CN110756177B - Preparation method and application of functionalized nano silicon dioxide/resorcinol-formaldehyde microspheres - Google Patents
Preparation method and application of functionalized nano silicon dioxide/resorcinol-formaldehyde microspheres Download PDFInfo
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Abstract
The invention provides a preparation method and application of functionalized nano silicon dioxide/resorcinol-formaldehyde microspheres, wherein the preparation method comprises the steps of preparing the nano silicon dioxide/resorcinol-formaldehyde microspheres and functionalizing the surfaces of the nano silicon dioxide/resorcinol-formaldehyde microspheres; ammonia is used as a catalyst. The preparation method comprises the following steps of: stirring and uniformly mixing a mixed solution of ethanol and water with concentrated ammonia water, sequentially adding TEOS, resorcinol and formaldehyde solution, stirring for reaction, and aging after the reaction is finished; and after the aging is finished, performing centrifugal separation, cleaning and drying to obtain the nano silicon dioxide/resorcinol-formaldehyde microspheres. And performing surface functionalization treatment to obtain the functionalized nano silicon dioxide/resorcinol-formaldehyde microspheres. The obtained microspheres can effectively adsorb hexavalent chromium in the solution.
Description
Technical Field
The invention belongs to the technical field of material science and engineering, and particularly relates to preparation of a functionalized nano silicon dioxide/resorcinol-formaldehyde microsphere and application of the functionalized nano silicon dioxide/resorcinol-formaldehyde microsphere in adsorption and removal of hexavalent chromium in a water body.
Background
Hexavalent chromium has a limited requirement for the content of hexavalent chromium in water bodies such as industrial wastewater, drinking water and the like, leather, textiles and toys in countries of the world due to its strong toxicity, strong carcinogenic and mutagenic effects and harm to the environment and human health. In order to meet the regulations of various countries and achieve effective removal of hexavalent chromium, methods such as electrochemical deposition, ion exchange, membrane separation, biological treatment, photocatalysis, solvent extraction, adsorption and the like are developed to convert hexavalent chromium into trivalent chromium with relatively low toxicity or remove hexavalent chromium as completely as possible. The hexavalent chromium is reasonably and effectively adsorbed by adopting a proper adsorbent, the cost is low, the effect is obvious, and the method is a removal mode which is applied more at present. How to prepare the adsorbent with high adsorption capacity by adopting simple synthesis steps and improve the removal efficiency of the adsorbent is a hot research problem.
Currently, activated carbon, zeolite, clay, nano materials, biological adsorbents and the like are mainly used for hexavalent chromium adsorption, wherein nano silicon dioxide has the characteristics of good water solubility, good thermal stability, high mechanical strength and the like, and organic or inorganic functional groups are easier to fix due to the existence of surface silicon hydroxyl (Si-OH). In the aspect of removing hexavalent chromium in aqueous solution, a surface modification mode is mostly adopted to prepare a silicon dioxide modified material, such as modified functional groups, polymers, biological materials, ionic liquids and the like. Wang et al prepared mesoporous silica by a template method and surface-modified with 1- (2-aminoethyl) -3-aminopropyltrimethoxysilane. Chowdhury, etc. adopts a microemulsion method to prepare polypyrrole nano particles, and grafts the polypyrrole nano particles on the surface of silicon dioxide modified with dimethyldichlorosilane. Chen et al modified the quaternary ammonium phosphonium ionic liquid on the silica surface by a sol-gel method.
The existing silica-based composite materials have the following drawbacks: (1) the preparation process is complex; (2) lack of available functional groups; (3) the absorption capacity to hexavalent chromium is low; (4) the absorption selectivity to hexavalent chromium is poor.
Disclosure of Invention
Aiming at the technical problems, the invention provides a preparation method and application of a functionalized nano silicon dioxide/resorcinol-formaldehyde microsphere, and aims to provide the following steps: through simple synthesis steps, the functional material with high adsorption capacity and good selectivity is prepared and used for adsorbing and removing hexavalent chromium in an aqueous solution.
In order to realize the purpose, the invention adopts the technical scheme that:
a preparation method of functionalized nano silicon dioxide/resorcinol-formaldehyde microspheres is characterized in that ammonia water is used as a catalyst, TEOS (tetraethyl orthosilicate) is hydrolyzed in ethanol-water solution to generate silicon dioxide particles, resorcinol and formaldehyde are polymerized to obtain an RF layer, and the functionalized nano silicon dioxide/resorcinol-formaldehyde microspheres are prepared after APTES modification.
