Preparation method of magnetic oil-absorbing resin based on high internal phase emulsion template

Abstract

The application discloses a preparation method of a magnetic oil-absorbing resin based on a high internal phase emulsion template. First, a certain amount of magnetic nanoparticles, an initiator and a surfactant are added into a solution containing monomers, a crosslinking agent and a pore-forming agent, and after being uniformly mixed, an oil phase is obtained; then, under mechanical stirring, a calcium chloride aqueous solution is slowly added into the oil phase to obtain a water-in-oil high internal phase emulsion; then, a polymerization reaction is carried out at 70 DEG C for about 24 hours; after being extracted by anhydrous ethanol by means of a Soxhlet extractor and vacuum dried, the magnetic oil-absorbing resin is obtained. By adjusting the content of the magnetic nanoparticles, the pore structure and oil-absorbing performance of the magnetic oil-absorbing resin are optimized, and a series of magnetic oil-absorbing resins are prepared, which exhibit good oil-absorbing performance, magnetic response and recycling performance.

Description

Technical Field

[0001] This invention belongs to the field of polymer material preparation technology, specifically relating to a method for preparing a magnetic oil-absorbing resin based on a high internal phase emulsion template. Background Technology

[0002] With the continued growth of global oil extraction, transportation, and consumption, oil spills and oily wastewater discharges pose a significant threat to the sustainable development of the ecological environment and marine economy. Therefore, developing effective technologies for removing oily pollutants from wastewater is crucial. Among various separation methods, physical adsorption based on oil-absorbing materials is considered a highly efficient method for separating oil-water mixtures due to its advantages of simple operation, low cost, and high efficiency. Hydrophobic and oleophilic surfaces, as well as porous frameworks, are essential conditions for preparing highly efficient oil-absorbing materials.

[0003] The water-in-oil emulsion template method is a simple and effective approach for preparing hydrophobic porous materials. This method is easy to operate, and the prepared materials possess advantages such as hierarchical porous structure and high porosity, making it particularly advantageous for preparing porous materials, especially oil-absorbing resins.

[0004] Smart oil-absorbing materials that respond to external stimuli (such as pH, electricity, photons, heat, or magnetic input) show significant advantages not only in accelerating oil-water separation efficiency but also in collecting oil or organic solvents. Therefore, designing "smart absorbents" for oil-water separation is highly advantageous. Among these, magnetically responsive smart materials have attracted considerable attention because they are easily guided to a contaminated area and collected using an external magnetic field. For example, nickel was successfully loaded onto a polydopamine-containing sponge via chemical deposition, resulting in a material with effective magnetic responsiveness. This magnetic sponge, floating on water, can be easily separated and controlled to move to a designated contaminated area under the influence of an external magnetic field.

[0005] This invention adds magnetic nanoparticles ZnFe2O4 to a continuous phase containing 4-tert-butylstyrene (tBS), divinylbenzene (DVB), and toluene, and then ultrasonically disperses the ZnFe2O4 solid particles to form a uniform continuous phase. Subsequently, a ZnFe2O4 / porous polymer composite oil-absorbing material with good magnetic responsiveness is prepared by a high internal phase emulsion template method. Summary of the Invention

[0006] The purpose of this invention is to address the shortcomings of existing technologies by providing a method for preparing a magnetic oil-absorbing resin based on a high internal phase emulsion template. The micro / nano particles ZnFe2O4 in this invention can stabilize the high internal phase emulsion. By adding ZnFe2O4 magnetic nanoparticles to the continuous phase, a magnetic oil-absorbing resin with a connected porous structure is prepared through high internal phase emulsion polymerization. The pore structure and oil-absorbing properties of the material are optimized by adjusting the content of the magnetic nanoparticles.

[0007] The objective of this invention is achieved through the following technical solution:

[0008] A method for preparing a magnetic oil-absorbing resin based on a high internal phase emulsion template specifically includes the following steps:

[0009] (1) A certain amount of magnetic nanoparticles, initiator AIBN and surfactant Span80 are added to a solution containing monomer, crosslinking agent divinylbenzene (DVB) and pore-forming agent. After thorough mixing, an oil phase is obtained. Then, calcium chloride aqueous solution is slowly added to the oil phase under mechanical stirring to obtain a water-in-oil emulsion with high internal phase.

[0010] (2) After sealing the high internal phase emulsion obtained in step (1), the crude product was obtained after polymerization at 70 °C for 24 hours. After Soxhlet extraction with anhydrous ethanol and vacuum drying, the hydrophobic porous composite material was obtained, which is the magnetic oil-absorbing resin.

[0011] The magnetic nanoparticles mentioned in step (1) are ZnFe2O4 with a diameter of 100-500 nanometers. The amount of magnetic nanoparticles added is 5% to 20% of the total mass of monomers and crosslinking agents, preferably 10%.

[0012] The monomer mentioned in step (1) is styrene or 4-tert-butylstyrene or other styrene monomers.

[0013] The molar ratio of the comonomer to the crosslinking agent in step (1) is 3:1.

[0014] The porogen mentioned in step (1) is toluene.

[0015] The beneficial effects of this invention are as follows:

[0016] (1) This invention develops a method for preparing a magnetic oil-absorbing resin based on a high internal phase emulsion template. The ZnFe2O4 magnetic nanoparticles selected in this method have stable physicochemical properties and suitable wettability. On the one hand, they can be used as an auxiliary stabilizer for high internal phase emulsions to reduce the amount of surfactant. On the other hand, they can impart magnetism to the material, which facilitates the guiding and positioning during the oil absorption process and the enrichment and separation after oil absorption.

