Oleophylic and hydrophobic sponge material as well as preparation and application thereof

Abstract

The invention discloses an oleophylic and hydrophobic sponge material as well as preparation and application thereof. The material comprises sponge and a carbon-containing hydrophobic film layer coated on a sponge framework, and lauric acid is coated on the carbon-containing hydrophobic film layer. The preparation method comprises the following steps: in an inert atmosphere, heating and carbonizing dried banana peel powder, carrying out alkali treatment on a product, heating and calcining, and carrying out acid pickling to obtain biomass derived carbon; the preparation method comprises the following steps: dispersing biomass derived carbon in a PDMS solution to obtain a carbon powder suspension, immersing a sponge in the carbon powder suspension, taking out the sponge after immersion, drying, immersing the sponge in liquid lauric acid, taking out the sponge after vacuum immersion, removing redundant lauric acid, uniformly smearing the carbon powder suspension on the outer surface of a sponge intermediate, and drying and solidifying to obtain the sponge. The material can be applied to adsorption and recovery of high-viscosity crude oil. In the oil-water separation process, the prepared composite material shows efficient adsorption capacity and rapid separation effect on high-viscosity crude oil, and has remarkable environmental and economic benefits.

Description

TECHNICAL FIELD

[0001] The present application relates to a crude oil adsorption material, in particular to an oleophilic hydrophobic sponge material and its preparation and application. BACKGROUND

[0002] In marine exploration and transportation, oil spill can be caused by accidents such as blowout, leakage, tanker collision, etc., resulting in energy waste and serious threat to marine ecology and health. Traditional measures include dispersion, skimming, bioremediation and combustion, but these methods often lead to resource waste and secondary pollution. Although the existing porous adsorption material has large adsorption capacity and high recovery efficiency, when it faces high viscosity crude oil, the crude oil is easy to adhere to the inner wall of the pore or the skeleton, blocking the pore, so that the internal porous structure of the adsorption material cannot fully contact and adsorb the crude oil, and the high efficient adsorption function of the porous structure cannot be fully played. In addition, even if the crude oil is adsorbed into the internal porous material by extrusion or other methods, the high viscosity will cause the crude oil to be difficult to release from the porous material, thereby resulting in low recovery efficiency of the crude oil and greatly limiting the recycling performance of the porous adsorption material.

[0003] In order to improve this situation, the existing research proposes to use photothermal materials (such as carbon materials) to convert solar energy into heat energy to reduce the viscosity of crude oil, thereby improving the crude oil adsorption and recovery capacity of porous adsorption materials. However, the instability of solar radiation intensity limits its application. Once the solar radiation is weakened or in the dark, the temperature of the material decreases rapidly, resulting in rapid increase of the viscosity of the crude oil, so that the adsorption and recovery of the material to the crude oil becomes difficult again.

[0004] Phase change materials (PCM), especially organic PCMs (such as polyethylene glycol, paraffin, fatty acid, lauric acid, etc.), are widely used in many fields due to their high phase change enthalpy, small volume change, non-toxicity and good cycle stability, which can store and release latent heat to regulate temperature. At present, there is no report on the development of composite adsorption materials combining the light-heat conversion of carbon materials and the adsorption characteristics of porous materials, and introducing organic phase change materials to integrate light-heat conversion and heat storage functions. How to improve the adsorption and recovery rate of traditional adsorption materials to high viscosity crude oil and the efficiency of heat utilization has become a technical problem to be solved. SUMMARY

[0005] The purpose of the present application is to provide an oleophilic hydrophobic sponge material to solve the problem of poor cycle adsorption capacity of existing adsorption materials to high viscosity crude oil. The second purpose of the present application is to provide an oleophilic hydrophobic sponge material to solve the problem of how to prepare an oleophilic hydrophobic sponge material. The third purpose of the present application is to provide an application of the oleophilic hydrophobic sponge material in high viscosity crude oil adsorption and recovery to solve the problem of how to efficiently and cyclically adsorb and recover high viscosity crude oil.

[0006] Technical solution: The present invention provides an oleophilic and hydrophobic sponge material, comprising a sponge and a carbon-containing hydrophobic film layer covering the sponge skeleton. The carbon-containing hydrophobic film layer is coated with lauric acid and is composed of biomass-derived carbon and polydimethylsiloxane.