Comprises the steps of preparing nano silicon dioxide/resorcinol-formaldehyde microspheres and functionalizing the surfaces of the nano silicon dioxide/resorcinol-formaldehyde microspheres.
The preparation method comprises the following steps of: fully mixing ethanol, water and strong ammonia water, adding TEOS, resorcinol, and water,And (3) stirring the formaldehyde solution for reaction, and pouring the solution into a high-pressure reaction kettle for continuous aging after the reaction is finished. After aging, centrifugally separating, respectively washing the obtained solid with absolute ethyl alcohol and ultrapure water, and drying to obtain nano silicon dioxide/resorcinol-formaldehyde microspheres, namely nano SiO 2 @ RF microspheres.
Surface functionalization of the nano silicon dioxide/resorcinol-formaldehyde microspheres: uniformly dispersing nano silicon dioxide/resorcinol-formaldehyde microspheres in a mixed solution of ethanol and water, adding concentrated ammonia water, uniformly mixing, dropwise adding 3-Aminopropyltriethoxysilane (APTES) for reaction, after the reaction is finished, performing centrifugal separation, respectively cleaning the obtained solid with absolute ethanol and ultrapure water, and drying to obtain the functionalized nano SiO 2 @ RF microspheres.
Preparing nano silicon dioxide/resorcinol-formaldehyde microspheres:
adding 30-40 mL of mixed solution of ethanol and water and 1-1.5 mL of concentrated ammonia water into a three-neck flask; the volume ratio of the ethanol to the water in the mixed solution is 2-4: 1; the concentrated ammonia water: the mass percentage concentration is 25% -28%.
Violently stirring the solution in the three-neck flask at 30-40 ℃ for 20-30 min, adding 1.2-1.5 mL of TEOS, continuously stirring for reacting for 30-40 min, adding 0.2-0.25 g of resorcinol, stirring for 10-30 min, adding 280-350 mu L of formaldehyde aqueous solution, and reacting for 24-26 h; the mass percentage concentration of the formaldehyde aqueous solution is 37-40%.
After the reaction is finished, pouring the solution in the three-neck flask into a hydrothermal reaction kettle, and aging for 24-26 h at 100-102 ℃.
After the aging reaction is finished, centrifuging the solution at the rotating speed of 7500-8500 rpm for 10-15 min; collecting the centrifuged solid;
cleaning the centrifuged solid with absolute ethyl alcohol for 3-5 times, and then cleaning with ultrapure water for 3-5 times;
drying the solid at 40-50 ℃ for 10-14 h to obtain the nano SiO 2 @ RF microspheres.
Surface functionalization of nano silicon dioxide/resorcinol-formaldehyde microspheres:
(1) mixing 70-80 mL of anhydrous ethanol and 10-20 mL of ultrapure water to obtain a mixed solution;
(2) 150-200 mg of nano SiO 2 Ultrasonically dispersing the @ RF microspheres in the mixed solution prepared in the step (1), and then adding 1.5-2 mL of concentrated ammonia water; and then placing the mixture in a water bath at the temperature of 30-40 ℃ to be vigorously stirred for 20-30 min, then dropwise adding 2-3 mL of APTES, and reacting for 10-12 h. The concentrated ammonia water: the mass percentage concentration is 25% -28%.
(3) After the reaction is finished, pouring the reaction liquid into a centrifugal tube, centrifuging the solution at the rotating speed of 7500-8500 rpm for 10-15 min, cleaning the centrifuged solid with absolute ethyl alcohol for 3-5 times, then cleaning with ultrapure water for 3-5 times, and drying at 40-50 ℃ for 10-14 h to obtain the functionalized nano SiO 2 @ RF microspheres.
