KR102316276B1 - Hierarchical chelate complex and method for preparing the same - Google Patents

Abstract

The present invention relates to a hierarchically porous chelate complex having excellent adsorption capability to anionic contaminants and cationic contaminants present in water or air, and a method for preparing the same. The method for preparing a hierarchically porous chelate complex according to the present invention includes the steps of: preparing polyacrylonitrile nanoparticles; preparing chelate nanoparticles having an amine group immobilized to the surfaces of polyacrylonitrile nanoparticles through the reaction of polyacrylonitrile nanoparticles with an amine compound; and preparing a hierarchically porous chelate complex, while linking a plurality of chelate nanoparticles by using a binder.

Description

Chelate complex having a multi-stage pore structure and a method for preparing the same {Hierarchical chelate complex and method for preparing the same}

The present invention relates to a chelate complex having a multi-stage pore structure and a method for preparing the same, and more particularly, to a chelate complex having a multi-stage pore structure having excellent adsorption performance for anionic and cationic contaminants present in water or air. and to a manufacturing method thereof.

With the development of industries such as textile, food, steel and petrochemical, electronics and semiconductor industries, the emission of water pollutants is on the rise due to the increasing number of industrial wastewater, domestic wastewater and livestock wastewater. Since most water pollutants contain cations such as various heavy metals that negatively affect the environment and anions such as phosphorus and nitrogen compounds, pollutants must be removed from water pollutants. For this purpose, many studies related to adsorbents are being conducted.

Currently, widely used materials include polymer resin adsorbents as presented in US Patent Nos. 5,403,492 and 5,378,802, but they have a small specific surface area and low adsorption performance, and most high-functional resins are powders, so facility costs And there is a problem that the management cost increases.

As another adsorbent technology, heavy metal adsorption technology (refer to Korean Patent Application Laid-Open No. 2015-003453) by collecting strains on a silica-based carrier has been proposed, but this requires a technology capable of stably operating a living strain and high operating cost. Therefore, various adsorbent technologies that can achieve efficient collection at low operating cost are required.

On the other hand, in various material fields such as pharmaceuticals, sensors, capacitors, and catalysts, as well as adsorbents, it is possible to reduce the size of the material to the maximum nanometer scale or create a porous structure for the purpose of increasing the efficiency according to the surface functionality of the material by increasing the contact area with the outside. is a subject of ever-increasing interest. Various porous nanomaterials have been the subject of numerous scientific publications and patent applications in the aforementioned fields. For example, polymer nanoparticles using metal nanoparticles (refer to Korean Patent Application Laid-Open No. 2013-0112208), a method for synthesizing porous zeolite using an organosilane type material (refer to Korean Patent Application Laid-Open No. 2016-0005054), etc. have been patented. there is a bar

Various nanometer-sized materials, which are being actively developed in the field of adsorbents, have relatively large specific surface areas and thus have a large contact area with the outside. Therefore, it boasts excellent performance in terms of functionality, but in actual use, it is easily blown away due to fluid flow due to its low density and small size, making it difficult to handle, and it is difficult to separate and recover after use, so it acts as a secondary environmental pollutant, causing harm to various animals and plants. There are problems that can be given.

For this reason, in the field of adsorption materials, a method of packing particles using a membrane to flow a fluid is used. The applied membrane as well as a small adsorbent size minimizes the porosity, which increases the pressure drop when the fluid is introduced, thereby lowering the process efficiency. It is well known as a factor causing

As a way to solve the problem of low porosity, it may be considered to convert the adsorbent into a porous structure. As a technology that can implement a porous structure, there is a method for manufacturing a porous structure using a porogen (refer to Korean Patent Application Laid-Open No. 2003-0082479). It is a technology that can easily control the size of pores. However, since the release of the porogen does not pass through the introduced functional particles, the surface of the dispersed particles is surrounded by the structure, so the possibility of exposure to the outside is low. As another technique, in the case of porous plastic polymerization technology (refer to Korean Patent Application Laid-Open No. 2007-0114120), a structure in which most of the particle surface inside the plastic is surrounded by a structure is expected, and the applicable particle types according to the plastic polymerization conditions are limited. Therefore, it is not suitable as an adsorbent. In addition, the hydrogel particle fixation technology using alginic acid (Korea Patent No. 1506094) relates to a method of forming a core/shell structure complex by forming an alginic acid membrane on the outside of the particle, and the movement of the adsorbate to the inside of the complex There are disadvantages of lowering the adsorption rate and lowering the adsorption performance because it interferes with the adsorption.

US Patent No. 5,403,492 US Patent No. 5,378,802 Korea Patent Publication No. 2015-003453 Korea Patent Publication No. 2013-0112208 Korean Patent Publication No. 2016-0005054 Korean Patent Publication No. 2003-0082479 Korean Patent Publication No. 2007-0114120 Korean Patent No. 1506094

Journal of Applied Polymer Science, Vol.101,2202-2209 (2006) Iranian Polymer Journal 19 (12),2010, 911-925

The present invention has been devised to solve the above problems, and provides a chelate complex having a multi-stage pore structure having excellent adsorption performance for anionic and cationic contaminants present in water or air, and a method for preparing the same. There is a purpose.

