CN114272904A - Preparation method of magnetic super-hydrophobic starch-based aerogel for oil-water separation - Google Patents
Preparation method of magnetic super-hydrophobic starch-based aerogel for oil-water separation Download PDFInfo
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Abstract
The invention discloses a preparation method of magnetic super-hydrophobic starch-based aerogel for oil-water separation, and belongs to the field of oil-water separation. The invention carries out hexadecyl trimethoxy silane modification on nano starch prepared by an enzymolysis regeneration method, takes the modified nano starch as a super-hydrophobic coating, and then carries out quick coprecipitation on Fe prepared by a quick coprecipitation method3O4The surface of the magnetic nano particle is modified by tetraethoxysilane and KH560 silane coupling agent in sequence, and the modified nano particle is preparedAnd (3) preparing the magnetic starch-based aerogel by compounding the shell-core structure magnetic nanoparticles and starch, and finally spraying the super-hydrophobic coating suspension on the surface of the aerogel to prepare the magnetic super-hydrophobic starch-based aerogel. The magnetic super-hydrophobic starch-based aerogel disclosed by the invention shows excellent water-oil selective absorptivity, namely an oil-water separation characteristic, can be used for remotely controlling floating oil absorption under the guidance of a magnetic field, can be adsorbed and recovered by a magnet after oil absorption is finished, and shows great potential for being applied to ocean oil leakage cleaning.
Description
Technical Field
The invention relates to a preparation method of magnetic super-hydrophobic starch-based aerogel for oil-water separation, and belongs to the field of oil-water separation.
Background
Petroleum is essential energy oil for daily life and production, but frequent marine oil spill accidents in recent years also attract attention. The leaked petroleum contains toxic compounds such as benzene, toluene and the like, and the toxic compounds can be rapidly diffused in a marine system under the action of ocean currents and ocean waves, so that serious toxicity is caused to lower algae to higher mammals, and huge economic and energy losses are brought to human society. In many conventional oil-water separation methods for cleaning oil spills, physical adsorbents have been widely used with relatively low cost and convenient operability. However, the traditional physical adsorbent has low hydrophobic property, low water-oil separation efficiency, and difficult convenient operation and recycling at sea. Therefore, the development of smart adsorbents with high water-oil selectivity is urgently needed.
Porous materials with low density and high specific area are commonly used as oil absorbents, and starch molecules can form a network-shaped gel structure in an environment without a crosslinking agent, and the gel can be converted into various porous starch-based adsorbing materials through different drying methods, and the materials are generally called starch-based aerogels. The prior research reports the application of starch-based aerogel in oil absorption (carbohydrate. polymer.2011, 86, 1181-.
In recent years, the inspired by a leaf-bearing bionic structure endows an adsorbent with super-hydrophobic property from two aspects of reducing surface energy and constructing a multi-level micro-nano rough structure, and further realizes efficient oil removal in water. However, no reports on the development and research of the super-hydrophobic starch-based aerogel related technology are found at present. In addition, magnetic adsorbents that respond to external magnetic fields have received much attention because they can be remotely controlled and recovered. For example, chinese patent CN 111589186 a reports a magnetic super-hydrophobic polyurethane sponge compounded with nano Fe3O4, which not only realizes oil-water separation, but also improves the recoverability of the polyurethane sponge.
Therefore, the magnetic super-hydrophobic starch-based aerogel is developed to realize the remote control oil-water separation and convenient recovery, and has very important application value.
Disclosure of Invention
[ problem ] to
Research reports that starch-based aerogel has good oil absorption performance, but the starch-based aerogel does not have water-oil selective absorption capacity and cannot realize efficient oil-water separation. In addition, the problems of remote control and recoverability of the adsorbent can be generally solved by the composite nano magnetic particles, but the magnetic particles tend to self-aggregate, and the dispersibility in the starch solution is poor. These deficiencies limit the development of magnetic starch-based aerogels and their application in marine oil spill clean-up.
[ solution ]
In order to solve the defects, the nano-starch prepared by modifying enzyme regeneration by hexadecyl trimethoxy silane is used as a coating to endow the starch-based aerogel with super-hydrophobicity. In addition, the invention adopts tetraethoxysilane and KH560 silane coupling agent to couple Fe3O4The nano particles are subjected to surface modification in sequence, so that the nano particles can be uniformly dispersed in a starch solution, and the starch-based aerogel is further endowed with magnetism. Magnetic superhydrophobic prepared by such methodThe starch-based aerogel can solve the problems of oil leakage cleaning on the water surface, water quality purification and the like.
