A kind of preparation method of the water-oil separating material with photothermal responseTechnical field
The present invention relates to water treatment field more particularly to a kind of preparation sides of the water-oil separating material with photothermal responseMethod.
Background technique
With the improvement of living standards with industrialized development, the yield of oily waste water increases year by year, seriously pollutesEnvironment.But traditional oily water separation technique such as adsorbs, is centrifuged often low separation efficiency, and operating process is complicated, easily occurs secondaryPollution.The development of membrane science technology is so that membrane separation technique is maximally efficient one of the method for current separation oily waste water, not onlySeparative efficiency is high, and easy to operate.And the more traditional film of nano fibrous membrane has bigger specific surface area, higher hole in recent yearsGap rate, has been applied in water-oil separating.
Although in the prior art it has been reported that the method for much preparing nanofiber water-oil separationg film, there are still divide, complex disposal process unstable from efficiency be easy to cause secondary pollution problems.Therefore, researcher further studies toolIt is controllable that condition may be implemented in the nano fibrous membrane of irritating responsiveness, such as humidity, temperature, pH, illumination under outside stimulusWater-oil separating.This controllable water-oil separationg film separates water-in-oil emulsion or water packet by the variation property of can choose of external conditionFat liquor, may be implemented the long-range control of processing Crude Oil at Sea incident of leakage, and can save consumables cost and reduce separationEnergy consumption.
It generally requires to be modified its surface using chemical method however, preparing this stimuli responsive material, introduces and ringGroup is answered, process flow is complicated, and it is expensive, seriously limit the development and application of this intellectual material.At the same time, greaseSeparation material often adheres to spot after separating for several times, influences separative efficiency, can only abandon or using complicated flushingEtc. technologies activation re-started to water-oil separating material, restore separative efficiency, process is extremely cumbersome.Therefore, using simple processWater-oil separating material is prepared, efficiently realizes water-oil separating, and the material has stimulating responsive, is occurred by responding its property, it can be achieved that function easy to clean, is conducive to reuse, this will provide a kind of thinking for the development of water-oil separating material for variation.
Summary of the invention
In view of this, in view of the drawbacks of the prior art and surface-functionalized complex process and material difficulty cleaning etc. askTopic, the invention proposes a kind of preparation methods of water-oil separating material with photothermal response, with acrylamide and acrylonitrileCopolymer be raw material, adulterate redox graphene, obtained by the method for electrostatic spinning with composite nano-fiber membrane knotThe water-oil separating material of structure.This method preparation process is simple and convenient, by the structure and itself and reduction-oxidation that control copolymerThe water-oil separating with good mechanical strength and sensitive photothermal response can be prepared in ratio of the graphene in spinning solutionMaterial can quickly and efficiently realize intelligent water-oil separating, and its property changes through response, and material is made to have easy cleaning, moreIt is secondary to maintain higher separative efficiency using remaining unchanged.
The specific technical proposal of the invention is: a kind of preparation method of the water-oil separating material with photothermal response,Be characterized in that the following steps are included:
1) copolymer of synthesis of acrylamide and acrylonitrile；
2) redox graphene is prepared；
3) copolymer and redox graphene are dissolved or is distributed in n,N-Dimethylformamide and obtain spinning solution, intoRow electrostatic spinning, electrospinning conditions are as follows: voltage 5-30kV, receiving distance is 10-20cm, fltting speed 0.5-1.5mL/H, receiving roll revolving speed are 80-1000rpm, electrospinning time 4-20h；The water-oil separating material with photothermal response is made；InstituteState that water-oil separating material is hydrophobic at room temperature, oleophylic, when it is under near infrared light, it is critical that material temperature is increased to its highestIt is transformed into hydrophilic, oleophobic when consolute temperature.
The present invention using electrospinning is prepared the water-oil separating material with photothermal response hydrophobic at room temperature, parentRedox graphene is added in oil, and material is more hydrophobic, can efficiently separate water-in-oil emulsion.Oil can pass through separation materialIt is collected, water is then trapped in separation material.And after being used for multiple times, the separating property of material can be declined, thisWhen so that material temperature is increased by illumination after, property is changed into oleophobic, hydrophilic, so that the dirt in separation materialStain is easily flush with water completely, and separation efficiency is restored.
