Preparation method of hyperbranched monomer modified high-density site nanosheet and application of hyperbranched monomer modified high-density site nanosheet in adsorbing blood lead

Abstract

The invention belongs to the technical field of environment-friendly and biomedical functional materials, and discloses a preparation method of a hyperbranched monomer modified high-density site nanosheet and application of the hyperbranched monomer modified high-density site nanosheet to adsorption of blood lead. According to the preparation method disclosed by the invention, a silicon dioxide nanosheet is prepared by utilizing a metastable state nano-emulsion, a brand new hyperbranched macromolecule modified nanosheet is designed and synthesized, and lead ion adsorption sites are introduced into a hyperbranched skeleton, so that the problem that the surface site density of an adsorbent is difficult to increase is solved, and the site density is greatly increased; and the coordination effect between the functional monomer and the lead ions is utilized to efficiently and quickly remove the lead ions in an aqueous solution and blood.

Description

Technical Field

[0001] The present invention belongs to the technical field of preparation of environmental protection and biomedical functional materials, and relates to a method for preparing a blood perfusion adsorbent suitable for effectively treating blood lead, in particular to a method for synthesizing a high-density site nanosheet adsorbent based on a metastable emulsion system and a hyperbranched monomer, and the application of the method in the field of adsorbing blood lead. Background Art

[0002] Lead exposure has become a major public health issue. Around the world, 815 million children (about one-third) have dangerous levels of lead in their blood, which even causes nearly 1 million deaths and disabilities each year. Long-term exposure to lead in a lead-contaminated environment will cause lead to enter the human body through skin inhalation, breathing, and diet, and will continue to accumulate in the human blood, tissues, and bones, leading to kidney damage, anemia, cardiovascular damage, and mental and behavioral abnormalities. Studies have shown that the half-life of lead in the blood is 35 days, while the half-life in soft tissue is longer (40 days), and the longest half-life in bones can be 20-30 years. Lead is a neurotoxic metal. Lead exposure is associated with a variety of neurodevelopmental disorders, including memory loss, impaired language function, intellectual impairment, motor skills and visual spatial ability, and is also associated with schizophrenia, Alzheimer's disease, and Parkinson's disease. Surveys have found that IQ loss caused by lead has caused significant economic losses in low-income, middle-income, and high-income countries around the world. According to the World Health Organization (WHO) standard, a blood lead level above 100 ppb is lead poisoning. Since children are in a critical period of growth and development, they are more likely to absorb lead. The toxic effects of blood lead on children's nervous system and organs are much greater than those on adults. Even at levels lower than the current international standards, it can still cause permanent damage to children's development. Therefore, eliminating lead from the blood is an effective and direct way to reduce the lead level in the body.

[0003] Hemoperfusion in vitro lead removal is the most promising treatment for blood lead after chelating agents, and can effectively avoid kidney damage caused by the metabolism of lead chelators. Hemoperfusion is a method of purifying blood through extracorporeal circulation using hemoperfusion adsorbents to achieve blood lead removal. Commercially available hemoperfusion adsorbents include activated carbon and resins, but they still need to be improved in terms of lead ion selectivity, adsorption capacity, and blood lead removal efficiency. Therefore, the development of hemoperfusion adsorbents with high adsorption capacity and fast adsorption rate is of great significance for achieving safe and efficient removal of blood lead.

[0004] The density of adsorbent surface sites is an important factor affecting its adsorption capacity. The functional monomers used in traditional surface modification strategies cannot significantly increase the density of adsorbent surface sites. Hyperbranched dendritic macromolecules have abundant terminal functional groups, their molecular chains are not easily entangled, and their viscosity is low, making them a good choice for constructing high-density site adsorbents. Compared with unbranched functional monomers, adsorbents modified with hyperbranched macromolecules can significantly increase the adsorption capacity. However, the hyperbranched macromolecules reported so far are mainly based on a dendritic skeleton, and the functional sites are concentrated at the ends of the molecules, ignoring the introduction of active sites on the hyperbranched macromolecular skeleton to increase the density of functional monomer sites. Summary of the invention

[0005] In view of the problems in the existing technology, the present invention firstly involves a metastable nanoemulsion and uses a strong alkaline catalytic condition to cause a silane coupling agent to undergo a rapid hydrolysis and condensation reaction at the droplet interface to generate a dense silica shell layer, which collapses to form a silica nanosheet. Secondly, a hyperbranched grafting unit B-= with four double bonds is designed and synthesized using N,N-methylenebisacrylamide and 1,6-hexanediamine, and a hyperbranched unit D-NH is synthesized by an amidation reaction between cystine and methacrylic anhydride. 2 Subsequently, a hyperbranched functional monomer with high-density sites was designed and synthesized through five ordered grafting polymerizations, and modified onto the surface of the nanosheets to prepare high-density site nanosheets. The specific effect of the nanosheets on lead ions was utilized to achieve rapid and efficient lead removal from aqueous solutions and blood.