The first object of the present invention is to provide a method for preparing magnetic super-hydrophobic starch-based aerogel, comprising the following steps:
(1) preparation of hydrophobic suspension:
adding nano starch into an ethanol solution containing hexadecyl trimethoxy silane and ammonia water, and uniformly mixing to obtain a hydrophobic suspension;
(2) preparation of magnetic starch-based aerogel:
modifying starch-containing KH560 silane coupling agent modified shell-core structure SiO2-Fe3O4Heating and pasting the aqueous solution of the magnetic particles, refrigerating, freezing and drying to obtain the magnetic starch-based aerogel;
(3) preparing magnetic super-hydrophobic starch-based aerogel:
and (3) spraying the hydrophobic suspension obtained in the step (1) on the surface of the magnetic starch-based aerogel obtained in the step (2), and drying to obtain the magnetic super-hydrophobic starch-based aerogel.
In one embodiment of the present invention, the concentration of hexadecyltrimethoxysilane by mass relative to ethanol in the step (1) is 0.1 to 2.5 wt%, and the concentration of ammonia by mass relative to ethanol is 8 to 12 wt%.
In one embodiment of the present invention, the nano starch in the step (1) is added in an amount of 0.1 to 2.5 wt% based on the mass of ethanol.
In one embodiment of the present invention, the preparation method of the nano starch in step (1) comprises the following steps:
dispersing starch in buffer solution, heating for gelatinization, and cooling; adding pullulanase for incubation; heating the incubated solution to inactivate enzyme, centrifuging, taking supernatant, recrystallizing, washing and drying to obtain the nano starch.
In one embodiment of the present invention, the starch in the preparation method of nano starch in step (1) is waxy corn starch; the concentration of the starch in the buffer solution is 8-12 wt%; the pH value of the buffer solution is 4.5-5.5; the heating gelatinization is carried out at 70-100 ℃ for 30-45 min; the temperature after cooling is 50-60 ℃; the pullulanase is added with the enzyme activity of 25-35 ASPU per gram of dry starch; the incubation temperature and the incubation time are respectively 50-60 ℃ and 6-10 hours; the enzyme is deactivated by heating in boiling water; the recrystallization temperature and time are respectively 3-5 ℃ and 6-10 hours.
In one embodiment of the present invention, the step (1) of uniformly mixing is performed by stirring at 200 to 500rpm for 0 to 8 hours.
In one embodiment of the present invention, the starch in step (2) includes one or more of tapioca starch, common corn starch, waxy corn starch, rice starch, wheat starch, and potato starch.
In one embodiment of the invention, the starch-containing and KH560 silane coupling agent modified shell-core structure SiO in the step (2)2-Fe3O4The concentration of starch in the aqueous solution of the magnetic particles is 4.0-10.0 wt% relative to water; the concentration of the KH560 silane coupling agent modified shell-core structure magnetic particles relative to water is 0.2-0.4 wt%.
In one embodiment of the invention, the heating gelatinization in the step (2) is carried out for 30-45 min at 70-100 ℃; the refrigeration temperature and the refrigeration time are respectively 3-5 ℃ and 20-30 hours; the freezing temperature and the freezing time are respectively-20 to-30 ℃ and 20 to 30 hours; the drying method is freeze drying.
In one embodiment of the present invention, the KH560 silane coupling agent modified shell-core structure SiO in step (2)2-Fe3O4The preparation method of the magnetic particles comprises the following steps:
will contain Fe3+And Fe2+Mixing the aqueous solution with an ammonia solution, and reacting at 65-75 ℃ and 500-700 rpm for 25-35 minutes under the protection of inert gas; after the reaction is finished, washing to obtain a product; adding ethanol, water, ethyl orthosilicate and ammonia water into the product, and reacting for 5-7 hours at 20-30 ℃ and 200-400 rpm; adding KH560 silane coupling agent, and reacting at 45-55 deg.C and 200-400 rpm for 1.5-2.5 hr to obtain KH560 silane coupling agent modified magnetic particles with shell-core structureAnd (4) adding the active ingredients.
In one embodiment of the present invention, the inert gas is one or both of argon and nitrogen.
In one embodiment of the present invention, the method for preparing the magnetic particles having a shell-core structure modified with the KH560 silane coupling agent in step (2) comprises Fe3+And Fe2+The volume ratio of the aqueous solution to the aqueous ammonia solution of (1): 9 to 11, wherein the concentration of ammonia water is 0.30 to 0.40mol/L, Fe2+With Fe3+The mass ratio of (1): 1.5-2.5; the addition amounts of ethanol, water, ethyl orthosilicate, ammonia water and KH560 are respectively 100, 20-30, 0.2-0.3, 4-6 and 0.1-0.3 g/g of product.
