Detailed Description
The endpoints of the ranges and any values disclosed herein are not limited to the precise range or value, and such ranges or values should be understood to encompass values close to those ranges or values. For ranges of values, between the endpoints of each of the ranges and the individual points, and between the individual points may be combined with each other to give one or more new ranges of values, and these ranges of values should be considered as specifically disclosed herein.
The following describes in detail specific embodiments of the present invention. It should be understood that the detailed description and specific examples, while indicating the present invention, are given by way of illustration and explanation only, not limitation.
In the present invention, the term "inorganic-organic coordination polymer" refers to a periodic network structure formed by bonding an inorganic metal center (single metal or metal cluster) and an organic small molecule ligand.
The invention provides a super-hydrophobic separation membrane, which comprises a substrate and nano sheets loaded on the substrate, wherein the nano sheets are formed by inorganic-organic coordination polymers, and the inorganic-organic coordination polymers are formed by coordination of transition elements and organic carboxylic acids.
According to the superhydrophobic separation membrane of the present invention, the transition element is preferably Ni.
The superhydrophobic separation membrane according to the present invention is not particularly limited, and the organic carboxylic acid is preferably a dibasic acid. Specifically, the organic carboxylic acid may be, for example, 5-tert-butyl-1, 3-phthalic acid, 1, 4-terephthalic acid (H)2BDC), 4 '-biphenyldicarboxylic acid, 2, 6-naphthalenedicarboxylic acid, 1, 4-naphthalenedicarboxylic acid, p-terphenyl-4, 4' -dicarboxylic acid and trans-1, 6-hexadiene diacid; preferably, the organic carboxylic acid is 5-tert-butyl-1, 3-benzenedicarboxylic acid.
In addition, the molar ratio of the inorganic element in the inorganic-organic coordination polymer to the inorganic element and the organic ligand in the inorganic-organic coordination polymer is preferably 1: 0.6-1.5, more preferably 1: 0.6-1.1.
In a preferred embodiment of the present invention, the transition element is Ni and the organic carboxylic acid is 5-tert-butyl-1, 3-phthalic acid.
In the present invention, the organic carboxylic acid may be any of various organic carboxylic acids having a functional group, and preferably, the organic carboxylic acid has a functional group-CH3、-CHO、-COOH、-COOCH3、-NO2、-NH2、-SO3H、-OH、-COCH3、-COCH2CH3、-COC(CH3)=CH2、-CO-OC(CH3)3、-NHCOCH3、-NHCOCH2CH3、-NHCOC(CH3)=CH2and-NHCO-OC (CH)3)3One or more of (a).
According to the super-hydrophobic separation membrane, the size of the nano sheet is 1.8-12 μm, and the thickness of the nano sheet is 1.9-10 nm; more preferably; the size of the nano sheet is 2-10 μm, and the thickness of the nano sheet is 2-8 nm. Here, "size of nanosheet" means the longest straight-line distance between two points of the nanosheet; similarly, the thickness of the nanosheet refers to the longest distance between two points in the thickness direction perpendicular to a straight line.
The super-hydrophobic separation membrane according to the present invention, which is not particularly limited to the porous substrate, may be any existing support having a porous structure, for example, a porous support of a metal or a non-metal material, including, but not limited to, a stainless steel mesh, a nickel mesh, a copper mesh, an aluminum mesh, porous alumina, porous silica, and the like.
The pore size of the substrate is also not particularly limited, and preferably, the pore size of the substrate is 5 to 80 μm.
The thickness of the substrate is also not particularly limited, and is preferably 500nm to 3 μm, more preferably 0.5 to 2 μm.
According to the superhydrophobic separation membrane of the present invention, the content of the nano sheet is preferably 3-9.5 wt%, more preferably 4-9 wt%, based on the total weight of the superhydrophobic separation membrane.