[0006] The present invention solves the problem that it is difficult to increase the site density on the surface of the adsorbent. A monomer hyperbranching strategy is adopted to design and synthesize hyperbranched monomers with high-density sites, and functional sites are introduced into the skeleton of the hyperbranched monomer to achieve a significant increase in the site density. The coordination effect between the functional monomers and lead ions is utilized to efficiently and quickly remove lead ions from aqueous solutions and blood.

[0007] The technical solution adopted by the present invention is:

[0008] A method for preparing a high-density site nanosheet modified by a hyperbranched monomer comprises the following steps:

[0009] (1) Preparation of silica nanosheets BM:

[0010] A mixed solution of ammonia water and potassium bromide KBr is added to ethanol, mixed evenly, and then added to n-pentanol, and shaken evenly to prepare a metastable nanoemulsion; then tetraethyl orthosilicate TEOS and 3-chloropropyltrimethoxysilane CPTMS are added to the metastable nanoemulsion prepared above, and stirred at a low speed to react to prepare silica nanosheets BM;

[0011] (2) Preparation of hyperbranched unit B-=:

[0012] N,N-methylenebisacrylamide MBA and 1,6-hexanediamine were completely dissolved in a mixture of methanol and water, stirred for reaction, the product was concentrated by rotary evaporation and a large amount of ethanol was added to obtain a white solid, which was filtered and vacuum dried to prepare a hyperbranched graft unit B-=;

[0013]

[0014] (3) Hyperbranched grafting unit D-NH 2 Preparation

[0015] Weigh cystine D-Cys and sodium hydroxide, add them into deionized water to completely dissolve them, then add methacrylic anhydride, and after the first stirring reaction is completed, add a large amount of acetone to the reaction solution to obtain a yellow oily product D;

[0016]

[0017] Then, product D was added with 1,6-hexanediamine, and a mixture of methanol and water was used as the reaction solvent for a second stirring reaction. After the reaction was completed, a large amount of acetone was added to obtain a dark yellow liquid product D-NH 2 ;

[0018]

[0019] (4) Preparation of ordered hyperbranched macromolecule G5:

[0020] 1) Take D-NH 2 Add B-=, use a mixture of methanol and water as the reaction solvent, seal and stir to react, and use rotary evaporation to remove most of the solvent to obtain the first-generation product G1;

[0021] 2) Take G1 and add D-NH 2 , react with stirring in a sealed container, and remove most of the solvent by rotary evaporation to obtain the second-generation product G2;

[0022] 3) Take the same reaction steps and add B-= to G2 to obtain the third generation product G3;

[0023] 4) Take G3 and add D-NH 2 , and obtain the fourth-generation product G4;

[0024] 5) Take G4 and add B-= to synthesize ordered hyperbranched monomer G5.

[0025] (5) Preparation of disordered hyperbranched macromolecule P5:

[0026] Take D-NH 2 B-= was added, and a mixture of methanol and water was used as solvent. The mixture was stirred for reaction, and concentrated by rotary evaporation to obtain a disorderly polymerized hyperbranched monomer P5.

[0027] (6) Ordered hyperbranched nanosheets HBM-NH 2 Preparation

[0028] Weigh copper chloride dihydrate and dissolve it in ethanol, add N,N,N',N',N"-pentamethyldiethylenetriamine PMDETA to obtain a copper ethanol mixture;

[0029] BM was fully dispersed in ethanol, G5 was added, nitrogen was introduced to create an anaerobic environment, and then copper mixed solution and ascorbic acid aqueous solution were added. The reaction was sealed in an anaerobic environment, and solid materials were obtained by centrifugation. All the obtained products were dispersed in a mixed solution of methanol and water, and excess D-NH 2 After stirring the reaction, the product HBM-NH 2 .

[0030] (7) Ordered hyperbranched nanosheets HBM-SO 3 Preparation

[0031] Accurately weigh TCEP and dissolve it in deionized water. Add HBM-NH 2 After the reaction, the product was separated by centrifugation and dispersed in water. The pH was adjusted to 1.0 with hydrochloric acid. Hydrogen peroxide was added and stirred to react to obtain a solid material HBM-SO 3 .

[0032] (8) Disordered hyperbranched nanosheets PBM-NH 2 Preparation

[0033] PBM-NH was prepared by replacing G5 with P5 under the same conditions as in step (6). 2 .

[0034] In step (1), the usage ratio of KBr, ammonia water, ethanol, n-pentanol, TEOS and CPTMS is 0.005-0.01 g): (0.2-0.5) mL: (0.5-4 mL): (8-13 mL): (0.05-0.15 mL): (0.05-0.015).

[0035] In step (2), the dosage ratio of MBA, 1,6-hexanediamine and methanol aqueous solution is (0.3-0.9 g): (0.05-0.15 g): (40-120 mL); the reaction temperature is 20-40° C., and the reaction time is 8-15 h.

[0036] In steps (2)-(5), the volume ratio of methanol to water in the mixed solution of methanol and water is 2:1.

