CN113648978A - Preparation method and application of aerogel with oriented neurovascular network structure - Google Patents
Preparation method and application of aerogel with oriented neurovascular network structure Download PDFInfo
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Abstract
The invention discloses a preparation method of aerogel with an oriented neurovascular network structure, which comprises the following steps: (1) preparing oriented composite aerogel by directional freeze drying of viscous dispersion formed by Kapok Fiber (KF) and Sodium Alginate (SA); (2) by CaCl2Crosslinking the solution and depositing Ag nanoparticles; (3) and (3) placing the crosslinked aerogel in an environment with the humidity of 65% for humidifying, and performing chemical vapor deposition modification by using a silane reagent to obtain the super-hydrophobic fiber aerogel. The invention utilizes kapok fiber with a hollow structure and adopts a directional freezing methodObtaining the neurovascular network structure aerogel with high orientation degree; the unique structure endows the aerogel with excellent dry and wet pressure recovery performance and stable oil liquid adsorption rate; the oriented channel formed by the SA provides sufficient space for the rapid transmission of oil, and the KF serving as a blood tube-shaped capillary network structure can rapidly capture tiny oil drops in water, so that multifunctional oil/water separation can be realized.
Description
Technical Field
The invention belongs to the technical field of oil spill adsorption materials, and particularly relates to a preparation method of aerogel which can be subjected to dry-wet pressing and has an oriented neurovascular network structure, and application of the aerogel prepared by the method in the aspect of oil-water emulsion separation.
Background
Frequent offshore oil leakage events and discharge of industrial oily wastewater not only bring serious pollution problems to the marine environment, but also threaten the survival of marine organisms. The viscous and heavy oil contamination adhering to the body or on the hairiness deprives marine organisms of the ability to fly, swim, slide, and even to regulate their own body temperature, resulting in a decrease in body temperature, drowning, and even death. 1 ton of leaked oil can form 12km on the water surface2The large-area oil film can obstruct the normal sea-air exchange process to cause climate abnormality, and can also influence the photosynthesis of marine plants and the circulation of food chains, thereby causing the unbalance of a marine ecosystem. Since the oil adsorbing material can recycle the oil spill while achieving in-situ oil spill treatment, and has little influence on the environment, it is considered to be an important way to treat oil leakage events and oily wastewater.
The oil adsorption material mainly comprises inorganic materials (zeolite, diatomite, perlite, graphite and the like), polymer foam (polyurethane, melamine and the like), silica gel sponge, carbon materials, biomass materials and the like. The biomass oil absorption material has the advantages of rich raw materials, low cost, environmental friendliness, biodegradability and the like, and is widely concerned by the field of oil spill treatment research. Many biomass oil-absorbing materials can be used to effectively remove oil pollutants in water and have high oil adsorption capacity, such as modified natural fibers, functionalized chitosan sponges, lignin foams, polylactic acid non-woven fabrics, and the like.
Wangzong Qian et al (CN110314657A) adopt natural herba seu radix Metaplexis fiber with super-hydrophobic (contact angle up to 151.12 deg.) and lipophilic property as oil-absorbing material, the saturated adsorption rates to vegetable oil, engine oil and diesel oil are 81.52, 77.62 and 57.22g/g, respectively, and the separation efficiency is 85.2% -98.0% in 4 oil-water separation cycles. Wang Yimin et al (CN111068625A) hydrophobicize and modify the konjac fine powder, and by adding lotus leaves with hydrophobic leaf surfaces and loofah sponge powder with high biocompatibility, the surface tension of the material is rapidly reduced, so that oil stains can be rapidly diffused into the interior, and the konjac fine powder has good oil-water selectivity. However, these materials still have the disadvantages of poor mechanical properties, inability to react quickly to oil contaminants, etc., and become one of the important reasons for restricting the practical application of oil-absorbing materials. In addition, in surfactant stabilized oil-in-water emulsions, these materials still present a great challenge in separating the emulsion, since oil droplets are more difficult to trap in smaller sizes (d < 20 μm).
Disclosure of Invention
Based on the technical problems, the invention provides a preparation method and application of aerogel with an oriented neurovascular network structure.