Preferably, in step 1), in terms of mg, mL, the synthetic method of the copolymer are as follows: successively weigh acrylonitrile 65-75mg, acrylamide 330-340mg, azodiisobutyronitrile 4.7-4.9mg are put into reaction vessel, then measure 5-7mL dimethylSulfoxide solution, nitrogen charging deoxidation, reaction obtain copolymer with methanol centrifugation, then dialysed with ultrapure water, and dry in vacuumIt is dry to be dried for standby.
Preferably, nitrogen charging deoxygenates the time as 25-35min in step 1), after reacting 6-10h at 55-65 DEG C, first is usedAlcohol centrifugation obtains copolymer, then is dialysed with ultrapure water, and is dried for standby being dried in vacuo 35-45 DEG C.
Preferably, the highest critical consolute temperature of the copolymer is 55-59 DEG C.
The temperature is relatively mild, water-oil separating material can be made to be warming up to highest in a short time under near infrared ray irradiation and facedBoundary's consolute temperature fast implements photothermal response under relatively low energy consumption.
Preferably, in step 2), in terms of g and mL, the redox graphene the preparation method comprises the following steps: by 0.8-1.2gGraphene oxide is distributed in 80-120mL water, is added to the container, and 13-17mL is added and is adjusted to hydration of the pH less than 10 with ammonium hydroxideHydrazine solution is heated to reflux, and is obtained black solid and is washed to neutrality with distillation, obtains redox graphene after freeze-drying.
Preferably, being warming up to 95-105 DEG C in step 2) and being heated to reflux 20-30h.
Preferably, the weight ratio of copolymer and redox graphene is 100-500: 1 in step 3).
Preferably, the concentration of copolymer is 2-10wt%, the concentration of redox graphene in spinning solution in step 3)For 0.02-0.1wt%.
The inventors discovered that the weight ratio of copolymer and redox graphene will affect water-oil separating material in spinning solutionMembrane structure feature.If redox graphene ratio is too low, photothermal response sensitivity is poor, and the hydrophobicity of film is low, shadowRing its separation to there is oily waste water existing for surfactant.If redox graphene ratio is excessively high, film brittleness will lead toBecome larger, mechanical strength becomes smaller.The concentration of copolymer also has in OK range in spinning solution simultaneously, too low to will lead to fiberAttenuate or does not become fiber, it is excessively high to block syringe needle, influence spinning process.
Preferably, the wavelength of the near infrared light is 790-810nm, irradiation time 50-70min in step 3).
Water-oil separating material made from the method is applied to water-oil separating, specifically: at room temperature by oil water mixtureIt is placed in water-oil separating material, the oil in oil water mixture is obtained by the water-oil separating material, collection, and oil water mixtureIn water be trapped in water-oil separating material；And by the way that after near infrared light, material temperature is higher than the critical molten temperature altogether of highestDegree has easy cleaning effect.
It is compared with the prior art, the beneficial effects of the present invention are:
The advantages of water-oil separating material of the invention, is as follows: by copolymer and redox graphene with temperature sensitive functionIt organically combines, the water-oil separating with photothermal response is prepared in suitable ratio range, using electrospinning in the twoMaterial has efficient separating property at room temperature.And when separating property declines after long-time is applied, it can lead toCrossing photo-thermal irradiation makes material itself that property transformation occur, to easily elute the spot of contamination, fast quick-recovery separating property is prolongedLong life.
Specific embodiment
The present invention will be further described with reference to the examples below.
Total embodiment
A kind of preparation method of the water-oil separating material with photothermal response, comprising the following steps:
1) acrylonitrile 65-75mg, acrylamide 330- successively the copolymer of synthesis of acrylamide and acrylonitrile: are weighed340mg, azodiisobutyronitrile 4.7-4.9mg, is put into reaction vessel, then measures 5-7mL dimethyl sulphoxide solution, nitrogen charging deoxidation25-35min obtains copolymer with methanol centrifugation, then dialysed with ultrapure water after reacting 6-10h at 55-65 DEG C,And it is dried for standby being dried in vacuo 35-45 DEG C.The highest critical consolute temperature of the copolymer is 55-59 DEG C.
2) it prepares redox graphene: 0.8-1.2g graphene oxide is distributed in 80-120mL water, container is addedIn, and 13-17mL is added and is adjusted to hydrazine hydrate solution of the pH less than 10 with ammonium hydroxide, it is warming up to 95-105 DEG C and is heated to reflux 20-30h,It obtains black solid and is washed to neutrality with distillation, obtain redox graphene after freeze-drying.