The invention also provides a preparation method of the super-hydrophobic separation membrane, which comprises the following steps:
1) a step of preparing an inorganic-organic coordination polymer crystal;
2) a step of exfoliating the nanosheets from the inorganic-organic coordination polymer crystals;
3) a step of bringing the suspension containing the nanoplatelets into contact with a porous substrate and removing the solvent,
wherein the inorganic-organic coordination polymer is formed by coordination of a transition element and an organic carboxylic acid.
According to the method for preparing the superhydrophobic separation membrane of the present invention, the transition element is preferably Ni.
In the method for producing a superhydrophobic separation membrane according to the present invention, the organic carboxylic acid is not particularly limited, and is preferably a dibasic acid. Specifically, the organic carboxylic acid may be, for example, 5-tert-butyl-1, 3-phthalic acid,1, 4-terephthalic acid (H)2BDC), 4 '-biphenyldicarboxylic acid, 2, 6-naphthalenedicarboxylic acid, 1, 4-naphthalenedicarboxylic acid, p-terphenyl-4, 4' -dicarboxylic acid and trans-1, 6-hexadiene diacid; preferably, the organic carboxylic acid is 5-tert-butyl-1, 3-benzenedicarboxylic acid.
In addition, the molar ratio of the inorganic element in the inorganic-organic coordination polymer to the inorganic element and the organic ligand in the inorganic-organic coordination polymer is preferably 1: 0.6-1.5, more preferably 1: 0.62-1.1.
In a preferred embodiment of the present invention, the transition element is Ni and the organic carboxylic acid is 5-tert-butyl-1, 3-phthalic acid.
In the present invention, the organic carboxylic acid may be any of various organic carboxylic acids having a functional group, and preferably, the organic carboxylic acid has a functional group-CH3、、-CHO、-COOH、-COOCH3、-NO2、-NH2、-SO3H、-OH、-COCH3、-COCH2CH3、-COC(CH3)=CH2、-CO-OC(CH3)3、-NHCOCH3、-NHCOCH2CH3、-NHCOC(CH3)=CH2and-NHCO-OC (CH)3)3One or more of (a).
According to the method for preparing a superhydrophobic separation membrane of the present invention, the inorganic-organic coordination polymer crystals can be obtained by a method generally used in the art for preparing inorganic-organic coordination polymer crystals. For example, the organic carboxylic acid can be obtained by heat-treating a solution containing an organic carboxylic acid and a salt containing a transition element. Specifically, the solution containing the organic carboxylic acid and the salt containing the transition element may be reacted at a temperature of 190 ℃ to 220 ℃ at a temperature rate of 1 to 3 ℃/min in an autoclave for 6 to 48 hours.
According to the preparation method of the super-hydrophobic separation membrane, preferably, the method for stripping the nanosheets from the inorganic-organic coordination polymer crystals comprises the following steps: subjecting a suspension containing inorganic-organic coordination polymer crystals to ultrasonic treatment, and then removing non-exfoliated crystal particles by centrifugation; or comprises the following steps: the step of subjecting the suspension containing the inorganic-organic coordination polymer crystals to heat treatment and then to freezing treatment is repeated, and then the non-exfoliated crystal particles are removed by centrifugation.
Preferably, the ultrasonic treatment conditions include: the ultrasonic power is 80-120W, the ultrasonic temperature is 10-40 ℃, and the ultrasonic time is 10-30 min.
Preferably, the conditions of the above heat treatment include: the heat treatment temperature is 60-100 deg.C, and the heat treatment time is 3-5 min.
Preferably, the conditions of the freezing treatment include: the freezing temperature is-40 to-196 ℃, and the freezing time is based on complete freezing.
Preferably, the step of subjecting the suspension containing the inorganic-organic coordination polymer crystals to heat treatment and then to freezing treatment is repeated 3 to 5 times.
Preferably, the content of the inorganic-organic coordination polymer crystals in the above suspension containing inorganic-organic coordination polymer crystals is 0.1 to 1.5 mg/mL.