[0007] Preferably, the biomass-derived carbon is a carbonization product of banana peel, and the sponge has a specific surface area of ​​100-200 m² / g. 2 / g, melamine sponge with a pore size of 25-100 μm.

[0008] The second aspect of this invention discloses a method for preparing the above-mentioned oleophilic and hydrophobic sponge material, comprising the following steps: (1) Under an inert atmosphere, the dried banana peel powder was heated and carbonized to obtain the first product; (2) The first product is dispersed in a strong alkaline aqueous solution to obtain a dispersion, and the dispersion is heated and calcined to obtain a second product. The second product is then acid-washed to obtain biomass-derived carbon. (3) Disperse biomass-derived carbon in polydimethylsiloxane solution to obtain carbon powder suspension, immerse sponge in carbon powder suspension, fully degas and impregnate, take out sponge and dry to obtain sponge intermediate; (4) Immerse the sponge intermediate in liquid lauric acid, vacuum impregnate it, remove the sponge intermediate, remove the excess lauric acid from the sponge intermediate, and before the lauric acid solidifies at room temperature, evenly coat the outer surface of the sponge intermediate with carbon powder suspension, and after drying and solidification, obtain the oleophilic and hydrophobic sponge material.

[0009] This invention involves uniformly dispersing biomass-derived carbon in a PDMS solution, modifying it onto the surface of a melamine sponge, and then impregnating it with molten lauric acid to form a C / PDMS / LA@MS composite material with excellent comprehensive properties. Through screening, this invention discovered that only lauric acid is compatible with specific biomass-derived carbon materials, enabling the composite material to maintain a high photothermal conversion rate and good latent heat storage and release performance. The heat energy converted through photoradiation and the good heat storage capacity reduce the viscosity of high-viscosity crude oil, improving the adsorption and recovery capacity of the porous material for high-viscosity crude oil.

[0010] Preferably, in step (1), the heating and carbonization conditions are to heat to 400-500℃ at a rate of 3-7℃ / min and carbonize for 1-3 hours.

[0011] Preferably, in step (2), the strong alkali aqueous solution is a 1-2M KOH or NaOH aqueous solution; the method of heating and calcining the dispersion is: heating the dispersion to 600-700℃ at 3-7℃ / min and holding it at that temperature for 1-3 h under an inert atmosphere.

[0012] The preparation process of the banana peel biomass-derived carbon material includes two high-temperature treatments: after the first high-temperature carbonization, high-temperature KOH activation is performed to enhance the pore structure and adsorption performance of the biomass-derived carbon.

[0013] Preferably, in step (2), the acid washing method is to wash the second product with a 0.5-1.5M hydrochloric acid aqueous solution until it becomes acidic.

[0014] Preferably, in step (3), the ratio of biomass-derived carbon to polydimethylsiloxane solution is 0.01-1g:1-100mL, and the polydimethylsiloxane solution is a polydimethylsiloxane saturated alkane solution with a concentration of 0.01-0.1g / mL.

[0015] Furthermore, the saturated alkane includes at least one of butane, pentane, hexane, and heptane.

[0016] Preferably, in step (4), the temperature of the liquid lauric acid is 80-90°C, the vacuum impregnation time is at least 6 hours, and the drying and solidification time is at least 3 hours.

[0017] The third aspect of this invention discloses the application of the above-mentioned oleophilic and hydrophobic sponge material in the adsorption and recovery of high-viscosity crude oil.

[0018] Beneficial effects: Compared with the prior art, the present invention has the following significant advantages: The composite material prepared by this invention exhibits high adsorption capacity and rapid separation effect for high viscosity crude oil during oil-water separation. At the same time, it achieves efficient heat energy storage and release in solar thermal management, with significant environmental and economic benefits. Compared with melamine sponge, the thermal conductivity of C / PDMS / LA@MS prepared by this invention is increased by 125.1%.

[0019] This invention utilizes waste banana peels to prepare porous biocarbon materials, achieving efficient utilization of waste. During the preparation process, the banana peels undergo high-temperature carbonization and chemical activation, transforming them into biomass-derived carbon materials with high specific surface area and porous structure. This provides a high-performance substrate for subsequent composite material preparation. This carbon material can synergistically enhance the heat conversion and utilization efficiency of the composite material with lauric acid, effectively reducing crude oil viscosity and improving the crude oil adsorption and recovery performance of the composite material. The C / PDMS / LA@MS composite material prepared in this invention possesses excellent photothermal conversion and thermal energy storage capabilities. Under sunlight, this material can rapidly convert solar energy into thermal energy, reducing crude oil viscosity. Simultaneously, the latent heat stored in the phase change material can regulate the system temperature. This significantly improves the adsorption efficiency for high-viscosity crude oil, solving the problem of low efficiency of traditional adsorbents in treating high-viscosity crude oil. By impregnating C / PDMS@MS sponges with lauric acid, the prepared composite material not only efficiently adsorbs oil but also optimizes the adsorption process through photothermal conversion and thermal energy storage, making it outstanding in handling high-viscosity crude oil spills.