3) copolymer and redox graphene are dissolved or are distributed in n,N-Dimethylformamide and obtain spinning solution,In, the weight ratio of copolymer and redox graphene is 100-500: 1；The concentration of copolymer is 2-10wt% in spinning solution,The concentration of redox graphene is 0.02-0.1wt%.
Carry out electrostatic spinning, electrospinning conditions are as follows: voltage 5-30kV, receiving distance is 10-20cm, and fltting speed is0.5-1.5mL/h, receiving roll revolving speed are 80-1000rpm, electrospinning time 4-20h；The grease point with photothermal response is madeFrom material；The water-oil separating material is hydrophobic at room temperature, oleophylic, when it is irradiated near infrared light (wavelength 790-810nm)After 50-70min, material temperature is increased to be transformed into hydrophilic, oleophobic when its highest critical consolute temperature.
Embodiment 1
By the copolymer and 0.05g redox graphene dissolution/dispersion of 5g acrylamide and acrylonitrile to 95g DMFIn, preparation obtain spinning solution, during electrostatic spinning voltage be 20kV, receive distance be 15cm, fltting speed 1.0mL/h,Receiving roll revolving speed is 300rpm, electrospinning time 6h, and the water-oil separating material A with photothermal response is prepared.
Embodiment 2
By the copolymer and 0.02g redox graphene dissolution/dispersion of 2g acrylamide and acrylonitrile to 98g DMFIn, preparation obtains spinning solution, and voltage is 5kV during electrostatic spinning, and receiving distance is 10cm, and fltting speed 0.5mL/h connectsReceipts roller revolving speed is 1000rpm, electrospinning time 20h, and the water-oil separating material B with photothermal response is prepared.
Embodiment 3
By the copolymer and 0.02g redox graphene dissolution/dispersion of 10g acrylamide and acrylonitrile to 90g DMFIn, preparation obtain spinning solution, during electrostatic spinning voltage be 30kV, receive distance be 20cm, fltting speed 0.75mL/h,Receiving roll revolving speed is 80rpm, electrospinning time 4h, and the water-oil separating material C with photothermal response is prepared.
Embodiment 4
By the copolymer and 0.03g redox graphene dissolution/dispersion of 7.5g acrylamide and acrylonitrile to 92.5gIn DMF, preparation obtains spinning solution, and voltage is 23kV during electrostatic spinning, and receiving distance is 12cm, fltting speed 1.5mL/H, receiving roll revolving speed are 500rpm, electrospinning time 15h, and the water-oil separating material D with photothermal response is prepared.
Embodiment 5
By the copolymer and 0.03g redox graphene dissolution/dispersion of 6g acrylamide and acrylonitrile to 94g DMFIn, preparation obtain spinning solution, during electrostatic spinning voltage be 18kV, receive distance be 18cm, fltting speed 1.25mL/h,Receiving roll revolving speed is 750rpm, electrospinning time 12h, and the water-oil separating material E with photothermal response is prepared.
Embodiment 6
By the copolymer and 0.02g redox graphene dissolution/dispersion of 8g acrylamide and acrylonitrile to 92g DMFIn, preparation obtain spinning solution, during electrostatic spinning voltage be 26kV, receive distance be 15cm, fltting speed 1.0mL/h,Receiving roll revolving speed is 200rpm, electrospinning time 8h, and the water-oil separating material F with photothermal response is prepared.
Comparative example 1
By the copolymer and 0.1g redox graphene dissolution/dispersion of 5g acrylamide and acrylonitrile into 95g DMF,Preparation obtains spinning solution, and voltage is 20kV during electrostatic spinning, and receiving distance is 15cm, fltting speed 1.0mL/h, receivesRoller revolving speed is 300rpm, electrospinning time 6h, and the water-oil separating material A1 with photothermal response is prepared.
Comparative example 2
By the copolymer and 0.005g redox graphene dissolution/dispersion of 5g acrylamide and acrylonitrile to 95g DMFIn, preparation obtain spinning solution, during electrostatic spinning voltage be 20kV, receive distance be 15cm, fltting speed 1.0mL/h,Receiving roll revolving speed is 300rpm, electrospinning time 6h, and the water-oil separating material A2 with photothermal response is prepared.