An application of a functionalized nano silicon dioxide/resorcinol-formaldehyde microsphere in absorption and removal of hexavalent chromium. The absorption of hexavalent chromium is carried out at the absorption temperature of 45 ℃ and the absorption capacity reaches 180.21 mg g -1 。
The invention has the following beneficial effects:
(1) the synthetic process is simple and the steps are few; the method for preparing the functionalized nano silicon dioxide/resorcinol-formaldehyde microspheres has a simple synthesis process, adopts a one-step method to synthesize the nano silicon dioxide/resorcinol-formaldehyde microspheres in one pot, uses APTES to perform surface functionalization, and only needs two steps to prepare the functionalized nano silicon dioxide/resorcinol-formaldehyde microspheres;
(2) the adsorption capacity to hexavalent chromium is high; the adsorption capacity increased with the temperature increase at 25 deg.C, 35 deg.C, and 45 deg.C, respectively 143.84 mg g -1 、149.40 mg g -1 And 180.21 mg g -1 。
(3) The absorption selectivity to hexavalent chromium is high; the concentration is 30 mg L -1 After the hexavalent chromium is adsorbed by the material, the removal efficiency is 99.93 percent, and the concentration is 30 mg L -1 Is mixed with hexavalent chromium in a concentration of 300 mg L -1 Any other commonly used cation or anion (Na) + 、K + 、Mg 2+ 、Ca 2+ 、Cu 2+ 、Fe 2+ 、Pb 2+ 、Co 2+ 、Ni 2+ 、Cr 3+ 、Cl − 、NO 3− 、NO 2− 、CO3 2− 、SO4 2− 、PO4 3− ) After blending and material adsorption, the removal efficiency is 99.31-99.92%, and the removal efficiency of hexavalent chromium is not affected.
(4) The material can be repeatedly used; the same batch of materials is adopted for carrying out adsorption-desorption experiments, and the hexavalent chromium removal efficiency is still higher than 85 percent after the materials are repeatedly used for 5 times.
Drawings
FIG. 1 is a process diagram of a preparation method of functionalized nano silica/resorcinol-formaldehyde microspheres in example 1;
FIG. 2 is a scanning electron microscope and a particle size distribution diagram of the functionalized nano-silica/resorcinol-formaldehyde microspheres of example 2;
FIG. 3 is a graph showing the static adsorption curves of the functionalized nano-silica/resorcinol-formaldehyde microspheres of example 3 for hexavalent chromium at different temperatures;
FIG. 4 is a bar graph of the competitive adsorption of hexavalent chromium with coexisting ions by the functionalized nano-silica/resorcinol-formaldehyde microspheres of example 4;
FIG. 5 is a column diagram of the number of times of repeated use of the functionalized nano-silica/resorcinol-formaldehyde microspheres for hexavalent chromium adsorption.
Detailed Description
The invention is further explained below with reference to the figures and examples.
Example 1 preparation method of functionalized nano silica/resorcinol-formaldehyde microspheres
a. Preparation of nano-silica/resorcinol-formaldehyde microspheres
Adding 40 mL of ethanol/water mixed solution with the volume ratio of 3:1 and 1.25 mL of strong ammonia water with the mass percentage concentration of 25% into a three-neck flask, violently stirring for 20 min at 30 ℃, adding 1.4 mL of TEOS, continuously stirring for reacting for 30min, adding 0.25 g of resorcinol, stirring for 30min, adding 350 mu L of formaldehyde aqueous solution, and reacting for 24 h; the mass percentage concentration of the formaldehyde aqueous solution is 37%.
After the reaction is finished, pouring the solution in the three-neck flask into a hydrothermal reaction kettle, and aging for 24 hours at 100 ℃.
After the aging reaction is finished, centrifuging the solution at the rotating speed of 7500 rpm for 10 min, and collecting the centrifuged solid; cleaning the centrifuged solid with anhydrous ethanol for 3 times, and then cleaning with ultrapure water for 3 times; drying at 50 ℃ for 10 h to obtain nano SiO 2 @ RF microspheres.
b. Surface functionalization of nanosilica/resorcinol-formaldehyde microspheres
(1) Mixing 70 mL of absolute ethyl alcohol and 10 mL of ultrapure water to obtain a mixed solution;
(2) 200 mg of nano SiO 2 Ultrasonically dispersing the @ RF microspheres in the mixed solution prepared in the step (1), and then adding 2 mL of concentrated ammonia water; then the mixture is placed in a water bath at 30 ℃ and stirred vigorously for 30min, and then 2 mL of APTES is added dropwise to react for 12 h. The concentrated ammonia water: the mass percentage concentration is 25%.
