WO2018194431A2 - Membrane including metal substrate layer and cnt/chitosan nanohybrid coating layer, and electrostatic dust collection system including same - Google Patents

Abstract

The present invention relates to a membrane including a metal substrate layer and a CNT/chitosan nanohybrid coating layer, and an electrostatic dust collection system including the same. The membrane of the present invention has excellent electrical conductivity and is thus capable of efficiently collecting dust, even with a low current, and has excellent mechanical strength and is thus suitable for application in various types of electrostatic dust collection systems.

Description

Membrane comprising metal base layer and CNT / chitosan nano hybrid coating layer and electrostatic dust collection system comprising the same

The present invention relates to a membrane comprising a metal substrate layer and a CNT / chitosan nano hybrid coating layer and an electrostatic precipitating system comprising the same.

Dust is classified into total dust, fine dust, and ultrafine dust according to its particle size. Among them, the fine dust means that the diameter is 10μm or less, the ultra-fine dust means that the diameter is 2.5μm or less. Among them, fine dust and ultrafine dust can penetrate into the alveoli of a person, which is a direct cause of various respiratory diseases after infiltration. Such fine dust and ultrafine dust are composed of ionic components such as sulfate, nitrate and ammonia, and harmful substances such as metal compounds and carbon compounds. These materials cause photochemical reactions in the atmosphere, producing fine dust and ultra-fine dust. These materials are mainly generated from automobile exhaust or smoke from factories. Due to the harmfulness of these substances, countries around the world strictly regulate the concentration of fine dust and ultrafine dust.

The fine dust is generally about 1/10 of the thickness of the hair, while the ultra fine dust is very small, about 1/40 or less, so it is almost invisible to the human eye and can not be filtered out of the airways. do. This can lead to heart disease and respiratory diseases.

In Korea, yellow dust from China occurs in spring, and in recent years, due to global warming, desertification of inland China has occurred, and the time of occurrence of yellow dust is also being accelerated. Yellow dust from China was analyzed to be five times more toxic than domestic yellow dust. In Beijing, the concentration of heavy metals is three times higher than that of Korea. Therefore, it is essential to wear a mask that can remove fine dust when going out.

In addition to the yellow dust, fine dust caused by air pollution is also a major threat to health, attentive environment that should not have impurities such as operating room, intensive care unit and semiconductor process room, and underground spaces that are not well ventilated such as subway For example, it is very important to block fine dust and ultrafine dust even in office spaces where printers are frequently used. Therefore, the development of filters, such as for vehicles, masks, printers, air cleaners, air conditioners, electric cleaners, special clean rooms, etc. that can remove such fine dust or ultra-fine dust is becoming important.

Conventional anti-vibration filter uses a filter method using a woven fabric or a nonwoven fabric. In other words, a filter having pores smaller than the particle size was manufactured, and a method of filtering large particles was selected. However, such a conventional dust filter has two problems. First, there is a limit to removing nano-sized ultrafine particles whose particle size is smaller than 2.5 μm. Secondly, in order to effectively remove fine dust and ultrafine dust, the pores of the filter have to be made small, which makes it difficult to move the air. As a result, it is necessary to manufacture a dustproof filter that has pores of a suitable size, which allows free access of air and can effectively remove ultra fine dust.

It is an object of the present invention to provide a membrane and an electrostatic precipitating system including the same which have excellent electrical conductivity and can effectively collect fine dust even at a low current.

In order to solve the above problems, the inventor of the present invention has completed the present invention by producing a membrane that has excellent electrical conductivity and can effectively collect fine dust even at a low current. Accordingly, the problem solving means of the present invention is as follows:

1. A membrane comprising a metal substrate layer and a CNT / chitosan nano hybrid coating layer coated on the metal substrate layer, wherein the CNT / chitosan nano hybrid is a CNT core surrounded by a chitosan shell.

2. The electrostatic dust collection system comprising the membrane of 1 above.

The membrane of the present invention includes CNTs in a high content, and has excellent electrical conductivity, and has excellent structural stability, and can effectively collect fine dust or ultrafine dust even at low current. In addition, by coating the CNT / chitosan nano-hybrid on the metal substrate it has sufficient electrical conductivity and can be mass-produced at high speed. The membrane of the present invention is thus suitable for use in electrostatic precipitating systems.