The technical solution adopted by the invention is as follows:
a preparation method of aerogel with an oriented neurovascular network structure comprises the following steps:
(1) removing wax on the surface of the kapok fiber to obtain the kapok fiber with hydrophilic performance;
(2) adding the kapok fiber with the hydrophilic property and the sodium alginate powder treated in the step (1) into water, fully stirring and defoaming to form a viscous dispersoid, then pouring the dispersoid into a mould, directionally freezing under the condition of liquid nitrogen, and drying in a freeze dryer after the directional freezing is finished to obtain the composite aerogel;
(3) crosslinking the composite aerogel obtained in the step (2), and specifically soaking the composite aerogel in CaCl2Cleaning the solution with deionized water, and soaking in AgNO at room temperature3Adding into solution, and adding into AgNO under 70-80 deg.C water bath condition3Adding glucose into the solution for reaction, and then pre-freezing and freeze-drying after the reaction is finished to obtain the crosslinked composite aerogel;
(4) and (4) performing chemical vapor deposition hydrophobic modification on the crosslinked composite aerogel obtained in the step (3) by adopting a silane reagent to obtain the super-hydrophobic composite aerogel.
Preferably, in the step (1), the step of removing the wax from the surface of the kapok fiber is as follows:
firstly, adding sodium chlorite and acetic acid into water to obtain a mixed solution; the content of sodium chlorite in the mixed solution is 1-3 wt%, and the volume ratio of the added amount of acetic acid to the mixed solution is 0.3-2 ml: 100 ml;
adding the kapok fiber into the mixed solution for treatment, and removing wax on the surface; the treatment temperature is 70-80 ℃, and the treatment time is 1-2 h; and cleaning and drying after the treatment is finished.
Preferably, in step (2): the mass fraction of the kapok fiber in the dispersion is 0.4-0.6 wt%, and the mass fraction of the sodium alginate in the dispersion is 0.6-0.8 wt%; and the dispersion is prepared by adding kapok fiber with hydrophilic property and sodium alginate powder into hot water of 60-70 deg.C.
Preferably, in step (2):
when the aerogel is frozen, the dispersoid can be poured into three-dimensional moulds with different shapes to prepare aerogel materials with different three-dimensional appearance structures so as to adapt to different oil absorption occasions;
a copper plate is arranged on the bottom surface of the three-dimensional mold, and ice crystals are promoted to grow in the direction vertical to the copper plate by the temperature gradient formed by the liquid nitrogen and the copper plate in the directional freezing process; sodium alginate in the freeze-dried composite aerogel forms an oriented pore structure, and kapok fibers are crossed in the sodium alginate sheets to form a neurovascular network structure.
Preferably, in step (3): the CaCl is2The concentration of the solution is 4-6 wt%, and the composite aerogel is in CaCl2The soaking time in the solution is 4-5 h; the AgNO3The concentration of the solution is 2-3g/L, and the composite aerogel is in AgNO3The soaking time in the solution is 2-3 h; adding glucose into AgNO3After the solution is added, the concentration is 1-2 wt%, and the reaction time is 0.5-1 h.
Preferably, in step (4): the humidity during hydrophobic modification is controlled to be 65-70%, and (CH) is adopted as a silane reagent during chemical vapor deposition3)3SiCl and SiCl4，(CH3)3SiCl and SiCl4The dosage ratio of the components is 1: 1, and the deposition is carried out at normal temperature, and the deposition reaction time is 10-15 min.
The aerogel with the oriented neurovascular network structure prepared by the preparation method can be used for separating oil-in-water emulsions and is matched with reciprocating high-frequency oscillation, and the separation efficiency is 99.36-99.67%.
