KR20160064725A - Method of Preparing Gas Separation Membrane Using iCVD Process - Google Patents

Abstract

The present invention relates to a producing method of a gas separation membrane which deposits or coats polymers on a substrate through an initiated chemical vapor deposition (iCVD) process using an initiator. The producing method of a gas separation membrane has excellent penetration ratio and selectivity for separating target gas from mixed gas.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to a method for preparing a gas separation membrane using a chemical vapor deposition (iCVD)

The present invention relates to a method for producing a gas separation membrane using an iCVD process using an initiator, and more particularly, to a process for producing a gas separation membrane by depositing or coating a polymer on a substrate using a chemical vapor deposition (iCVD) And a method for producing the gas separation membrane.

Since a polymer material is a nonvolatile material having a large molecular weight, a vapor deposition process can not generally be applied. Instead, the polymer thin film can be obtained by vapor phase polymerization in which the monomer having volatility is vaporized and the polymerization reaction of the polymer and the film formation process are simultaneously carried out.

Initiative Chemical Vapor Deposition (iCVD) process employs a free radical radical polymerization, which is already well known for its liquid phase process. In the iCVD process, an initiator and a monomer are vaporized to cause a polymer reaction in a gas phase, thereby depositing a polymer thin film on the surface of the substrate. When the initiator and the monomer are merely mixed, the polymerization reaction does not occur. However, when the initiator is decomposed by the high temperature filament located in the gas phase reactor to generate radicals, the monomer is activated and the chain polymerization reaction is performed. Peroxide such as tert-butyl peroxide (TBPO) is mainly used as an initiator. This material is a volatile substance having a boiling point of about 110 ° C, and pyrolysis occurs at about 150 ° C. Therefore, when the temperature of the high temperature filament used in iCVD is maintained around 200 ~ 250 ° C, the gas phase reaction can be easily induced. The temperature of the filament is sufficiently high to pyrolyze TBPO, but at the same time, most organic materials, including monomers used in iCVD, are not pyrolyzed at such temperatures. The free radical formed through the decomposition of the initiator transfers the radical to the vinyl (CH ₂ ═CH-) group in the monomer, causing a chain reaction to form a polymer, and the polymer material thus formed is cooled to a low temperature And is deposited on the held substrate. Since the driving force used in the polymer polymerization is only the high temperature of the filament, and since various types of monomer materials are not chemically damaged at the temperature of the filament, the polymer thin film is also a polymer thin film Can be switched.

On the other hand, gas separation membranes can be used or used in various industrial processes, including the production of oxygen-enriched air, the separation of carbon dioxide or moisture from natural gas, and the recovery of gases from vent gases such as coal- . The components of the exhaust gas of the power plant are highly dependent on the fuel source, while the exhaust gases are oxidized and tend to be composed of N ₂ , O ₂ , H ₂ O, CO ₂ , SO ₂ , NO _x and HCl . The gas separation membrane needs to separate target gas species from the mixture of gases. Usually, one gas that becomes the target gas to be separated from one or more other gases in the gas mixture is carbon dioxide. In this case, the carbon dioxide is preferably separated from hydrogen, nitrogen and / or methane. Other preferred gas separation include oxygen / nitrogen (i.e., separating oxygen gas from nitrogen gas), helium / nitrogen, and helium / methane.

Polymers used in gas separation membranes must meet certain criteria. One is that the gas can permeate through the membrane, so that a proper gas flow must occur during separation. The second criterion is the selective separation of the target gas from other gases, i. E., The selectivity of the film. Briefly, the selectivity is measured by the permeability (P _A ) of the target gas-gas A relative to the permeability (P _B ) of the other gas species-gas B.

P _A / P _B

The third criterion is that there is a need for the membrane to have good thermal and mechanical properties to provide structural stability to the gas separation membrane so that it can be carried out under pressure in the separation process.

