A hyperbranched polysiloxane modified oxidized nanocellulose aerogel, and a preparation method and application thereof

Abstract

The application provides a hyperbranched polysiloxane modified oxidized nanocellulose aerogel as well as a preparation method and application thereof. The preparation method comprises the following steps: mixing oxidized nanocellulose and Tris-HCl solution to prepare an oxidized nanocellulose suspension, adding hyperbranched polysiloxane (TA-HBPSi) derived from tannic acid and cashew phenol to carry out reaction, and carrying out freeze drying to obtain the oxidized nanocellulose aerogel (TA-HBPSi@TOCNF). The prepared oxidized nanocellulose aerogel has a highly complete three-dimensional network structure, enhanced mechanical performance, and a porous structure on the surface, so that the aerogel has more active sites, thereby improving the adsorption capacity. The aerogel is green and environmentally friendly, has excellent adsorption effect, and has a good application prospect in environmental pollution treatment.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of environmental governance, more particularly, to a hyperbranched polysiloxane modified oxidized nanocellulose aerogel and a preparation method and application thereof. BACKGROUND

[0002] Pesticides and heavy metals are common pollutants with high toxicity and carcinogenicity. Waste discharge, mining, wastewater irrigation and other behaviors have seriously polluted water bodies and soils, and thus have posed a serious challenge to China's ecological system. Among them, imazalil is often used to protect crops such as grains and fruits from fungal invasion, and excessive use has resulted in its large residue in the environment. Cadmium is a toxic heavy metal commonly found in metallurgy, mining, and chemical industries. Long-term exposure to cadmium-containing environments can cause serious damage to the kidneys, bones, lungs, and nervous system. The pollution of imazalil and cadmium has attracted widespread attention. In order to reduce their harm in the environment, monitoring and management need to be strengthened, and effective measures need to be taken to reduce pollution. Therefore, environmental and ecological protection and pollution remediation have attracted widespread attention. How to effectively repair and manage soil and water bodies while researching efficient, economical, and environmentally friendly treatment technologies and methods is a technical problem that needs to be solved.

[0003] In order to reduce the damage of pollutants to the environment, current treatment methods mainly include chemical precipitation, ion exchange, biological remediation, mechanical extraction, and adsorption.

[0004] In the adsorption method, aerogel materials have the advantages of low density, high porosity, and high specific surface area, and have become a new type of adsorbent. Currently, traditional aerogel adsorbents used in wastewater treatment have high cost, complex preparation process, high energy consumption, poor selective adsorption capacity, and difficulty in recycling. More importantly, the composition of polluted water bodies is generally complex, and most traditional aerogels can only remove one type of pollutant, which greatly limits their practical application in adsorbing pollutants. Therefore, there is an urgent need to develop a new type of aerogel adsorbent with low cost, renewability, and multiple rapid adsorption effects.

[0005] Cellulose, as a natural polymer, has gradually attracted widespread attention from researchers. Cellulose is a fibrous, capillary-rich, stereoregular polymer with porous structure and a large specific surface area, which is beneficial for the physical adsorption of heavy metal ions. Cellulose aerogel adsorbents mainly utilize the functional groups on their surface to chelate and adsorb heavy metal ions. However, natural cellulose has very few surface active groups and contains a large number of impurities, surface colloids, pigments, etc., resulting in a weak adsorption capacity for metal ions. In addition, the inherent strong hydrophilicity of cellulose causes the aerogel to easily collapse upon contact with aqueous solutions, destroying its three-dimensional structure and causing it to easily disperse in water, thus limiting its application in environmental pollution control. Therefore, to improve the multifunctional adsorption effect of cellulose aerogels, functional modification of the cellulose surface is necessary. Summary of the Invention

[0006] To address the aforementioned technical problems in the existing technology, this application provides a method for preparing hyperbranched polysiloxane-modified oxidized nanocellulose aerogel. This method involves reacting tannic acid and cashew phenol-derived alkyl groups followed by modification of the oxidized nanocellulose, resulting in an oxidized nanocellulose aerogel that is resistant to imidacloprid and Cd. 2+ It has a synergistic adsorption effect.

