Disclosure of Invention
In view of the above, the invention aims to provide starch modified filter paper, a preparation method and an application thereof, the method is simple, and the prepared modified filter paper is suitable for oil-water separation of oily wastewater or demulsification separation of oil-water emulsion.
The invention provides a preparation method of starch modified filter paper, which comprises the following steps:
and (3) spraying the starch nanoparticle aqueous dispersion on the surface of the cellulose qualitative filter paper with the average pore diameter of 20-30 microns, putting the cellulose qualitative filter paper into a cross-linking agent solution with the mass concentration of 8-12%, reacting, and performing post-treatment to obtain the starch modified filter paper.
Preferably, the mass concentration of the aqueous dispersion of the starch nano microspheres is 0.05-0.5%.
Preferably, the cross-linking agent in the cross-linking agent solution is selected from one or more of glyoxal, succinaldehyde, and glutaraldehyde.
Preferably, the reaction time is 30 minutes to 5 hours;
the reaction temperature is 25-50 ℃.
Preferably, the particle size of the starch nanospheres in the starch nanosphere water dispersion liquid is 80-120 nm.
Preferably, the post-processing comprises:
and washing the reacted filter paper with ethanol and deionized water alternately and repeatedly, and drying to obtain the starch modified filter paper.
Preferably, the aqueous dispersion of the starch nanospheres is prepared by the following method:
esterifying starch with acetic anhydride and succinic anhydride to obtain starch ester;
and dripping water into the acetone solution of the starch ester to obtain a nano microsphere dispersion, and drying to obtain the starch nano microsphere aqueous dispersion.
The invention provides starch modified filter paper which is prepared by the preparation method of the technical scheme.
The invention provides the starch modified filter paper prepared by the preparation method in the technical scheme or the application of the starch modified filter paper in the technical scheme in oil-water separation of oily wastewater and/or demulsification separation of oil-water emulsion.
The invention provides a preparation method of starch modified filter paper, which comprises the following steps: and (3) spraying the starch nano microsphere aqueous dispersion on the surface of the cellulose qualitative filter paper with the average pore diameter of 20-30 microns, then putting the cellulose qualitative filter paper into a cross-linking agent solution, reacting, and performing post-treatment to obtain the starch modified filter paper. The method provided by the invention is simple, the surface of the cellulose qualitative filter paper is modified with the nano-scale hydrophilic particles, the micro-nano structure on the surface of the filter paper can be regulated and controlled, and the cellulose qualitative filter paper can be used as an oil-water separation material. The starch nano microspheres are used for modifying the surface of qualitative filter paper, so that the raw material cost can be reduced, the prepared separation membrane has biodegradability, the starch is renewable, the source is wide, and the large-scale production and application of the separation membrane are facilitated. The experimental results show that: the underwater dichloroethane contact angle of the starch modified filter paper is 148.5-155.5 degrees; the separation efficiency of the oil-water mixture is 99.81 plus or minus 0.02 percent to 99.96 plus or minus 0.02 percent; the separation efficiency of the emulsion is 99.75 +/-0.02-99.95 +/-0.02%.
Detailed Description
The invention provides a preparation method of starch modified filter paper, which comprises the following steps:
and (3) spraying the starch nanoparticle aqueous dispersion on the surface of the cellulose qualitative filter paper with the average pore diameter of 20-30 microns, putting the cellulose qualitative filter paper into a cross-linking agent solution with the mass concentration of 8-12%, reacting, and performing post-treatment to obtain the starch modified filter paper.
In the invention, the starch modified filter paper mainly comprises cellulose, and countless micron-sized pores are formed on the surface of the starch modified filter paper and can be used for liquid to pass through; the surface of the filter paper is modified with nano-scale hydrophilic particles, and the micro-nano structure on the surface of the filter paper is regulated and controlled, so that the filter paper can be used as an oil-water separation material.
In the invention, the mass concentration of the starch nano microsphere water dispersion is 0.05-0.5%. The particle size of the starch nano-microsphere in the starch nano-microsphere aqueous dispersion is 80-120 nm. The starch nano microspheres are used for modifying the surface of qualitative filter paper, so that the raw material cost can be reduced, the prepared separation membrane has biodegradability, the starch is renewable, the source is wide, and the large-scale production and application of the separation membrane are facilitated. The starch nano microsphere aqueous dispersion is preferably prepared by the following method:
esterifying starch with acetic anhydride and succinic anhydride to obtain starch ester;
and dripping water into the acetone solution of the starch ester to obtain a nano microsphere dispersion, and drying to obtain the starch nano microsphere aqueous dispersion.