[0037] In step (3), the usage ratio of D-Cys, sodium hydroxide, deionized water and methacrylic anhydride is (0.1-1.0 g): (0.4-4.0 g): (8-80 mL): (0.36-3.6 mL); the usage ratio of product D and 1,6-hexanediamine is (0.1-1.0 g): (0.04-0.8 g), the reaction temperature of the first stirring reaction and the second stirring reaction are both 25-50° C., and the reaction time is both 5-15 h.

[0038] In step (4),

[0039] When preparing G1, D-NH 2 The molar ratio of B-= is 1:6, the reaction temperature is 60-90°C, and the reaction time is 20-40h;

[0040] When preparing G2, G1 and D-NH 2 The molar ratio is 1:18, the reaction temperature is 80-99°C, and the reaction time is 40-60h;

[0041] When preparing G3, the molar ratio of G2 and B-= is 1:90, the reaction temperature is 80-99°C, and the reaction time is 50-70h;

[0042] When preparing G4, G3 and D-NH 2 The molar ratio is 1:270; the reaction temperature is 80-99°C and the reaction time is 50-70h;

[0043] When preparing G5, the molar ratio of G4 and B-= is 1:1350, the reaction temperature is 80-99°C, and the reaction time is 50-70h.

[0044] In step (5), D-NH 2 The molar ratio of B-= is 1:5.004, the reaction temperature is 80-99°C, and the reaction time is 20-40h.

[0045] In step (6),

[0046] In the copper-ethanol mixture, the ratio of cupric chloride dihydrate, ethanol and PMDETA is (10-100 mg): (1-6 mL): (0.5-1 mL);

[0047] The usage ratio of cupric chloride dihydrate, BM, ascorbic acid aqueous solution and G5 is: (10-100 mg): (0.2-1.2 g): (2-6 mL): (2-20 mL), and the concentration of ascorbic acid aqueous solution is 0.1-0.2 g / mL;

[0048] The temperature of the sealed reaction in an anaerobic environment is 45-65°C and the time is 5-15h.

[0049] In the modified D-NH 2 During the process, the reaction temperature is 50-80°C. In step (7), TCEP, HBM-NH 2 The dosage ratio of hydrogen peroxide is (0.2-0.8g): (0.4-1.6g): (2-8mL), the reaction temperature is 30-70°C, and the reaction time is 15-30h.

[0050] The high-density site nanosheet HBM-NH modified by the hyperbranched monomer prepared in the present invention is 2 、HBM-SO 3 or PBM-NH 2 Used for removing lead ions from aqueous solution or blood.

[0051] For comparison, the present invention also prepared unbranched nanosheets BM-NH 2 :

[0052] Weigh copper chloride dihydrate, dissolve it in ethanol, and add PMDETA to obtain a copper ethanol mixture.

[0053] Disperse BM in 40 mL of ethanol, add B-=, and introduce nitrogen to create an oxygen-free environment. Then add the copper ethanol mixture and the ascorbic acid solution prepared in advance, continue to ventilate and deoxygenate. After the ventilation is completed, seal the reaction. Then disperse the solid material separated by centrifugation in a mixed solution of methanol and water, add D-NH 2 After stirring the reaction, the product BM-NH 2 .

[0054] In the copper-ethanol mixture, the usage ratio of cupric chloride dihydrate, ethanol and PMDETA is (10-100 mg): (1-6 mL): (0.5-1 mL);

[0055] The dosage ratio of BM, ascorbic acid aqueous solution and B-= is (0.2-1.2g): (2-6mL): (0.1-0.6g), the concentration of ascorbic acid aqueous solution is 0.1-0.2g / mL; the reaction temperature is 30-70°C, and the reaction time is 15-30h. Compared with the prior art, the beneficial effects of the present invention are as follows:

[0056] The present invention prepares silica nanosheets by using a solvent-induced emulsified metastable emulsion, and successfully prepares nanosheets with high-density sites by using a new hyperbranched monomer synthesis method, which is applied to the removal of lead in aqueous solution and blood. The method for preparing nanosheets with high-density sites has the following advantages:

[0057] The invention adopts a solvent-induced emulsification method to prepare a metastable nanoemulsion, which has the advantage of low emulsification energy consumption, and uses the solvent-induced emulsification method as a droplet reactor to prepare silicon dioxide nanosheets using the strong catalytic effect of ammonia water. The method is simple to operate, has a rapid reaction, and has simple reaction conditions.

[0058] By using the hyperbranching strategy, adsorption sites were first introduced into the molecular skeleton of hyperbranched macromolecules, which greatly increased the number and density of functional sites. They were then modified to the surface of nanosheets using grafting polymerization to increase the surface sites of the adsorbent and improve the adsorption performance.

[0059] The hyperbranched nanosheets prepared by the invention have excellent blood compatibility and perform well in the application of removing blood lead. BRIEF DESCRIPTION OF THE DRAWINGS

[0060] Figure 1 These are SEM images (a and b) of BM when the amount of KBr is 0.0066 g in step (1) of Example 1 and TEM images (c and d) of BM when the amount of KBr is 0.01 g.