In one embodiment of the present invention, the spraying amount of the hydrophobic suspension in the step (3) is 0.0005 to 0.0015g/cm2。
The second purpose of the invention is the magnetic super-hydrophobic starch-based aerogel prepared by the method.
The third purpose of the invention is to apply the magnetic super-hydrophobic starch-based aerogel disclosed by the invention to the field of oil-water separation.
In one embodiment of the invention, the application comprises cleaning of oil spills at sea.
[ advantageous effects ]
(1) In the preparation method of the magnetic super-hydrophobic starch-based aerogel for oil-water separation, the used base and coating raw materials are low-cost degradable starch, toxic hydrophobic modification reagents containing fluorine, chlorine and the like are not involved in the preparation and modification processes, and secondary pollution is not easily generated in practical application.
(2) The invention adopts hexadecyl trimethoxy modified nanometer starch suspension as the raw material of the surface coating, and endows the starch-based aerogel with super-hydrophobic characteristics (the contact angle is more than 151.5 degrees and more than 150.0 degrees, and the sliding angle is less than 8.0 degrees and less than 10.0 degrees).
(3) The invention adopts a rapid coprecipitation method to prepare Fe3O4Nano particles are sequentially modified by tetraethoxysilane and KH560 silane coupling agent to make Fe3O4The surface of the nano particle is covered with SiO2A shell layer which provides more hydroxyl groups for the KH560 silane coupling agent to graft, and improves Fe3O4The surface potential of the nano particles improves the dispersibility of the nano particles in aqueous solution.
(4) The invention relates to Fe modified by tetraethoxysilane and KH560 silane coupling agent3O4The nano particles are compounded with starch to prepare magnetic starch-based aerogel, Fe3O4The nanoparticles were uniformly dispersed in the aerogel and fixed therein via an ether bond, giving a saturation magnetization of 5.04emu/g to the starch-based aerogel.
(5) The magnetic super-hydrophobic starch-based aerogel provided by the invention shows excellent water-oil selective absorptivity, namely an oil-water separation characteristic, can be subjected to remote control floating oil absorption under the guidance of a magnetic field, can be recovered by magnet adsorption after oil absorption is finished, and shows great potential for being applied to ocean oil leakage cleaning.
Drawings
FIG. 1 is an X-ray diffraction pattern of the magnetic super-hydrophobic starch-based aerogel prepared in example 1.
FIG. 2 is a scanning electron microscope image of the magnetic super-hydrophobic starch-based aerogel prepared in example 1.
Fig. 3 is a hysteresis regression curve of the magnetic superhydrophobic starch-based aerogel prepared in example 1.
FIG. 4 is a graph of water contact angles of magnetic superhydrophobic starch-based aerogels prepared in example 2 and comparative example 1 after treatment with coating suspensions having different contents of hexadecyltrimethoxysilane.
Fig. 5 is a water contact angle of the magnetic super-hydrophobic starch-based aerogels prepared in example 3 and comparative example 2 after being treated with coating suspensions with different nano-starch contents.
FIG. 6 shows the water contact angles of the magnetic super-hydrophobic starch-based aerogel prepared in example 4 after being treated with coating suspensions for different stirring times.
FIG. 7 is a bar graph of the absorption capacity of the magnetic super-hydrophobic starch-based aerogel for oil-water separation prepared in example 1 for various organic liquids.
FIG. 8 shows the oil absorption condition at the water bottom of the magnetic super-hydrophobic starch-based aerogel for oil-water separation prepared in example 1.
Fig. 9 is a water contact angle of the magnetic starch-based aerogel prepared in comparative example 1 without the super-hydrophobic nano-starch coating treatment.
FIG. 10 shows the water bottom oil absorption of the magnetic starch-based aerogel prepared by the treatment of the non-excess water nano-starch coating prepared in comparative example 1.
FIG. 11 is a scanning electron microscope image of the distribution state of the magnetic particles without the modification of tetraethoxysilane and KH560 silane coupling agent in the super-hydrophobic starch-based aerogel prepared in the comparative example 5.
Fig. 12 is a surface potential histogram of the shell-core structure magnetic particles prepared in example 1 and comparative examples 5, 6, and 7.
Detailed Description
The following description of the preferred embodiments of the present invention is provided for the purpose of better illustrating the invention and is not intended to limit the invention thereto.
The reagents or instruments used in the examples are not indicated by the manufacturer, and are regarded as conventional products commercially available.
The test method comprises the following steps:
1. measurement of Water contact Angle and sliding Angle
Contact angle and sliding angle of 5. mu.L and 10. mu.L water droplets on the sample surface were measured using KRUSS DSA100 contact angle measuring instrument, respectively.