The chelate complex having a multi-stage pore structure for achieving the above object is an aggregate of chelate nanoparticles, and the aggregate of chelate nanoparticles is provided with a multi-stage pore structure, and the chelate nanoparticles are connected to each other by a binder and form a multi-stage pore structure. It is exposed to the outside through the chelate nanoparticles and characterized in that an amine group capable of adsorption to cationic or anionic contaminants is provided on the surface of the chelate nanoparticles.

In addition, the method for preparing a chelate complex having a multi-stage pore structure according to the present invention comprises the steps of preparing polyacrylonitrile nanoparticles; preparing chelate nanoparticles in which an amine group is immobilized on the surface of polyacrylonitrile nanoparticles through the reaction of polyacrylonitrile nanoparticles with an amine compound; and preparing a chelate complex in which a plurality of chelate nanoparticles are connected by a binder and include a multi-stage pore structure.

In the step of preparing polyacrylonitrile nanoparticles, an acrylonitrile monomer, a polymerization initiator, a surfactant and distilled water are mixed and stirred to prepare polyacrylonitrile nanoparticles through a polymerization reaction of the acrylonitrile monomer, and the interface The active agent is a first surfactant having an amphiphilic functional group that suppresses the aggregation of polyacrylonitrile, and stabilizes the surface energy of the polyacrylonitrile colloid by lowering the polyacrylonitrile colloid. and a second surfactant that increases the number of ronitrile colloidal particles to induce formation of uniformly sized polyacrylonitrile nanoparticles.

The first surfactant is 4-nonylphenyl 3-sulfopropylether (KPE), and the 4-nonylphenyl 3-sulfopropylether (KPE) is a hydrophilic polyacrylonitrile colloid When mixed with 4-nonylphenyl 3-sulfopropyl ether (KPE), the hydrophilic ether group is combined with polyacrylonitrile, and the hydrophobic functional group of 4-nonylphenyl 3-sulfopropyl ether (KPE) faces outward. It is possible to suppress the aggregation phenomenon of acrylonitrile.

The second surfactant may be sodium dodecyl sulfate. The hydrophilic functional group of sodium dodecyl sulfate binds to the polyacrylonitrile colloid to lower the surface energy of the polyacrylonitrile colloid to stabilize it. It serves to induce the production of polyacrylonitrile nanoparticles of uniform size by increasing the

100 to 300 parts by weight of acrylonitrile monomer, 500 to 1500 parts by weight of distilled water, and 0.1 to 10 parts by weight of a surfactant are mixed with respect to 1 part by weight of the polymerization initiator, and the first surfactant and the second surfactant are 45: 55 to 55: It is mixed in a weight ratio of 45.

In the step of preparing the chelate nanoparticles, polyacrylonitrile nanoparticles are dispersed in a liquid amine compound, a catalyst is added, and then heated, and the amine groups are immobilized on the surface of the polyacrylonitrile nanoparticles through a chelate reaction to immobilize the chelate nanoparticles. make the particles.

The amine compound is a primary or more amine compound having an alkyl group.

The amine compound is ethylenediamine, diethylenetriamine, tris(2-aminoethylamine), -1,3-diamine (propane-1,3-diamine) , methane triamine, 3- (2-aminoethyl) pentane-1,5-diamine (3- (2-aminoethyl) pentane-1,5-diamine), melamine (melamine), diaminofura It may be any one of zan (diaminofurazan), diaminopyridine (diaminopyridine), and diaminopyrimidine (diaminopyrimidine), or a combination thereof.

In the manufacturing process of chelate nanoparticles, 10 to 30 parts by weight of polyacrylonitrile nanoparticles are mixed with respect to 100 parts by weight of the amine compound, and 1 to 10 parts by weight of the catalyst is mixed with respect to 100 parts by weight of polyacrylonitrile nanoparticles. do.

The step of preparing the chelate complex includes a process of preparing a first solution containing chelate nanoparticles and a binder and a second solution for solidifying the chelate nanoparticles droplets, and preparing the first solution as chelate nanoparticles droplets using a nozzle. 2 The process of dropping into the solution, the process of solidifying the chelate nanoparticle droplets in the second solution, the process of freezing the solidified chelate nanoparticle droplets, and freeze-drying the solidified chelate nanoparticle droplets in a frozen state It consists of sublimating the moisture contained in the chelate nanoparticle droplets to prepare a chelate complex.

The first solution is a mixture of chelate nanoparticles and a binder in a solvent.

The binder may be alginic acid, or a non-polymer binder or a polymer binder may be used. The non-polymer binder is a molecule including at least two functional groups selected from amine, cyanate, alcohol, and carboxyl, and the polymer binder is polyvinyl alcohol, polyethylene, polypropylene, poly Vinyl chloride (polyvinyl chloride), polycaprolactone (polycaprolactone), polyethylene glycol (polyethyleneglycol), polystyrene (polystyrene), polyacrylonitrile (polyacrylonitrile), polysulfone (polysulfone) any one or a combination thereof.