[0061] Figure 2 Figures ad are SEM images of BM when the amount of ethanol used in step (1) of Example 1 was 1 mL, 1.5 mL, 2 mL and 2.5 mL respectively.

[0062] Figure 3 This is the H NMR spectrum of B-= prepared in Example 1 in deuterated water solvent.

[0063] Figure 4 This is the H NMR spectrum of D prepared in Example 1 in deuterated water solvent.

[0064] Figure 5 is the D-NH prepared in Example 1 2 H NMR spectrum in deuterated water solvent.

[0065] Figure 6 is the D-NH prepared in Example 1 2 and B-=(a) and the infrared absorption spectra of the grafted polymerization products G1-G5 prepared in Example 1 (b).

[0066] Figure 7 HBM-NH obtained in Examples 1-3 and Comparative Example 1 2 、HBM-SO 3 、PBM-NH 2 and BM-NH 2 Infrared absorption spectrum.

[0067] Figure 8 HBM-NH obtained in Examples 1-3 and Comparative Example 1 2、HBM-SO 3 、PBM-NH 2 and BM-NH 2 Adsorption capacity under different pH environments (a), adsorption kinetics and pseudo-first-order and pseudo-second-order kinetics (b), intraparticle diffusion (c) and Elovich model (d) fitting curves.

[0068] Fig. 9 HBM-NH obtained in Examples 1-3 and Comparative Example 1 2 (a) HBM-SO 3 (c) PBM-NH 2 (d) and BM-NH 2 (b) Adsorption isotherms at different temperatures and their Langmuir and Freundlich model fitting curves.

[0069] Fig.10 is HBM-NH in Example 1 2 In the adsorption of Pb 2+ XPS full spectrum analysis before and after (a), XPS fine spectrum of Pb4f (b), adsorbed Pb 2+ XPS high-resolution spectra of O1s (c), N1s (d) before and after adsorption (e), N1s (f).

[0070] Fig.11 The HBM-NH at different mass concentrations in Examples 1 and 2 2 and HBM-SO 3 Hemolysis rate diagram (a) and hemolysis photos (b and c) of HBM-NH at different mass concentrations 2 (d) and HBM-SO 3 (e) Coagulation time graph.

[0071] Fig.12 In Example 1, HBM-NH 2 Pb 2+ Competitive adsorption performance (a), HBM-NH 2 The blood lead removal capacity and removal rate (b). Specific embodiments

[0072] Example 1

[0073] Ordered hyperbranched nanosheets HBM-NH 2 Preparation

[0074] (1) 0.01 g of potassium bromide (KBr) was dissolved in 0.42 mL of ammonia water, and then 3.0 mL of ethanol was added. After hand-shaking, the mixture was transferred to a round-bottom flask containing 10 mL of n-pentanol and hand-shaked to mix evenly. 100 μL of TEOS and 10 μL of CPTMS were added successively and hand-shaked to mix evenly again. The mixture was placed in a water bath at 25°C and reacted at 80 rpm for 40 min. After centrifugation, the mixture was washed with ethanol to obtain the product BM.

[0075] Referring to the above steps, the effects of KBr dosage of 0.0066 g and different ethanol dosages (1.0 mL, 1.5 mL, 2.0 mL, and 2.5 mL) on the morphology of BM were also explored.

[0076] like Figure 1 As shown, with the increase of KBr dosage, the radius of the nanosheet increases;

[0077] like Figure 2 As shown, with the increase of ethanol dosage, the outline of the nanosheets becomes clearer, indicating that the increase of ethanol dosage promotes the growth of silica.

[0078] (2) First, 0.6167 g MBA (0.004 mol) and 0.1162 g 1,6-hexanediamine (0.001 mol) were accurately weighed and completely dissolved in 80 mL of a mixture of methanol and water (volume ratio 2:1). The mixture was then placed in a constant temperature sand bath at 30°C and stirred for 10 h. The product was concentrated by rotary evaporation, and a large amount of ethanol was added to obtain a white solid B-=.

[0079] like Figure 3 As shown, B-=double bond in the molecule and the skeleton characteristic peaks of 1,6-hexanediamine appeared, indicating that it was successfully synthesized.

[0080] (3) Weigh 0.4806 g (0.002 mol) of D-Cys and add it to 40 mL of deionized water. Add 2.0 g of sodium hydroxide to completely dissolve it, then add 1.8 mL (0.006 mol) of methacrylic anhydride and stir at 40°C for 12 h. After the reaction is completed, add a large amount of acetone to the reaction solution to obtain a yellow oil D, which is vacuum dried and characterized by NMR.

[0081] Take 0.544g of the above product D, add 0.372g of 1,6-hexanediamine, use a mixture of methanol and water (volume ratio 2:1) as the reaction solvent (60mL), and react at 40°C for 24 hours. After the reaction is completed, add a large amount of acetone to obtain a dark yellow liquid product D-NH 2 , vacuum dried and used for NMR testing.