2. Magnetic correlation characterization test
Measuring the X-ray diffraction spectrum of the magnetic particles by using a D2 PHASER 154X-ray diffractometer; observing the dispersion state of the magnetic particles by adopting an S-4800 field emission scanning electron microscope; measuring the magnetism of the sample in a magnetic field of 20kOe by using a PPMS Dynacool vibration sample magnetometer; the particle surface potential of the magnetic particles was measured using a zetasizerano zs90 nanometer particle size potential analyzer.
3. Measurement of oil absorption Capacity
Weighing the prepared magnetic super-hydrophobic starch-based aerogel for oil-water separation, and marking the weight as m1Put into a beaker filled with 30g of organic liquid, and the organic liquid is addedThe mass of the liquid is recorded as m2(i.e., m)2Equal to 30g), take out the aerogel after 45 minutes of absorption, weigh the mass m of the organic liquid remaining in the beaker3The formula is calculated according to the oil absorption capacity:
oil absorption capacity ═ m2-m3)/m1
Example 1
A method for preparing magnetic super-hydrophobic starch-based aerogel, comprising the steps of:
(1) preparing nano starch:
dispersing waxy corn starch in a buffer solution with the pH value of 5.0, and heating and gelatinizing the waxy corn starch at the temperature of 95 ℃ for 45min, wherein the concentration of the waxy corn starch in the buffer solution is 10.0 wt%; cooling to 55 deg.C, adding pullulanase into the above solution with enzyme activity of 30ASPU per gram dry starch, incubating at 55 deg.C for 8 hr, heating in boiling water to inactivate enzyme, and centrifuging to obtain supernatant; and then recrystallizing the supernatant for 8 hours at 4 ℃, washing the obtained precipitate to be neutral, and drying to obtain the nano starch.
(2) Preparation of hydrophobic suspension:
preparing an absolute ethanol solution with the concentration of hexadecyl trimethoxy silane of 1.5 wt% and the concentration of ammonia water of 10.0 wt%, immediately adding the nano starch in the step (1) with the amount of 1.5 wt% relative to the amount of the absolute ethanol into the solution, and stirring at 300rpm for 5 hours to obtain a hydrophobic suspension;
(3) preparation of magnetic particles of shell-core structure
Under the protection of argon, FeCl is contained3And FeCl2With 0.38mol/L aqueous ammonia in a ratio of 1: 10v/v mixing and stirring the reaction at 600rpm at 70 ℃ for 30 minutes; after the reaction is finished, washing to obtain a product; wherein Fe2+With Fe3+The mass ratio of (1): 2;
adding ethanol, water, ethyl orthosilicate and ammonia water into the product at the ratio of 100 g/g, 25 g/g, 0.25 g/g and 5g/g (relative to the product), stirring at 25 ℃ and 300rpm for 6 hours, adding 0.2g/g (relative to the product) of KH560 silane coupling agent into the product, and continuously stirring at 50 ℃ and 300rpm for 2 hours to prepare the magnetic particles with the shell-core structure;
(4) preparation of magnetic starch-based aerogel:
heating and gelatinizing an aqueous solution containing potato starch and the shell-core structure magnetic particles in the step (3) at 95 ℃ for 45min, and then sequentially refrigerating at 4 ℃ for 24 hours, freezing at-30 ℃ for 24 hours and freeze-drying to obtain the magnetic starch-based aerogel; wherein the concentration of potato starch relative to water is 8.0 wt%; the concentration of the shell-core structure magnetic particles with respect to water was 0.3 wt%;
(5) preparing magnetic super-hydrophobic starch-based aerogel:
spraying the hydrophobic suspension obtained in the step (2) on the surface of the magnetic starch-based aerogel obtained in the step (4), and drying to obtain the magnetic super-hydrophobic starch-based aerogel, wherein the spraying amount of the hydrophobic suspension is 0.001g/cm2。
The obtained magnetic super-hydrophobic starch-based aerogel is tested, and the test results are as follows:
FIG. 1 is an X-ray diffraction pattern of a magnetic super-hydrophobic starch-based aerogel; as can be seen from fig. 1: fe appears in an X-ray diffraction pattern of the magnetic super-hydrophobic starch-based aerogel3O4All characteristic peaks of the nanoparticles.
FIG. 2 is a scanning electron microscope image of magnetic super-hydrophobic starch-based aerogel. As can be seen from fig. 2: fe3O4The nanoparticles are uniformly dispersed and complexed therein.
Fig. 3 is a hysteresis regression curve of magnetic superhydrophobic starch-based aerogels. As can be seen from fig. 3: the hysteresis regression line shows that it is given a saturation magnetization of 5.04 emu/g.