The content of the chelate nanoparticles in the first solution is 5 to 40 parts by mass based on 100 parts by mass of the first solution, and the content of the binder is 2 to 10 parts by mass based on 100 parts by mass of the chelate nanoparticles.

The content of the alginic acid binder is preferably applied in an amount of 0.2 to 1 parts by weight based on 100 parts by weight of the first solution. In addition, the content of the polymer binder may be applied in an amount of 5 to 20 parts by weight based on 100 parts by weight of the first solution.

The chelate complex having a multi-stage pore structure and a method for manufacturing the same according to the present invention have the following effects.

As the multi-stage pore structure is formed, the proportion of chelate nanoparticles exposed to water or air is increased to double the adsorption performance of amine groups. As the polyacrylonitrile nanoparticles can be prepared in a uniform size, the aggregation of the chelate nanoparticles in the chelate complex can be minimized, thereby optimizing the adsorption properties by the amine group. In addition, when applied to a filtration membrane, it is possible to minimize the pressure drop phenomenon.

1 is a flow chart for explaining a method of manufacturing a chelate complex having a multi-stage pore structure according to an embodiment of the present invention.
2 and 3 are schematic views for explaining a method of manufacturing a chelate complex having a multi-stage pore structure according to an embodiment of the present invention.
Figure 4 shows the particle size distribution of the polyacrylonitrile nanoparticles (PAN-NP) prepared in Experimental Example 1 and the chelate nanoparticles (APAN-NP) prepared in Experimental Example 2.
5 is a real photograph of the chelate complex prepared in Experimental Example 5;
6 is a SEM photograph of the chelate complex prepared in Experimental Example 5;
7 is an FT-IR analysis result for each of the polyacrylonitrile nanoparticles prepared in Experimental Example 1, the chelate nanoparticles prepared in Experimental Example 2, and the chelate complex prepared in Experimental Example 5;
Figure 8 shows the adsorption characteristics of the chelate complex according to the pH concentration of wastewater.
Figure 9 shows the adsorption characteristics of the chelate complex according to the concentration of heavy metals in wastewater.
10 shows the adsorption rate characteristics of the chelate complex.
11 is a result of performing an adsorption experiment of each chelate complex according to the concentration of heavy metal cations in wastewater, and taking an SEM picture for each chelate complex.
12 is a graph showing the pressure drop characteristics according to the flow rate when the adsorbent is applied to the membrane.
13 is a real photograph showing a tendency to be dispersed in the second solution because the binder does not sufficiently connect the nanoparticles when the chelate complex is formed under the conditions below the minimum content of the binder used compared to the injected nanoparticles.

The present invention provides a technique for a chelate complex having a multi-stage pore structure.

In the chelate complex according to the present invention, a plurality of chelate nanoparticles are linked through a binder, and an amine group is immobilized on the surface of the chelate nanoparticles. The amine group immobilized on the surface of the chelate nanoparticles serves to adsorb anionic and cationic contaminants.

In providing an amine group on the surface of the nanoparticles and adsorbing anionic and cationic contaminants through the amine group, the ratio of amine groups exposed to the outside (ie, water or air) should be high in order to double the adsorption performance. .

Since 'nanoparticles with immobilized amine groups' are very small in size, a plurality of 'nanoparticles with immobilized amine groups' are applied as adsorbents in the form of aggregates. As the nanoparticles form an aggregate, only some of the nanoparticles are exposed to the outside, and the adsorption performance by the amine group is inevitably lower than expected. Therefore, a technique for immobilizing nanoparticles to a porous structure is being studied, but as mentioned in the previous 'technology behind the invention', if the content of the used binder is high, the ratio of the non-adsorbent binder is high, so the adsorption capacity is expected to decrease. When the adsorbent forms a core-shell structure and the nanoparticles are located therein, the adsorption performance of the nanoparticles is further reduced. At the same time, since nanoparticles are very small in size, they tend to agglomerate with each other due to hydrophilicity and electrostatic attraction during the manufacturing process. It acts as a factor that lowers the adsorption performance by air.

Accordingly, in order to maximize the adsorption performance of 'nanoparticles with immobilized amine groups', two requirements must be satisfied. First, aggregation of nanoparticles should be minimized, and second, pores should be secured in the aggregate and the proportion of nanoparticles exposed to the outside should be high.

The present invention provides a chelate complex that satisfies these requirements.

The chelate complex according to the present invention has a form in which a plurality of chelate nanoparticles form an aggregate, and the chelate complex has multi-stage pores. In addition, in the present invention, the plurality of chelate nanoparticles form a form in which agglomeration is minimized, which is implemented by the manufacturing method according to the present invention. Together with this, the plurality of chelate nanoparticles are connected by a binder to form an aggregate.