[0082] like Figure 4As shown, the characteristic peaks of double bond, methyl and methylene on cystine indicate that cystine reacts with methacrylic anhydride and D is successfully prepared.

[0083] like Figure 5 As shown in the figure, the signal peak of the carbon-carbon double bond of D disappears. At the same time, due to the addition reaction, characteristic peaks appear near 2.31ppm and 2.71ppm, which are respectively attributed to the hydrogen at h (tertiary carbon) and j (tertiary carbon) and g (methylene) in the molecule. The signal peaks of the methylene f formed after the addition reaction of 1,6-hexanediamine appear at 2.4ppm and 2.53ppm, indicating that D reacts with 1,6-hexanediamine to form D-NH 2 Preparation successful.

[0084] (4) Preparation of ordered hyperbranched macromolecule G5

[0085] 1) D-NH 2 (1.0equiv), add B-=(6.0equiv), use a mixture of methanol and water (volume ratio 2:1) as the reaction solvent, stir at 80°C, react in a sealed container for 24 hours, and then remove most of the solvent by rotary evaporation to obtain the first generation product (G1);

[0086] 2) Take G1 (1.0 equiv) and add D-NH 2 (18 equiv), stirred at 90 °C, sealed and reacted for 48 h, and then most of the solvent was removed by rotary evaporation to obtain the second generation product (G2);

[0087] 3) Take the same reaction steps, take G2 (1.0 equiv), add B-= (90.0 equiv), and obtain the third generation product (G3);

[0088] 4) Take G3 (1.0 equiv) and add D-NH 2 (270.0equiv), and the fourth generation product (G4) was obtained;

[0089] 5) Take G4 (1.0 equiv) and add B-= (1350.0 equiv) to synthesize the ordered hyperbranched monomer G5.

[0090] The G1-G5 products were concentrated by rotary evaporation and then dried in vacuum, and characterized by NMR and IR.

[0091] like Figure 6 As shown in a, D-NH 2 The appearance of the characteristic peaks of amino and amide in the infrared spectrum of , and the appearance of the characteristic peaks of double bond and carbonyl in the B-= spectrum, indicate that the two were successfully prepared.

[0092] like Figure 6As shown in b, the amino group appeared and the double bond disappeared, indicating that G1-G5 were successfully prepared.

[0093] (5) Weigh 50 mg of copper chloride dihydrate, dissolve it in 3.0 mL of ethanol, add 500 μL of PMDETA, prepare 3.0 mL of ascorbic acid solution (0.2 g), fully disperse 0.6 g of BM in 40 mL of ethanol, add 10 mL of G5, pass nitrogen to create an anaerobic environment, then add the copper ethanol mixture and the ascorbic acid aqueous solution prepared in advance, continue to ventilate for 5.0 min and then seal the reaction. At 50 ° C and 1000 rpm, react for 8.0 h and then centrifuge to obtain a solid material, which is washed three times with water and ethanol respectively. All the obtained products are dispersed in a mixed solution of methanol and water (volume ratio is 2:1), and 10 mL of D-NH 2 , stirred at 1000 rpm at 70 °C, and the product was collected after 12 h of reaction, and washed with water and ethanol to obtain hyperbranched nanosheets HBM-NH 2 .

[0094] like Figure 7 As shown, HBM-NH 2 The characteristic peaks of amino groups, silica skeletons and amide bonds in the spectrum indicate that the preparation is successful.

[0095] Example 2 Ordered hyperbranched nanosheets HBM-SO 3 Preparation

[0096] Accurately weigh 0.5 g TCEP and dissolve it in 30 mL of deionized water. Add 1.0 g HBM-NH prepared in step (1) 2 , reacted at 1000rpm, 40℃ for 16h. The product was separated by centrifugation and washed with water three times. Then dispersed in 50mL water, adjusted pH to 1.0 with hydrochloric acid, added with 5.0mL hydrogen peroxide, stirred at 50℃ for 24h, and separated by centrifugation to obtain solid material HBM-SO 3 , wash with water until neutral.

[0097] like Figure 7 As shown in the figure, the appearance of the characteristic peak of the sulfonic acid group indicates that HBM-SO 3 Preparation was successful.

[0098] Example 3: Disordered hyperbranched nanosheets PBM-NH 2 Preparation

[0099] Steps (1) to (3) are the same as steps (1) to (3) of Example 1;

[0100] (4) Take D-NH 2(1.0equiv), add B-=(5.004equiv), use a mixture of methanol and water (volume ratio 2:1) as solvent, stir and react at 90°C for 48h to obtain a disordered polymerized hyperbranched monomer P5, which is concentrated by rotary evaporation and used as a standby. (5) Under the same reaction conditions as step (5) of Example 1, only G5 is replaced by P5, 10mL P5 is added, the disordered hyperbranched monomer is grafted on the surface of the nanosheet, and then excess D-NH 2 Modify the terminal groups to obtain nanosheets of PBM-NH 2 .