[0007] To achieve the above objectives, the technical solution of the present invention is as follows:

[0008] A method for preparing hyperbranched polysiloxane-modified oxidized nanocellulose aerogel includes the following steps:

[0009] Preparation of S1 and Tris-HCl solution: Tris(hydroxymethyl)aminomethane was dissolved in water, and then hydrochloric acid was added to adjust the pH to 8.0-9.0 to obtain the Tris-HCl solution;

[0010] S2. Mix oxidized nanocellulose and Tris-HCl solution to obtain an oxidized nanocellulose suspension;

[0011] S3. Add tannic acid to the Tris-HCl solution, and then add the cashew phenol derivative alkane solution to the Tris-HCl solution containing tannic acid to react and obtain TA-HBPSi;

[0012] S4. Add the TA-BHPSi to the oxidized nanocellulose suspension for reaction, and then freeze-dry the reacted material to obtain the nanocellulose aerogel.

[0013] The cashew phenol derivative alkyl is prepared by reacting cashew phenol glycidyl ether with propylaminotriethoxysilane.

[0014] In some embodiments, in step S2, oxidized nanocellulose and Tris-HCl solution are mixed, then water is added, and the mixture is sonicated to obtain an oxidized nanocellulose suspension.

[0015] In some embodiments, in step S3, the mass ratio of the tannic acid to the cashew phenol derivative is 20-30:32-45.

[0016] In some embodiments, in step S4, the mass ratio of the oxidized cellulose to the TA-BHPSi is 1:0.01-0.10.

[0017] In some embodiments, the concentration of the nanocellulose suspension is 0.1-1.0 wt%.

[0018] In some embodiments, the preparation of the cashew phenol derivative includes the following steps:

[0019] Cashew phenol glycidyl ether and propylaminotriethoxysilane are mixed and reacted under nitrogen protection at 80-100°C to obtain the cashew phenol derivative alkane.

[0020] The mass ratio of cashew phenol glycidyl ether to aminopropyltriethoxysilane is 1:20-80.

[0021] In some embodiments, the mass concentration of the tannic acid is 0.2-1.0 g / mL.

[0022] In some embodiments, the mass concentration of the cashew phenol derivative is 0.01-0.05 g / mL.

[0023] In some embodiments, the organic solvent is an alcohol solvent; preferably, it is at least one of ethanol, propanol, isopropanol, butanol, and 2-isobutanol.

[0024] The present invention also provides oxidized cellulose nanoparticles aerogels obtained by the preparation method of any of the above embodiments.

[0025] This invention also provides the application of the above-mentioned oxidized nanocellulose aerogel as an adsorbent in environmental remediation.

[0026] This invention also provides the application of the above-mentioned oxidized nanocellulose aerogel as an adsorbent for the adsorption of imidacloprid and heavy metal ions. Preferably, the heavy metal ion is Cd. 2+ .

[0027] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0028] The modification mechanism of this invention is as follows: Figure 1 and Figure 2As shown, based on the excellent modification properties of tannic acid (TA), it is first reacted with cashew phenol derivative (CDA). CDA can be fixed on the aromatic ring structure of TA through hydrolysis / condensation reaction, so that the obtained TA-HBPSi has a structure with a hard core composed of TA and a soft shell composed of CDA, and a large number of long aliphatic chains are grafted on its surface. Due to the combination of rigid ring and flexible aliphatic chain, a microphase separation structure is constructed between TA-HBPSi and brittle nanofiber network, thereby improving the interfacial interaction between TA-HBPSi and oxidized nanofiber, improving the mechanical properties of aerogel, and at the same time, giving the oxidized nanofiber aerogel a larger pore structure and significantly increased surface roughness, thus increasing the active sites of the aerogel.

[0029] The oxidized cellulose nanogel prepared in this application exhibits excellent adsorption performance when used as an adsorbent material in environmental remediation. Specifically, the oxidized cellulose nanogel prepared in this application shows good adsorption performance for imazalil and the heavy metal Cd. 2+ It exhibits excellent adsorption performance.

[0030] Furthermore, the preparation method described in this application is low-cost, produces no secondary pollution, and yields an environmentally friendly aerogel with excellent adsorption performance, making it a promising candidate for environmental pollution control. Attached Figure Description

[0031] Figure 1 This is a schematic diagram of the reaction between tannic acid (TA) and cashew phenol derivative (CDA).