(3) After the reaction is finished, pouring the reaction liquid into a centrifuge tube, centrifuging the solution at the rotating speed of 7500 rpm for 10 min, cleaning the solid after centrifugation by absolute ethyl alcohol for 3 times, then cleaning by ultrapure water for 3 times, and drying at 50 ℃ for 10 h to obtain the functionalized nano SiO 2 @ RF microspheres.
The process schematic diagram of the preparation method of the functionalized nano silicon dioxide/resorcinol-formaldehyde microspheres is shown in the attached figure 1.
Preparing the obtained nano SiO 2 @ RF microsphere and functionalized nano SiO 2 The @ RF microsphere is in a regular spherical shape and rough in surface as shown in an attached figure 2. From the particle size distribution diagram, the nano SiO 2 The average particle size of the @ RF material is about 203 nm, and the average particle size of the APTES modified material is about 211 nm, which indicates that the surface modification of the material is successful.
Example 2 functionalized Nano SiO 2 Experiment of adsorption effect of @ RF microspheres on hexavalent chromium solution at different temperatures
1. Experiment on the adsorption effect of the hexavalent chromium solution at 25 ℃:
the prepared concentration was 30 mg L -1 、50 mg L -1 、100 mg L -1 、150 mg L -1 、200 mg L -1 、250 mg L -1 、300 mg L -1 、350 mg L -1 、400 mg L -1 The hexavalent chromium solution of (a).
Weighing multiple parts of 5 mg functionalized nano SiO 2 @ RF microspheres, which are respectively placed in 10 mL round-bottom centrifuge tubes, and 5 mL prepared L with the concentration of 30-400 mg L are respectively added -1 The pH value of the gradient hexavalent chromium solution is adjusted to 2.0, and the solution is uniformly dispersed by ultrasonic. The centrifuge tubes were simultaneously placed on a thermostatted gas bath shaker at a temperature of 25 ℃ and adsorbed by reciprocal shaking at 150 rpm for 24 h. And after the adsorption reaction is finished, centrifuging the centrifugal tube at the rotating speed of 7500 rpm for 10 min, taking the upper layer solution, acidifying by phosphoric acid, developing the color by 1, 5-diphenyl carbodihydrazide (DPC), and detecting the concentration of the residual hexavalent chromium in the solution by using an ultraviolet-visible spectrophotometer (UV-vis).
Triplicate determinations were made.
And an adsorption effect experiment of the hexavalent chromium solution at 35 ℃ is carried out:
the prepared concentration was 30 mg L -1 、50 mg L -1 、100 mg L -1 、150 mg L -1 、200 mg L -1 、250 mg L -1 、300 mg L -1 、350 mg L -1 、400 mg L -1 The hexavalent chromium solution of (a).
Weighing multiple parts of 5 mg functionalized nano SiO 2 @ RF microspheres, which are respectively placed in 10 mL round-bottom centrifuge tubes, and 5 mL prepared L with the concentration of 30-400 mg L are respectively added -1 The pH value of the gradient hexavalent chromium solution is adjusted to 2.0, and the solution is uniformly dispersed by ultrasonic. The centrifuge tubes were simultaneously placed on a thermostatted gas bath shaker at a temperature of 35 ℃ and adsorbed by reciprocal shaking at 150 rpm for 24 h. And after the adsorption reaction is finished, centrifuging the centrifugal tube at the rotating speed of 7500 rpm for 10 min, taking the upper layer solution, acidifying by phosphoric acid, developing by DPC, and detecting the concentration of the residual hexavalent chromium in the solution by UV-vis.
Triplicate determinations were made.
And an experiment on the adsorption effect of the hexavalent chromium solution at 45 ℃:
the prepared concentration was 30 mg L -1 、50 mg L -1 、100 mg L -1 、150 mg L -1 、200 mg L -1 、250 mg L -1 、300 mg L -1 、350 mg L -1 、400 mg L -1 To obtain a hexavalent chromium solution.
Weighing multiple parts of 5 mg functionalized nano SiO 2 @ RF microspheres, which are respectively placed in 10 mL round-bottom centrifuge tubes, and 5 mL prepared L with the concentration of 30-400 mg L are respectively added -1 The pH value of the gradient hexavalent chromium solution is adjusted to 2.0, and the solution is uniformly dispersed by ultrasonic. The centrifuge tubes were simultaneously placed on a thermostatted gas bath shaker at a temperature of 45 ℃ and adsorbed by reciprocal shaking at 150 rpm for 24 h. And after the adsorption reaction is finished, centrifuging the centrifugal tube at the rotating speed of 7500 rpm for 10 min, taking the upper-layer solution, acidifying by phosphoric acid, performing DPC color development, and detecting the concentration of the residual hexavalent chromium in the solution by using UV-vis.