Preferably, the conditions of the centrifugation include: the centrifugation temperature is 10-40 ℃, the centrifugation speed is 8000-12000r.p.m, and the centrifugation time is 10-30 min.
In order to further increase the purity of the nanosheets obtained, the resulting colloidal suspension is preferably allowed to stand for 1-4 weeks after the non-exfoliated crystalline particles are removed by centrifugation.
The method for preparing the superhydrophobic separation membrane according to the present invention is not particularly limited, and may be any existing support having a porous structure, for example, a porous support of a metal or a non-metal material, including, but not limited to, a stainless steel mesh, a nickel mesh, a copper mesh, an aluminum mesh, porous alumina, porous silica, and the like.
The pore size of the substrate is also not particularly limited, and preferably, the pore size of the substrate is 5 to 80 μm.
The thickness of the substrate is also not particularly limited, and is preferably 500nm to 3 μm, more preferably 0.5 to 2 μm.
According to the preparation method of the superhydrophobic separation membrane of the present invention, preferably, the suspension containing the nanosheets is contacted with the porous substrate in such a manner that the suspension containing the nanosheets is coated on the porous substrate.
According to the method for preparing the superhydrophobic separation membrane of the present invention, preferably, the solvent is removed by drying.
According to the preparation method of the superhydrophobic separation membrane of the present invention, preferably, the suspension containing the nano-sheets is used in an amount such that the content of the nano-sheets is 3 to 9.5 wt%, more preferably 4 to 9 wt%, based on the total weight of the superhydrophobic separation membrane.
In addition, the invention also provides application of the super-hydrophobic separation membrane in oil-water separation.
The oil phase which can be separated by the super-hydrophobic separation membrane provided by the invention comprises pure components which are not dissolved in water and low-polarity solvents such as petroleum, vegetable oil, gasoline, diesel oil, n-hexane, cyclohexane, n-heptane, n-octane, n-butanol, ethyl acetate, benzene, toluene, chloroform and the like or a mixture of the pure components.
The water phase that can be separated by the super-hydrophobic separation membrane provided by the invention includes, but is not limited to, pure water, aqueous sodium chloride solution, aqueous potassium chloride solution, aqueous copper chloride solution, aqueous iron chloride solution, aqueous sodium nitrate solution, aqueous potassium nitrate solution, aqueous copper sulfate solution and other pure water solutions with single solute or mixed solution thereof.
The present invention will be described in detail below by way of examples, but the present invention is not limited to the following examples.
The surface morphology of the nano-sheet prepared by the invention is observed through a transmission electron microscope spectrogram (purchased from JSM-2200FS model of JEOL company).
The surface appearance of the super-hydrophobic separation membrane prepared by the invention is observed by a scanning electron microscope (purchased from JEOL JSM-6510A).
The contact angle was measured by a contact angle measuring instrument (purchased from shanghai chinno precision instruments ltd. CA100A model), the volume of the sample used was 5uL, six positions were selected at different positions for the same sample to be measured, and the average value was taken as the hydrophobic angle of the sample.
In the case where no particular mention is made, commercially available products are used as the starting materials.
Example 1
(1) Synthetic crystal
0.075g of 5-tert-butyl-1, 3-phthalic acid and 0.15g of nickel nitrate hexahydrate are suspended in 7.5mL of 20 v% ethylene glycol aqueous solution, then the mixture is placed into a 20mL autoclave, heated to 210 ℃ at a heating rate of 2 ℃/min, and after 24h, the reaction is stopped by cooling to room temperature, and light green needle crystals are obtained. Washing with deionized water and methanol for 5 times to completely remove residual ligand and metal salt, and drying at 60 deg.C to obtain inorganic-organic coordination polymer crystal formed by coordination of nickel and 5-tert-butyl-1, 3-phthalic acid.