Compared with the prior art, the invention has the following advantages:
a. the method is characterized in that Kapok Fiber (KF) and Sodium Alginate (SA) are used as natural construction materials, the SA forms a pore structure with orientation by a directional freezing technology, and the KF in a hollow structure is crossed in an SA sheet to form a neurovascular network structure; due to the oriented sheet structure of the SA and the supporting effect of the neurovascular network KF, the compression performance of the aerogel is effectively enhanced. Benefiting from the excellent wet compression recovery performance of aerogel, aerogel can be expanded in oil again after manual extrusion and adsorbs oil, so show good reuse performance and stable oil adsorption capacity.
b. The prepared composite aerogel oil absorption material has excellent mechanical compression performance and repeated oil absorption performance due to the oriented flaky stacked SA layers and the crossed tubular KF network structure; KF can be used as a neural capillary network structure to quickly capture micro oil drops in water, thereby achieving quick oil liquid transmission and oil pollutant removal.
c. In the process of preparing the composite aerogel, Ag nano particles are adopted for attachment and the (CH) is adopted3)3SiCl and SiCl4The normal-temperature chemical gas phase modification step further improves the mechanical property of the aerogel and the quick reaction property of oil pollutants, and finally the super-hydrophobic oil absorption material which can recover under dry and wet pressure and can quickly capture and conduct oil is prepared.
d. The super-hydrophobic aerogel prepared by the invention has excellent recovery performance under dry and wet pressure states, can recover oil liquid in an extrusion mode, and has stable oil absorption rate (81.1% -89.8% of the initial oil absorption rate after 10 times of adsorption and extrusion cycles).
e. In the oil adsorption process, an oriented channel formed by the SA provides sufficient space for oil, and the rapid conduction of the oil is ensured; and KF can be used as a vascular capillary network to quickly capture tiny oil drops in water, thereby being beneficial to efficient oil/water separation. The composite aerogel prepared by the invention can separate various oil-in-water emulsions, and is matched with reciprocating high-frequency oscillation, so that the separation efficiency is 99.36-99.67%.
f. The biomass oil absorption material with excellent mechanical stability, namely the composite aerogel (O-KFs/SA), prepared by the invention can quickly capture oil liquid, can be repeatedly used, realizes multifunctional oil/water separation, especially can realize high-efficiency oil-in-water emulsion separation, and has important practical effect on the application of the biomass oil absorption material to actual oil/water separation.
Drawings
FIG. 1 is an SEM image of the microstructure of the finally prepared composite aerogel (O-KFs/SA) according to the present invention; wherein (a) is a transverse microscopic morphology structure SEM image, and (b) is a longitudinal microscopic morphology structure SEM image;
FIG. 2 is an O-KFs/SA static water contact angle image;
FIG. 3 is a stress-strain plot of O-KFs/SA; wherein (a) is a stress-strain plot under dry conditions and (b) is a stress-strain plot under wet conditions;
FIG. 4 shows the adsorption capacity of O-KFs/SA for different oils;
FIG. 5 is a graph of oil absorption capacity change during O-KFs/SA re-use;
fig. 6 is an image of an oil-in-water emulsion (toluene-in-water) before (a) and after (b) separation.
Detailed Description
The invention discloses a preparation method of a dry-wet pressure aerogel with an oriented neurovascular network structure and application of the dry-wet pressure aerogel in oil-water emulsion separation. The method comprises the following steps: (1) preparing the oriented composite aerogel by using a viscous dispersion formed by Kapok Fiber (KF) with wax removed from the surface and Sodium Alginate (SA) through a directional freeze-drying technology; (2) passing the composite aerogel through CaCl2Crosslinking the solution and depositing Ag nanoparticles; (3) placing the crosslinked aerogelAnd (3) carrying out humidity adjustment treatment under the environment with the humidity of 65%, and carrying out chemical vapor deposition modification by using a silane reagent to obtain the super-hydrophobic fiber aerogel. The invention utilizes kapok fiber with a hollow structure to obtain the neurovascular network structure aerogel with high orientation degree by a directional freezing method; the unique structure endows the aerogel with excellent dry and wet pressure recovery performance and stable oil liquid adsorption rate; the oriented channel formed by the SA provides sufficient space for the rapid transmission of oil, and the KF serving as a neural capillary network structure can rapidly capture tiny oil drops in water, so that multifunctional oil/water separation can be realized. The invention also provides an oscillation-assisted oil-in-water emulsion separation method, and the composite aerogel prepared by the invention has the separation efficiency of the oil-in-water emulsion reaching 99.39-99.68% by a reciprocating high-frequency oscillation-assisted method, thereby becoming a simple and efficient scheme for treating the oily wastewater by potentially replacing a membrane material.