1 is a schematic of the core-shell structure of a CNT / chitosan membrane.

Figure 2 is a simplified view of the case where the membrane layer is disposed on both sides of the filtration layer in the electrostatic dust collection system of the present invention.

Figure 3 is a simplified diagram of the case where the membrane layer is disposed on one side of the filtration layer in the electrostatic dust collection system of the present invention.

4 is an HR-TEM (A), FE-SEM (B) image and photograph (C) of CNT-chitosan 50.

FIG. 5 is an enlarged SEM image of FIG. 4C.

6 is an HR-TEM image of CNT- chitosan 25, 50, 75 and pure CNTs (pCNTs).

7 shows FTIR spectra of pure CNT, chitosan and CNT / chitosan membranes.

FIG. 8 shows a graph depicting the results of thermogravimetric analysis of pure CNT, chitosan and CNT / chitosan membranes.

FIG. 9A is a graph showing the change in thickness and surface resistance according to the CNT weight% change of the CNT / chitosan membrane, and FIG. 9B is a graph showing the change in tensile strength and elastic modulus according to the CNT weight% change.

10 is a graph showing the change in elongation rate according to the CNT weight% change of the CNT / chitosan membrane.

11 is a graph showing tensile-stress curves of pure chitosan and CNT- chitosan 25, 50, 75, 85.

12 shows Raman spectra of pure chitosan and CNT / chitosan membranes.

FIG. 13 shows XPS data C 1s (A), N 1s (B), and O 1s (C) of CNT / chitosan membranes.

14 to 18 is a view showing the SEM image of the membrane surface of the present invention when exposed to outside air for 3 hours under a voltage of 0 to 12V, the case of 0V 14, 15V and 15V In FIG. 16 and 9V, FIG. 17 and 12V are shown in FIG. 18.

Figure 19 compares the membrane surface of the present invention after adsorption of fine dust and after washing it.

20 is a photograph showing the Al / CNT membrane prepared in Example 2 of the present invention.

21 shows a conceptual diagram and actual manufacturing results of the cylindrical electrostatic dust collecting system of the second embodiment of the present invention.

22 is a graph showing the fine dust removal rate measured when only the nonwoven fabric is mounted in the cylindrical electrostatic dust collecting system of Example 2 of the present invention.

FIG. 23 is a graph showing the fine dust removal rate measured when only the nonwoven fabric and wool are mounted in the cylindrical electrostatic dust collecting system of Example 2 of the present invention.

24 is a graph showing the fine dust removal rate measured when only the nonwoven fabric, wool and Al foil is mounted on the cylindrical electrostatic dust collecting system of Example 2 of the present invention.

25 is a graph showing the fine dust removal rate measured in the cylindrical electrostatic dust collecting system of Example 2 of the present invention.

FIG. 26 is a measurement of the maximum adsorption capacity of the fine dust of the cylindrical electrostatic dust collecting system of Example 2 of the present invention, and an Al electrode and a carbon fiber electrode were used as a comparative example instead of the Al / CNT membrane.

Figure 27 shows the results of measuring the change in fine dust removal rate according to the size change of the cylindrical electrostatic filter, the left side when the size is 1.5 times (medium size in Example 2), the right side when the size is doubled ( The result of large size in Example 2 is shown.

The present invention includes a metal substrate layer and a CNT / chitosan nano hybrid coating layer coated on the metal substrate layer, wherein the CNT / chitosan nano hybrid is directed to a membrane wherein the CNT core is surrounded by a chitosan shell.

In the membrane of the present invention, the CNT / chitosan nanohybrid has a core / shell structure and refers to a nanoparticle having a CNT core surrounded by a chitosan shell. If CNTs and chitosan are simply mixed or used in the form of composites, CNTs may not be uniformly distributed and may be concentrated in some areas, which may weaken the mechanical strength of the entire membrane and adversely affect the electrical conductivity of the membrane. Can be crazy On the other hand, the core / shell structure of the present invention allows the CNTs to be uniformly distributed, so that the membrane of the present invention can contain a high content of CNTs, while maintaining its excellent mechanical strength. The core / shell structure of the CNT / chitosan nano hybrid of the present invention is shown in FIG. 1.

