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

Abstract

The invention discloses a preparation method of magnetic oil-absorbing resin based on a high internal phase emulsion template. The preparation method comprises the following steps: firstly, adding a certain amount of magnetic nanoparticles, an initiator and a surfactant into a solution containing a monomer, a cross-linking agent and a pore-foaming agent, fully and uniformly mixing to obtain an oil phase, slowly dropwise adding a calcium chloride aqueous solution into the oil phase under a mechanical stirring condition to obtain a water-in-oil type high internal phase emulsion, and carrying out ultrasonic dispersion on the water-in-oil type high internal phase emulsion. And then carrying out polymerization reaction at 70 DEG C for about 24 hours, carrying out Soxhlet extraction by using absolute ethyl alcohol, and carrying out vacuum drying to obtain the magnetic oil-absorbing resin. By adjusting the content of the magnetic nanoparticles, the pore structure and the oil absorption performance of the magnetic oil absorption resin are optimized, a series of magnetic oil absorption resins are prepared, and the oil absorption performance, the magnetic responsiveness and the recycling performance are good.

Description

Technical Field

[0001] The invention belongs to the technical field of polymer material preparation, and in particular relates to a method for preparing a magnetic oil-absorbing resin based on a high internal phase emulsion template. Background Art

[0002] As global oil production, transportation and consumption continue to grow, oil spills and oily wastewater discharges greatly threaten and affect the sustainable development of the ecological environment and the marine economy. Therefore, it is crucial to develop effective technologies for removing oily pollutants from wastewater. Among various separation methods, physical adsorption based on oil-absorbing materials has the advantages of simple operation, low cost and high efficiency, and is considered to be an efficient method for separating oil-water mixtures. The hydrophobic and oleophilic surface and porous structure skeleton are necessary conditions for the preparation of efficient oil-absorbing materials.

[0003] The water-in-oil high internal phase emulsion template method is a simple and effective method for preparing hydrophobic porous materials. The method is simple to operate, and the prepared materials have advantages such as hierarchical porous structure and high porosity, which has great advantages in 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 great advantages not only in accelerating the efficiency of oil-water separation, but also in targeting the collection of oil or organic solvents. Therefore, it is more advantageous and advantageous to design "smart absorbents" for oil-water separation. Among them, magnetically responsive smart materials have attracted great attention. Because they can be easily guided to a contaminated area and collected by using an external magnetic field. For example, metal nickel was successfully loaded on a sponge containing polydopamine on the surface by chemical deposition, and the prepared material has effective magnetic responsiveness. This magnetic sponge floating on water can be easily separated and controlled to move to a designated contaminated area under the action of an external magnetic field.

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

[0006] The object of the present invention is to provide a method for preparing a magnetic oil-absorbing resin based on a high internal phase emulsion template in view of the deficiencies of the prior art. The micro-nano particles ZnFe2O4 in the present invention can stabilize the high internal phase emulsion, and the ZnFe2O4 magnetic nanoparticles are added to the continuous phase to prepare a magnetic oil-absorbing resin with a connected porous structure through high internal phase emulsion polymerization. By adjusting the content of the magnetic nanoparticles, the pore structure and oil absorption performance of the material can be optimized.

[0007] The objective of the present invention is achieved through the following technical solutions: A method for preparing a magnetic oil-absorbing resin based on a high internal phase emulsion template specifically comprises the following steps: (1) A certain amount of magnetic nanoparticles, initiator AIBN and surfactant Span80 are added to a solution containing monomers, crosslinking agent divinylbenzene (DVB) and porogen, and the mixture is fully mixed to obtain an oil phase. Then, a calcium chloride aqueous solution is slowly added dropwise to the oil phase under mechanical stirring to obtain an oil-in-water type high internal phase emulsion; (2) The high internal phase emulsion obtained in step (1) is sealed and subjected to polymerization reaction at 70° C. for 24 hours to obtain a crude product. After Soxhlet extraction with anhydrous ethanol and vacuum drying, a hydrophobic porous composite material is obtained, which is the magnetic oil-absorbing resin.

[0008] The magnetic nanoparticles described in step (1) are ZnFe2O4, and their diameter is 100-500 nanometers. The amount of magnetic nanoparticles added is 5% to 20% of the total mass of the monomer and the cross-linking agent, preferably 10%.

[0009] The monomer described in step (1) is a styrene monomer such as styrene or 4-tert-butylstyrene.

[0010] The molar ratio of the comonomer to the crosslinking agent in step (1) is 3:1.

[0011] The porogen in step (1) is toluene.

[0012] The beneficial effects of the present invention are: (1) The present 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 the method have stable physical and chemical properties and suitable wettability. On the one hand, they can be used as an auxiliary stabilizer for the high internal phase emulsion to reduce the amount of surfactant used. At the same time, they can give the material magnetism, which is convenient for guiding and positioning during the oil absorption process and enrichment and separation after oil absorption.

[0013] (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. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 SEM image of magnetic nanoparticles ZnFe2O4; Figure 2 The SEM images of Examples 1-3 and Comparative Example: (a1, a2) Comparative Example; (b1, b2) Example 1; (c1, c2) Example 2 and (d1, d2) Example 3, show the interconnected porous structure of the magnetic oil-absorbing resin.