Example 2 optimization of hexadecyltrimethoxysilane
The procedure (2) in example 1 was adjusted to:
preparing an absolute ethanol solution with the concentration of hexadecyl trimethoxy silane of 0.5, 1.0, 1.5, 2.0 and 2.5wt percent and the concentration of ammonia water of 10.0wt percent, immediately adding the nano starch in the step (1) of the amount of 1.5wt percent relative to the amount of the absolute ethanol into the solution, and stirring at 300rpm for 5 hours to obtain a hydrophobic suspension;
the rest is kept the same as example 1, and the magnetic super-hydrophobic starch-based aerogel is obtained.
The obtained magnetic super-hydrophobic starch-based aerogel is tested, and the test result is shown in fig. 4:
as can be seen from fig. 4: the water contact angles of the surfaces of the magnetic starch-based aerogels prepared with the concentrations of hexadecyltrimethoxysilane of 0.5, 1.0, 1.5, 2.0 and 2.5wt are 104.4 °, 138.6 °, 151.5 °, 151.1 ° and 150.6 °, respectively, and the surfaces of the magnetic starch-based aerogels spray-treated with a coating suspension containing more than 1.5 wt% of hexadecyltrimethoxysilane can achieve a superhydrophobic degree.
Example 3 optimization of Nano-starch
The procedure (2) in example 1 was adjusted to:
preparing an absolute ethanol solution with the concentration of hexadecyl trimethoxy silane of 1.5 wt% and the concentration of ammonia water of 10.0 wt%, immediately adding the nano starch in the step (1) with the dosage of 0.5, 1.0, 1.5, 2.0 and 2.5 wt% relative to the absolute ethanol into the solution, and stirring at 300rpm for 5 hours to obtain a hydrophobic suspension;
the rest is kept the same as example 1, and the magnetic super-hydrophobic starch-based aerogel is obtained.
The obtained magnetic super-hydrophobic starch-based aerogel is tested, and the test result is shown in fig. 5:
as can be seen from fig. 5: when the concentration of the nano starch is 0.5, 1.0, 1.5, 2.0 and 2.5 wt%, the water contact angles of the surface of the prepared magnetic starch-based aerogel are respectively 141.2 degrees, 147.3 degrees, 151.5 degrees, 144.3 degrees and 131.4 degrees, the sliding angles are respectively 25.7 degrees, 13.9 degrees, 8.0 degrees, 8.9 degrees and 9.4 degrees, and the surface of the magnetic starch-based aerogel sprayed and treated by the coating suspension containing 1.5 wt% of the nano starch can reach the super-hydrophobic degree.
Example 4
The procedure (2) in example 1 was adjusted to:
preparing an absolute ethanol solution with 1.5 wt% of hexadecyl trimethoxy silane and 10.0 wt% of ammonia water, immediately adding 1.5 wt% of the nano starch in the step (1) relative to the amount of the absolute ethanol into the solution, and stirring at 300rpm for 0, 1, 2, 3, 4, 5, 6, 7 and 8 hours to obtain a hydrophobic suspension;
the rest is kept the same as example 1, and the magnetic super-hydrophobic starch-based aerogel is obtained.
The obtained magnetic super-hydrophobic starch-based aerogel is tested, and the test result is shown in fig. 6:
as can be seen from fig. 6: the water contact angles of the surfaces of the magnetic starch-based aerogels treated by the hydrophobic suspensions respectively obtained by stirring for 0, 1, 2, 3, 4, 5, 6, 7 and 8 hours are respectively 34.2 degrees, 66.0 degrees, 126.8 degrees, 132.6 degrees, 145.9 degrees, 151.5 degrees, 151.6 degrees, 151.9 degrees and 151.9 degrees, the sliding angles are respectively more than 90.0 degrees, 42.5 degrees, 23.0 degrees, 14.2 degrees, 8.0 degrees, 8.9 degrees, 8.7 degrees and 8.1 degrees, and the surfaces of the magnetic starch-based aerogels treated by spraying the coating suspensions stirred for more than 5 hours can achieve the super-hydrophobicity.
Example 5 oil-water separation
Selecting the magnetic super-hydrophobic starch-based aerogel prepared in example 1 to perform oil absorption capacity test on organic liquid; the test results are shown in fig. 7 and 8:
as can be seen from fig. 7: the magnetic super-hydrophobic starch-based aerogel for oil-water separation prepared in example 1 has absorption capacities of 3.96, 3.01, 3.95, 4.13, 2.57, 3.40, 6.34, 7.53, 5.25, 4.36, 3.34 and 3.36g/g for olive oil, gasoline, toluene, silicone oil, N-hexane, cyclohexane, dichloromethane, chloroform, dimethyl sulfoxide, N-dimethylformamide, acetone and ethanol, respectively; namely: the magnetic super-hydrophobic starch-based aerogel can effectively adsorb various organic liquids, wherein the chloroform absorption capacity is the best.