In the present invention, the CNT is short for carbon nanotubes, and includes both single-walled carbon nanotubes and multi-walled carbon nanotubes. The chitosan refers to a polymer compound deacetylated chitin, the degree of deacetylation may be 75 to 85%, the molecular weight may be 50000 to 190000 Da, but within the range that can achieve the object of the present invention If not limited to this.

In the membrane of the present invention, the metal substrate includes all metal substrates on which the CNT / chitosan nanohybrid can be coated, and is preferably a metal substrate having an oxide film formed on a surface thereof. When the surface of the metal substrate is oxidized, functional groups present in the oxidized portion of the surface and the chitosan of the CNT / chitosan nanohybrid can bond hydrogen, which allows the substrate layer to be strongly bonded to the coating layer. The metal of the metal base is preferably selected from the group consisting of iron, gold, silver, copper, platinum, titanium, aluminum and palladium, and particularly preferably aluminum and copper.

When the CNT / chitosan nano hybrid is manufactured by coating a metal substrate, the size of the manufacturable membrane can be increased, and the preparation time of the membrane can be shortened. The metal substrate also imparts structural stability and electrical conductivity to the membrane, making the membrane of the present invention suitable for use in electrostatic precipitating systems.

In the membrane of the present invention, the coating layer preferably comprises 25 to 90% by weight of CNT based on the total weight of the coating layer. If the CNT content is less than this, the electrical conductivity of the membrane is low, which is not suitable for use in an electrostatic precipitating system, and if more than this, the mechanical strength of the membrane may be weakened.

In the membrane of the present invention, the coating layer preferably has an electrical resistance of 50Ω or less. If the electrical resistance is larger than this, a high voltage is required to generate an electric field, which lowers the energy efficiency of the electrostatic precipitating system.

In the membrane of the present invention, the coating layer is preferably coated with a weight of 0.5 to 2.5 times the weight, based on the weight of the metal base layer, it is particularly preferably 1 to 1.5 times. If the weight of the coating layer is less than this, the dust collection capacity of the electrostatic dust collection system is lowered, if more than this may reduce the structural stability of the membrane.

In the membrane of the present invention, the coating layer preferably has a specific surface area of 50 to 150m ² / g. If the specific surface area is smaller than this, the dust collecting capacity of the electrostatic precipitating system will be reduced, and if the specific surface area is larger, the structural stability of the membrane may be reduced.

The present invention also the membrane layer; And a filtration layer.

In the electrostatic dust collection system of the present invention, the filtration layer refers to a layer having a function of filtering dust on a filtration principle, and may include a general cloth, a cabin filter, a nonwoven fabric or a wool layer.

The general fabrics collectively refer to woven and knitted fabrics composed of fibers.

In the electrostatic dust collection system of the present invention, the membrane layer may be disposed on either side or one side of the filtration layer. The simplified electrostatic dust collection system when the membrane layer is disposed on both sides of the filtration layer is shown in FIG. 2, and the simplified electrostatic dust collection system when the membrane layer is disposed on one side of the filtration layer is simplified. Same as FIG. 3.

In FIG. 2, air containing dust is introduced parallel to the two membrane layers through the filtration layer. Due to the attraction by the electric field generated in the membrane layer by an external power source, the dust of the introduced air is attracted to both membrane layers and collected, and the dedusted air passes through the filtration layer and is discharged out of the dust collection system.

In FIG. 3, air containing dust is introduced in a direction perpendicular to the membrane layer through the filtration layer. The dust from the introduced air is attracted to the membrane layer surrounding the filtration layer and collected by the attraction of the electric field generated in the membrane layer by an external power source, and the dedusted air passes through the filtration layer and is discharged outside the dust collection system. do.

The electrostatic dust collecting system of the present invention may have a planar shape or a cylindrical shape, and a representative example of the planar form is shown in FIG. 2, and a representative example of the cylindrical form is shown in FIG. 3. In addition to the cylindrical and planar form, any form can be used without limitation as long as it can utilize the principles of the electrostatic dust collecting system of the present invention.

It is preferable that the electrostatic dust collection system of the present invention has an electrical resistance of 50 Ω or less. If the electrical resistance is larger than this, a high voltage is required to generate the electric field required for driving the dust collecting system, thereby reducing the energy efficiency of the electrostatic dust collecting system.