[0015] Figure 3 XRD patterns of Examples 1-3 and Comparative Example: The characteristic peak of ZnFe2O4 appears in the spectrum of magnetic oil-absorbing resin, and the intensity of the characteristic peak increases with the increasing amount of ZnFe2O4.

[0016] Figure 4 Hysteresis loop diagram of Examples 1 to 3. The saturation magnetic properties of the composite material increase with the addition of ZnFe2O4, proving that the addition of ZnFe2O4 particles can give the material better magnetic responsiveness.

[0017] 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 water bottom (both oils were stained with Sudan II for clear observation); Figure 6 The n-hexane droplet was cleaned using magnetic guidance Example 2, indicating that magnetic responsiveness can be used for guided positioning. DETAILED DESCRIPTION

[0018] The present invention is further described below in conjunction with specific embodiments, but the present invention is not limited to these embodiments.

[0019] Example 1 A certain amount of ZnFe2O4 particles, 0.015 g of initiator AIBN and 0.15 g of surfactant Span 80 were dispersed into a solution containing a hydrophobic monomer 4-tert-butylstyrene. tBS (0.39 g), crosslinker DVB (0.11 g) and porogen toluene (0.5 ml) were added to the oil phase (ZnFe2O4 was added in an amount of 5% of the total mass of the monomer and crosslinker), and then ultrasonically dispersed and transferred to a 50 mL two-necked flask equipped with a stirrer. 30 ml of 10% calcium chloride aqueous solution was slowly added to the two-necked flask under stirring as the dispersed phase. After the addition was completed, stirring was continued for 1.5 h to form a viscous emulsion. The high internal phase emulsion was placed in an oven and polymerized at 70 ° C for 24 h. Soxhlet extraction was performed with anhydrous ethanol to remove the residual surfactant and unreacted monomer in 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 and 88 g / g for n-hexane and dichloromethane, respectively.

[0020] Example 2: The specific experimental steps are the same as those in Example 1. The amount of ZnFe2O4 added to the oil phase is 10% of the total mass of the monomer and the crosslinker. The contact angle is 152°, and the adsorption amounts for n-hexane and dichloromethane are 36 g / g and 80 g / g, respectively.

[0021] Example 3: The specific experimental steps are the same as those in Example 1. The amount of ZnFe2O4 added to the oil phase is 20% of the total mass of the monomer and the crosslinker. The contact angle is 146°, and the adsorption amounts for n-hexane and dichloromethane are 33 g / g and 71 g / g, respectively.

[0022] Comparative Example 1: The specific experimental steps are the same as those in Example 1, except that no ZnFe2O4 magnetic nanoparticles are added to the oil phase. The contact angle is 140°, and the adsorption amounts of n-hexane and dichloromethane are 52 g / g and 99 g / g, respectively.

[0023] Taking into account the oil absorption performance and magnetic strength of the material, the appropriate addition amount of ZnFe2O4 is 10% of the total mass of the monomer and cross-linking agent.

[0024] The above description is only a preferred embodiment of the present invention. All equivalent changes and modifications made according to the scope of the patent application of the present invention should fall within 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: The steps include: (1) A certain amount of magnetic nanoparticles, initiator AIBN and surfactant Span80 are added to a solution containing monomers, crosslinking agent divinylbenzene and porogen, and the mixture is fully mixed to obtain an oil phase. Then, a calcium chloride aqueous solution is slowly added dropwise to the oil phase under mechanical stirring to obtain an oil-in-water type high internal phase emulsion; (2) The high internal phase emulsion obtained in step (1) is sealed and subjected to polymerization reaction at 70°C for a certain period of time to obtain a crude product, which is then subjected to Soxhlet extraction with anhydrous ethanol and vacuum drying to obtain a magnetic oil-absorbing resin.

2. The method for preparing a magnetic oil-absorbing resin based on a high internal phase emulsion template according to claim 1, characterized in that: The magnetic nanoparticles described in step (1) are ZnFe2O4, and their diameter is 100-500 nanometers.

3. The method for preparing a magnetic oil-absorbing resin based on a high internal phase emulsion template according to claim 2, characterized in that: The added amount of magnetic nanoparticles ZnFe2O4 is 5% to 20% of the total mass of the monomer and the cross-linking agent.

4. The method for preparing a magnetic oil-absorbing resin based on a high internal phase emulsion template according to claim 2, characterized in that: The monomer described in step (1) is styrene or 4-tert-butylstyrene.

5. The method for preparing a magnetic oil-absorbing resin based on a high internal phase emulsion template according to claim 1, characterized in that: The molar ratio of the monomer to the cross-linking agent in step (1) is 3:

1.

6. The method for preparing a magnetic oil-absorbing resin based on a high internal phase emulsion template according to claim 1, characterized in that: The porogen in step (1) is toluene.

7. The method for preparing a magnetic oil-absorbing resin based on a high internal phase emulsion template according to claim 1, characterized in that: The polymerization reaction time in step (2) is 24 hours.

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