(2) Stripping the nano-sheets:
treating the n-hexane suspension containing nanosheet crystals at a concentration of 1.0mg/mL in an ultrasonic bath for 20min (ultrasonic power of 100W and ultrasonic temperature of 25 ℃), centrifuging at 10000 r.p.m. for 20min to obtain a colloidal suspension of the nanosheets to remove non-exfoliated particles, and further purifying the nanosheets by allowing the colloidal suspension to stand for about 1 week.
(3) Preparation of two-dimensional super-hydrophobic separation membrane
And (3) dripping the n-hexane suspension containing the stripped nano sheets on a stainless steel net in a manner that the content of the nano sheets in the obtained two-dimensional super-hydrophobic separation membrane is 4.02 wt%, and heating a treated stainless steel net carrier (the mesh is 400 meshes, and the thickness is 2 microns) on an electric hot plate to keep the liquid drop temperature at 100 ℃ so as to completely evaporate the n-hexane, thereby obtaining the two-dimensional super-hydrophobic separation membrane A1.
FIG. 1 is an XRD pattern of the inorganic-organic coordination polymer crystal prepared in this example, from which it can be seen that Ni and an organic carboxylic acid coordinated inorganic-organic coordination polymer crystal were successfully synthesized by a solvothermal method; the sharp peak type shows that the diffraction intensity is high, and the synthesized crystal has good crystallinity.
FIG. 2 is a scanning electron microscope photograph of an inorganic-organic coordination polymer crystal prepared in this example, from which it can be seen that the inorganic-organic coordination polymer crystal has a layered structure; the atoms in each layer of the 2D layered structure are linked by strong covalent and coordination bonds, while the layers are loosely linked together by van der waals interactions, which are easily broken to give the nanosheets.
Fig. 3 is a transmission electron microscope spectrogram of the two-dimensional nanosheet prepared in this example, from which it can be seen that the size of the two-dimensional nanosheet is 10 μm and the thickness is 2 nm.
According to a scanning electron microscope picture of the two-dimensional super-hydrophobic separation membrane prepared by the embodiment, the two-dimensional nanosheets are loaded on the porous metal substrate in a wrapping manner.
The contact angle of the two-dimensional super-hydrophobic separation membrane prepared in the embodiment to a water drop in air is 151 degrees, and the hydrophobic property of the two-dimensional super-hydrophobic separation membrane in air is verified.
Fig. 4 is a photograph of a contact angle of the two-dimensional super-hydrophobic separation membrane prepared in this example to an oil drop (1, 2-dichloroethane) in air, wherein the contact angle is 0 degree, and the super-oleophilic property of the two-dimensional super-hydrophobic separation membrane is verified.
Example 2
(1) Synthetic crystal
0.075g of 5-tert-butyl-1, 3-phthalic acid and 0.15g of zinc nitrate hexahydrate are suspended in 7.5mL of 20 v% aqueous ethylene glycol solution, and then the mixture is placed into a 20mL autoclave and heated to 210 ℃ at a heating rate of 2 ℃/min for 24h, and then the reaction is stopped by cooling to room temperature to obtain pale green needle crystals. Washing with deionized water and methanol for 5 times to completely remove residual ligand and metal salt, and drying at 60 deg.C to obtain inorganic-organic coordination polymer crystal formed by coordination of zinc and 5-tert-butyl-1, 3-phthalic acid.
(2) Stripping the nano-sheets:
the bulk crystals were dispersed in n-hexane at a concentration of 1.0mg/mL and heated in a hot water bath (80 ℃) for 3min and then immediately cooled in a liquid nitrogen bath (-196 ℃) until complete freezing. After that, the solidified mixture was thawed again in a hot water bath (80 ℃). The freeze-thaw cycle was repeated 3 times depending on the solvent. And centrifuging at 10000r.p.m for 20min to remove the unexfoliated blocky crystals from the supernatant to obtain a colloidal suspension of the nanosheets, and further purifying the nanosheets by allowing the colloidal suspension to stand for about 1 week.