In the electrostatic precipitating system of the present invention, it is preferable that the air velocity of the gas passing through the filtration layer is from 0.001 to 5 m / s. If the wind speed is lower than this, the amount of air that can be purified per unit time is not enough, if high, there is a problem that the dust collection performance is not enough.

In the electrostatic dust collection system of the present invention, it is preferable that the differential pressure before and after passing through the filtration layer is 100 Pa or less, and when the differential pressure is larger than this, there is a problem that the dust collection efficiency is not sufficient.

Example

Hereinafter, preferred preparation examples and experimental examples are presented to help understand the present invention. However, the following Preparation Examples and Experimental Examples are provided only for easier understanding of the present invention, and the contents of the present invention are not limited by the Preparation Examples and Experimental Examples. In the preparation of the present invention, when the CNT content of the membrane is% by weight, it is named CNT-chitosan x.

Example 1. CNT / chitosan nano hybrid coating layer

material

Multi-walled carbon nanotubes (> 95%, outer radius 20-30 nm, length 10-30 μm) were obtained from EMP (EM-Power Co., Republic of Korea). Low molecular weight chitosan (MW = 50000-190000, 75-85% deacetylation) was purchased from Sigma-Aldrich (United States). All chemicals, including glacial acetic acid, sodium hydroxide and organic solvents, were purchased from Sigma-Aldrich and used without further purification.

Preparation Example 1-1. Preparation of CNT-chitosan 50 Membrane

Prior to using carbon nanotubes (CNT), reflux in 5N hydrochloric acid for one day to remove all possible impurities. Thereafter, 200 mg of chitosan was dissolved in 50 mL (pH <2) of a 1: 1 mixture of 5N hydrochloric acid and glacial acetic acid for 24 hours. Then 200 mg of CNT was added to the chitosan solution and homogenized with a high pressure homogenizer (Nano DeBEE 45-3, BEE International, South Easton MA). 2N sodium hydroxide was added to the acidic CNT-chitosan solution and neutralized slowly. Were removed. The CNT-chitosan solution was sonicated for 30 minutes in a suitable sized container, and placed in a fume hood and at room temperature for 2 days. The solution was then dried to prepare a membrane.

Preparation Example 1-2. Preparation of CNT-chitosan 25 Membrane

A membrane was prepared in the same manner as in Preparation Example 1, except that carbon nanotubes were used at 25 wt%.

Preparation Example 1-3. Preparation of CNT-chitosan 75 Membrane

The membranes were prepared in the same manner as in Preparation Example 1, except that 75% by weight of carbon nanotubes were used.

Preparation Example 1-4. Preparation of CNT-chitosan 85 Membrane

A membrane was prepared in the same manner as in Preparation Example 1, except that 85 wt% of the carbon nanotubes were used.

Experimental Example 1-1. Morphology Analysis of CNT-chitosan Membrane

The shape of the CNT-chitosan membrane was analyzed using a high resolution electron transmission microscope (HR-TEM; JEM 3010, JEOL, Japan) and a field emission scanning electron microscope (FE-SEM; MIRA II LMH microscope, Tescan, Czech Republic). . Samples were sputter-coated with gold prior to SEM analysis. The results are shown in Figures 4-6. 4 is an HR-TEM (A), FE-SEM (B) image and photograph (C) of CNT-chitosan 50. 5 is an enlarged view of C of FIG. 4 by SEM. 6 is an HR-TEM photograph of CNT- chitosan 25, 50, 75 and pure CNTs.

Experimental Example 1-2. Characterization of CNT-chitosan Membrane

To characterize the CNT-chitosan membrane, a thermogravimetric analyzer (TGA; Seiko Exstar 6000 TG / DTA6100, Japan) and a Fourier transform infrared spectrometer (FTIR; JASCO 470 PLUS, Japan) were used. Samples were heated in the range 25-900 ° C. at a rate of 10 ° C./min using 4 mg of sample. FT-IR spectra were measured in the solid state and in the range from 400 to 4000 cm ⁻¹ . Experiments were also performed on pure chitosan and CNT for comparison, and the results of the FT-IR are shown in FIG. 7 and the results of TGA are shown in FIG. 8.