Triplicate determinations were made.
And calculating the adsorption capacity according to the ratio of the content difference of the hexavalent chromium in the solution before and after adsorption to the material usage.
Drawing the functionalized nano SiO by taking the concentration of hexavalent chromium as an abscissa and the adsorption capacity as an ordinate 2 The results of the static adsorption curves of the @ RF microspheres for hexavalent chromium solutions at temperatures of 25 ℃, 35 ℃ and 45 ℃ are shown in FIG. 3.
As can be seen from the figure, under the conditions of the temperature of 25 ℃, 35 ℃ and 45 ℃, the functionalized nano SiO 2 The adsorption capacity of the @ RF microspheres for hexavalent chromium increases with increasing temperature and increases with increasing concentration. Under three temperature conditions, the nano-SiO has higher adsorption capacity and is functionalized at the temperature of 45 DEG C 2 The adsorption capacity of the @ RF microspheres on hexavalent chromium reaches 180.21 mg g -1 。
Example 3 functionalized Nano-SiO 2 Competitive adsorption experiment of @ RF microspheres on hexavalent chromium
Selecting possible cation (Na) in industrial waste water containing chromium + 、K + 、Mg 2+ 、Ca 2+ 、Cu 2+ 、Fe 2+ 、Pb 2+ 、Co 2+ 、Ni 2+ 、Cr 3+ ) And anions (Cl) − 、NO 3 − 、NO 2 − 、CO 3 2− 、SO 4 2− 、PO 4 3− ) And carrying out competitive adsorption experiments with hexavalent chromium. The operation steps are as follows:
weighing multiple parts of 5 mg functionalized nano SiO 2 @ RF microspheres, placed in 10 mL round-bottom centrifuge tubes, respectively, and added with 5 mL L of 30 mg L -1 The hexavalent chromium solution is prepared by adjusting the pH value of the solution to 2.0, uniformly dispersing by ultrasonic treatment, and respectively adding the hexavalent chromium solution with the concentration of 300 mg.L -1 Na (b) of + 、K + 、Mg 2+ 、Ca 2+ 、Cu 2+ 、Fe 2+ 、Pb 2+ 、Co 2+ 、Ni 2+ 、Cr 3+ 、Cl − 、NO 3 − 、NO 2 − 、CO 3 2− 、SO 4 2− 、PO 4 3− A solution of one of the cations or anions. The centrifuge tubes were simultaneously placed on a thermostatted gas bath shaker at a temperature of 25 ℃ and adsorbed by reciprocal shaking at 150 rpm for 24 h. And after the adsorption reaction is finished, centrifuging the centrifugal tube at the rotating speed of 7500 rpm for 10 min, taking the upper layer solution, acidifying by phosphoric acid, carrying out color development by DPC, and detecting the concentration of the residual hexavalent chromium in the solution by UV-vis.
Triplicate determinations were performed.
And calculating the removal rate (%) by the ratio of the concentration difference of the hexavalent chromium in the solution before and after adsorption to the initial concentration. The results are shown in FIG. 4, where the competitive adsorption column plots ion species on the abscissa and removal rate on the ordinate.
When the solution only contains hexavalent chromium, contains hexavalent chromium and single competitive cation or anion with the concentration of 10 times, the absorption of the hexavalent chromium in the solution is basically not influenced, which shows that coexisting ions can not compete with the hexavalent chromium for the functionalized nano SiO 2 The active sites on the surface of the @ RF microsphere can effectively avoid the interference of other ions.
Example 4 functionalized Nano SiO 2 Adsorption-desorption experiment of @ RF microspheres on hexavalent chromium solution
First adsorption-desorption experiment:
(1) functionalized nano SiO 2 Adsorption experiment of @ RF microspheres on hexavalent chromium solution
Weighing 50 mg portions of functionalized nano SiO 2 @ RF microspheres, respectively placed in 50 mL round-bottom centrifuge tubes, respectively added with 50 mL L of 30 mg L -1 The pH value of the hexavalent chromium solution is adjusted to 2.0, and the hexavalent chromium solution is uniformly dispersed by ultrasonic. The centrifuge tubes were simultaneously placed on a thermostatted gas bath shaker at a temperature of 25 ℃ and adsorbed by reciprocal shaking at 150 rpm for 12 h. After the adsorption reaction is finished, centrifuging the centrifugal tube at the rotating speed of 7500 rpm for 10 min to obtain solid, namely the functionalized nano SiO adsorbed with hexavalent chromium 2 @ RF microspheres.