In summary, the adsorption performance by amine groups was improved by the preparation of a chelate nanoparticle cluster with minimized agglomeration, the connection between the chelate nanoparticles using an optimal binder, and the formation of a multi-stage pore structure in the chelate complex through water removal. can be maximized

Hereinafter, a chelate complex having a multi-stage pore structure and a method for manufacturing the same according to the present invention will be described in detail with reference to the drawings. First, a method for preparing the chelate complex will be described.

The manufacturing method of the chelate complex having a multi-stage pore structure according to the present invention is largely divided into a polyacrylonitrile (PAN, polyacrylonitrile) nanoparticle manufacturing process (S101), a chelate nanoparticle manufacturing process (S102), and a chelate complex manufacturing process (S103). separated (see FIG. 1).

Through the polyacrylonitrile (PAN, polyacrylonitrile) nanoparticle manufacturing process, aggregation between polyacrylonitrile nanoparticles is minimized and polyacrylonitrile nanoparticles of uniform size are manufactured. The polyacrylonitrile nanoparticle manufacturing process is specifically as follows.

An acrylonitrile monomer, a polymerization initiator, a surfactant and distilled water are prepared. When an acrylonitrile monomer, a polymerization initiator and a surfactant are added to a reactor equipped with distilled water and stirred under a certain temperature, the acrylonitrile monomer is polymerized to form polyacrylonitrile (PAN) (FIG. 2(a), see (b)).

Polyacrylonitrile (PAN) forms a colloid in distilled water. Due to the unstable state, spontaneous polymerization occurs toward the end of the chain and agglomeration occurs. The spontaneous polymerization and agglomeration of polyacrylonitrile (PAN) prevents the nanoparticle formation of polyacrylonitrile (PAN), and even if polyacrylonitrile nanoparticles (PAN-NPs) are generated, the particle size distribution becomes large. .

In order to minimize the aggregation of polyacrylonitrile and to increase the production efficiency of nanoparticles and to generate nanoparticles of a uniform size, the first surfactant and the second surfactant are added together. The first surfactant serves to suppress the aggregation of polyacrylonitrile, and the second surfactant lowers and stabilizes the surface energy of the polyacrylonitrile colloid and, through the characteristic of forming micelles, polyacryl It serves to induce the production of polyacrylonitrile nanoparticles of uniform size by increasing the number of ronitrile colloidal particles.

In one embodiment, 4-nonylphenyl 3-sulfopropylether (KPE) is applied as the first surfactant, and sodium dodecyl sulfate (SDS) is used as the second surfactant. can be applied.

4-nonylphenyl 3-sulfopropyl ether (KPE) is a material having both a hydrophilic functional group and a hydrophobic functional group. When mixed with a hydrophilic polyacrylonitrile colloid, the hydrophilicity of 4-nonylphenyl 3-sulfopropyl ether (KPE) is The ether group is bonded to the polyacrylonitrile and the hydrophobic functional group of 4-nonylphenyl 3-sulfopropyl ether (KPE) is directed outward, thereby preventing aggregation of the polyacrylonitrile. In other words, 4-nonylphenyl 3-sulfopropyl ether (KPE) serves to uniformly disperse polyacrylonitrile in a solvent through the above-described properties.

Sodium dodecyl sulfate (SDS) has a large tendency to form micelles, so polyacrylonitrile uniformly dispersed by 4-nonylphenyl 3-sulfopropyl ether (KPE) is granulated . Through this, it is possible to form nanoparticles of polyacrylonitrile having a uniform size.

In this way, it is possible to minimize the aggregation of polyacrylonitrile through the input of the first surfactant and the second surfactant and to generate polyacrylonitrile nanoparticles of a uniform size. Here, when only the first surfactant is used without adding the second surfactant, the polymer polymerization reaction is dominant, so that the polyacrylonitrile is not made into nanoparticles.

As the first surfactant, an amphiphilic surfactant including both a hydrophilic functional group and a hydrophobic functional group in addition to 4-nonylphenyl 3-sulfopropyl ether (KPE) may be applied, and the second surfactant is also sodium dodecyl sulfate (SDS) In addition, surfactants with a strong tendency to lower surface energy to stabilize colloids and form micelles can be applied.

As a polymerization initiator for inducing a polymerization reaction of the acrylonitrile monomer, potassium persulfate may be applied as an embodiment.

In the polyacrylonitrile nanoparticle manufacturing process as described above, it is preferable that 100 to 300 parts by weight of an acrylonitrile monomer, 500 to 1500 parts by weight of distilled water, and 0.1 to 10 parts by weight of a surfactant are mixed with respect to 1 part by weight of the polymerization initiator. . In addition, in order to minimize the aggregation of polyacrylonitrile and to produce polyacrylonitrile nanoparticles of uniform size, the first surfactant and the second surfactant are added in a weight ratio of 45:55 to 55:45. It is preferable to be

When the preparation of the polyacrylonitrile nanoparticles is completed, the chelate nanoparticles preparation process proceeds as follows. The manufacturing process of chelate nanoparticles is a process of immobilizing amine groups on the surface of polyacrylonitrile nanoparticles by inducing a chelate bond between polyacrylonitrile nanoparticles and amine groups (see FIGS. 1 and 2 (c)).