[0020] The C / PDMS@MS sponge prepared in this invention inherits the high adsorption performance of porous biochar and enhances the material's mechanical stability and hydrophobicity through the introduction of PDMS. In oil-water separation applications, this composite material exhibits higher efficiency and selectivity. Specifically, by combining porous biochar with PDMS, the prepared C / PDMS@MS sponge not only possesses excellent adsorption capacity but also efficiently adsorbs oil in various oil-water mixtures while preventing water from entering the porous composite material. This effect significantly enhances the application potential of composite porous materials in the field of oil-water separation, enabling more effective treatment of oily wastewater in practical operations. Attached Figure Description

[0021] Figure 1 XRD images of C, LA, MS, C / PDMS@MS and C / PDMS / LA@MS materials prepared in Example 1; Figure 2 The image shows a scanning electron microscope (SEM) image of the C / PDMS / LA@MS material prepared in Example 1. Figure 3 Water contact angle diagram of C / PDMS / LA@MS prepared in Example 1; Figure 4 The image shows the adsorption and release mass of crude oil using C / PDMS / LA@MS prepared in Example 1. Figure 5 The graphs show the photothermal conversion performance of the C / PDMS@MS sponge and C / PDMS / LA@MS composite phase change material prepared in Example 1 before oil absorption and after 5 cycles. Detailed Implementation

[0022] The technical solution of the present invention will be further described below with reference to the accompanying drawings.

[0023] Example 1: A method for preparing an oleophilic and hydrophobic sponge material is as follows: (1) Fresh banana peels were cut into small pieces and dried in an oven at 60°C for 24 h to ensure complete dehydration. The dried banana peels were then pulverized into fine powder using a laboratory grinder. The pulverized powder was transferred to a ceramic boat and placed in a tube furnace. The furnace was heated to 450°C at a heating rate of 5°C / min under a nitrogen atmosphere and held for 2 h to obtain the carbonized product. After cooling, the carbonized product was ground into powder. 2 g of the carbonized product was weighed and placed in a mortar. 2 g of potassium hydroxide (KOH) solid and 25 mL of water were added and thoroughly mixed. The mixture was transferred back to the ceramic boat and placed in a tube furnace again. The furnace was heated to 650°C at a heating rate of 5°C / min under a nitrogen atmosphere and held for 2 h. After the reaction was completed, the product was washed with 1 mol / L hydrochloric acid aqueous solution until acidic to remove residual KOH and impurities. Finally, the product was dried and collected to obtain biomass-derived carbon, labeled as C.

[0024] (2) The purchased (specific surface area 154 m²) 2 Melamine sponge (MS) with an average pore size of 60 μm (g) was ultrasonically cleaned multiple times with alcohol and water, each time for 10 min, to ensure the sponge surface was clean and free of impurities. The cleaned sponge was then dried in an oven at 60°C for later use. 0.1 g of C powder was uniformly dispersed in 10 mL of polydimethylsiloxane (PDMS) solution (prepared by dissolving 4 g of PDMS in 100 mL of n-hexane), and ultrasonically treated for 10 min to ensure uniform dispersion of the C powder in the PDMS solution, forming a homogeneous C / PDMS suspension. A 1.5 cm × 1.5 cm × 1.5 cm melamine sponge was immersed in the C / PDMS suspension and ultrasonically treated again for 10 min to ensure full absorption of the C / PDMS suspension. Subsequently, the sponge was repeatedly squeezed to ensure the sponge skeleton was fully coated with C powder. The treated sponge was dried in an oven at 60°C for 12 h to remove excess organic solvent and moisture, thus successfully preparing the C / PDMS@MS sponge. (3) Heat an appropriate amount of lauric acid (LA) in an oven at 80°C until it is completely melted, ensuring that the lauric acid is completely converted into a liquid state. Immerse the prepared C / PDMS@MS sponge completely in the molten liquid lauric acid and impregnate it under vacuum for 12 hours to ensure that the sponge fully adsorbs lauric acid to a saturated state. After impregnation with lauric acid, remove the sponge, place it on filter paper, and transfer it to a vacuum drying oven at 80°C to stand for 2 hours to remove excess lauric acid. Remove the C / PDMS@MS sponge, and at room temperature, before the lauric acid solidifies, evenly drip the C / PDMS suspension onto the entire outer surface of the C / PDMS@MS sponge to seal the large pores on the outer surface of the frame and prevent the lauric acid from leaking during subsequent use. The final composite material obtained after drying and solidification is labeled as C / PDMS / LA@MS.