[0101] like Figure 7 As shown in the figure, the appearance of the characteristic peaks of amino and amide functional groups indicates that PBM-NH 2 Preparation was successful.

[0102] Comparative Example 1 Unbranched Nanosheet BM-NH 2 Preparation

[0103] Weigh 50 mg of copper chloride dihydrate, dissolve it in 3.0 mL of ethanol, add 500 μL of PMDETA, fully disperse 0.6 g of BM in 40 mL of ethanol, add 0.3 g of B-=, pass nitrogen to create an anaerobic environment, then add the copper ethanol mixture and 3.0 mL of ascorbic acid solution (0.2 g) prepared in advance, continue to ventilate for 5.0 min, seal the reaction, 50 ° C, 1000 rpm, 8.0 h. After the reaction is completed, centrifuge to separate the solid material BM-NH 2 , washed with water and freeze-dried.

[0104] like Figure 7 As shown in the figure, the appearance of the characteristic peaks of amino and amide functional groups indicates that BM-NH 2 Preparation was successful.

[0105] Test 1:

[0106] Take 4.0mL of Pb at different pH (3.0, 4.0, 5.0 and 6.0) 2+ solution (100 mg / L) in a 10 mL centrifuge tube, and 1.0 mg of adsorbent (HBM-NH 2 、HBM-SO 3 、PBM-NH 2 or BM-NH 2 ), placed in a constant temperature and humidity chamber, statically adsorbed for 3.0 h, centrifuged, and the supernatant was taken to detect the remaining Pb 2+ Solution concentration, three parallel experiments were performed for each group of experiments.

[0107] like Figure 8 As shown in a, HBM-NH2 、HBM-SO 3 、PBM-NH 2 and BM-NH 2 The adsorption capacity of lead ions was 6. When the pH was 6, the four adsorbents showed better adsorption performance. 2 Has the highest adsorption capacity.

[0108] Test 2:

[0109] Accurately weigh 1.0 mg of adsorbent (HBM-NH 2 、HBM-SO 3 、PBM-NH 2 or BM-NH 2 ), add 4.0mL of Pb 2+ Solution (100 mg / L) was statically adsorbed at 25°C for 1.0 min, 2.0 min, 5.0 min, 10 min, 30 min, 60 min and 120 min, and the supernatant was taken to detect the remaining Pb by flame atomic absorption (FAAS). 2+ Concentration, three parallel experiments were carried out in each group of experiments, and the adsorption capacity of each adsorbent at different adsorption times was calculated.

[0110] like Figure 8 As shown in b, it is HBM-NH 2 、HBM-SO 3 、PBM-NH 2 and BM-NH 2 The kinetic adsorption data of lead ions and the fitting of pseudo-first-order and pseudo-second-order kinetic models showed that all four adsorbents were in line with the pseudo-second-order kinetic model, indicating that the adsorption of lead ions was mainly chemical adsorption.

[0111] Figure 8 c is the intra-particle diffusion model of adsorption kinetics, indicating that the adsorption process consists of three stages: liquid film diffusion, pore diffusion, and adsorption equilibrium;

[0112] Figure 8 d is the Elovich model fitting, which shows that the adsorption process of the four adsorbents is an adsorption process in which the adsorption rate gradually decreases as the adsorption sites are occupied.

[0113] Test 3:

[0114] Take 50mg / L, 100mg / L, 150mg / L, 200mg / L and 250mg / L of Pb respectively 2+ solution, add 1.0 mg of adsorbent (HBM-NH 2 、HBM-SO 3 、PBM-NH 2 or BM-NH2 ), static adsorption was performed at 15℃, 25℃ and 37℃ for 1.0h, and residual Pb was detected after adsorption. 2+ Solution concentration, three parallel experiments were performed for each group of experiments to calculate the different initial Pb 2+ The adsorption capacity of each adsorbent under the same experimental steps

[0115] like Fig. 9 As shown in ad, they are HBM-NH 2 BM-NH 2 、HBM-SO 3 and PBM-NH 2 The adsorption isotherms of lead ions, as well as the Langmuir and Freundlich model fitting, show that the four adsorbents are more consistent with the Langmuir model fitting process, indicating its monolayer adsorption process.

[0116] like Fig.10 As shown, HBM-NH 2 The XPS analysis spectrum shows that N1s and O1s shift before and after adsorption, indicating that the adsorption and separation of lead ions is based on amino, carboxyl and imino groups.

[0117] Test 4:

[0118] Take 2% of the cell suspension and add different masses of adsorbent HBM-NH 2 or HBM-SO 3 , the adsorbent concentrations were controlled to be 0.2 mg / mL, 0.4 mg / mL, 0.6 mg / mL, 0.8 mg / mL and 1.0 mg / mL. After incubation for 1.0 h, centrifuge at 2000 rpm for 10 min, take the supernatant, and use an ultraviolet spectrophotometer (UV-Vis) to detect the absorbance of hemoglobin at 541 nm. Three sets of parallel experiments were performed at the same time, and formula (4.2) was used to calculate the different amounts of HBM-NH 2 and HBM-SO 3 hemolysis rate.