[0032] Figure 2 This is a schematic diagram of the reaction process for nanocellulose aerogel;

[0033] Figure 3 The images shown are transmission electron microscope (TEM) images of nanocellulose aerogels from Example 1, Comparative Example 1, and Comparative Example 2; where a is a TEM image of the aerogel from Comparative Example 2; b is a TEM image of the aerogel from Comparative Example 1; and c is a TEM image of the aerogel from Example 1.

[0034] Figure 4 Morphology and SEM images of the nanocellulose aerogels of Example 1, Comparative Example 1, and Comparative Example 2 are shown.

[0035] Figure 5 The N2 adsorption-desorption curves and pore distribution diagrams of the nanocellulose aerogels of Example 1, Comparative Example 1, and Comparative Example 2 are shown; wherein, Figure a is the N2 adsorption-desorption curve and Figure b is the pore distribution diagram.

[0036] Figure 6 The graph shows the adsorption effect of nanocellulose aerogels on imazalil in Example 1, Comparative Example 1, and Comparative Example 2.

[0037] Figure 7 Figure 1 shows the effect of different initial concentrations of imazalil on the adsorption of imazalil by TA-HBPSi@TOCNF aerogel.

[0038] Figure 8 The effect of different pH values ​​of imidazol solutions on the adsorption of imidazol by TA-HBPSi@TOCNF aerogel and the percentage of imidazol ionization in aqueous solutions at different pH values ​​are shown in the figure.

[0039] Figure 9 In the middle, figure a shows the addition of Cd. 2+ Effect of TA-HBPSi@TOCNF aerogel on adsorption of imazalil, Figure b shows the adsorption of Cd. 2 + And imidazol for Cd adsorption by TA-HBPSi@TOCNF aerogel 2+ The impact. Detailed Implementation

[0040] Numerous specific details are set forth in the following description to provide a full understanding of the invention. However, the invention can be practiced in many other ways different from those described herein, and similar modifications can be made by those skilled in the art without departing from the spirit of the invention. Therefore, the invention is not limited to the specific embodiments disclosed below.

[0041] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. The terminology used herein in the description of the invention is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention.

[0042] In the following examples, the oxidized nanocellulose (TOCNF) used was produced by Tianjin Wood Elf Co., Ltd., with a diameter of 5-7 nm; the cashew phenol derivative alkyl was prepared by the method provided in this application; and the Tris-HCl solution was prepared by the method provided in this application.

[0043] Preparation of cashew phenol derivative alkane: Weigh 0.5g cashew phenol glycidyl ether and 25g propylaminotriethoxysilane (APTES) and place them in a three-necked round-bottom flask equipped with a stir bar, thermometer and condenser; then introduce nitrogen gas into the apparatus, heat in a water bath under nitrogen protection, and stir for 1 hour after the temperature rises to 85°C; after the reaction is completed, allow it to cool naturally to room temperature to obtain a brown liquid, which is cashew phenol derivative alkane.

[0044] Preparation of Tris-HCl solution: Weigh 1.21 g of Tris and dissolve it in 50 mL of deionized water. Then add 14.7 mL of 0.1 mol / L HCl and mix well. Adjust the pH to 8.5 and bring the volume to 100 mL.

[0045] Example 1

[0046] A method for preparing hyperbranched polysiloxane-modified oxidized nanocellulose aerogel includes the following steps:

[0047] S1. Preparation of oxidized nanocellulose suspension: 44.44g of oxidized nanocellulose was added to 35.56g of water and 1mL of Tris-HCl solution, the pH was adjusted to 8.5, and the mixture was sonicated for 30min to obtain an oxidized nanocellulose suspension with a concentration of 0.5wt%.

[0048] S2. Preparation of cashew phenol derivative solution: Add 0.72g of cashew phenol derivative to 25ml of anhydrous ethanol and dissolve it completely to obtain cashew phenol derivative solution.

[0049] Preparation of S3 and TA-HBPSi: Tannic acid was added to Tris-HCl solution, and then cashew phenol derivative alkane solution was added dropwise to Tris-HCl solution containing tannic acid. The mixture was stirred at room temperature for 12 h, and then the organic solvent was removed by rotary evaporation to obtain TA-HBPSi.