[0025] XRD analysis was performed on LA, MS, and the C, C / PDMS@MS, and C / PDMS / LA@MS materials prepared by the above method. The results are as follows: Figure 1 As shown, MS is at 3314 cm⁻¹ -1 The peak at 1460 cm⁻¹ is attributed to the NH stretching vibration in melamine sponge. -1 1324 cm -1 and 981 cm -1 The peak represents the bending vibration of CH. 1539 cm⁻¹ -1 1152 cm -1 and 805 cm -1 The peak values ​​at 2954 cm⁻¹ belong to C=N stretching vibration, CO stretching vibration, and S-triazine ring bending vibration, respectively. C / LA / PDMS@MS at 2954 cm⁻¹ -1 2914 cm -1 2849 cm -1 1302 cm -1 723 cm -1 and 682 cm -1 A series of absorption peaks appear at 1693 cm⁻¹, indicating stretching and bending of the alkyl chain CH. -1 Location, 1473 cm -1 There are a series of absorption peaks at 1430 cm⁻¹ that are due to the stretching of C=O. -1 and 937 cm -1 The absorption peaks at 1067 cm⁻¹ represent the stretching and bending vibrations of C-OH in its infrared spectrum. These absorption peaks all belong to LA, indicating successful LA encapsulation. -1 This corresponds to the stretching vibration peak of C or COC at 1254 cm⁻¹. -1 and 792 cm -1 The absorption peaks at the point are caused by the bending vibrations of Si-CH3 and Si-O, and these absorption peaks indicate the successful grafting of PDMS.

[0026] The prepared C / PDMS / LA@MS material was subjected to SEM and water contact angle testing. The results are as follows: Figure 2 and Figure 3As shown, MS exhibits a connected three-dimensional network structure with high porosity, providing ample space for crude oil storage. Magnified images reveal a smooth surface structure of the melamine sponge skeleton. In C / PDMS@MS and C / PDMS / LA@MS sponges, C coats the MS framework, increasing the sponge's roughness and mechanical strength, which is beneficial for capillary forces encapsulating PDMS and LA. Furthermore, PDMS and LA act as binders, uniformly loading C onto the sponge fiber skeleton. It can be clearly observed that LA and PDMS are uniformly coated on the MS surface, resulting in a black composite sponge. This not only improves photothermal conversion capabilities but also enhances the sponge's roughness and specific surface area. The good combination of MS and C also better maintains the shape stability of the composite sponge during phase transition. Importantly, the composite sponges C / PDMS@MS and C / PDMS / LA@MS retain a good porous structure, providing possibilities for subsequent crude oil adsorption. Additionally, thanks to the excellent hydrophobicity of LA, the water contact angle of C / PDMS / LA@MS increases to 147.8°. Characterization results showed that the oil contact angle of all samples was almost 0°, proving that the modified sponge in this study was selective for oil and water.

[0027] Example 2: A method for preparing an oleophilic and hydrophobic sponge material is as follows: (1) The dried banana peel powder was transferred to a porcelain boat and placed in a tube furnace. Under a nitrogen atmosphere, the mixture was heated to 400°C at a heating rate of 3°C / min and held for 3 hours to obtain the carbonized product. After cooling, the carbonized product was ground into powder. 2g of the carbonized product was weighed and placed in a mortar, along with 3g of NaOH solid and 25mL of water. The mixture was stirred thoroughly. The mixture was then transferred back to the porcelain boat and placed in the tube furnace again. Under a nitrogen atmosphere, the mixture was heated to 600°C at a heating rate of 3°C / min and held for 3 hours. After the reaction was complete, the product was washed with a 1mol / L hydrochloric acid aqueous solution until acidic. Finally, the product was dried and collected to obtain biomass-derived carbon.