(2) Functionalized nano SiO adsorbed with hexavalent chromium 2 Desorption experiments for @ RF microspheres
The obtained functionalized nano SiO adsorbed with hexavalent chromium 2 @ RF microsphere, ultrasonically cleaning with 50 mL of ultrapure water, and adding 100 mL of 0.5 mol L -1 Carrying out ultrasonic dispersion and oscillation desorption on NaOH for 12h, then centrifuging, washing the obtained solid with 200 mL of ultrapure water until the pH value is neutral, and then drying the material in a vacuum drying oven at 50 ℃ for 12h to finish the desorption experiment.
The above procedure is the first adsorption-desorption experiment.
Functionalized nano SiO 2 Repeated use experiment of @ RF microspheres
Weighing multiple 5 mg of the functionalized nano SiO obtained after the first adsorption-desorption experiment is finished 2 @ RF microspheres, placed in 10 mL round-bottom centrifuge tubes, respectively, and added with 5 mL L of 30 mg L -1 The pH value of the hexavalent chromium solution is adjusted to 2.0, and the hexavalent chromium solution is uniformly dispersed by ultrasonic. The centrifuge tubes were simultaneously placed on a thermostatted gas bath shaker at a temperature of 25 ℃ and adsorbed by reciprocal shaking at 150 rpm for 24 h. And after the adsorption reaction is finished, centrifuging the centrifugal tube at the rotating speed of 7500 rpm for 10 min, taking the upper layer solution, acidifying by phosphoric acid, carrying out color development by DPC, and detecting the concentration of the residual hexavalent chromium in the solution by UV-vis.
Five replicates were tested.
And calculating the removal rate (%) according to the ratio of the concentration difference of the hexavalent chromium in the solution before and after adsorption to the initial concentration, and calculating the removal rate (%) obtained after the solution is reused for the first time.
Collecting the second adsorption experiment back separationFunctionalized nano SiO with hexavalent chromium adsorbed on core 2 @ RF microsphere, functionalized nano SiO with hexavalent chromium adsorbed thereon 2 The desorption experiment of the @ RF microspheres desorbs the material, i.e., completes the second adsorption-desorption experiment.
Weighing 5 mg of the functionalized nano SiO obtained after the second adsorption-desorption experiment is finished 2 The @ RF microspheres were placed in a 10 mL round-bottom centrifuge tube, operated according to the adsorption experiment described above, and the removal rate was calculated as the removal rate obtained after the second reuse.
Five replicates were tested.
Collecting the functionalized nano SiO with hexavalent chromium adsorbed by centrifugation after the third adsorption experiment 2 @ RF microsphere, functionalized nano SiO with hexavalent chromium adsorbed thereon 2 The desorption experiment of the @ RF microspheres desorbs the material, namely, the third adsorption-desorption experiment is completed.
And so on.
Functionalized nano SiO 2 The @ RF microspheres are repeatedly used for 5 times, namely the functionalized nano SiO in the same batch 2 @ RF microspheres completed 6 adsorption experiments, 5 desorption experiments. The results are shown in FIG. 5.
As can be seen from the attached figure 5, the prepared functionalized nano SiO 2 @ RF microsphere was used repeatedly 5 times at a concentration of 30 mg L -1 The removal efficiency of the hexavalent chromium solution is still maintained to be more than 85 percent, which shows that the material has better reusability and higher stability in the absorption of hexavalent chromium.
All percentages used in the present invention are weight percentages and all proportions described in the present invention are mass proportions, unless otherwise indicated.
Finally, it should be noted that: although the present invention has been described in detail with reference to the foregoing embodiments, it will be apparent to those skilled in the art that changes may be made in the embodiments and/or equivalents thereof without departing from the spirit and scope of the invention. Any modification, equivalent replacement, or improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.