Specifically, after evenly dispersing the polyacrylonitrile nanoparticles in the liquid amine compound, the reaction catalyst is added, and then heated to a certain temperature, the chelate reaction proceeds and the amine group is immobilized on the surface of the polyacrylonitrile nanoparticles. Through this, polyacrylonitrile nanoparticles having an amine group on the surface, that is, chelate nanoparticles are generated.

The amine compound is a material capable of performing a ligand role by binding to the polyacrylonitrile nanoparticles, and may be a primary or more amine compound having an alkyl group, and may have a cyclic structure. In one embodiment, as the amine compound, ethylenediamine (ethylenediamine, EDA), diethylenetriamine (DETA), tris(2-aminoethylamine), propane-1,3- Diamine (propane-1,3-diamine), methane triamine, 3- (2-aminoethyl) pentane-1,5-diamine (3- (2-aminoethyl) pentane-1,5-diamine ), melamine, diaminofurazan, diaminopyridine, and any one of diaminopyrimidine or a combination thereof may be applied.

In addition, as a catalyst of the chelate reaction, a non-metal-based Lewis acid may be used, and in detail, _{any one of boron trifluoride dihydrate (BF 3} ·2H ₂ O), acetic acid, and hydrochloric acid may be used.

In the manufacturing process of chelate nanoparticles, 10 to 30 parts by weight of polyacrylonitrile nanoparticles are mixed with respect to 100 parts by weight of the amine compound, and 1 to 10 parts by weight of the catalyst is mixed with respect to 100 parts by weight of polyacrylonitrile nanoparticles. It is preferable to be

When the preparation of the chelate nanoparticles is completed, the chelate complex preparation process proceeds as follows.

A first solution and a second solution are prepared, respectively.

The first solution is a mixture of chelate nanoparticles and a binder in a solvent, and the second solution is a solution for solidifying the binder included in the second solution.

Alginic acid may be typically applied as the binder to be mixed with the first solution, and a non-polymeric binder or a polymeric binder may be used in addition to alginic acid. The non-polymer binder includes molecules including at least two functional groups selected from among amine, cyanate, alcohol, and carboxyl, and the functional group can chelate various cations such as calcium, iron, and nickel. In addition, as a polymer binder, polyvinyl alcohol, polyethylene, polypropylene, polyvinyl chloride, polycaprolactone (PCL), polyethylene glycol, polystyrene ( polystyrene), polyacrylonitrile, polysulfone, or a combination thereof may be used. The polymer binder is dissolved in the solvent of the first solution, and has a property that it can be diluted and precipitated in the solvent of the second solution through a solvent exchange mechanism.

^{Calcium ions (Ca 2+} ) are dissolved in the second solution to solidify the binder.

The solvent of the second solution may have the same density or greater density than the solvent of the first solution. Water may be used as the solvent of the first solution, and the solvent of the second solution is water, dimethyl sulfoxide (DMSO), dimethyl formamide (DMF), N-methyl-2-pyrrolydone (NMP), or tetrahydrofuran (THF). Either one can be used.

In a state in which the first solution and the second solution are prepared, the first solution is dropped into the second solution one drop at a time using a nozzle. At this time, the first solution may be dropped at a flow rate of 0.1 to 20 ml/min, and the diameter of the nozzle may be adjusted to 0.001 to 10 mm according to the viscosity of the first solution and the size of the desired chelate complex.

When the first solution droplet, that is, the chelate nanoparticle droplet falls on the second solution through the nozzle, the binder contained in the chelate nanoparticle droplet is solidified by the calcium component of the second solution, and the solidified chelate nanoparticle liquid A small amount is precipitated at the bottom of the second solution (see Fig. 3 (a)).

Next, after withdrawing the solidified chelate nanoparticle droplets from the second solution, the solidified chelate nanoparticle droplets are frozen at 0° C. or lower. Then, when the solidified chelate nanoparticle droplets in a frozen state are freeze-dried to sublimate moisture contained in the solidified chelate nanoparticle droplets, the preparation of the chelate complex is completed (see FIG. 3 (b)).

The chelate complex completed through the above process forms a structure in which a plurality of chelate nanoparticles are connected by a binder, and pores are formed in the portion from which moisture is removed.

A plurality of chelate nanoparticles form a form connected by a binder in a state where aggregation is minimized, and as the number of chelate nanoparticles exposed to the external environment increases due to the multi-stage pore structure formed in the chelate complex, cationic contaminants by amine groups and improved adsorption performance for anionic contaminants.