The invention will be further illustrated with reference to specific examples:
example 1
(1) The Kapok Fiber (KF) is put into an aqueous solution (200mL) containing 1 wt% of sodium chlorite and 1.5mL of acetic acid, treated for 2h under the condition of a water bath at 75 ℃, taken out, washed and dried.
(2) Adding the treated KF and Sodium Alginate (SA) powder (0.5 wt%/0.67 wt%) into hot water (240mL) at 60 deg.C, stirring thoroughly and defoaming to obtain dispersion; pouring the obtained viscous dispersion into a Polytetrafluoroethylene (PTFE) mold, placing a copper plate at the bottom of the mold, performing directional freezing under the condition of liquid nitrogen (freezing time is 0.5h), then drying in a freeze dryer, and performing freeze drying for 48h to obtain the kapok fiber/sodium alginate composite aerogel with oriented pores.
(3) Soaking the composite aerogel in CaCl2The solution (5 wt%) is washed by deionized water and soaked in AgNO for 4h3In solution (3g/L) for 2h, then to AgNO3And adding 1 wt% of glucose into the solution, reacting for 1h under the condition of 80 ℃ water bath, cleaning, pre-freezing again, and freeze-drying to obtain the cross-linked composite aerogel.
(4) Will crosslinkThe composite aerogel is subjected to humidity regulation for 12 hours under the condition that the relative humidity is 65 percent, and (CH) is adopted3)3SiCl and SiCl4Chemical vapor deposition method for super-hydrophobic modification, (CH)3)3SiCl and SiCl4The dosage ratio of the super-hydrophobic composite aerogel and the super-hydrophobic composite aerogel is 1: 1, the deposition is carried out at normal temperature, and the deposition reaction time is 10min, so that the super-hydrophobic composite aerogel (O-KF/SA) is obtained.
In the method, during the directional freezing process, the ice crystals are promoted to grow along the direction vertical to the copper plate by the temperature gradient formed by the liquid nitrogen and the copper plate. SA in the freeze-dried composite aerogel forms an oriented pore structure, and KF is crossed in the SA sheet to form a neurovascular network structure.
When the aerogel is frozen, the dispersoid can be poured into three-dimensional moulds with different shapes to prepare aerogel materials with different three-dimensional structures so as to adapt to different oil absorption occasions.
The super-hydrophobic composite aerogel prepared by the method is subjected to an oil-in-water emulsion experiment: putting the super-hydrophobic composite aerogel (O-KF/SA) into an oil-in-water emulsion stabilized by Sodium Dodecyl Sulfate (SDS), and putting the oil-in-water emulsion into a multi-purpose speed-regulating oscillator, wherein the oscillator performs reciprocating motion at the oscillation frequency of 200-280rpm, the amplitude is 20mm, and the oscillation time is 30 min.
Further, the content of SDS was 0.1mg/mL, and the volume ratio of water to oil was 99: 1, the oil liquid is n-hexane, toluene, diesel oil and soybean oil respectively.
Example 2
(1) Putting Kapok Fiber (KF) into an aqueous solution (200mL) containing 2 wt% of sodium chlorite and 2mL of acetic acid, treating for 2h under the condition of 75 ℃ water bath, taking out, cleaning and drying.
(2) Adding the treated KF and Sodium Alginate (SA) powder (0.4 wt%/0.7 wt%) into hot water (240mL) at 70 ℃, and fully and uniformly stirring and defoaming to obtain a dispersion; pouring the obtained viscous dispersion into a Polytetrafluoroethylene (PTFE) mold, placing a copper plate at the bottom of the mold, performing directional freezing under the condition of liquid nitrogen (freezing time is 1h), then drying in a freeze dryer, and performing freeze drying for 48h to obtain the kapok fiber/sodium alginate composite aerogel with oriented pores.