In the case of FT-IR, pure CNTs did not show any characteristic peaks. This is because there is no functional group on the surface. On the other hand, 50% by weight of CNT-chitosan membrane showed the following peak of the same type as chitosan.

-3120-3385 cm ^-1 (stretch of -OH and -NH of chitosan)

-2925 and 2856 cm ^-1 (stretch of -CH of chitosan)

1654 cm ^-1 (C = C stretch of pure CNT)

-1632 cm ^-1 (extended C = O of chitosan)

These IR spectra indicate that CNTs are well functionalized with chitosan.

In the case of thermogravimetric analysis, major mass loss occurred in the range of 600 to 700 ° C. for pure CNTs, but mass loss occurred in two steps for pure chitosan. The first stage is near about 300 ° C. where the polymer structure is broken and the decomposition of glucosamine units occurs, and the second stage is 400 to 600 ° C. where oxidative degradation occurs. The 50 wt% CNT-chitosan membrane showed a clear two stage degradation. The first step is between 200 and 300 ° C. resulting from loss of chitosan, and the second step is between 500 and 600 ° C. where decomposition of CNT occurs. The thermal decomposition temperature of both materials moved to the lower side as compared to the pure case. This is because the weight concentration of each component is half lower as compared to the pure case.

Experimental Example 1-3. Mechanical Characterization of CNT-chitosan Membrane

The thickness, electrical resistance, tensile strength, modulus of elasticity, and elongation of surface chitosan were measured for each CNT-chitosan membrane. It was also measured for pure chitosan for comparison. The results are shown in Table 1 below.

sample	Chitosan thickness (nm)	Surface resistance (Ω / sq)	Tensile Strength (MPa)	Modulus of elasticity (N / mm)	Elongation (%)
Chitosan	ND	> 10¹²	14.814 ± 1.433	5.501 ± 1.367	217.2 ± 21.113
CNT-chitosan 25	6.528 ± 1.0788	16.51 ± 0.651	37.557 ± 1.678	16.253 ± 2.068	76.3 ± 6.472
CNT-chitosan 50	3.542 ± 0.1906	8.477 ± 0.377	51.039 ± 1.104	22.754 ± 2.128	67.1 ± 4.359
CNT-chitosan 75	1.211 ± 0.1172	5.133 ± 0.068	36.113 ± 1.772	27.263 ± 1.115	40.7 ± 5.669
CNT-chitosan 85	ND	4.861 ± 0.128	14.251 ± 1.839	24.02 ± 2.029	13.3 ± 1.115

 (ND means that the value is not determined.) FIG. 9 shows a comparison of changes in thickness and resistance of chitosan and tensile strength and modulus of elasticity according to CNT content. Also shown in Figure 10 is a graph showing the change in elongation rate according to the CNT content.

Tensile-stress curves were also obtained for each membrane and chitosan. The result is shown in FIG.

Experimental Example 1-4. Surface analysis of CNT-chitosan membrane

For analyzing the surface of the CNT-chitosan membrane, Raman spectra (Horiba LabRam Aramis IR2, Japan) and X-ray photoelectron spectroscopy (XPS; AES-XPS ESCA 2000, Thermo Fisher Scientific, United States) were used. The results are shown in Figure 12 (Raman spectrum) and Figure 13 (XPS).

Raman spectra are an efficient way to analyze carbon nanocomponents. The D-band at 1350 cm ⁻¹ shows the presence of sp³ hybrid carbon. It also relates to a disordered graphite structure proportional to the amount of amorphous carbon in the dispersed state. The high frequency of 1580 cm ^-1 G-band shows the structural strength of sp² hybrid carbon with CNT oscillation mode. The sharpness of the G and G` peaks is related to the fact that nanotubes may exhibit metal-like conductivity.

XPS shows three characteristic peaks.

284.60 eV (C 1s)

399.63-400.16eV (N 1s)

532.36-533.17eV (O 1s)

The C 1s, N 1s and O 1s of XPS data obtained from the functionalized CNTs exhibit binding energies of 280-295, 395-410 and 525-540eV, respectively. The C 1s spectrum of the chitosan functionalized CNTs shows that the sp2 carbon atoms of the CNT molecules are strongly attached to the chitosan molecules. These XPS data show that the CNT surface is well functionalized with chitosan.