As can be seen from fig. 8: the magnetic super-hydrophobic starch-based aerogel for oil-water separation prepared in the embodiment 1 can completely absorb oil drops at the bottom of water, is not wetted by water, has good selective water-oil absorption, and realizes water-oil separation.
Comparative example 1
The steps (1), (2) and (5) of the example 1 are omitted, namely the super-hydrophobic suspension spraying treatment is not carried out on the magnetic starch-based aerogel, and the rest is consistent with the example 1, so that the magnetic starch-based aerogel is obtained.
The resulting magnetic starch-based aerogels were tested and the results are shown in fig. 9 and 10:
as can be seen from fig. 9: the water contact angle of the surface of the obtained magnetic starch-based aerogel is 0 degrees, because the porous aerogel can completely absorb water drops without being covered by the super-hydrophobic silanized nano starch coating, and the water repellency, namely the selective absorbency of anhydrous oil is not shown.
As can be seen from fig. 10: the obtained magnetic starch-based aerogel is completely soaked by water and cannot absorb oil drops at the water bottom, and oil-water separation cannot be realized.
Comparative example 2
The hexadecyl trimethoxy silane in step (2) of example 1 was omitted, and the rest was the same as in example 1, to obtain a magnetic starch-based aerogel.
The obtained magnetic starch-based aerogel was tested, and the test results were as follows:
the water contact angle of the magnetic starch-based aerogel is 31.3 degrees, because the surface of the aerogel is not modified by hexadecyl trimethoxy silane which can reduce the surface energy, the surface of the aerogel presents stronger hydrophilicity and does not meet the requirement of super hydrophobicity.
Comparative example 3
The step (1) of the example 1 is not carried out, the nano starch in the step (2) of the example 1 is omitted, and the rest is consistent with the step (1) of the example 1, so that the magnetic starch-based aerogel is obtained.
The obtained magnetic starch-based aerogel was tested, and the test results were as follows:
the water contact angle and the sliding angle of the surface of the magnetic starch-based aerogel are respectively 130.2 degrees and 40.0 degrees, because no nano starch capable of constructing a multi-layer micro-nano structure exists, the roughness of the aerogel is not enough to meet the requirement of super hydrophobicity.
Comparative example 4
The step (3) in the example 1 is not carried out, the magnetic particles with the shell-core structure in the step (4) in the example 1 are omitted, and the rest is consistent with the example 1, so that the super-hydrophobic starch-based aerogel is obtained.
The obtained super-hydrophobic starch-based aerogel is tested, and the test results are as follows:
the saturation magnetization of the super-hydrophobic starch-based aerogel is 0.00emu/g, namely, the super-hydrophobic starch-based aerogel is nonmagnetic.
Comparative example 5 No modification
The tetraethoxysilane and KH560 silane coupling agent in the step (3) of the example 1 are omitted, and the rest is consistent with the example 1, so that the magnetic super-hydrophobic starch-based aerogel is obtained.
The obtained super-hydrophobic starch-based aerogel is tested, and the test result is shown in fig. 11:
as can be seen from fig. 11: fe modified by silane coupling agent without tetraethoxysilane and KH5603O4The nanoparticles are present in the aerogel in an aggregated form, not homogeneously dispersed.
Comparative example 6 Ethyl orthosilicate alone
KH560 silane coupling agent in step (3) of example 1 was omitted, and the others were kept the same as in example 1, to obtain magnetic particles of a shell-core structure.
Comparative example 7 KH560 silane coupling agent alone
Tetraethoxysilane in step (3) of example 1 was omitted, and the same procedure as in example 1 was repeated to obtain magnetic particles having a shell-core structure.
The shell-core structure magnetic particles obtained in example 1 and comparative examples 5, 6 and 7 were tested, and the test results are shown in fig. 12:
as can be seen from fig. 12: tetraethoxysilane alone, KH560 silane coupling agent alone, and Fe without tetraethoxysilane and KH560 silane coupling agent modification3O4The surface potentials of the nanoparticles were-4.52, 6.33 and-5.46 mV, respectively, while the surface potential of the magnetic particles with a shell-core structure described in example 1 was raised to 10.53mV, indicating that the surface modification combination of tetraethoxysilane and KH560 silane coupling agent enhances the repulsion between particles (i.e., reduces the mutual attraction between particles), so that the magnetic particles can be more stably and uniformly dispersed in the aqueous starch solution and aerogel.
Comparative example 8
The hexadecyl trimethoxy silane in the example 1 is adjusted to be trichlorosilane, and the rest is consistent with the example 1, so that the magnetic super-hydrophobic starch-based aerogel is obtained.