Claims (2)
1. A preparation method of functionalized nano silicon dioxide/resorcinol-formaldehyde microspheres is characterized by comprising the following steps: the preparation method comprises the steps of preparing nano silicon dioxide/resorcinol-formaldehyde microspheres and functionalizing the surfaces of the nano silicon dioxide/resorcinol-formaldehyde microspheres; ammonia water is used as a catalyst;
the preparation method comprises the following steps of: stirring and uniformly mixing a mixed solution of ethanol and water with concentrated ammonia water, then sequentially adding TEOS, resorcinol and formaldehyde solution, stirring and reacting, and pouring the solution into a high-pressure reaction kettle for aging after the reaction is finished; after the aging is finished, performing centrifugal separation, respectively washing the obtained solid with absolute ethyl alcohol and ultrapure water, and drying to obtain nano silicon dioxide/resorcinol-formaldehyde microspheres;
the mixed solution of ethanol and water: the volume ratio of the ethanol to the water is 2-4: 1; the concentrated ammonia water: the mass percentage concentration is 25-28%; and (3) stirring: stirring for 20-30 min at 30-40 ℃;
the addition of TEOS: adding TEOS and stirring for 30-40 min; the addition of resorcinol: adding resorcinol and stirring for 10-30 min; the mass percentage concentration of the formaldehyde solution is 37-40%; the reaction is as follows: the reaction time is 24-26 h;
and (3) aging: the aging temperature is 100-102 ℃, and the aging time is 24-26 h; and (3) centrifuging: centrifuging the solution at 7500-8500 rpm for 10-15 min; and (3) drying: the drying temperature is 40-50 ℃, and the drying time is 10-14 h;
the surface of the nano silicon dioxide/resorcinol-formaldehyde microspheres is functionalized: uniformly dispersing the nano silicon dioxide/resorcinol-formaldehyde microspheres into a mixed solution of ethanol and water, adding concentrated ammonia water, uniformly stirring, dropwise adding 3-aminopropyltriethoxysilane for reaction, after the reaction is finished, performing centrifugal separation, respectively cleaning the obtained solid with absolute ethanol and ultrapure water, and drying to obtain functionalized nano silicon dioxide/resorcinol-formaldehyde microspheres;
the mixed solution of ethanol and water: according to the weight ratio of anhydrous ethanol to ultrapure water of 7-8: 1-2 by volume; adding concentrated ammonia water: the mass percentage concentration of the strong ammonia water is 25% -28%, and the adding amount of the strong ammonia water is as follows: adding 1 mL of concentrated ammonia water into each 100mg of nano silicon dioxide/resorcinol-formaldehyde microspheres;
and (3) stirring: stirring in a water bath at 30-40 ℃ for 20-30 min; the reaction is as follows: the reaction time is 10-12 h; and (3) centrifuging: the centrifugal rotating speed is 7500-8500 rpm, and the centrifugal time is 10-15 min; and (3) drying: the drying temperature is 40-50 ℃, and the drying time is 10-14 h.
2. The application of the functionalized nano silicon dioxide/resorcinol-formaldehyde microsphere obtained by the preparation method according to claim 1 is characterized in that: the functionalized nano silicon dioxide/resorcinol-formaldehyde microspheres are used for adsorbing hexavalent chromium in a solution.
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| Publication number | Priority date | Publication date | Assignee | Title |
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| CN108579684A (en) * | 2018-05-08 | 2018-09-28 | 李涛 | A method of being modified spherical porous silica removal heavy metal containing sewage and its organic pollution |
| CN110048101A (en) * | 2019-04-03 | 2019-07-23 | 江苏科技大学 | A kind of silicon oxygen carbosphere composite negative pole material and the preparation method and application thereof |
| CN110078521A (en) * | 2019-05-13 | 2019-08-02 | 西北工业大学 | A kind of submicron order silicon nitride hollow microsphere and preparation method |
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| Publication number | Priority date | Publication date | Assignee | Title |
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| CN108579684A (en) * | 2018-05-08 | 2018-09-28 | 李涛 | A method of being modified spherical porous silica removal heavy metal containing sewage and its organic pollution |
| CN110048101A (en) * | 2019-04-03 | 2019-07-23 | 江苏科技大学 | A kind of silicon oxygen carbosphere composite negative pole material and the preparation method and application thereof |
| CN110078521A (en) * | 2019-05-13 | 2019-08-02 | 西北工业大学 | A kind of submicron order silicon nitride hollow microsphere and preparation method |
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