[0050] S4. Add the TA-HBPSi prepared in step S3 to the oxidized cellulose nanoparticle suspension, stir at room temperature until completely dissolved, and then freeze-dry the mixed wet gel sample for 12 hours to obtain cellulose nanoparticle aerogel (TA-HBPSi@TOCNF).

[0051] Comparative Example 1

[0052] The preparation of an oxidized cellulose nanogel includes the following steps:

[0053] S1. The preparation of the oxidized nanocellulose suspension is the same as in Example 1;

[0054] S2, the preparation of the cashew phenol derivative alkyl solution is the same as in Example 1;

[0055] S3. According to the contents of each raw material in Table 1 below, add tannic acid solution and cashew phenol derivative alkane solution to oxidized cellulose suspension, stir at room temperature for 6 hours, and then freeze-dry the obtained wet gel sample for 12 hours to obtain oxidized nanocellulose aerogel (TA@TOCNF-CDA).

[0056] Table 1 Raw material ratio of TA@TOCNF-CDA aerogel

[0057] Sample TO CNF (g) TA (g) CDA (g) TA @ TO CNF - CDA - 1 40 0.02 0.2 TA @ TO CNF - CDA - 2 40 0.04 0.4 TA @ TO CNF - CDA - 3 40 0.06 0.6

[0058] Comparative Example 2

[0059] An oxidized cellulose nanoparticle suspension was prepared using the method described in Example 1, and then freeze-dried for 12 hours to obtain a cellulose nanoparticle aerogel, TOCNF aerogel.

[0060] The TA-HBPSi@TOCNF aerogel prepared in Example 1, the TA@TOCNF-CDA-1 aerogel prepared in Comparative Example 1, and the TOCNF aerogel prepared in Comparative Example 2 were subjected to relevant performance tests, as follows:

[0061] I. Transmission electron microscopy was performed on TA-HBPSi@TOCNF aerogel, TA@TOCNF-CDA-1 aerogel, and TOCNF aerogel. The results are as follows: Figure 3 As shown in the figure. Among them, figure a is a TEM image of TOCNF aerogel; figure b is a TEM image of TA@TOCNF-CDA-1 aerogel; and figure c is a TEM image of TA-HBPSi@TOCNF aerogel.

[0062] like Figure 3 The unmodified nanocellulose aerogel, as shown in Figure a, exhibits a loose, non-entangled structure. The TA@TOCNF-CDA-1 aerogel, modified with tannic acid and cashew phenol derivatives, as shown in Figure b, shows a changed microstructure with a certain degree of entanglement. The TA-HBPSi@TOCNF aerogel prepared by the method of this invention, as shown in Figure c, not only shows an entangled structure but also clearly demonstrates TA-HBPSi distribution within the cellulose structure, resulting in tighter adhesion between the cellulose fibers. This enhances the mechanical properties of the nanocellulose aerogel, making it less prone to loosening and brittleness, and providing better adsorption space for the adsorbate. Furthermore, Figure c further illustrates the successful adhesion of TA-HBPSi to the cellulose backbone.

[0063] II. SEM analysis was performed on TA-HBPSi@TOCNF aerogel, TA@TOCNF-CDA-1 aerogel, and TOCNF aerogel. The results are as follows: Figure 4 As shown in the figure. Among them, figures a and d are the morphology and SEM images of TOCNF aerogel, respectively; figures b and e are the morphology and SEM images of TA@TOCNF-CDA-1 aerogel, respectively; figures c and f are the morphology and SEM images of TA-HBPSi@TOCNF aerogel, respectively.

[0064] like Figure 4As shown in figures a, b, and c, all three types of aerogels exhibit a porous structure with a certain degree of surface roughness. Figure d shows that the TOCNF aerogel has a sheet-like porous structure, exhibiting a three-dimensional structure overall. Figures e and f show that the modified aerogels retain their original three-dimensional porous structure, but the porous structure of the TA-HBPSi@TOCNF aerogel is more clearly visible, and the surface is rougher. This indicates that the addition of TA-HBPSi makes the structure between the cellulose molecules in the aerogel more robust and the pores larger. SEM results show that TA-HBPSi can act as a multifunctional adhesion platform to fix hydrophobic CDA molecules onto the cellulose backbone and significantly improve the roughness of the aerogel.