And (3) carrying out performance test on the obtained magnetic super-hydrophobic starch-based aerogel, wherein the test result is as follows:
since the hydrogen chloride (i.e., hydrochloric acid) generated in the modification process can hydrolyze the starch, the starch-based aerogel modified by trichlorosilane is fragile, has high brittleness and extremely poor mechanical properties.
Comparative example 9
The hexadecyl trimethoxy silane in the example 1 is adjusted to be polydimethylsiloxane, and the rest is consistent with the example 1, so that the magnetic super-hydrophobic starch-based aerogel is obtained.
And (3) carrying out performance test on the obtained magnetic super-hydrophobic starch-based aerogel, wherein the test result is as follows:
because the polydimethylsiloxane, a prepolymer reagent, needs to be cured at a high temperature (80-160 ℃) for a long time, the starch-based aerogel modified by the polydimethylsiloxane can be obviously deformed and cracked in the curing process.
Claims (10)
1. A method for preparing magnetic super-hydrophobic starch-based aerogel is characterized by comprising the following steps:
(1) preparation of hydrophobic suspension:
adding nano starch into an ethanol solution containing hexadecyl trimethoxy silane and ammonia water, and uniformly mixing to obtain a hydrophobic suspension;
(2) preparation of magnetic starch-based aerogel:
modifying starch-containing KH560 silane coupling agent modified shell-core structure SiO2-Fe3O4Heating and pasting the aqueous solution of the magnetic particles, refrigerating, freezing and drying to obtain the magnetic starch-based aerogel;
(3) preparing magnetic super-hydrophobic starch-based aerogel:
and (3) spraying the hydrophobic suspension obtained in the step (1) on the surface of the magnetic starch-based aerogel obtained in the step (2), and drying to obtain the magnetic super-hydrophobic starch-based aerogel.
2. The method according to claim 1, wherein the concentration of hexadecyltrimethoxysilane by mass relative to the mass of the ethanol in the step (1) is 0.1-2.5 wt%.
3. The method according to claim 1, wherein the nano starch is added in an amount of 0.1 to 2.5 wt% based on the mass of ethanol in the step (1).
4. The method according to claim 1, wherein the starch-containing KH560 silane coupling agent-modified SiO with shell-core structure in step (2)2-Fe3O4The concentration of starch in the aqueous solution of the magnetic particles is 4.0-10.0 wt% relative to water; the concentration of the KH560 silane coupling agent modified shell-core structure magnetic particles relative to water is 0.2-0.4 wt%.
5. The method according to claim 1, wherein the KH560 silane coupling agent modified shell-core structure SiO of step (2)2-Fe3O4The preparation method of the magnetic particles comprises the following steps:
will contain Fe3+And Fe2+Mixing the aqueous solution with an ammonia solution, and reacting at 65-75 ℃ and 500-700 rpm for 25-35 minutes under the protection of inert gas; after the reaction is finished, washing to obtain a product; adding ethanol, water, ethyl orthosilicate and ammonia water into the product, and reacting for 5-7 hours at 20-30 ℃ and 200-400 rpm; then adding KH560 silane coupling agent, and reacting at 45-55 deg.C and 200-400 rpm for 1.5-2.5 hr to obtain the magnetic particles with shell-core structure modified by KH560 silane coupling agent.
6. The method according to claim 5, wherein the KH560 silane coupling agent modified shell-core structure magnetic particles prepared in the step (2) are Fe-containing particles3+And Fe2+The volume ratio of the aqueous solution to the aqueous ammonia solution of (1): 9 to 11, wherein the concentration of ammonia water is 0.30 to 0.40mol/L, Fe2+With Fe3+The mass ratio of (1): 1.5-2.5; the addition amounts of ethanol, water, ethyl orthosilicate, ammonia water and KH560 are respectively 100, 20-30, 0.2-0.3 and 46 and 0.1 to 0.3g/g product.
7. The method according to claim 1, wherein the preparation method of the nano starch in the step (1) comprises the following steps:
dispersing starch in buffer solution, heating for gelatinization, and cooling; adding pullulanase for incubation; heating the incubated solution to inactivate enzyme, centrifuging, taking supernatant, recrystallizing, washing and drying to obtain the nano starch.
8. The method according to claim 7, wherein the starch in the process for preparing nano-starch of step (1) is waxy corn starch; the concentration of the starch in the buffer solution is 8-12 wt%; the pH value of the buffer solution is 4.5-5.5; the heating gelatinization is carried out at 70-100 ℃ for 30-45 min; the temperature after cooling is 50-60 ℃; the pullulanase is added with the enzyme activity of 25-35 ASPU per gram of dry starch; the incubation temperature and the incubation time are respectively 50-60 ℃ and 6-10 hours; the enzyme is deactivated by heating in boiling water; the recrystallization temperature and time are respectively 3-5 ℃ and 6-10 hours.