[0028] (2) Purchased (specific surface area 200 m²) 2Melamine sponge (MS) with an average pore size of 40 μm (g / g) was ultrasonically cleaned multiple times with alcohol and water, each time for 10 min, to ensure the sponge surface was clean and free of impurities. The cleaned sponge was then dried in an oven at 60°C for later use. 0.05 g of biomass-derived carbon powder was uniformly dispersed in 100 mL of a 0.1 g / mL polydimethylsiloxane solution in n-pentane and ultrasonically treated for 10 min to form a homogeneous C / PDMS suspension. A 1.5 cm × 1.5 cm × 1.5 cm melamine sponge was immersed in the C / PDMS suspension and ultrasonically treated again for 10 min to ensure full absorption of the C / PDMS suspension. Subsequently, the sponge was repeatedly squeezed to ensure the sponge skeleton was fully coated with biomass-derived carbon powder. The treated sponge was dried in an oven at 60°C for 12 h to remove excess organic solvents and moisture, thus successfully preparing the C / PDMS@MS sponge. (3) Heat an appropriate amount of lauric acid (LA) in a 90°C oven until it is completely melted, ensuring that the lauric acid is completely converted into a liquid state. Immerse the prepared C / PDMS@MS sponge completely in the molten liquid lauric acid and impregnate it under vacuum for 6 hours. After impregnation with lauric acid, remove the sponge, place it on filter paper, and transfer it to a 90°C vacuum drying oven to stand for 4 hours. Remove the C / PDMS@MS sponge, and at room temperature, before the lauric acid solidifies, evenly drop the C / PDMS suspension onto the entire outer surface of the C / PDMS@MS sponge to seal the large pores on the outer surface of the frame. After drying and solidification, the final composite material is labeled as C / PDMS / LA@MS.

[0029] Example 3: A method for preparing an oleophilic and hydrophobic sponge material is as follows: (1) The dried banana peel powder was transferred to a porcelain boat and placed in a tube furnace. Under a nitrogen atmosphere, the mixture was heated to 500°C at a heating rate of 7°C / min and held for 1 hour to obtain the carbonized product. After cooling, the carbonized product was ground into powder. 2g of the carbonized product was weighed and placed in a mortar, along with 1.5g of KOH solid and 25mL of water. The mixture was stirred thoroughly. The mixture was then transferred back to the porcelain boat and placed in the tube furnace again. Under a nitrogen atmosphere, the mixture was heated to 700°C at a heating rate of 7°C / min and held for 1 hour. After the reaction was complete, the product was washed with a 1 mol / L hydrochloric acid aqueous solution until acidic. Finally, the product was dried and collected to obtain biomass-derived carbon.

[0030] (2) Purchased (specific surface area 100 m²) 2Melamine sponge (MS) with an average pore size of 80 μm (g / g) was ultrasonically cleaned multiple times with alcohol and water, each time for 10 min, to ensure the sponge surface was clean and free of impurities. The cleaned sponge was then dried in an oven at 60°C for later use. 0.01 g of biomass-derived carbon powder was uniformly dispersed in 10 mL of a 0.01 g / mL polydimethylsiloxane solution in n-heptane and ultrasonically treated for 10 min to form a homogeneous C / PDMS suspension. A 1.5 cm × 1.5 cm × 1.5 cm melamine sponge was immersed in sufficient C / PDMS suspension and ultrasonically treated again for 10 min to ensure full absorption of the C / PDMS suspension. Subsequently, the sponge was repeatedly squeezed to ensure the sponge skeleton was fully coated with biomass-derived carbon powder. The treated sponge was dried in an oven at 60°C for 12 h to remove excess organic solvents and moisture, thus successfully preparing the C / PDMS@MS sponge. (3) Heat an appropriate amount of lauric acid (LA) in an oven at 80°C until it is completely melted, ensuring that the lauric acid is completely converted into a liquid state. Immerse the prepared C / PDMS@MS sponge completely in the molten liquid lauric acid and impregnate it under vacuum for 24 hours. After the lauric acid impregnation is completed, remove the sponge, place it on filter paper, and transfer it to a vacuum drying oven at 80°C to stand for 3 hours. Remove the C / PDMS@MS sponge, and at room temperature, before the lauric acid solidifies, evenly drop the C / PDMS suspension onto the entire outer surface of the C / PDMS@MS sponge. After drying and solidification, the final composite material is labeled as C / PDMS / LA@MS.