The copolymer of embodiment 1-6 and acrylamide and acrylonitrile in comparative example 1-2 the preparation method comprises the following steps: successively claimingIt takes acrylonitrile (70mg, 0.986mmol), acrylamide (333mg, 6.283mmol), azodiisobutyronitrile (AIBN, 4.82mg,0.029mmol), it is put into round-bottomed flask, then measures 6mL dimethyl sulfoxide (DMSO) solution, nitrogen charging deoxygenates 30min, at 60 DEG CAfter lower reaction 8h, the copolymer of acrylamide and acrylonitrile is obtained with methanol centrifugation, then dialysed with ultrapure water, andIt is dried for standby for 40 DEG C in vacuum oven.The highest critical consolute temperature of the copolymer of obtained acrylamide and acrylonitrile is57℃。
The preparation process of embodiment 1-6 and the redox graphene in comparative example 1-2 are as follows: by 1g graphene oxide pointIt is scattered in 100mL aqueous solution, is added in round-bottomed flask, and 15mL pH is added and is adjusted to hydrazine hydrate solution less than 10 with ammonium hydroxide,100 DEG C of reflux for 24 hours, obtain black solid and are washed to neutrality with distillation, obtain redox graphene after freeze-drying.
Performance test
1) basic performance of water-oil separating material
Mechanical strength is measured by universal testing machine, and flux passes through self-control oily-water seperating equipment measurement.Water-oil separatingEfficiency test process is as follows: weighing 0.5g span 80,90g n-hexane, 10g deionized water, mechanical stirring is at lotion.It will preparationObtained water-oil separating material is fixed on oily-water seperating equipment, pours into above-mentioned emulsion, keeps a height of 20 ± 0.5cm of fluid column, andRecord the content of water in the time and separation front and back solution that grease is kept completely separate.The calculation formula of water-oil separating efficiency are as follows:
As a result as shown in the table:
| Water-oil separating material | Tensile strength (MPa) | Flux (Lm-2h-1bar-1) | Separative efficiency |
| A | 2.74 | 53486.8±138.5 | 99.5% |
| B | 3.12 | 51674.3±155.2 | 99.3% |
| C | 2.63 | 54362.6±186.4 | 99.7% |
| D | 3.01 | 52081.3±205.6 | 99.1% |
| E | 2.99 | 52982.7±237.3 | 99.6% |
| F | 2.81 | 53832.1±315.5 | 99.2% |
| A1 | 3.25 | 45482.7±214.8 | 90.3% |
| A2 | 1.43 | 50486.8±138.5 | 98.1% |
From the above results, the accounting of redox graphene too low (comparative example 1) will lead to grease point in spinning solutionRelatively relatively low from the flux of material, separative efficiency is poor；And the accounting of redox graphene excessively high (comparative example 2) can then be damagedThe tensile strength of water-oil separating material, while having minimal effect to separative efficiency.Therefore, redox graphene in spinning solutionAccounting should be selected in suitable range.
2) photothermal response of water-oil separating material
Using n-hexane lotion as separation object, long-time water-oil separating is carried out using water-oil separating material A, A1, A2,After respective flux decline 10%.By water-oil separating material 808nm near infrared light 60min, so that temperature is reached highest and faceIt more than boundary's consolute temperature, then is rinsed with 50mL deionized water, carries out water-oil separating test after drying process again.As a result as followsShown in table:
| Water-oil separating material | Flux (Lm-2h-1bar-1) | Separative efficiency |
| A | 52987.3±183.4 | 99.1% |
| A1 | 40482.7±214.8 | 83.5% |
| A2 | / | / |
As seen from the above table, materials A is changed into hydrophilic, oleophobic after photothermal response, is simply rinsed with deionized waterAfter removal, flux and separative efficiency are restored.Materials A 1 is then that flux and separative efficiency have different degrees of decline, tableRedox graphene is less in bright separation material, affects photo-thermal efficiency, and the spot accumulated on material after responding is caused to failIt thoroughly cleans, affects the separating property of material.And materials A 2 is ruptured due to material fragility, can not be made againWith.Again show that the dosage of redox graphene in spinning solution is more crucial.
Raw materials used in the present invention, equipment is unless otherwise noted the common raw material, equipment of this field；In the present inventionMethod therefor is unless otherwise noted the conventional method of this field.
The above is only presently preferred embodiments of the present invention, is not intended to limit the invention in any way, it is all according to the present inventionTechnical spirit any simple modification, change and equivalent transformation to the above embodiments, still fall within the technology of the present invention sideThe protection scope of case.