(3) Soaking the composite aerogel in CaCl2The solution (4 wt%) is washed by deionized water and soaked in AgNO for 4h3In solution (2g/L) for 2h, then to AgNO3And adding 1 wt% of glucose into the solution, reacting for 1h under the condition of 80 ℃ water bath, cleaning, pre-freezing again, and freeze-drying to obtain the cross-linked composite aerogel.
(4) Conditioning the cross-linked composite aerogel for 12h under the condition that the relative humidity is 70 percent, and adopting (CH)3)3SiCl and SiCl4Chemical vapor deposition method for super-hydrophobic modification, (CH)3)3SiCl and SiCl4The dosage ratio of the super-hydrophobic composite aerogel and the super-hydrophobic composite aerogel is 1: 1, the deposition is carried out at normal temperature, and the deposition reaction time is 10min, so that the super-hydrophobic composite aerogel (O-KF/SA) is obtained.
Example 3
(1) Putting Kapok Fiber (KF) into an aqueous solution (200mL) containing 1 wt% of sodium chlorite and 2mL of acetic acid, treating for 1h under the condition of 80 ℃ water bath, taking out, cleaning and drying.
(2) Adding the treated KF and Sodium Alginate (SA) powder (0.4 wt%/0.6 wt%) into hot water (240mL) at 70 ℃, and fully and uniformly stirring and defoaming to obtain a dispersion; pouring the obtained viscous dispersion into a Polytetrafluoroethylene (PTFE) mold, placing a copper plate at the bottom of the mold, performing directional freezing under the condition of liquid nitrogen, drying in a freeze dryer, and performing freeze drying for 48 hours to obtain the kapok fiber/sodium alginate composite aerogel with oriented pores.
(3) Soaking the composite aerogel in CaCl2The solution (6 wt%) is washed by deionized water and soaked in AgNO for 5h3In solution (2g/L) for 3h, then to AgNO3And adding 1 wt% of glucose into the solution, reacting for 0.5h under the condition of 80 ℃ water bath, cleaning, pre-freezing again, and freeze-drying to obtain the cross-linked composite aerogel.
(4) Conditioning the cross-linked composite aerogel for 12h under the condition that the relative humidity is 70 percent, and adopting (CH)3)3SiCl and SiCl4Chemical vapor deposition method for super-hydrophobic modification, (CH)3)3SiCl and SiCl4The dosage ratio of the super-hydrophobic composite aerogel and the super-hydrophobic composite aerogel is 1: 1, the deposition is carried out at normal temperature, and the deposition reaction time is 15min, so that the super-hydrophobic composite aerogel (O-KF/SA) is obtained.
Taking the composite aerogel O-KF/SA sample prepared in the example 1, carrying out material apparent morphology observation, element component analysis, compression performance test and water contact angle test, and evaluating the oil absorption multiplying power and the oil-water separation efficiency of the sample, wherein the method and the result are as follows:
(1) material structure and surface water contact angle
FIG. 1 is SEM image of cross section (a) and longitudinal section (b) of O-KF/SA in example 1, ice crystals grow perpendicular to the copper plate due to temperature gradient of the copper plate during freezing, oriented pores are obtained after freeze drying, introduced hollow KF cross exists in the SA sheet structure, and unique neurovascular network cross structure is shown. After hydrophobic modification of Ag nanoparticles and a low surface energy substance silane reagent, a randomly grown methyl silicon nanowire covering layer is formed on the surface of O-KF/SA, and the existence of Ag and Si elements is further confirmed in an element spectrogram. Due to the existence of the hydrophobic methyl silicon nanowire covering layer, the contact angle of the O-KF/SA surface is 153.6 +/-0.4 degrees (as shown in figure 2), which indicates that the aerogel has super-hydrophobic performance.
The compression performance test is carried out on O-KF/SA, and the result of FIG. 3(a) shows that the O-KF/SA only generates slight plastic deformation under the condition of high compression strain (60%), the height of the O-KF/SA can be recovered to 96% of the initial height after the pressure is released, and the O-KF/SA shows excellent compression recovery performance. Due to the accumulation of plastic deformation from multiple compressions, the sample exhibited 12.0% irreversible deformation after 50 load-unload cycles, but still had good compression recovery. The excellent recovery performance is mainly derived from the unique lamellar structure of SA, SA can provide enough space to cope with elastic deformation when a sample is stressed, and KF in a neurovascular network shape provides supporting force for an SA layer, so that SA can recover to the original position after the stress is released, and the collapse deformation of the sample structure is avoided.