[0031] Comparative Example 1: Everything else is the same as in Example 1, except that: Replace lauric acid with polyethylene glycol-200.

[0032] Comparative Example 2: Everything else is the same as in Example 1, except that: Replace lauric acid with paraffin.

[0033] Comparative Example 3: Everything else is the same as in Example 1, except that: Replace lauric acid with sorbitan monolaurate-40.

[0034] Comparative Example 4: Everything else is the same as in Example 1, except that: Replace banana peels with orange peels. Comparative Example 5: Everything else is the same as in Example 1, except that: In step (2), C powder is replaced with graphite powder.

[0035] Comparative Example 6: Everything else is the same as in Example 1, except that: Replace PDMS with polyvinylpyrrolidone.

[0036] Comparative Example 7: Everything else is the same as in Example 1, except that: In step (2), C powder is not added, and PDMS solution is used for impregnation directly.

[0037] The composite porous materials prepared in Examples 1-3 and Comparative Examples 1-7 were tested for their adsorption and recovery performance on high-viscosity crude oil, using the following methods: To evaluate the adsorption efficiency of the material for high-viscosity crude oil, the initial mass m0 of the material was first recorded. Then, each composite porous material sample was immersed in high-viscosity crude oil (viscosity 46.1 mPa·s), air was expelled, and the sample was allowed to stand for 200 s to reach saturation adsorption. Afterward, the sample was removed and re-weighed to obtain m1. The oil absorption capacity (in grams per gram) was calculated using the formula Q = (m1 - m0) / m0. Crude oil in the porous composite material samples was recovered by compression (mechanical compression). When external force was applied, crude oil could be squeezed out of the sponge. With increasing pressure and time, the amount of collected crude oil increased, and most of the crude oil adsorbed by the composite sponge could be recovered. The composite porous material was compressed to 60% of its indented sponge volume for 5 minutes.

[0038] Before each immersion in crude oil, each composite porous material sample was either irradiated with a 200W xenon lamp for 200 seconds or pretreated in the dark. The oil absorption and release amounts of the irradiated and dark-protected composite porous material samples were measured for the first adsorption and release, and after three cycles of adsorption and release. The test results are as follows: Table 1. Crude oil adsorption / release performance of different composite porous material samples under light-illuminated or light-protected conditions.

[0039] As shown in Table 1, under illumination, the crude oil adsorption and release performance of Comparative Examples 1-3 and the C / PDMS@MS sponge group was significantly lower than that of Example 1. However, under light-shielded conditions, there was no difference in crude oil adsorption and release performance. This indicates that only lauric acid in the organic PCM can effectively store and slowly release latent heat in the composite system to reduce the viscosity of crude oil, thereby significantly improving the crude oil adsorption and release performance of the composite system. PEG, paraffin, and laurate esters do not possess this ability. Under illumination, the crude oil adsorption and release performance of Comparative Examples 4 and 5 was also significantly lower than that of Example 1. This indicates that although all are carbon materials, only biomass-derived carbon from banana peels has a good photothermal conversion effect in the composite system. Graphite particles or other biomass-derived carbon cannot exert good photothermal conversion performance in the PDMS and lauric acid system, thus failing to efficiently adsorb and release high-viscosity crude oil. Comparative Example 7 shows that the entire composite system relies on biomass-derived carbon to exert photothermal conversion performance and generate heat. In the absence of biomass-derived carbon, the temperature of the entire composite system cannot rise, thus failing to reduce the viscosity of crude oil, resulting in poor adsorption and release of high-viscosity crude oil.

[0040] Under illumination, the crude oil adsorption-release cycle test was performed on the C / PDMS / LA@MS material prepared in Example 1. The results are as follows: Figure 4 As shown, C / PDMS / LA@MS has excellent photothermal conversion performance and has a high adsorption capacity for high-viscosity crude oil under solar irradiation, with an adsorption capacity of 3.2 g. However, after 5 cycles, due to the increasing amount of residual crude oil inside, the adsorption and release of oil both decreased, but the adsorption capacity was still 2.4 g.