[0119] like Fig.11 As shown in a, it is HBM-NH 2 and HBM-SO 3 The hemolysis rate analysis chart at different doses showed that the hemolysis rate was lower than 1% (lower than the safety threshold of 5%), indicating good blood compatibility.

[0120] like Fig.11 b and c are HBM-NH 2 and HBM-SO 3 Actual picture of hemolysis at different doses.

[0121] Test 5:

[0122] Take sodium citrate anticoagulated platelet-poor plasma and add HBM-NH 2 or HBM-SO 3 The concentrations were set to 0.5 mg / L and 1.0 mg / L, respectively. After thorough mixing, the mixture was incubated in a constant temperature water bath at 37°C for 1.0 h. The APTT, TT and PT times were determined using an automatic coagulometer. Three parallel experiments were performed for each group of experiments to ensure the accuracy of the results.

[0123] like Fig.11 d and e are HBM-NH 2 and HBM-SO 3 In the coagulation time analysis chart at different doses, the coagulation times were all within the safe range, indicating that the two adsorbents had little effect on coagulation and had good blood compatibility.

[0124] Test 6:

[0125] Use potassium chloride, sodium chloride, anhydrous calcium chloride, magnesium sulfate and lead nitrate to prepare a mixed ion solution with an ion concentration of 100 mg / L (the molar concentrations of each ion are 2.56 mmol / L, 4.35 mmol / L, 2.5 mmol / L, 4.16 mmol / L and 0.48 mmol / L, respectively). Take 4.0 mL of the mixed ion solution and add 1.0 mg of HBM-NH 2 , placed in a constant temperature and humidity chamber, static adsorption for 1.0h, after the adsorption, take the supernatant, detect the concentration of each ion, and carry out three sets of parallel experiments at the same time to calculate HBM-NH 2 Adsorption capacity of various ions.

[0126] like Fig.12 As shown in a, it is HBM-NH 2 The adsorption performance of lead ions was analyzed in a simulated blood ion environment. It still has a high adsorption capacity for lead ions, indicating its excellent selectivity.

[0127] Test 7:

[0128] Fresh blood was taken and different concentrations of lead ion physiological saline solution were added to dilute the lead-contaminated blood into concentrations of 100 μg / L, 200 μg / L, 300 μg / L and 400 μg / L, respectively. The blood was incubated for 1.0 h and the blood with different blood lead concentrations was taken and HBM-NH 2 The concentration was controlled to be 0.5 mg / mL, mixed evenly, incubated at 37°C for 1.0 h, centrifuged and the supernatant was taken. The digestion solution prepared with 5 mL of a mixture of nitric acid and hydrogen peroxide (volume ratio of 3:4) was digested at 180°C for 4.0 h, and then the volume was fixed in a 10.0 mL volumetric flask. The remaining Pb was detected by ICP-OES.2+ Concentration, calculate blood lead adsorption amount and removal rate.

[0129] like Fig.12 As shown, HBM-NH 2 The analysis chart of the adsorption performance of blood lead shows that it has a good effect on removing blood lead.

Claims

1. A method for preparing a high-density site nanosheet modified with a hyperbranched monomer, characterized in that: The steps include: (1) Preparation of silica nanosheets BM: A mixed solution of ammonia water and potassium bromide KBr is added to ethanol, mixed evenly, and then added to n-pentanol, and shaken evenly to prepare a metastable nanoemulsion; then tetraethyl orthosilicate TEOS and 3-chloropropyltrimethoxysilane CPTMS are added to the metastable nanoemulsion prepared above, and stirred at a low speed to react to prepare silica nanosheets BM; (2) Preparation of hyperbranched unit B-=: N,N-methylenebisacrylamide MBA and 1,6-hexanediamine were completely dissolved in a mixture of methanol and water, stirred for reaction, the product was concentrated by rotary evaporation and a large amount of ethanol was added to obtain a white solid, which was filtered and vacuum dried to prepare a hyperbranched graft unit B-=; (3) Preparation of hyperbranched grafting unit D-NH2 Weigh cystine D-Cys and sodium hydroxide, add them into deionized water to completely dissolve them, then add methacrylic anhydride, and after the first stirring reaction is completed, add a large amount of acetone to the reaction solution to obtain a yellow oily product D; Then, product D was added with 1,6-hexanediamine, and a mixture of methanol and water was used as the reaction solvent for a second stirring reaction. After the reaction was completed, a large amount of acetone was added to obtain a dark yellow liquid product D-NH2; (4) Preparation of ordered hyperbranched macromolecule G5: 1) Take D-NH2 and add B-=, use a mixture of methanol and water as the reaction solvent, seal and stir the reaction, and remove most of the solvent by rotary evaporation to obtain the first-generation product G1; 2) Add D-NH2 to G1, stir the mixture in a sealed container, and remove most of the solvent by rotary evaporation to obtain the second-generation product G2; 3) Take the same reaction steps and add B-= to G2 to obtain the third generation product G3; 4) Take G3 and add D-NH2 to obtain the fourth-generation product G4; 5) Take G4 and add B-= to synthesize ordered hyperbranched monomer G5; (5) Preparation of disordered hyperbranched macromolecule P5: Take D-NH2 and add B-=, use a mixture of methanol and water as solvent, stir to react, and after rotary evaporation and concentration, obtain a disorderly polymerized hyperbranched monomer P5; (6) Preparation of ordered hyperbranched nanosheets HBM-NH2 Weigh copper chloride dihydrate and dissolve it in ethanol, add N,N,N',N',N"-pentamethyldiethylenetriamine PMDETA to obtain a copper ethanol mixture; Fully disperse BM in ethanol, add G5, introduce nitrogen to create an anaerobic environment, then add copper mixed solution and ascorbic acid aqueous solution, seal the reaction in an anaerobic environment, centrifuge to obtain solid material, disperse all the obtained products in a mixed solution of methanol and water, add excess D-NH2, stir the reaction, and collect the product HBM-NH2; (7) Preparation of ordered hyperbranched nanosheets HBM-SO3 Accurately weigh TCEP and dissolve it in deionized water, add HBM-NH2, after the reaction is completed, centrifuge and separate the product and disperse it in water, adjust the pH to 1.0 with hydrochloric acid, add hydrogen peroxide, stir and react to obtain a solid material HBM-SO3; (8) Preparation of disordered hyperbranched nanosheets PBM-NH2 PBM-NH2 was prepared by replacing G5 with P5 under the same conditions as step (6).