(3) Preparation of two-dimensional super-hydrophobic separation membrane
And (3) dripping the n-hexane suspension containing the stripped nano sheets on a stainless steel net in a manner that the content of the nano sheets in the obtained two-dimensional super-hydrophobic separation membrane is 8.88 wt%, and heating a treated stainless steel net carrier (the mesh is 400 meshes, and the thickness is 2 microns) on an electric hot plate to keep the liquid drop temperature at 100 ℃ so as to completely evaporate the n-hexane, thereby obtaining the two-dimensional super-hydrophobic separation membrane A2.
The size of the two-dimensional nanosheet is 2 μm and the thickness is 8nm as can be seen from a spectrogram of a transmission electron microscope.
According to a scanning electron microscope picture, the two-dimensional nano sheets are loaded on the porous metal substrate in a wrapping mode.
The contact angle of the two-dimensional super-hydrophobic separation membrane on a water drop in the air is 150.4 degrees, and the hydrophobic property of the two-dimensional super-hydrophobic separation membrane in the air is verified.
The super-oleophilic property of the oil drop (1, 2-dichloroethane) is verified by a contact angle photo of a two-dimensional super-hydrophobic separation membrane in air, wherein the contact angle photo is 0 degree.
Example 3
(1) Synthesis of bulk crystals and (2) exfoliation of the nanosheets was the same as in example 2.
(3) Preparation of two-dimensional super-hydrophobic separation membrane
And (3) dripping the n-hexane suspension containing the stripped nano sheets on a stainless steel net in a manner that the content of the nano sheets in the obtained two-dimensional super-hydrophobic separation membrane is 4.44 wt%, and heating a treated stainless steel net carrier (500 meshes, the thickness of 2 mu m) on an electric hot plate to keep the temperature of the liquid drops at 100 ℃ so as to completely evaporate the n-hexane, thereby obtaining the two-dimensional super-hydrophobic separation membrane A3.
The size of the two-dimensional nanosheet is 8 μm and the thickness is 6nm as can be seen from a spectrogram of a transmission electron microscope.
According to a scanning electron microscope picture, the two-dimensional nano sheets are loaded on the porous metal substrate in a wrapping mode.
The contact angle of the two-dimensional super-hydrophobic separation membrane on a water drop in the air is 151 degrees, and the hydrophobic property of the two-dimensional super-hydrophobic separation membrane in the air is verified.
The super-oleophilic property of the oil drop (1, 2-dichloroethane) is verified by a contact angle photo of a two-dimensional super-hydrophobic separation membrane in air, wherein the contact angle photo is 0 degree.
Example 4
(1) Synthesis of bulk crystals and (2) exfoliation of the nanosheets was the same as in example 2.
(3) Preparation of two-dimensional super-hydrophobic separation membrane
And (3) dripping the n-hexane suspension containing the stripped nano sheets on a stainless steel net in a manner that the content of the nano sheets in the obtained two-dimensional separation membrane is 5.01 wt%, and heating the treated stainless steel net carrier (800 meshes and the thickness of 2 mu m) on an electric hot plate to keep the temperature of the liquid drops at 100 ℃ so as to completely evaporate the n-hexane, thereby obtaining the two-dimensional super-hydrophobic separation membrane A4.
The size of the two-dimensional nanosheet is 6 μm and the thickness is 6nm as can be seen from a spectrogram of a transmission electron microscope.
According to a scanning electron microscope picture, the two-dimensional nano sheets are loaded on the porous metal substrate in a wrapping mode.
The contact angle of the two-dimensional super-hydrophobic separation membrane on a water drop in the air is 150 degrees, and the hydrophobic property of the two-dimensional super-hydrophobic separation membrane in the air is verified.
The super-oleophilic property of the oil drop (1, 2-dichloroethane) is verified by a contact angle photo of a two-dimensional super-hydrophobic separation membrane in air, wherein the contact angle photo is 0 degree.