The two criteria of the permeability of the film to the gas and the selectivity of the film in the target gas with respect to the other gas are usually opposite to each other. As the permeability of the membrane increases, its selectivity tends to decrease (the permeability for all gases tends to increase). Likewise, as the selectivity of the film in the target gas for the other gas increases, the transmittance for the target gases tends to decrease. These effects have been studied and the upper limits for the combination of transmittance and selectivity are shown. A plot of the upper limit of transmittance versus selectivity is known as Robeson's upper bound. In general, it is known to be difficult to develop a film that provides a combination of transmittance and selectivity beyond the upper limit of Robeson's.

As a result, the present inventors have made intensive efforts to solve the above problems. As a result, the present inventors have found that when a gas separation membrane is produced by depositing or coating a polymer on a substrate using a chemical vapor deposition (iCVD) process using an initiator, It was confirmed that the transmittance and selectivity for separation were excellent, and the present invention was completed.

An object of the present invention is to provide a gas separation membrane having improved transmittance and selectivity and a method of manufacturing the same.

In order to accomplish the above object, the present invention provides a process for producing an iCVD reactor, comprising: (a) injecting a monomer and an initiator into an iCVD reactor; (b) fixing the porous substrate to the bottom of the reactor; And (c) depositing a polymer on the porous substrate. The present invention also provides a method of manufacturing a gas separation membrane using a chemical vapor deposition reactor (iCVD) using an initiator.

The present invention also have been manufactured by the manufacturing method of the gas separation membrane, the substrate is a nitrile (polyacrylonitrile) to a polyacrylate, CO ₂ transmission rate is 30 ~ 90barrer, a CO ₂ CO ₂ / N ₂ selectivity of 18 to 20 Thereby providing a separation membrane. The unit of permeability is barrer, which is 1 barrer = 10 ^-10 cm ³ (STP) cm ^-2 s ^-1 cmHg ^-1 when converted to SI units.

The present invention also have been manufactured by the manufacturing method of the gas separation membrane, the substrate is polydimethylsiloxane (polydimethylsiloxane), and, CO ₂ permeability was 900 ~ 3800barrer a, CO ₂ / N ₂ selectivity of 10 to 19 of CO ₂ separation membrane .

The gas separation membrane produced according to the present invention is excellent in the transmittance and selectivity for separating the target gas from the mixed gas and can save time and cost used for gas separation, Separation or separation of natural gas.

1 is a graph showing CO ₂ selectivity and transmittance of the gas separation membrane prepared in Example 1 using a chemical vapor deposition (iCVD) process using an initiator according to the present invention.
FIG. 2 is a photograph (left) / (right) of a substrate before coating a polymer using a chemical vapor deposition (iCVD) process using an initiator.
3 is a graph showing CO ₂ selectivity and transmittance of the gas separation membrane prepared in Example 2 using a chemical vapor deposition (iCVD) process using an initiator according to the present invention.
FIG. 4 is a device for testing the transmittance of a gas separation membrane manufactured using a chemical vapor deposition (iCVD) process using an initiator according to the present invention.

In the present invention, when a gas separation membrane is produced by depositing or coating a polymer on a substrate using a chemical vapor deposition (iCVD) process using an initiator, a gas separation membrane having excellent permeability and selectivity for separating a target gas from a mixed gas And the like.

In the present invention, a gas separation membrane was prepared by depositing or coating a polymer on a substrate using a chemical vapor deposition (iCVD) process using an initiator. As a result, it was confirmed that the prepared gas separation membranes had much improved transmittance and selectivity compared to substrates not coated with polymer.

Accordingly, in one aspect, the present invention provides a process for preparing an iCVD reactor, comprising: (a) injecting a monomer and an initiator into an iCVD reactor; (b) fixing the porous substrate to the bottom of the reactor; And (c) depositing a polymer on the porous substrate. The present invention relates to a method for producing a gas separation membrane using a chemical vapor deposition reactor (iCVD) using an initiator.

The present invention is characterized in that various kinds of polymers are coated on various porous substrates using an iCVD process (iCVD) reactor to fabricate a gas separation membrane.