In the chelate complex manufacturing process, the content of the chelate nanoparticles is 5 to 40 parts by mass based on 100 parts by mass of the first solution, and the content of the binder is 2 to 10 parts by mass based on 100 parts by mass of the chelate nanoparticles. At this time, the content of the binder is very important. As described above, the present invention implements that the chelate nanoparticles are connected to each other by a binder and that the chelate complex has a multi-stage pore structure. In the process of preparing the chelate complex, if the amount of the binder is less than necessary, the connection between the chelate nanoparticles is made. It is not possible to form a chelate complex because it does not lose strength, and if the amount of the binder is more than necessary, each chelate nanoparticle forms a core-shell structure, so that adsorption performance by amine groups cannot be expected.

When using the alginic acid binder, the content of the alginic acid binder may be set to 0.2 to 1 parts by weight based on 100 parts by weight of the first solution. When the content of the alginic acid binder is less than 0.2 parts by weight, the connection between the chelate nanoparticles by the alginic acid binder is not made, and when the content of the alginic acid binder is greater than 1 part by weight, a core-shell structure is formed. Meanwhile, when using the polymer binder as described above, the content of the polymer binder may be set to 5 to 20 parts by weight based on 100 parts by weight of the first solution. 13 shows the case where the content of the alginic acid binder is less than 0.2 parts by weight relative to 100 parts by weight of the first solution, it can be confirmed that the chelate nanoparticles are not connected to each other and are dispersed in the second solution.

Above, the chelate complex having a multi-stage pore structure according to the present invention and a method for preparing the same have been described. Hereinafter, the present invention will be described in more detail through experimental examples.

Experimental Example 1: Preparation of polyacrylonitrile nanoparticles

20 g of acrylonitrile monomer, 0.1 g of potassium persulfate as a polymerization initiator, 0.2 g of sodium dodecyl sulfate (SDS) as the first surfactant, and 0.4 g of 4-nonylphenyl 3-sulfopropyl ether (KPE) as the second surfactant was mixed with 500 ml of distilled water, equipped with a reflux cooler, and polymerized at 200 rpm and atmospheric pressure at a reaction temperature of 60° C. for 2 hours to synthesize polyacrylonitrile nanoparticles.

Experimental Example 2: Preparation of chelate nanoparticles

250 ml of diethylenetriamine containing 25 g of polyacrylonitrile nanoparticles prepared in Experimental Example 1 was placed in a 500 ml round-bottom flask, and then evenly dispersed at room temperature for 30 minutes. 0.25 g of boron triple chloride dihydrate was diluted to 10 wt% in deionized water, 2 ml of which was added, and then stirred again at room temperature for about 30 minutes. After the catalyst was evenly dispersed, a reflux condenser was installed, and the reaction was carried out for 45 minutes at a reaction temperature of 110 ° C. After the reaction was completed and cooled to room temperature, the reactant was washed with water and dried to obtain chelate nanoparticles.

Figure 4 shows the particle size distribution of the polyacrylonitrile nanoparticles (PAN-NP) prepared in Experimental Example 1 and the chelate nanoparticles (APAN-NP) prepared in Experimental Example 2, polyacrylonitrile nanoparticles It can be seen that the particle diameter of (PAN-NP) is about 130-160 μm, and the particle diameter of chelate nanoparticles (APAN-NP) is about 200-300 μm.

Experimental Example 3: Preparation of chelate nanoparticles to which a catalyst is not applied

In preparing the chelate nanoparticles, chelate nanoparticles were prepared without applying boron triple chloride dihydrate as a catalyst. Other experimental methods were applied in the same manner as in Experimental Example 2, and the reaction time was applied as 120 minutes.

Experimental Example 4: Preparation of chelate nanoparticles using ethylenediamine

Chelate nanoparticles were prepared by applying the same method as in Experimental Example 2, except that ethylenediamine was applied as an amine compound. In the case of Experimental Example 2, diethylenetriamine was applied as an amine compound.

Experimental Example 5: Preparation of chelate complex using alginic acid binder

500 ml of a second solution, which is distilled water containing 1M calcium cation, was placed in a reactor, and the first solution, which is distilled water containing 0.5 wt% of alginic acid and 10 wt% of chelate nanoparticles, was dropped into the second solution using a nozzle dropwise. . The nozzle was spaced 15 cm from the second solution surface. As soon as the first solution passes through the nozzle and touches the surface of the second solution, a droplet (chelate nanoparticle droplet) is formed, and the droplet moves downward due to the density difference and is solidified. After leaving for about 30 minutes, the solidified chelate nanoparticle droplets are taken out due to the solidification of alginic acid, frozen at a temperature below 0°C for about 2 hours, and freeze-dried to completely sublimate the moisture contained in the ‘solidified chelate nanoparticle droplets’. A chelate complex having a multi-stage pore structure was prepared.