[0065] III. The specific surface area and pore structure of TA-HBPSi@TOCNF aerogel, TA@TOCNF-CDA-1 aerogel, and TOCNF aerogel were further analyzed using a fully automated specific surface area analyzer. The analysis results are shown in Table 2 and... Figure 5 As shown.

[0066] Table 2. BET parameters of the aerogels prepared in Example 1 and Comparative Examples 1-2

[0067]

[0068]

[0069] IV. The effects of TA-HBPSi@TOCNF aerogel, TA@TOCNF-CDA-1 aerogel, and TOCNF aerogel on imidacloprid and Cd. 2+ Adsorption performance study

[0070] (I) Study on the adsorption performance of imazalil

[0071] 1. Preparation of imazalil solution:

[0072] (1) Preparation of standard solution: Weigh 0.05g of high-purity imazalil technical (99.8%), dissolve it in methanol in a 50ml volumetric flask, make up to volume and shake well to obtain a 1g / L imazalil standard solution. The imazalil solution required for the following experiments is prepared by diluting this standard solution by a certain factor.

[0073] (2) Preparation of standard curve: The imidazolium standard solution was serially diluted to 1.25, 2.5, 5, 10 and 20 mg / L, filtered through a 0.22 μm filter membrane, and detected by high performance liquid chromatography to plot the standard curve.

[0074] 2. Imazalil Adsorption Experiment

[0075] Static adsorption experiments were used to evaluate the adsorption performance of different aerogels. The effects of adsorption time, pH and initial concentration on the adsorption of imidacloprid by aerogels were assessed using a single-factor controlled variable method.

[0076] (1) Batch adsorption: 0.09 g of each aerogel was placed in an Erlenmeyer flask containing 100 mL of imidacloprid (10 mg / L) solution. The flask was shaken and adsorbed at 25℃ and 160 rpm for 48 h. At intervals of 0.5, 1, 3, 6, 9, 12, 24, 36, and 48 h, 1 mL of the sample was taken, filtered through a 0.22 μm filter membrane, and the residual imidacloprid concentration was detected by HPLC. The adsorption effects of different aerogels on imidacloprid are shown below. Figure 6 As shown.

[0077] (2) Effect of initial concentration: 5, 10, 20, 50, and 100 mg / L imidacloprid solutions were prepared, and 100 mL of each solution was placed in an Erlenmeyer flask. 0.09 g of TA-HBPSi@TOCNF aerogel was weighed and added to the imidacloprid experimental solutions of different concentrations. The solutions were shaken and adsorbed at 25℃ and 160 rpm for 48 h. At intervals of 0.5, 1, 3, 6, 9, 12, 24, 36, and 48 h, 1 mL of the sample was taken, filtered through a 0.22 μm filter membrane, and the residual imidacloprid concentration was detected by HPLC. The detection results are as follows: Figure 7 As shown.

[0078] (3) pH effect: Prepare 100 mL of imidacloprid-containing solution, and adjust the pH to 3, 5, 7, 9, and 11 using NaOH and HCl respectively; weigh 0.09 g of TA-HBPSi@TOCNF aerogel and add it to the solution. After adsorption by shaking at 25℃ and 160 rpm for 48 h, take 1 mL of the sample to be tested, filter it through a 0.22 μm filter membrane, and detect the residual imidacloprid concentration by HPLC. The detection results are as follows. Figure 8 As shown

[0079] (ii) Regarding Cd 2+ Adsorption experiment

[0080] 1. Cd 2+ Solution preparation

[0081] (1) Preparation of standard solution: Weigh 0.023 g of cadmium sulfate, dissolve it in 10 ml of deionized water and dilute to volume, then shake well to obtain 1 g / L Cd. 2+ Standard solution. The Cd required for the following experiments. 2+ The solution is prepared by diluting the standard solution by a certain factor.

[0082] (2) Standard curve preparation: Cd 2+ The standard solution was serially diluted to 1.25, 2.5, 5, 10, and 20 mg / L, and a standard curve was plotted.