The deposition of step (c) can be performed at a temperature of 25 to 45 and a pressure of 150 to 350 mTorr. By controlling the temperature and pressure, the reaction rate and reaction pattern can be controlled by controlling the flow rate of monomer and initiator. The temperature shown above is the temperature of the substrate on which the sample is placed, that is, the temperature of the sample. If the temperature of the substrate is too low, the condensation will occur and the uniform thin film will not be formed and only the oligomers will be formed. If the temperature is too high, the molecules in the gaseous phase will not adsorb onto the sample and the reaction will not occur . Also, if the pressure is increased or decreased too much, it will also have a bad influence on making a uniform thin film, so proper pressure control is necessary.

In the present invention, the porous substrate may be formed of a material selected from the group consisting of polyacrylonitrile, polydimethylsiloxane, polyethersulfone (PES), polysulfone (PSF) and polyvinylidene fluoride Poly (vinylidenedifluoride), PVDF), and the like.

In the present invention, the monomer may include a vinyl group. Examples of the compound include 2,4,6,8-tetramethyl-2,4,6,8-tetravinylcyclotetrasiloxane ( 2,4,6,8-tetramethyl-2,4,6,8-tetravinylcyclotetrasiloxane (V4D4), 1,3,5-trimethyl-1,3,5-trivinylcyclotrisiloxane 1,3,5-trivinyl-cyclotrisiloxane (V3D3), hexavinyldisiloxane (HVDS), glycidylmethacrylate (GMA), divinylbenzene, diethylene glycol divinyl ether, diethylene glycol Diacrylate, ethylene glycol dimethacrylate, and 1,3-diethenyl-1,1,3,3-tetramethyl-disiloxane. However, the present invention is not limited thereto, and the compound In addition, among vinyl monomers, all materials having suitable vapor pressure can be deposited.

In the step (a), the flow rate ratio of the monomer and the initiator may be 1: 1 to 4: 1, preferably 1: 1 to 3: 1. A film may not be formed, or a condensation may occur and a uniform film may not be formed.

The deposition in the step (c) may be performed for 10 minutes to 12 hours, preferably 40 minutes to 10 hours, while maintaining the temperature of the substrate at 25 to 45 ° C and the pressure of the chamber in the reactor at 150 to 350 mTorr If the temperature of the substrate in the reactor is less than 150 mTorr or more than 350 mTorr, the deposition rate may be slowed down when the temperature of the substrate is less than 25 ° C. There is a problem that the deposition is not performed or the deposition rate is slowed down. Since the deposition time is related to the deposition thickness, when the deposition time exceeds 10 minutes to 12 hours, there is a problem that the deposition thickness becomes thin or thick.

The monomer may be added to the monomer vessel of the iCVD reactor before the step (a) and heated to 30 to 45 ° C, and the initiator may be added to the initiator cylinder of the iCVD reactor and maintained at room temperature.

A chemical vapor deposition reactor (iCVD) using an initiator used in the present invention is a device for decomposing an initiator of a gas phase into radicals to cause polymerization of a monomer. As the initiator, peroxide such as tert-butyl peroxide (TBPO) is mainly used, which is a volatile substance having a boiling point of about 110 ° C., and pyrolysis occurs at about 150 ° C. Benzophenone, which decomposes by heat such as tert-butyl peroxide (TBPO) to form radicals, and decomposes by light such as UV to form radicals, may also be used.

The iCVD process does not seem to be much different from the conventional inorganic thin film deposition CVD process because the thin film is deposited by the energy supply of the heated filament heat source or UV. However, the iCVD process is performed at a low filament temperature between 200 ° C. and 350 ° C. And the temperature of the substrate surface on which the polymer thin film is deposited can be kept as low as 10 to 50 ° C. Because of these low surface temperatures, iCVD can be used to coat polymer films on multiple substrates that are susceptible to mechanical and chemical impacts, such as paper or cloth. And because the process is done in vacuum between 50 mTorr and 1000 mTorr, no high vacuum equipment is needed and the amount of monomer and initiator is controlled by the injection valve.

The thickness of the polymer deposited in the gas separation membrane according to the present invention may be 50 to 1200 nm, preferably 100 to 1100 nm.