The esterification temperature is 45-55 ℃, and more preferably 50 ℃.
In the invention, the cellulose qualitative filter paper with the average pore diameter of 20-30 microns is preferably a commercially available product.
In the present invention, the cross-linking agent in the cross-linking agent solution is selected from one or more of glyoxal, succinaldehyde, and glutaraldehyde. The mass concentration of the cross-linking agent solution is 8-12%.
In the invention, the reaction temperature is preferably 25-50 ℃; the reaction time is 30 min-5 h.
In the present invention, the post-processing includes:
and washing the reacted filter paper with ethanol and deionized water alternately and repeatedly, and drying to obtain the starch modified filter paper.
The starch modified filter paper prepared by the method provided by the invention is a hydrophilic oil-water separation membrane.
The invention provides starch modified filter paper which is prepared by the method of the technical scheme.
The invention provides the starch modified filter paper prepared by the preparation method in the technical scheme or the application of the starch modified filter paper in the technical scheme in oil-water separation of oily wastewater and/or demulsification separation of oil-water emulsion.
FIG. 1 shows an oil-water separator according to the present invention. The separation device comprises a separated liquid containing glass vessel, a separated liquid containing glass vessel and a separation membrane between the two vessels. The oil-water performance of the starch modified filter paper is tested by adopting the oil-water separation device.
In order to further illustrate the present invention, the following examples are provided to describe a starch modified filter paper and its preparation method and application in detail, but they should not be construed as limiting the scope of the present invention.
Example 1
Preparing 0.05% starch nano microsphere water dispersion, and spraying on qualitative filter paper. Soaking the sprayed filter paper into 10% glutaraldehyde water solution for reaction at 25 ℃ for 3 hours; taking out the cross-linked filter paper, and repeatedly washing with ethanol and deionized water to remove unreacted starch balls and glutaraldehyde; placing the washed filter paper in an oven to dry to constant weight to obtain an oil-water separation membrane, namely starch modified filter paper; the microscopic morphology of the filter paper before and after crosslinking is observed by a Scanning Electron Microscope (SEM), as shown in figure 2, figure 2 is a scanning electron microscope image of the nano starch, the original filter paper and the crosslinked and modified filter paper in example 1, wherein a is a scanning electron microscope image of the starch nano microsphere; b is a scanning electron microscope image of the original filter paper; c is a scanning electron microscope image of the cross-linked and modified filter paper, and d is a scanning electron microscope image of the cross-linked and modified filter paper amplified by c.
The invention tests the contact angle of the cross-linked filter paper in the air and the contact angle of the underwater dichloroethane drop, and the test chart is shown in figure 3, and figure 3 is the test chart of the contact angle of the modified filter paper prepared in the embodiment 1 of the invention in the air and the contact angle of the underwater dichloroethane drop; FIG. 3 shows that the surface of the separation membrane is super-hydrophilic in air and super-oleophobic under water, and the contact angle of the dichloroethane liquid drop under water is measured and the results are shown in Table 1.
And (4) carrying out oil-water separation by using a self-made oil-water separation device. The starch-modified filter paper was placed between two glassware sets (see fig. 1), white oil and water at pH 1 were mixed in a volume ratio of 20:80 to form an oil-water mixture, which was poured into the apparatus shown in fig. 1 to separate oil from water, and the separation efficiency was calculated by the chromatography according to formula 1, and the results are shown in table 1. Adding a Tween 20 and Tween 80 mixed surfactant which accounts for 3.8 percent of the total weight into a white oil and water mixture system with the pH value of 1 in a volume ratio of 20:80, and emulsifying to prepare an oil-in-water emulsion. The emulsion was poured into an apparatus shown in FIG. 1 for oil-water separation, and the separation efficiency was calculated by the following equation 1 through chromatography, and the results are shown in Table 1.
Separation efficiency (%) - (1-Cp/C0) × 100%, formula 1
C0: oil content before separation, mg/ml; cp: the oil content in the filtrate after separation is mg/ml.
Examples 2 to 4
Aqueous dispersions of starch nanospheres were prepared at concentrations of 0.1%, 0.3% and 0.5%, respectively, and the procedure was otherwise the same as in example 1.
Example 5
Preparing 0.05% starch nano microsphere water dispersion, and spraying on qualitative filter paper. Soaking the sprayed filter paper into 10% glyoxal water solution to react for 30 minutes at 50 ℃; taking out the cross-linked filter paper, and repeatedly washing with ethanol and deionized water to remove unreacted starch balls and glyoxal; and (3) placing the washed filter paper in an oven to dry to constant weight to obtain an oil-water separation membrane, namely the starch modified filter paper. The contact angles of the filter paper after crosslinking with water drops in air and dichloroethane under water were measured and are shown in Table 1.