Experimental Example 1-5. Fine dust removal test of CNT-chitosan 50 membrane

The surface of the membrane when exposed to outside air for 3 hours under a voltage of 0 to 12V was observed by SEM image to qualitatively determine the degree of adsorption of fine dust. In the case of 0V, in FIG. 14, in the case of 3V, in FIG. 15, in the case of 6V, in FIG. 16, in the case of 9V, in FIG. 18, and in case of 12V, FIG. 18 is shown. It was. From this, it was confirmed that the surface of the membrane was covered with fine dust as the voltage increased and a strong electric field was generated.

Example 2 Membrane comprising metal layer and CNT / chitosan nano hybrid coating layer and electrostatic dust collection system using same

Preparation Example 2-1. Preparation of Membrane Including Aluminum Layer and CNT / chitosan Nano Hybrid Coating Layer

Chitosan was dissolved in 150 ml of 1% acetic acid and hydrochloric acid solution (pH 2.0), and CNT was added, followed by sufficient stirring. Chitosan 0.7g and CNT 0.7g (Chit-pCNT50), Chitosan 0.35g and CNT 1.05g (Chit-pCNT75), Chitosan 0.14g and CNT 1.26g (Chit-pCNT90) The solution was prepared and sufficiently dispersed through stirring and dispersing equipment. Then, the pH was slowly increased to 9-10 by adding 5% aqueous ammonia or basic solution to each solution.

After spreading the Al thin film flat on the hot plate, the three solutions prepared above are dispersed on the thin film, respectively. Then, by controlling the temperature in the range of 60 to 70 ℃ dried, immersed in 5% ammonia water and then taken out, washed with water and ethanol and dried to prepare a membrane comprising an aluminum layer and CNT / chitosan nano hybrid coating layer, this Referred to as Al / CNT membrane. In the case of the membrane containing no aluminum layer, it took 5 days to manufacture under the existing room temperature conditions, but it was possible to manufacture a large area membrane in 1 minute on the Al thin film. Its nano surface area was determined to be greater than 80 m ² / g. Both surface photographs of the prepared Al / CNT are shown in FIG. 20.

Preparation Example 2-2. Fabrication of Cylindrical Electrostatic Dust Collecting System

In order to apply the membrane prepared in Preparation Example 2-1 to an air purifier and a building vent, a cylindrical electrostatic dust collecting system was manufactured. A cylindrical frame was fabricated by 3D printing technique, and the dust collecting system was composed of a three-layer structure of a first filtration layer (nonwoven fabric), a second filtration layer (wool), and an electrostatic CNT filter layer, and a CNT-chitosan 50 on the CNT filter layer. Al / CNT membrane using the membrane was applied. The conceptual diagram and the actual production result thereof are shown in FIG. 21. Cylindrical frame is manufactured in three sizes: small, medium and large. The small size is 10cm long, the outer diameter is 7cm, the inner diameter is 4cm, the medium size is 15cm, the outer diameter is 10.5cm, the inner diameter is 6cm, and the large size is 20cm. It has a diameter of 14 cm and an inner diameter of 8 cm.

Comparative Example 2-1. Maximum removal rate of fine dust by nonwoven fabric only

In order to confirm the fine dust removal superiority of the electrostatic dust collection system of the present invention, a dust collecting system composed of only a nonwoven fabric or a nonwoven fabric / wool was used as a comparative example. The removal rates for PM 1.0, 2.5 and 10 dusts were measured at constant wind speeds for the 2, 4, 6, 8 and 10 nonwoven fabrics. The PM 1.0, 2.5, and 10 dusts refer to dusts having particle diameters of 1, 2.5, and 10 μm or less, respectively. The results are shown in FIG. 22. It was confirmed that the nonwoven fabric alone did not remove PM 1.0 and 2.5 dusts well, and even if the number of nonwoven fabrics increased, only the removal rate for PM 10.0 dust increased, but the removal rates for PM 1.0 and 2.5 dust did not increase.