[0017] (2) The addition of magnetic nanoparticles can also adjust the pore size and surface hydrophobicity of the oil-absorbing material, thereby promoting the oil absorption process. Attached Figure Description

[0018] Figure 1 SEM image of magnetic ZnFe2O4 nanoparticles;

[0019] Figure 2 SEM images of Examples 1-3 and Comparative Examples: (a1, a2) Comparative Example; (b1, b2) Example 1; (c1, c2) Example 2 and (d1, d2) Example 3, showing the interconnected porous structure of the magnetic oil-absorbing resin.

[0020] Figure 3 XRD patterns of Examples 1-3 and the comparative example. Characteristic peaks of ZnFe2O4 appeared in the magnetic oil-absorbing resin spectrum, and the intensity of the characteristic peaks increased with the increasing amount of ZnFe2O4.

[0021] Figure 4 Hysteresis loop diagrams for Examples 1-3. The saturation magnetic properties of the composite material continuously increase with the addition of ZnFe2O4, demonstrating that the addition of ZnFe2O4 particles can give the material better magnetic responsiveness.

[0022] Figure 5 Actual oil-water separation diagram of Example 2: (a) Removal of ethyl acetate from the water surface; (b) Removal of dichloromethane from the bottom of the water (both oils were stained with Sudan II for clear observation);

[0023] Figure 6 Using magnetically guided Example 2 to clean n-hexane droplets demonstrates that they can be guided and positioned using magnetic responsiveness. Detailed Implementation

[0024] The present invention will be further described below with reference to specific embodiments, but the present invention is not limited to these embodiments.

[0025] Example 1

[0026] A certain amount of ZnFe2O4 particles, 0.015 g of initiator AIBN, and 0.15 g of surfactant Span 80 were dispersed in a solution containing the hydrophobic monomer 4-tert-butylstyrene. tZnFe2O4 was ultrasonically dispersed in an oil phase containing BS (0.39 g), crosslinking agent DVB (0.11 g), and pore-forming agent toluene (0.5 ml) (5% of the total mass of monomer and crosslinking agent). The mixture was then transferred to a 50 mL two-necked flask equipped with a stirrer. 30 ml of a 10% (w / w) calcium chloride aqueous solution was slowly added to the flask under stirring. After the addition was complete, stirring continued for 1.5 h to form a viscous emulsion. The emulsion was placed in an oven and polymerized at 70 °C for 24 h. Soxhlet extraction with anhydrous ethanol was performed to remove residual surfactants and unreacted monomers from the polymer. Finally, after vacuum drying overnight, ZnFe2O4 / polyHIPE porous oil-absorbing resin was obtained, with a contact angle of 151° and adsorption capacities of 45 g / g for hexane and 88 g / g for dichloromethane.

[0027] Example 2: The specific experimental steps are the same as in Example 1. The amount of ZnFe2O4 added in the oil phase is 10% of the total mass of monomer and crosslinking agent. The contact angle is 152°. The adsorption amounts of n-hexane and dichloromethane are 36 g / g and 80 g / g, respectively.

[0028] Example 3: The specific experimental steps are the same as in Example 1. The amount of ZnFe2O4 added in the oil phase is 20% of the total mass of monomer and crosslinking agent. The contact angle is 146°. The adsorption amounts of n-hexane and dichloromethane are 33 g / g and 71 g / g, respectively.

[0029] Comparative Example 1: The specific experimental steps were the same as in Example 1, but no ZnFe2O4 magnetic nanoparticles were added to the oil phase. The contact angle was 140°, and the adsorption capacities for n-hexane and dichloromethane were 52 g / g and 99 g / g, respectively.

[0030] Taking into account the oil absorption properties and magnetic strength of the material, the appropriate addition amount of ZnFe2O4 is 10% of the total mass of monomer and crosslinking agent.

[0031] The above description is only a preferred embodiment of the present invention. All equivalent changes and modifications made within the scope of the claims of the present invention should be included in the scope of the present invention.

Claims

1. A method for preparing a magnetic oil-absorbing resin based on a high internal phase emulsion template, characterized in that, Includes the following steps: (1) A certain amount of magnetic nanoparticles, initiator AIBN and surfactant Span80 are added to a solution containing monomer, crosslinking agent divinylbenzene and pore-forming agent toluene. After thorough mixing, an oil phase is obtained. Then, calcium chloride aqueous solution is slowly added to the oil phase under mechanical stirring to obtain a water-in-oil emulsion with high internal phase. (2) After sealing the high internal phase emulsion obtained in step (1), the crude product was obtained by polymerization reaction at 70 °C for 24 h. After Soxhlet extraction with anhydrous ethanol and vacuum drying, magnetic oil-absorbing resin was obtained. The magnetic nanoparticles mentioned in step (1) are ZnFe2O4 with a diameter of 100-500 nanometers; the amount of ZnFe2O4 magnetic nanoparticles added is 10% of the total mass of the monomer and crosslinking agent. The monomer mentioned in step (1) is styrene or 4-tert-butylstyrene; The molar ratio of monomer to crosslinking agent in step (1) is 3:1.

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