5 is an actual photograph of the chelate complex prepared in Experimental Example 5, and FIG. 6 is an SEM photograph of the chelate complex prepared in Experimental Example 5. Referring to FIG. 5, it can be seen that the chelate complex can be prepared in a certain size, and referring to FIG. 6, the chelate nanoparticles are connected to each other in a state where aggregation phenomenon is minimized along with the formation of a multi-stage pore structure in the chelate complex. It can be confirmed that there is

In addition, the surface properties of the polyacrylonitrile nanoparticles prepared in Experimental Example 1, the chelate nanoparticles prepared in Experimental Example 2, and the chelate complex prepared in Experimental Example 5 were confirmed through FT-IR analysis.

Referring to 'a' of FIG. 7, in the case of polyacrylonitrile nanoparticles prepared in Experimental Example 1, 2230 cm ^{- 1} peak can be confirmed. In the case of the chelate nanoparticles prepared in Experimental Example 2 (see 'b' in FIG. 7 ), ^{it can be confirmed that the 2230 cm -1} peak disappears as the amination proceeds and a peak related to a new amine compound is generated. In the case of the chelate complex prepared in Experimental Example 5 (see 'c' in FIG. 7), as alginic acid was introduced to increase the surface hydroxyl functional groups, a wide peak was formed in the range of ^{about 3800 to 2000 cm -1} can be checked

Experimental Example 6: Preparation of chelate complex using polysulfone binder

500 ml of dimethyl formaldehyde in which 1M calcium cations are dissolved is put into the reaction tank as the second solution, and the dimethylformaldehyde solution containing 10 wt% of polysulfone and 10 wt% of chelate nanoparticles, that is, the first solution, is used with a nozzle. Thus, it was dropped into the second solution one drop at a time. The nozzle was spaced 15 cm from the second solution surface. As soon as the first solution passes through the nozzle and touches the surface of the second solution, a droplet (chelate nanoparticle droplet) is formed, and the droplet moves downward due to the density difference and is solidified. After leaving for about 30 minutes, the solidified chelate nanoparticle droplets are taken out due to the solidification of alginic acid, frozen at a temperature below 0°C for about 2 hours, and freeze-dried to completely sublimate the moisture contained in the ‘solidified chelate nanoparticle droplets’. A chelate complex having a multi-stage pore structure was prepared.

Experimental Example 7: Adsorption Characteristics of Chelate Complex

Various adsorption experiments were performed using the chelate complex prepared in Experimental Example 5.

8 is a graph showing the adsorption characteristics of the chelate complex according to the pH concentration of wastewater, and as shown in FIG. 8, various heavy metal cations (Cu ²⁺ , Cd ²⁺ , Pb ²⁺ ) in a wide range of pH 3 to 8 It can be seen that the adsorption performance is excellent.

9 shows the adsorption characteristics of the chelate complex according to the concentration of heavy metals in the wastewater, and as shown in FIG. 9, it can be confirmed that the adsorption performance of the chelate complex is maintained even at a high concentration of heavy metal contamination of ∼75,000 mg/L. This is presumed to be due to the formation of a multi-stage pore structure in the chelate complex, which increases the proportion of chelate nanoparticles exposed to the outside, thereby improving the adsorption properties of amine groups.

In addition, FIG. 10 shows the adsorption rate characteristics of the chelate complex. As a result of measuring the adsorption rate of the chelate complex in wastewater having a concentration of heavy metal cations of 20,000 ppm, it can be seen that the adsorption amount of heavy metal cations at the beginning of the reaction rapidly increases. , this is a result confirming that the rate of adsorption of contaminants by the chelate complex is very fast.

11 is a result of performing an adsorption experiment of each chelate complex according to the concentration of heavy metal cations in the wastewater, and taking an SEM photograph for each chelate complex. Referring to FIG. 11 , when the Pb ²⁺ concentration in the wastewater is 50,000 ppm It can be seen that a large amount of Pb ²⁺ is adsorbed to the chelate complex and the multi-stage pore structure of the chelate complex ^{is blocked by Pb 2+} , but at 30,000 ppm or less, ^{even though a large amount of Pb 2+} is adsorbed, the multi-stage pore structure of the chelate complex is still can be checked.

12 shows the pressure drop characteristics according to the flow rate when the adsorbent is applied to the membrane. Commercial polymer beads (HCR-S), glass beads, and each of the chelate complexes prepared in Experimental Example 5 were applied to the membrane, and then the pressure strengthening characteristics according to the flow rate were measured. As a result, as shown in FIG. 12 , it can be seen that the pressure drop rapidly proceeds from a very low flow rate in the commercial polymer beads (HCR-S), and in the case of the glass beads, the pressure drop rapidly increases from the point in time when the flow speed is 0.12 m/s or more. In contrast to the increase, in the case of the chelate complex prepared in Experimental Example 5 of the present invention, it can be confirmed that the pressure drop proceeds when the flow rate is 0.17 m/s or more. Therefore, even when the chelate complex of the present invention is applied to a membrane, superior pressure drop characteristics can be expected compared to the conventional adsorbent.