Comparative Example 2-2. Maximum removal rate of fine dust by nonwoven fabric / wool

Six nonwoven fabrics were used as fixed values, and the removal rates for PM 1.0, 2.5, and 10 dusts were measured at constant wind speeds using 2g, 4g, 6g, 8g, and 10g. The results are shown in FIG. Although the removal rate was increased as compared with the use of only nonwoven fabrics, the removal rate was still around 50%, and even the largest amount of ultrafine dust, PM 1.0 dust, only 34% was removed. Confirmed.

Experimental Example 2-1. Maximum dust removal rate measurement by cylindrical electrostatic precipitating system

With 6 nonwoven fabrics and 10 g of wool as fixed values, Al foil and Al / CNT membrane (CNT-chitosan 50) were mounted on the filter layer to measure fine dust removal rate. A fine dust removal rate was optimized by flowing a current of 0 to 10 A through the membrane, and the result of using only Al foil is shown in FIG. 24 and the result of using an Al / CNT membrane. When Al / CNT membrane was used, it showed better removal rate than Al foil alone, PM 1.0, 2.5, and 10 dust showed about 80%, and PM 2.5 and 1.0 dust removal rate was greatly increased. It was.

Experimental Example 2-2. Maximum adsorption capacity measurement of fine dust by cylindrical electrostatic precipitating system

As in Experimental Example 2-1, 6 nonwoven fabrics and 10 g of wool were fixed, and an Al / CNT membrane (CNT-chitosan 50) was mounted on the filter layer to measure fine dust maximum adsorption capacity. An Al electrode and a carbon fiber electrode were mounted as a comparative example instead of the Al / CNT membrane, and the experiment was performed at 0.46V. The results are shown in FIG. The Al / CNT membrane maintained 80% removal efficiency for 70 hours, while the remaining Al and carbon fibers maintained their initial adsorption rate only for 10-20 hours. The maximum dust adsorption capacity of the Al / CNT membrane calculated from this is 20.1 mg / g.

Experimental Example 2-3. Measurement of the change of fine dust removal rate according to the size change of the cylindrical electrostatic filter

Ten nonwoven fabrics were fixed and filled with 40 to 70 g of wool according to the filter size, and then Al / CNT membranes were mounted on the filter layer to prepare three kinds of cylindrical electrostatic filters having different sizes. A current of 0 to 5 A was applied to the membrane, and the result is shown in FIG. 27. PM 1.0, 2.5 and 10 dust all showed a removal rate of 81 to 86%, it was confirmed that the removal rate increases by 1-2% as the size of the filter increases.

[Description of the code]

1, 1 ′: metal base layer

2, 2 ': coating layer

3: filtration layer

Claims (14)

1. And a metal base layer and a CNT / chitosan nano hybrid coating layer coated on the metal base layer, wherein the CNT / chitosan nano hybrid is a CNT core surrounded by a chitosan shell.
2. The membrane of claim 1, wherein the metal is selected from the group consisting of iron, gold, silver, copper, platinum, titanium, aluminum, and palladium.
3. The membrane of claim 1, wherein the coating layer comprises 25 to 90 weight percent of CNTs based on the total weight of the coating layer.
4. The membrane of claim 1, wherein the coating layer has an electrical resistance of 5 Ω or less.
5. The membrane of claim 1, wherein the coating layer is coated at a weight of 0.5 to 2.5 times the weight of the metal substrate layer.
6. The membrane of claim 1, wherein the coating layer has a specific surface area of 50 to 150 m ² / g.
7. A membrane layer according to any one of claims 1 to 6; And a filtration layer.
8. 8. The electrostatic precipitator system of claim 7, wherein the filtration layer is selected from the group consisting of ordinary cloth, cabin filter, nonwoven fabric and wool.
9. 8. The electrostatic dust collection system of claim 7, wherein a membrane layer is disposed on either or one side of the filtration layer.
10. 10. The electrostatic precipitator system of claim 9, having a planar shape.
11. 10. The capacitive dust collection system according to claim 9, having a cylindrical shape.
12. The capacitive dust collection system according to claim 7, having an electrical resistance of 50 Ω or less.
13. 8. The electrostatic dust collection system according to claim 7, wherein the wind speed of the gas passing through the filter bed is 0.001 to 5 m / s.
14. The electrostatic dust collecting system according to claim 7, wherein the differential pressure before and after passing through the filtration layer is 100 Pa or less.

Images