(2) Oil wetting and oil absorption properties
Due to the existence of the methyl silicon nanowire covering layer with low surface energy on the surface of O-KF/SA, the material is endowed with excellent oleophylic property (oil contact angle-0 ℃) and a highly-oriented pore structure, and the characteristic of rapid penetration of oil on the surface of O-KF/SA is ensured. 50 mul of soybean oil can be quickly absorbed by the material within 1.2s, and even for high-viscosity engine oil 20w-50, the soybean oil can completely permeate into the material within 4.8 s. Due to the excellent oleophylic property and the highly porous neurovascular network structure, the figure 4 shows that the adsorption capacity of the material to different oil liquids and organic solvents can reach 30 g/g-63 g/g. In addition, the O-KF/SA was tested for wet compression performance by immersing it in an absolute ethanol solution and manually pressing, and the O-KF/SA deformed by wet compression was swollen after re-immersing in the absolute ethanol solution, and fig. 3(b) shows that it shows excellent wet shape recovery performance (97.3% -91.2%) in 10 wet pressing cycles.
In view of the characteristics of the aerogel, oil recovery and next oil adsorption are realized by manually extruding the aerogel full of oil, and in the process of 10 times of adsorption-desorption cycles, the aerogel can still keep 81.14% -89.82% of the initial adsorption capacity after 10 times of cycles although irreversible structural deformation exists (figure 5). Compared with other recovery methods, such as distillation, solvent extraction and the like, the method has the advantages of simplicity, high efficiency, time saving and energy saving.
(3) Oil-in-water emulsion separation
The separation of oil-in-water emulsions is particularly important to the environment but is more challenging because of the oil droplet diameter < 20 μm. In this invention, to separate different oil-in-water emulsions (n-hexane in water, toluene in water, diesel oil in water, soybean oil in water), O-KF/SA samples were placed in glass bottles containing the oil-in-water emulsions and kept in a mechanical shaker for 30min with continuous high frequency shaking. As the mechanical shaking process proceeded, the original milky-white oil-in-water emulsion was observed to gradually become transparent, no minute n-hexane droplets were observed under an optical microscope (fig. 6), the separation efficiency obtained by the test was 99.52%, and the Total Organic Carbon (TOC) content in the separated water sample was less than 51.41 mg/L. Furthermore, the separation efficiencies for toluene-in-water, diesel-in-water, and soybean-in-water were 99.68%, 99.39%, and 99.54%, respectively, indicating the great potential of O-KF/SA in separating oil-in-water emulsions.
Oil-in-water emulsion separation mechanism:
in general, the surface of the tiny oil droplets in an emulsion system is covered with a surfactant, the hydrophilic end of which extends into the water, isolating the tiny oil droplets from the solid oil absorbing material, resulting in inefficient droplet capture, and therefore the inability of most materials to separate surfactant stabilized oil droplets from the oil-in-water emulsion. However, it is conceivable that the kinetic energy recoil of the surfactant coated oil droplets as they impact the solid surface causes the droplets to deform, flatten out and spread out horizontally, creating an opportunity for demulsification, whereby the droplets come into contact with the lipophilic material; when the solid has sufficient oleophilic properties, oil droplets are adsorbed onto the oleophilic material before a backflushing process occurs. In other words, the oil droplets may be absorbed by the superoleophilic material under the impact leaving only the surfactant. Therefore, the invention creates repeated oscillation conditions to apply kinetic energy to emulsified oil drops, so that the micro oil drops collide with O-KF/SA with super-oleophilic property, thereby realizing the rapid capture of the micro oil drops in the oil-in-water emulsion and achieving the high-efficiency oil-in-water emulsion separation.