And (4) carrying out oil-water separation by using a self-made oil-water separation device. The starch-modified filter paper was placed between two glassware sets (see fig. 1), white oil and water at pH 1 were mixed in a volume ratio of 20:80 to form an oil-water mixture, which was poured into the apparatus shown in fig. 1 to separate oil from water, and the separation efficiency was calculated by the chromatography according to formula 1, and the results are shown in table 1.
Adding a Tween 20 and Tween 80 mixed surfactant which accounts for 3.8 percent of the total weight into a white oil and water mixture system with the pH value of 1 in a volume ratio of 20:80, and emulsifying to prepare an oil-in-water emulsion. The emulsion was poured into an apparatus shown in FIG. 1 for oil-water separation, and the separation efficiency was calculated by the following equation 1 through chromatography, and the results are shown in Table 1.
Example 6
Preparing 0.05% starch nano microsphere water dispersion, and spraying on qualitative filter paper. Soaking the sprayed filter paper into 10% succinaldehyde water solution to react for 5 hours at 40 ℃; taking out the cross-linked filter paper, and repeatedly washing with ethanol and deionized water to remove unreacted starch balls and succinaldehyde; and (3) placing the washed filter paper in an oven to dry to constant weight to obtain an oil-water separation membrane, namely the starch modified filter paper. The contact angles of the filter paper after crosslinking with water drops in air and dichloroethane under water were measured and are shown in Table 1.
And (4) carrying out oil-water separation by using a self-made oil-water separation device. The starch-modified filter paper was placed between two glassware sets (see fig. 1), white oil and water at pH 1 were mixed in a volume ratio of 20:80 to form an oil-water mixture, which was poured into the apparatus shown in fig. 1 to separate oil from water, and the separation efficiency was calculated by the chromatography according to formula 1, and the results are shown in table 1.
Adding a Tween 20 and Tween 80 mixed surfactant which accounts for 3.8 percent of the total weight into a white oil and water mixture system with the pH value of 1 in a volume ratio of 20:80, and emulsifying to prepare an oil-in-water emulsion. The emulsion was poured into an apparatus shown in FIG. 1 for oil-water separation, and the separation efficiency was calculated by the following equation 1 through chromatography, and the results are shown in Table 1.
TABLE 1 Underwater oil contact angle and oil-water separation efficiency of starch-modified filter papers prepared in examples 1 to 6
|
Underwater dichloroethane contact angle
|
Oil-water mixture separation efficiency (%)
|
Emulsion separation efficiency (%)
|
Example 1
|
155.3°
|
99.85±0.02
|
99.75±0.02
|
Example 2
|
155.5
|
99.95±0.02
|
99.85±0.02
|
Example 3
|
154.1
|
99.87±0.02
|
99.95±0.02
|
Example 4
|
148.5
|
99.81±0.02
|
99.83±0.02
|
Example 5
|
151.3
|
99.95±0.02
|
99.87±0.02
|
Example 6
|
155.8
|
99.96±0.02
|
99.92±0.02 |
From the above examples, the present invention provides a preparation method of starch modified filter paper, comprising the following steps: and (3) spraying the starch nano microsphere aqueous dispersion on the surface of the cellulose qualitative filter paper with the average pore diameter of 20-30 microns, then putting the cellulose qualitative filter paper into a cross-linking agent solution, reacting, and performing post-treatment to obtain the starch modified filter paper. The method provided by the invention is simple, the surface of the cellulose qualitative filter paper is modified with the nano-scale hydrophilic particles, the micro-nano structure on the surface of the filter paper can be regulated and controlled, and the cellulose qualitative filter paper can be used as an oil-water separation material. The starch nano microspheres are used for modifying the surface of qualitative filter paper, so that the raw material cost can be reduced, the prepared separation membrane has biodegradability, the starch is renewable, the source is wide, and the large-scale production and application of the separation membrane are facilitated. The experimental results show that: the underwater dichloroethane contact angle of the starch modified filter paper is 148.5-155.5 degrees; the separation efficiency of the oil-water mixture is 99.81 plus or minus 0.02 percent to 99.96 plus or minus 0.02 percent; the separation efficiency of the emulsion is 99.75 +/-0.02-99.95 +/-0.02%.
The foregoing is only a preferred embodiment of the present invention, and it should be noted that, for those skilled in the art, various modifications and decorations can be made without departing from the principle of the present invention, and these modifications and decorations should also be regarded as the protection scope of the present invention.