1 g of the modified oxidized and carbonized waste clay was mixed with 0.8 g of phenolic resin, 0.8 g of polyetheramine curing agent and 10 ml of a mixed solution of ethyl acetate and ethanol, respectively, and the coating was obtained after stirring and ultrasonic circulation for three times;

[0095] 8. Spray the coating on both sides of the prepared substrate respectively. The spray gun pressure is 20 MPa and the nozzle is 20 cm away from the substrate. Then, cure it to obtain a super hydrophobic thermal management coating. The curing temperature is 120°C, the pressure is 1 MPa, and the curing time is 2 hours.

[0096] The present invention provides a kind of modified waste clay synthetic super hydrophobic thermal management composite coating and preparation method thereof, in the preparation process, first waste clay powder is carbonized, oxidized, on the one hand can significantly improve its uniformity of distribution in solvent, and then can significantly improve its dispersion performance in spray coating.On the other hand, waste clay can make it obtain extremely high absorbance and reflectivity respectively in sunlight band after carbonization and oxidation treatment, and then can obtain waste clay powder of high reflectivity and absorbance, for the functionalization of waste clay lays a good foundation.Material self-cleaning function can be further given by hydrophobic treatment, and hydrophobically modified waste clay can have excellent mechanical properties, while having a larger specific surface area, it is helpful to form a synergistically enhanced effect with the friction and wear performance of super hydrophobic thermal management coating. By hydrolyzing and condensing hexadecane trimethylsiloxane (HDTMS) and tetraethyl orthosilicate (TEOS), low surface energy polysiloxane (POS) was modified on the surface of carbonized and oxidized waste clay, and then the modified powder and epoxy resin (EP) were used as the main raw materials. The two powders were sprayed on both sides of the substrate through a spraying process to prepare a super-hydrophobic thermal management composite coating. The composite coating prepared in this way has excellent super-hydrophobic properties, good chemical stability and self-cleaning properties on both sides. At the same time, the white cooling surface can provide a good cooling effect due to its ultra-high reflectivity in the solar band and extremely high emissivity in the infrared band, while the high absorbance of the black heating surface in the solar band provides the coating with considerable heating capacity.

[0097] The composite coating prepared by this method can significantly reduce energy consumption in heating and cooling, and greatly reduce the cost of human maintenance.

Claims

1. A method for preparing a super-hydrophobic thermal management composite coating synthesized from modified waste clay, characterized in that: The steps include: Step 1: placing the waste clay in a ball mill for ball milling to obtain waste clay powder, and then evenly dividing the waste clay powder into two parts; Step 2: Carbonizing a portion of the waste clay powder in a tube furnace to obtain carbonized waste clay powder; Step 3: performing an air-burning oxidation treatment on a portion of the waste clay powder in a tube furnace to obtain an oxidized waste clay powder; Step 4: adding the waste clay powders in step 2 and step 3 to a mixed solution of hexadecyltrimethylsiloxane, tetraethyl silicate, ammonia water and ethanol for hydrophobic treatment to obtain a dispersion; Step 5: centrifuging, washing and drying the dispersion in sequence to obtain modified oxidized waste clay powder and carbonized waste clay powder respectively; Step 6: Washing, drying, and plasma treating both sides of the substrate in sequence; Step 7: mixing the oxidized waste clay powder and the carbonized waste clay powder with a resin and a curing agent respectively, adding them into a solvent for stirring, and preparing a spray coating by ultrasonic oscillation treatment; Step 8: Use a spray gun to spray the spray coating on both sides of the prepared substrate, and after curing, obtain a modified waste clay synthetic super-hydrophobic thermal management composite coating.

2. The method for preparing a super-hydrophobic thermal management composite coating synthesized from modified waste clay according to claim 1, characterized in that: During the ball milling process in step 1, the rotation speed of the ball mill is 400 r / min and the ball milling time is 6 h.

3. The method for preparing a super-hydrophobic thermal management composite coating synthesized from modified waste clay according to claim 1, characterized in that: During the carbonization treatment in step 2, the temperature of the tube furnace is 600° C. and the carbonization time is 5 hours. At the same time, during the carbonization treatment, argon gas is filled into the tube furnace to form a protective atmosphere.

4. The method for preparing a super-hydrophobic thermal management composite coating synthesized from modified waste clay according to claim 1, characterized in that: During the oxidation treatment in step 3, the temperature of the tube furnace is 500° C., and the oxidation time is 5 hours. Meanwhile, during the oxidation treatment, no inert gas is filled into the tube furnace.

5. The method for preparing a super-hydrophobic thermal management composite coating synthesized from modified waste clay according to claim 1, characterized in that: During the hydrophobic treatment in step 4, the mass fraction of hexadecyltrimethylsiloxane in the mixed solution is 3-5wt%, the mass fraction of tetraethyl silicate is 3-7wt%, and the mass fraction of ammonia water is 20-26wt%.

6. The method for preparing a super-hydrophobic thermal management composite coating synthesized from modified waste clay according to claim 1, characterized in that: During the centrifugal treatment process in step 5, the centrifuge speed is 8000 r / min, the centrifugal time is 5 min, and at the same time, the centrifugal treatment process and the washing treatment are repeated for 3 to 5 times.

7. The method for preparing a super-hydrophobic thermal management composite coating synthesized from modified waste clay according to claim 1, characterized in that: During the plasma treatment process in step six, the power of the plasma treatment is 50 to 150 W, and the treatment time is 30 to 35 minutes.

8. The method for preparing a super-hydrophobic thermal management composite coating synthesized from modified waste clay according to claim 1, characterized in that: In step seven, the resin includes one or more of epoxy resin, polyimide resin, polyamide-imide or phenolic resin; the curing agent includes one or more of methylhexahydrophthalic anhydride, polyetheramine or polydiimide; the ratio of the resin to the curing agent is 1:1; and the solvent is a mixed solution of ethyl acetate and ethanol in a ratio of 2:

3.

9. The method for preparing a super-hydrophobic thermal management composite coating synthesized from modified waste clay according to claim 1, characterized in that: During the spraying operation in step eight, the spray gun pressure is 20-25 MPa, and the vertical distance between the spray gun outlet and the substrate is 18-20 cm; the mass fraction of the resin in the super-hydrophobic thermal management composite coating is 30%-40%, the curing temperature is 110-130°C, the curing pressure is 0.5-1 MPa, and the curing time is 1-2 h.

10. A modified waste clay composite coating for super hydrophobic thermal management, characterized in that: The super-hydrophobic thermal management composite coating is prepared by the method for preparing a modified waste clay composite coating as described in any one of claims 1 to 9.

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