Due to the novel oriented neurovascular network structure, in the oil drop flattening process, the hollow KF serving as a neurocapillary network structure can quickly capture tiny oil drops in the emulsion, and the oriented channels provide sufficient space for oil drop transmission. Further, oil drops deposited on the surface of the material can attract other tiny oil drops again, so that the continuous oil drop capturing and gathering process realizes an O-KF/SA efficient emulsion separation process.
The invention selects natural kapok fiber and sodium alginate as a construct, and the composite aerogel prepared by directional freeze drying has an oriented neurovascular network structure, is attached with Ag nanoparticles and has a structure of (CH)3)3SiCl and SiCl4The super-hydrophobic oil absorption material (O-KF/S) which can recover under dry and wet pressure and can quickly capture and conduct oil is prepared by normal-temperature chemical vapor modificationA) In that respect The oil absorption material has excellent mechanical compression performance and repeated oil absorption performance due to the oriented flaky stacked SA layer and the crossed tubular KF network structure; KF can be used as a neural capillary network structure to quickly capture micro oil drops in water, thereby achieving quick oil liquid transmission and oil pollutant removal. In addition, the O-KF/SA prepared by the invention combines an oscillation auxiliary method to show great potential in the process of separating oil-in-water emulsion.
The embodiments described above are presented to enable a person having ordinary skill in the art to make and use the invention. It is to be understood that the above description is not intended to limit the present invention, and the present invention is not limited to the above examples, and those skilled in the art may make modifications, alterations, additions or substitutions within the spirit and scope of the present invention.
Claims (7)
1. A preparation method of aerogel with an oriented neurovascular network structure is characterized by comprising the following steps:
(1) removing wax on the surface of the kapok fiber to obtain the kapok fiber with hydrophilic performance;
(2) adding the kapok fiber with the hydrophilic property and the sodium alginate powder treated in the step (1) into water, fully stirring and defoaming to form a viscous dispersoid, then pouring the dispersoid into a mould, directionally freezing under the condition of liquid nitrogen, and drying in a freeze dryer after the directional freezing is finished to obtain the composite aerogel;
(3) crosslinking the composite aerogel obtained in the step (2), and specifically soaking the composite aerogel in CaCl2Cleaning the solution with deionized water, and soaking in AgNO at room temperature3Adding into solution, and adding into AgNO under 70-80 deg.C water bath condition3Adding glucose into the solution for reaction, and then pre-freezing and freeze-drying after the reaction is finished to obtain the crosslinked composite aerogel;
(4) and (4) performing chemical vapor deposition hydrophobic modification on the crosslinked composite aerogel obtained in the step (3) by adopting a silane reagent to obtain the super-hydrophobic composite aerogel.
2. The method for preparing the aerogel with the oriented neurovascular network structure according to claim 1, wherein in the step (1), the step of removing the wax on the surface of the kapok fiber is as follows:
firstly, adding sodium chlorite and acetic acid into water to obtain a mixed solution; the content of sodium chlorite in the mixed solution is 1-3 wt%, and the volume ratio of the added amount of acetic acid to the mixed solution is 0.3-2 ml: 100 ml;
adding the kapok fiber into the mixed solution for treatment, and removing wax on the surface; the treatment temperature is 70-80 ℃, and the treatment time is 1-2 h; and cleaning and drying after the treatment is finished.
3. The method for preparing the aerogel with the oriented neurovascular network structure according to claim 1, wherein in the step (2): the mass fraction of the kapok fiber in the dispersion is 0.4-0.6 wt%, and the mass fraction of the sodium alginate in the dispersion is 0.6-0.8 wt%; and the dispersion is prepared by adding kapok fiber with hydrophilic property and sodium alginate powder into hot water of 60-70 deg.C.
4. The method for preparing the aerogel with the oriented neurovascular network structure according to claim 1, wherein in the step (2):
when the aerogel is frozen, the dispersoid can be poured into three-dimensional moulds with different shapes to prepare aerogel materials with different three-dimensional appearance structures so as to adapt to different oil absorption occasions;
a copper plate is arranged on the bottom surface of the three-dimensional mold, and ice crystals are promoted to grow in the direction vertical to the copper plate by the temperature gradient formed by the liquid nitrogen and the copper plate in the directional freezing process; sodium alginate in the freeze-dried composite aerogel forms an oriented pore structure, and kapok fibers are crossed in the sodium alginate sheets to form a neurovascular network structure.