[0041] The photothermal conversion performance of the C / PDMS@MS sponge, C / PDMS / LA@MS composite phase change material (before the first adsorption and after 5 cycles), C, LA, MS from Example 1, and composite phase change materials prepared in each comparative example were tested respectively, using the following methods: Different samples were placed under a xenon lamp simulating sunlight to study their photothermal conversion capacity, and the temperature change over time was recorded using an infrared thermal imager. A temperature of 1.0 kW / m² was recorded. 2 Temperature at the top of C / PDMS@MS and C / PDMS / LA@MS under illumination intensity (1 sun).

[0042] The results are as follows Figure 5 As shown, Figure 5In the diagram, "Light on" represents the sunlight exposure stage, and "Light off" represents the light-shielded stage. After 5 cycles, the thermal storage performance of C / PDMS / LA@MS decreased with increasing cycle number because a small amount of LA was squeezed out along with the crude oil in each cycle. Notably, after 5 cycles, the heat retention capacity of C / PDMS / LA@MS was still superior to that of C / PDMS@MS, demonstrating that C / PDMS / LA@MS still possesses exothermic capabilities after 5 repeated cycles. The photothermal conversion performance of the composite phase change materials prepared in Comparative Examples 1-7 was significantly inferior to that of Example 1.

Claims

1. An oleophilic hydrophobic sponge material, characterized in that, The hydrophobic sponge material comprises a sponge and a carbon-containing hydrophobic film layer coated on the sponge framework, wherein the carbon-containing hydrophobic film layer is coated with lauric acid and is composed of biomass-derived carbon and polydimethylsiloxane.

2. The oleophilic hydrophobic sponge material of claim 1, wherein, The biomass-derived carbon is a carbonization product of banana peel, and the sponge is a melamine sponge having a specific surface area of 100-200 m 2 / g and a pore size of 25-100 μm.

3. The method for preparing the lipophilic hydrophobic sponge material according to claim 1 or 2, comprising the following steps: (1) carbonizing dry banana peel powder under an inert atmosphere to obtain a first product; (2) dispersing the first product in a strong alkaline aqueous solution to obtain a dispersion, heating and calcining the dispersion to obtain a second product, and obtaining biomass-derived carbon after acid washing the second product; (3) dispersing the biomass-derived carbon in a polydimethylsiloxane solution to obtain a carbon powder suspension, immersing a sponge in the carbon powder suspension, taking out the sponge after sufficient exhaust impregnation, and drying the sponge to obtain a sponge intermediate; (4) immersing the sponge intermediate in liquid lauric acid, taking out the sponge intermediate after vacuum impregnation, removing excess lauric acid from the sponge intermediate, and evenly applying the carbon powder suspension to the outer surface of the sponge intermediate at room temperature before the lauric acid solidifies, and drying and solidifying to obtain the lipophilic hydrophobic sponge material.

4. The method of claim 3, wherein the lipophilic hydrophobic sponge material is prepared by the steps of: In step (1), the carbonization conditions are heating at 3-7 ℃ / min to 400-500 ℃ for 1-3 h.

5. The method for preparing the oleophilic and hydrophobic sponge material according to claim 3, characterized in that, In step (2), the strong alkaline aqueous solution is a 1-2 M KOH or NaOH aqueous solution; and the method for heating and calcining the dispersion is heating the dispersion at 3-7 ℃ / min to 600-700 ℃ for 1-3 h under an inert atmosphere.

6. The method of claim 3, wherein the lipophilic hydrophobic sponge material is prepared by the steps of: In step (2), the acid washing method is washing the second product to be acidic with a 0.5-1.5 M hydrochloric acid aqueous solution.

7. The method for preparing the oleophilic and hydrophobic sponge material according to claim 3, characterized in that, In step (3), The solid-liquid ratio of the biomass-derived carbon to the polydimethylsiloxane solution is 0.01-1 g:1-100 mL, and the polydimethylsiloxane solution is a saturated alkane solution of polydimethylsiloxane with a concentration of 0.01-0.1 g / mL.

8. The method of claim 7, wherein the lipophilic hydrophobic sponge material is prepared by the steps of: The saturated alkane includes at least one of butane, pentane, hexane, and heptane.

9. The method for preparing the oleophilic and hydrophobic sponge material according to claim 3, characterized in that, In step (4), the temperature of the liquid lauric acid is 80-90 ℃, the vacuum impregnation time is at least 6 h, and the drying and solidification time is at least 3 h.

10. The lipophilic hydrophobic sponge material according to claim 1 or 2 for use in the adsorption and recovery of high-viscosity crude oil.

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