2. The preparation method according to claim 1, characterized in that: In step (1), the usage ratio of KBr, ammonia water, ethanol, n-pentanol, TEOS and CPTMS is 0.005-0.01 g): (0.2-0.5) mL: (0.5-4 mL): (8-13 mL): (0.05-0.15 mL): (0.05-0.015).

3. The preparation method according to claim 1, characterized in that: In step (2), the dosage ratio of MBA, 1,6-hexanediamine and methanol aqueous solution is (0.3-0.9 g): (0.05-0.15 g): (40-120 mL); the reaction temperature is 20-40° C., and the reaction time is 8-15 h.

4. The preparation method according to claim 1, characterized in that: In steps (2)-(5), the volume ratio of methanol to water in the mixed solution of methanol and water is 2:

1.

5. The preparation method according to claim 1, characterized in that: In step (3), The usage ratio of D-Cys, sodium hydroxide, deionized water and methacrylic anhydride is (0.1-1.0 g): (0.4-4.0 g): (8-80 mL): (0.36-3.6 mL); The usage ratio of product D and 1,6-hexanediamine is (0.1-1.0g): (0.04-0.8g), The reaction temperature of the first stirring reaction and the second stirring reaction are both 25-50°C, and the reaction time is both 5-15h.

6. The preparation method according to claim 1, characterized in that: In step (4), When preparing G1, the molar ratio of D-NH2 and B-= is 1:6, the reaction temperature is 60-90°C, and the reaction time is 20-40h; When preparing G2, the molar ratio of G1 to D-NH2 is 1:18, the reaction temperature is 80-99°C, and the reaction time is 40-60h; When preparing G3, the molar ratio of G2 and B-= is 1:90, the reaction temperature is 80-99°C, and the reaction time is 50-70h; When preparing G4, the molar ratio of G3 to D-NH2 is 1:270; the reaction temperature is 80-99°C, and the reaction time is 50-70h; When preparing G5, the molar ratio of G4 and B-= is 1:1350, the reaction temperature is 80-99°C, and the reaction time is 50-70h.

7. The preparation method according to claim 1, characterized in that: In step (5), the molar ratio of D-NH2 and B-= is 1:5.004, the reaction temperature is 80-99°C, and the reaction time is 20-40h.

8. The preparation method according to claim 1, characterized in that: In step (6), In the copper-ethanol mixture, the ratio of cupric chloride dihydrate, ethanol and PMDETA is (10-100 mg): (1-6 mL): (0.5-1 mL); The usage ratio of cupric chloride dihydrate, BM, ascorbic acid aqueous solution and G5 is: (10-100 mg): (0.2-1.2 g): (2-6 mL): (2-20 mL), and the concentration of ascorbic acid aqueous solution is 0.1-0.2 g / mL; The sealed reaction temperature in an oxygen-free environment is 45-65°C and the time is 5-15h; During the modification of D-NH2, the reaction temperature is 50-80°C.

9. The preparation method according to claim 1, characterized in that: In step (7), the dosage ratio of TCEP, HBM-NH2 and hydrogen peroxide is (0.2-0.8 g): (0.4-1.6 g): (2-8 mL), the reaction temperature is 30-70°C, and the reaction time is 15-30 h.

10. Use of the high-density site nanosheet modified with a hyperbranched monomer prepared by the preparation method according to any one of claims 1 to 9 for removing lead ions from aqueous solution or blood.

Images