5. The method for preparing the aerogel with the oriented neurovascular network structure according to claim 1, wherein the step (A) is3) The method comprises the following steps: the CaCl is2The concentration of the solution is 4-6 wt%, and the composite aerogel is in CaCl2The soaking time in the solution is 4-5 h; the AgNO3The concentration of the solution is 2-3g/L, and the composite aerogel is in AgNO3The soaking time in the solution is 2-3 h; adding glucose into AgNO3After the solution is added, the concentration is 1-2 wt%, and the reaction time is 0.5-1 h.
6. The method for preparing the aerogel with the oriented neurovascular network structure according to claim 1, wherein in the step (4): the humidity during hydrophobic modification is controlled to be 65-70%, and (CH) is adopted as a silane reagent during chemical vapor deposition3)3SiCl and SiCl4，(CH3)3SiCl and SiCl4The dosage ratio of the components is 1: 1, and the deposition is carried out at normal temperature, and the deposition reaction time is 10-15 min.
7. The aerogel with oriented neurovascular network structure prepared by the preparation method of any one of claims 1 to 6 can be used for separating oil-in-water emulsions, and the separation efficiency is 99.36 to 99.67 percent by matching with reciprocating high-frequency oscillation.
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Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN115282888A (en) * | 2021-12-22 | 2022-11-04 | 青岛大学 | Preparation method and application of super-hydrophobic aerogel with ultra-fast oil adsorption capacity and high compression recovery performance |
| CN116580520A (en) * | 2023-07-14 | 2023-08-11 | 江苏恒力化纤股份有限公司 | Fire disaster early warning aerogel and preparation method thereof |
Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103992503A (en) * | 2014-05-27 | 2014-08-20 | 哈尔滨工业大学 | Preparation method of seaweed cellulose aerogel-carbamic acid alkyl ester type oil gelling agent composite oil spill control material |
| CN108654579A (en) * | 2018-05-17 | 2018-10-16 | 江苏大学 | A kind of preparation method of sodium alginate/cattail/graphene oxide composite aerogel |
-
2021
- 2021-08-16 CN CN202110935978.7A patent/CN113648978B/en active Active
Patent Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103992503A (en) * | 2014-05-27 | 2014-08-20 | 哈尔滨工业大学 | Preparation method of seaweed cellulose aerogel-carbamic acid alkyl ester type oil gelling agent composite oil spill control material |
| CN108654579A (en) * | 2018-05-17 | 2018-10-16 | 江苏大学 | A kind of preparation method of sodium alginate/cattail/graphene oxide composite aerogel |
Non-Patent Citations (3)
| Title |
|---|
| 刘亚迪;裴莹;郑学晶;汤克勇;: "纤维素基气凝胶的制备及功能材料构建" * |
| 李飞;邢丽;向军辉;赵春林;李真酉;章婷;付蕊;: "疏水性纤维素-SiO_2复合气凝胶的非超临界制备" * |
| 陈苏琴;邓稳;左克曼;吴伟兵;: "交联型超双疏细菌纤维素复合气凝胶" * |
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN115282888A (en) * | 2021-12-22 | 2022-11-04 | 青岛大学 | Preparation method and application of super-hydrophobic aerogel with ultra-fast oil adsorption capacity and high compression recovery performance |
| CN115282888B (en) * | 2021-12-22 | 2024-02-02 | 青岛大学 | Preparation method and application of super-hydrophobic aerogel with super-fast oil adsorption capacity and high compression recovery performance |
| CN116580520A (en) * | 2023-07-14 | 2023-08-11 | 江苏恒力化纤股份有限公司 | Fire disaster early warning aerogel and preparation method thereof |
| CN116580520B (en) * | 2023-07-14 | 2023-09-19 | 江苏恒力化纤股份有限公司 | Fire disaster early warning aerogel and preparation method thereof |
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