Example 5
(1) Bulk crystals were synthesized as in example 2.
(2) Exfoliated nanoplatelets are the same as in example 1.
(3) The preparation of the two-dimensional superhydrophobic separation membrane was the same as in example 3, to obtain a two-dimensional superhydrophobic separation membrane a 5.
The size of the two-dimensional nanosheet is 4 μm and the thickness is 4nm as can be seen from a spectrogram of a transmission electron microscope.
According to a scanning electron microscope picture, the two-dimensional nano sheets are loaded on the porous metal substrate in a wrapping mode.
The contact angle of the two-dimensional super-hydrophobic separation membrane on a water drop in the air is 150.1 degrees, and the hydrophobic property of the two-dimensional super-hydrophobic separation membrane in the air is verified.
The super-oleophilic property of the oil drop (1, 2-dichloroethane) is verified by a contact angle photo of a two-dimensional super-hydrophobic separation membrane in air, wherein the contact angle photo is 0 degree.
Example 6
(1) Bulk crystals were synthesized as in example 2.
(2) Exfoliated nanoplatelets are the same as in example 1.
(3) The preparation of the two-dimensional superhydrophobic separation membrane was the same as in example 4, to obtain a two-dimensional superhydrophobic separation membrane a 6.
The size of the two-dimensional nanosheet is 12 μm and the thickness is 8nm as can be seen from a spectrogram of a transmission electron microscope.
According to a scanning electron microscope picture, the two-dimensional nano sheets are loaded on the porous metal substrate in a wrapping mode.
The contact angle of the two-dimensional super-hydrophobic separation membrane on a water drop in the air is 150 degrees, and the hydrophobic property of the two-dimensional super-hydrophobic separation membrane in the air is verified.
The super-oleophilic property of the oil drop (1, 2-dichloroethane) is verified by a contact angle photo of a two-dimensional super-hydrophobic separation membrane in air, wherein the contact angle photo is 0 degree.
Example 7
(1) Bulk crystals were synthesized as in example 2.
(2) Stripping the nanosheets:
the crystals were dispersed in ethanol at a concentration of 1.0mg/mL and heated in a hot water bath (80 ℃) for 3min, then immediately cooled in a liquid nitrogen bath (-196 ℃) until complete freezing. After that, the solidified mixture was thawed again in a hot water bath (80 ℃). The freeze-thaw cycle was repeated 5 times depending on the solvent. The non-exfoliated crystal particles were removed from the supernatant by centrifugation at 10000r.p.m for 20min, resulting in a colloidal suspension of nanoplatelets (the tyndall effect was observed), which was further purified by allowing the colloidal suspension to stand for about 1 week.
(3) Preparing a two-dimensional super-hydrophobic separation membrane:
and (3) dripping the n-hexane suspension containing the stripped nano sheets on a stainless steel net in a manner that the content of the nano sheets in the obtained two-dimensional super-hydrophobic separation membrane is 6.03 weight percent, and heating a treated stainless steel net carrier (400 meshes, the thickness of 2 mu m) on an electric hot plate to keep the temperature of the liquid drops at 100 ℃ so as to completely evaporate ethanol, thereby obtaining the two-dimensional super-hydrophobic separation membrane A7.
The size of the two-dimensional nanosheet is 4 μm and the thickness is 8nm as can be seen from a spectrogram of a transmission electron microscope.
According to a scanning electron microscope picture, the two-dimensional nano sheets are loaded on the porous metal substrate in a wrapping mode.
The contact angle of the two-dimensional super-hydrophobic separation membrane on a water drop in the air is 150.1 degrees, and the hydrophobic property of the two-dimensional super-hydrophobic separation membrane in the air is verified.
The super-oleophilic property of the oil drop (1, 2-dichloroethane) is verified by a contact angle photo of a two-dimensional super-hydrophobic separation membrane in air, wherein the contact angle photo is 0 degree.