[0083] 2. Cd2+ Adsorption experiment

[0084] Take 0.09g of each TA-HBPSi@TOCNF aerogel and place it in a container containing 100mL of Cd. 2+ The experimental solution was placed in conical flasks with concentrations of 0.1, 0.2, 0.5, 1, and 1.5 mg / L. The solution was shaken and adsorbed at 25°C and 160 rpm for 48 h. At certain time intervals (0.5, 1, 3, 6, 9, 12, 24, 36, and 48 h), 1 mL of the sample was taken, filtered through a 0.22 μm filter membrane, and its concentration was detected by inductively coupled plasma optical emission spectrometry (ICP).

[0085] (III) Imazalil and Cd 2+ Adsorption experiment

[0086] Take 0.09g of each of the different aerogels and place them in 100mL of a solution containing imazalil (10mg / L) and Cd. 2+ In a mixed solution of (0.1, 0.2, 0.5, 1, 1.5) mg / L, adsorption was performed by shaking at 25℃ and 160 rpm for 48 h. 1 mL of the sample was taken at regular intervals (0.5, 1, 3, 6, 9, 12, 24, 36, 48) h, filtered through a 0.22 μm filter, and pyrazole was detected by HPLC, while Cd was detected by inductively coupled plasma atomic emission spectrometry. 2+ Concentration. Detection results are as follows: Figure 9 As shown.

[0087] In the above experiment, the HPLC detection conditions for imazalil were as follows:

[0088] Chromatographic column: ZORBAX SB-C18 column (5-μm particle size, 150×4.6mm id)

[0089] Mobile phase: methanol: sodium dihydrogen phosphate aqueous solution (0.025 mol / L, pH=2.5) = 70:30 (V / V);

[0090] Flow rate: 1 mL / min;

[0091] Detection wavelength: 229nm;

[0092] Injection volume: 10 μL;

[0093] Column temperature: 30℃.

[0094] Cd 2+ Testing conditions:

[0095] Inductively coupled plasma atomic emission spectrometry (ICP) was used to detect the concentration of heavy metal ions Cd2+. After adsorption equilibrium, the sample was removed, filtered through a filter membrane, and then the metal concentration was tested. The standard curve was determined using standard solutions. The instrument resolution was 0.007 nm, with an accuracy of RSD% < 2.0% and a stability of RSD% < 3.0%.

[0096] like Figure 6 Compared to TOCNF aerogel, TA@TOCNF-CDA aerogel and

[0097] TA-HBPSi@TOCNF aerogel exhibits excellent adsorption performance for imazalil. Among other things,

[0098] The equilibrium adsorption capacity of TA-HBPSi@TOCNF aerogel can reach 8.04 mg / g, which is higher than that of other aerogels.

[0099] The equilibrium adsorption efficiency of TA@TOCNF-CDA aerogel is as high as 50.6% at 5.34 mg / g.

[0100] like Figure 7 The equilibrium adsorption capacity of TA-HBPSi@TOCNF aerogel for imazalil increased with increasing initial imazalil concentration; when the imazalil solution concentration increased from 5 mg / L to 100 mg / L, the equilibrium adsorption capacity increased from 5.21 mg / g to 15.55 mg / g. Furthermore, the adsorption rate gradually approached equilibrium with adsorption time. This is mainly because, in the initial stage of adsorption, the active functional groups on the aerogel provided a large number of adsorption sites for imazalil, resulting in a rapid increase in the adsorption rate. As the adsorption process continued, these adsorption sites were gradually occupied, reducing the effective interaction between the aerogel and imazalil.

[0101] Figure 8 In the figure, a) shows the effect of pH on the adsorption of imidacloprid by TA-HBPSi@TOCNF aerogel; b) shows the percentage of imidacloprid ionization in aqueous solutions at different pH values. Figure 8 Different pH values ​​have a certain impact on the adsorption effect of aerogel on imidazolium. When the pH is around 7, the aerogel adsorption effect on imidazolium is the best, reaching 7.89 mg / g.