9. The magnetic super-hydrophobic starch-based aerogel prepared by the method of any one of claims 1 to 8.
10. Use of the magnetic superhydrophobic starch-based aerogel of claim 9 in the field of oil-water separation.
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| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN115232356A (en) * | 2022-06-27 | 2022-10-25 | 华南理工大学 | Starch-based aerogel and preparation method and application thereof |
| WO2023098009A1 (en) * | 2021-12-03 | 2023-06-08 | 江南大学 | Preparation method for magnetic super-hydrophobic starch-based aerogel useful for oil-water separation |
Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN104694001A (en) * | 2014-12-12 | 2015-06-10 | 杭州师范大学 | Preparation method of superhydrophobic superparamagnetic silicone resin composite coating |
| CN105924686A (en) * | 2016-04-13 | 2016-09-07 | 四川大学 | Biology base polymer aerogel oil absorption material and preparation method thereof |
| CN110479218A (en) * | 2019-09-03 | 2019-11-22 | 东北林业大学 | A method of super-hydrophobic super-oleophylic aerogel material is prepared using nano-cellulose and nanoparticle as raw material |
| CN110724308A (en) * | 2019-10-15 | 2020-01-24 | 浙江农林大学 | Super-hydrophobic magnetic mixture and preparation method and application thereof |
| WO2021069783A1 (en) * | 2019-10-07 | 2021-04-15 | Consejo Superior De Investigaciones Científicas | Method for preparing hydrophobic aerogels |
Family Cites Families (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN105126767B (en) * | 2015-08-28 | 2017-11-14 | 南京理工大学 | A kind of super-hydrophobic hollow Fe3O4/ mesoporous silicon dioxide nano composite, preparation method and applications |
| US20210179797A1 (en) * | 2017-10-25 | 2021-06-17 | University Of Ulsan Foundation For Industry Cooperation | Complex and material containing same for oil-water separation |
| CN108031448A (en) * | 2017-12-27 | 2018-05-15 | 西北师范大学 | A kind of preparation method of zein base porous hydrophobic oil absorption material |
| CN114272904B (en) * | 2021-12-03 | 2022-11-22 | 江南大学 | Preparation method of magnetic super-hydrophobic starch-based aerogel for oil-water separation |
-
2021
- 2021-12-03 CN CN202111474867.7A patent/CN114272904B/en active Active
-
2022
- 2022-06-07 WO PCT/CN2022/097254 patent/WO2023098009A1/en unknown
Patent Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN104694001A (en) * | 2014-12-12 | 2015-06-10 | 杭州师范大学 | Preparation method of superhydrophobic superparamagnetic silicone resin composite coating |
| CN105924686A (en) * | 2016-04-13 | 2016-09-07 | 四川大学 | Biology base polymer aerogel oil absorption material and preparation method thereof |
| CN110479218A (en) * | 2019-09-03 | 2019-11-22 | 东北林业大学 | A method of super-hydrophobic super-oleophylic aerogel material is prepared using nano-cellulose and nanoparticle as raw material |
| WO2021069783A1 (en) * | 2019-10-07 | 2021-04-15 | Consejo Superior De Investigaciones Científicas | Method for preparing hydrophobic aerogels |
| CN110724308A (en) * | 2019-10-15 | 2020-01-24 | 浙江农林大学 | Super-hydrophobic magnetic mixture and preparation method and application thereof |
Non-Patent Citations (3)
| Title |
|---|
| GOLNOOSH AKHLAMADI ET AL.: "Sustainable and superhydrophobic cellulose nanocrystal-based aerogel derived from waste tissue paper as a sorbent for efficient oil/water separation", 《PROCESS SAFETY AND ENVIRONMENTAL PROTECTION》 * |
| 尚倩倩 等: "超疏水磁性纤维素气凝胶的制备及其吸油性能", 《林业工程学报》 * |
| 翟界秀: "常压干燥制备淀粉-SiO2气凝胶的研究", 《中国优秀硕士学位论文全文数据库 工程科技Ⅰ辑 (月刊)》 * |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2023098009A1 (en) * | 2021-12-03 | 2023-06-08 | 江南大学 | Preparation method for magnetic super-hydrophobic starch-based aerogel useful for oil-water separation |
| CN115232356A (en) * | 2022-06-27 | 2022-10-25 | 华南理工大学 | Starch-based aerogel and preparation method and application thereof |
| CN115232356B (en) * | 2022-06-27 | 2023-08-18 | 华南理工大学 | Starch-based aerogel and preparation method and application thereof |
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