Example 8
(1) Bulk crystals were synthesized as in example 2.
(2) Stripping the nanosheets:
the ethanol suspension containing crystals with a concentration of 1.0mg/mL is treated in an ultrasonic bath for 20min (ultrasonic power 100W, ultrasonic temperature 25 ℃), a colloidal suspension of the nanoplatelets is obtained after centrifugation at 10000 r.p.m. for 20min to remove the non-exfoliated particles, and further purification of the nanoplatelets is performed by leaving the colloidal suspension to stand for about 1 week.
(3) The two-dimensional superhydrophobic separation membrane was prepared in the same manner as in example 7 to obtain a two-dimensional superhydrophobic separation membrane A8.
The size of the two-dimensional nanosheet is 10 μm and the thickness is 4nm as can be seen from a spectrogram of a transmission electron microscope.
According to a scanning electron microscope picture, the two-dimensional nano sheets are loaded on the porous metal substrate in a wrapping mode.
The contact angle of the two-dimensional super-hydrophobic separation membrane on a water drop in the air is 150 degrees, and the hydrophobic property of the two-dimensional super-hydrophobic separation membrane in the air is verified.
The super-oleophilic property of the oil drop (1, 2-dichloroethane) is verified by a contact angle photo of a two-dimensional super-hydrophobic separation membrane in air, wherein the contact angle photo is 0 degree.
Test example 1
The two-dimensional super-hydrophobic separation membranes prepared in examples 1 to 8 were fixed in an oil-water separation apparatus shown in fig. 5, and a mixture of cyclohexane and water (volume ratio 1: 1) was poured into the oil-water separation apparatus, and the oil phase flowed into a glass bottle rapidly, and the water phase was retained by the super-hydrophobic separation membrane and was not flowed, and after a period of time (40 minutes), no water was dropped, and it was confirmed that the water phase and the oil phase were completely separated.
Test example 2
The two-dimensional superhydrophobic separation membranes prepared according to examples 1-8 were used to separate various oil/water mixtures according to the following methods, and the test structures are shown in table 1.
1) Experimental apparatus as shown in fig. 5, a separation membrane was fixed between two glassware articles shown as a in fig. 5, a glass tube having an outer diameter of 30 mm and a length of 20 cm was attached, the middle was sealed with a silica gel pad, the upper and lower portions of the glassware articles were fixed together with metal clips, the glassware articles were fixed on a stand, a beaker was used as a receiving vessel, and the apparatus was tilted to allow oil to permeate through a hydrophobic membrane (water-dyed blue and oil-dyed red) when testing a light oil/water mixture.
2) Mixing the water phase and the oil phase according to a volume ratio of 1: 1 mixing to obtain an oil-water mixed phase.
3) The oil-water mixed phase was poured into an oil-water separation apparatus shown as a in FIG. 5, and the oil phase rapidly flowed into a beaker.
TABLE 1
In test example 2, the super-hydrophobic separation membrane provided by the invention has hydrophobic performance, oil permeates through the membrane and water is trapped under the action of gravity based on good hydrophobicity, an oil phase is collected by a beaker, and a water phase is stably trapped on the membrane and cannot flow through the membrane, so that oil-water separation is effectively realized.
Moreover, as can be seen from table 1, the super-hydrophobic separation membrane provided by the present invention has a separation efficiency of 98.5% or more, a good oil-water separation performance, and can be recycled for many times. In addition, since Dichloromethane (DCM) is slightly soluble in water, the separation efficiency of the mixture of dichloromethane and water is about 96.5%.
The preferred embodiments of the present invention have been described above in detail, but the present invention is not limited thereto. Within the scope of the technical idea of the invention, many simple modifications can be made to the technical solution of the invention, including combinations of various technical features in any other suitable way, and these simple modifications and combinations should also be regarded as the disclosure of the invention, and all fall within the scope of the invention.