[0102] Figure 9 In the diagram, a represents Cd. 2+ Effect of TA-HBPSi@TOCNF aerogel on adsorption of imazalil, Figure b shows the adsorption of Cd. 2+ And imidazolium adsorption of Cd 2+ The impact. For example... Figure 9 When adding Cd 2+ At a concentration of 1.5 mg / L, the maximum adsorption capacity of TA-HBPSi@TOCNF aerogel for imazalil (10 mg / L) was 9.66 mg / g; when adsorbing Cd alone...2+ At that time, the aerogel is effective against Cd. 2+ The maximum adsorption capacity of Cd (1.5 mg / L) was 0.26 mg / g, while the adsorption capacity increased to 0.88 mg / g after the addition of imazalil. Experimental results demonstrate that Cd... 2+ The coexistence of thiamethoxam and imazalil leads to an increase in the equilibrium adsorption capacity of TA-HBPSi@TOCNF aerogel for both target pollutants, thereby enhancing the adsorption effect.

[0103] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0104] The embodiments described above are merely illustrative of several implementations of the present invention, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the invention patent. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these all fall within the protection scope of the present invention. Therefore, the protection scope of this invention patent should be determined by the appended claims.

Claims

1. The application of a hyperbranched polysiloxane-modified oxidized nanocellulose aerogel as an adsorbent for the adsorption of imidacloprid and heavy metal ions, characterized in that, Includes the following steps: The hyperbranched polysiloxane-modified oxidized nanocellulose aerogel was reacted in a mixed solution containing imidacloprid and heavy metal ions; wherein the heavy metal ions were Cd. 2+ ; The preparation method of the hyperbranched polysiloxane-modified oxidized nanocellulose aerogel includes the following steps: Preparation of S1 and Tris-HCl solution: Dissolve tris(hydroxymethyl)aminomethane in water, then add hydrochloric acid to adjust the pH to 8.0-9.0 to obtain the Tris-HCl solution; S2. Mix the oxidized nanocellulose and the Tris-HCl solution to obtain an oxidized nanocellulose suspension; S3. Add tannic acid to the Tris-HCl solution, and then add cashew phenol derivative alkane solution to the Tris-HCl solution containing tannic acid to react and obtain TA-HBPSi; S4. Add the TA-HBPSi to the oxidized nanocellulose suspension for reaction, and then freeze-dry the reacted material to obtain the hyperbranched polysiloxane modified oxidized nanocellulose aerogel. The cashew phenol derivative alkyl is prepared by reacting cashew phenol glycidyl ether and aminopropyltriethoxysilane.

2. The application of the hyperbranched polysiloxane-modified oxidized nanocellulose aerogel according to claim 1 as an adsorbent for adsorbing imidacloprid and heavy metal ions, characterized in that, In step S3, the mass ratio of the tannic acid to the cashew phenol derivative is 20-30:32-45.

3. The application of the hyperbranched polysiloxane-modified oxidized nanocellulose aerogel according to claim 1 as an adsorbent for adsorbing imidacloprid and heavy metal ions, characterized in that, In step S4, the mass ratio of the oxidized nanocellulose to the TA-HBPSi is 1:0.01-0.

10.

4. The application of the hyperbranched polysiloxane-modified oxidized nanocellulose aerogel according to claim 1 as an adsorbent for adsorbing imidacloprid and heavy metal ions, characterized in that, The concentration of the oxidized nanocellulose suspension is 0.1-1.0 wt%.

5. The application of the hyperbranched polysiloxane-modified oxidized nanocellulose aerogel according to claim 1 as an adsorbent for adsorbing imidacloprid and heavy metal ions, characterized in that, The preparation of the cashew phenol derivative includes the following steps: Cashew phenol glycidyl ether and aminopropyltriethoxysilane are mixed and reacted under nitrogen protection at 80-100°C to obtain the cashew phenol derivative alkane. The mass ratio of cashew phenol glycidyl ether to aminopropyltriethoxysilane is 1:20-80.

6. The application of the hyperbranched polysiloxane-modified oxidized nanocellulose aerogel according to claim 1 as an adsorbent for adsorbing imidacloprid and heavy metal ions, characterized in that, The mass concentration of the tannic acid is 0.2-1.0 g / mL; the mass concentration of the cashew phenol derivative is 0.01-0.05 g / mL.

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