Claims (18)

preparing polyacrylonitrile nanoparticles;
preparing chelate nanoparticles in which an amine group is immobilized on the surface of polyacrylonitrile nanoparticles through the reaction of polyacrylonitrile nanoparticles with an amine compound; and
Preparing a chelate complex including a multi-stage pore structure with a plurality of chelate nanoparticles connected by a binder;
The step of preparing the chelate nanoparticles,
After dispersing polyacrylonitrile nanoparticles in a liquid amine compound, a catalyst is added and then heated, and amine groups are immobilized on the surface of polyacrylonitrile nanoparticles through a chelate reaction to prepare chelate nanoparticles,
The catalyst is boron trifluoride dihydrate (BF ₃ ·2H ₂ O),
The step of preparing the chelate complex,
A process of preparing a first solution containing chelate nanoparticles and a binder and a second solution for solidifying the chelate nanoparticles droplet;
The process of dropping the first solution into the second solution as chelate nanoparticles using a nozzle;
a process in which the chelate nanoparticle droplets are solidified in the second solution;
Freezing the solidified chelate nanoparticle droplets;
It comprises the process of preparing a chelate complex by sublimating the moisture contained in the solidified chelate nanoparticle droplet by freeze-drying the solidified chelate nanoparticle droplet in the frozen state,
The binder is alginic acid, a non-polymer binder or a polymer binder,
The content of the chelate nanoparticles in the first solution is 5 to 40 parts by mass based on 100 parts by mass of the first solution, and the content of the binder is 2 to 10 parts by mass based on 100 parts by mass of the chelate nanoparticles. A method for producing a chelate complex having
According to claim 1, wherein the step of preparing the polyacrylonitrile nanoparticles,
Polyacrylonitrile nanoparticles are prepared through polymerization of acrylonitrile monomer by mixing and stirring acrylonitrile monomer, polymerization initiator, surfactant and distilled water,
The surfactant is a first surfactant having an amphiphilic functional group that suppresses aggregation of polyacrylonitrile, and stabilizes by lowering the surface energy of polyacrylonitrile colloid. Through the characteristic of forming micelles A method for producing a chelate complex having a multi-stage pore structure, comprising a second surfactant that increases the number of polyacrylonitrile colloidal particles to induce the production of polyacrylonitrile nanoparticles of uniform size.
According to claim 2, wherein the first surfactant is 4-nonylphenyl 3-sulfopropylether (KPE, 4-nonylphenyl 3-sulfopropylether),
When 4-nonylphenyl 3-sulfopropyl ether (KPE) is mixed with a hydrophilic polyacrylonitrile colloid, the hydrophilic ether group of 4-nonylphenyl 3-sulfopropyl ether (KPE) is combined with polyacrylonitrile, A method for producing a chelate complex having a multi-stage pore structure, characterized in that the hydrophobic functional group of 4-nonylphenyl 3-sulfopropyl ether (KPE) is directed outward to suppress the aggregation of polyacrylonitrile.
The method of claim 2, wherein the second surfactant is sodium dodecyl sulfate.
The method according to claim 2, wherein 100 to 300 parts by weight of acrylonitrile monomer, 500 to 1500 parts by weight of distilled water, and 0.1 to 10 parts by weight of a surfactant are mixed with respect to 1 part by weight of the polymerization initiator,
A method for producing a chelate complex having a multi-stage pore structure, characterized in that the first surfactant and the second surfactant are mixed in a weight ratio of 45: 55 to 55: 45.
delete The method according to claim 1, wherein the amine compound is a primary or more amine compound having an alkyl group.
According to claim 1, wherein the amine compound is ethylenediamine (ethylenediamine), diethylenetriamine (diethylenetriamine), tris (2-aminoethylamine (tris(2-aminoethyl)amine), propane-1,3-diamine (propane) -1,3-diamine), methane triamine, 3-(2-aminoethyl)pentane-1,5-diamine (3-(2-aminoethyl)pentane-1,5-diamine), melamine (melamine), diaminofurazan (diaminofurazan), diaminopyridine (diaminopyridine) and diaminopyrimidine (diaminopyrimidine), characterized in that any one or a combination thereof, a method for producing a chelate complex having a multi-stage pore structure.
The method of claim 1, wherein in the manufacturing process of the chelate nanoparticles, 10 to 30 parts by weight of the polyacrylonitrile nanoparticles are mixed with respect to 100 parts by weight of the amine compound, and the catalyst is mixed with 100 parts by weight of the polyacrylonitrile nanoparticles. A method for producing a chelate complex having a multi-stage pore structure, characterized in that 1 to 10 parts by weight are mixed.
delete delete delete According to claim 1, wherein the binder is a non-polymer binder or a polymer binder,
The non-polymer binder is a molecule containing at least one functional group selected from amine, cyanate, alcohol, and carboxyl,
The polymer binder is polyvinyl alcohol, polyethylene, polypropylene, polyvinyl chloride, polycaprolactone, polyethylene glycol, polystyrene, poly Acrylonitrile (polyacrylonitrile), polysulfone (polysulfone) any one or a method for producing a chelate complex having a multi-stage pore structure, characterized in that a combination thereof.
delete delete delete delete delete

Images