In one embodiment of the present invention, a liquid monomer is put into a monomer vessel of an iCVD reactor and heated to a predetermined temperature (V3D3: 40 DEG C, V4D4: 38 DEG C). TBPO (tert-butyl peroxide) is used as an initiator. The initiator is placed in the initiator bottle and kept at room temperature. The monomers and initiator are flowed in the iCVD reactor at a weight ratio of 2: 1 or 1: 1. The temperature of the filament in the reactor is maintained at 180 占 폚. The polyacrylonitrile substrate temperature in the reactor was kept constant (V3D3: 40 ° C, V4D4: 30 ° C) and the circular substrate was fixed firmly on the bottom without bubbles. The pressure in the chamber is also kept constant (V3D3: 300 mTorr, V4D4: 300 mTorr, HVDS: 220 mTorr, GMA: 200 mTorr). After a certain time, a polyacrylonitrile substrate having a suitable thickness of a polymer deposited or coated can be obtained.

Accordingly, the invention from another point of view, have been manufactured by the above method, the substrate is (polyacrylonitrile) polyacrylonitrile, CO ₂ transmission rate is 30 ~ 90barrer, a CO ₂ CO ₂ / N ₂ selectivity of 18 to 20 Separator.

In another embodiment of the present invention, the monomers are put into a monomer vessel of an iCVD reactor and heated to a constant temperature (V3D3: 40 DEG C, V4D4: 38 DEG C, HVDS: 40 DEG C, GMA: 35 DEG C). TBPO (tert-butyl peroxide) is used as an initiator. The initiator is placed in the initiator bottle and kept at room temperature. The monomer and initiator are flowed into the iCVD reactor at a flow rate ratio of 2: 1 or 1: 1. The flow rate (unit: sccm) ratio can be said to be the gas volume ratio in the chamber per unit time. The temperature of the filament in the reactor is maintained at 180 占 폚. The polydimethylsiloxane substrate temperature in the reactor is kept constant (V3D3: 40 ° C, V4D4: 30 ° C, HVDS: 30 ° C, GMA: 25 ° C), and the circular substrate is firmly fixed on the floor without bubbles. The pressure in the chamber is also kept constant (V3D3: 300 mTorr, V4D4: 300 mTorr, HVDS: 220 mTorr, GMA: 200 mTorr). After a predetermined time, a polydimethylsiloxane substrate on which a polymer having an appropriate thickness is deposited or coated can be obtained.

Therefore, the invention in another aspect, have been manufactured by the above method, the substrate is a polydimethylsiloxane (polydimethylsiloxane), CO ₂ transmission rate is _{900 ~ 3800barrer, CO 2 / N} 2 selectivity of 10 to 19 of CO ₂ Separator.

The PAN substrate is a substrate that only serves as a support with a porosity property without selectivity. Therefore, the polymer thin film stacked thereon plays a role of the gas selectivity. The gas selectivity is a property of the material. As the thickness of the polymer thin film becomes thicker, the gas permeability decreases. In the present invention, the kind of the polymer deposited on the substrate is changed to separate the gas into a free volume in the polymer thin film because the thin polymer film exhibits a large gas selectivity. This is because the free volume can vary depending on the type of polymer and how it is made. Also, the thickness is adjusted to obtain appropriate selectivity and transmittance.

The PDMS itself has gas selectivity and also serves as a support. Although both the selectivity and the transmittance are high, it is the most preferable embodiment. However, since the two are inversely correlated with each other, the closest selectivity and transparency to the robeson upper bound have the most excellent effect can do.

[Example]

Hereinafter, the present invention will be described in more detail with reference to Examples. It is to be understood by those skilled in the art that these embodiments are only for illustrating the present invention and that the scope of the present invention is not construed as being limited by these embodiments.

Example 1: Preparation of pV3D3 deposited PAN substrate

(ICVD and oCVD, Advanced Functional Materials , Volume 18, Issue 7, pages 979992, April 11, 2008), which is hereby incorporated by reference. .

First, 25 g of liquid monomer V3D3 (2,4,6,8-Tetramethyl-2,4,6,8-tetravinylcyclotetrasiloxane, TCI T2523) was added to the monomer vessel of the iCVD reactor and heated to 40 ° C. As an initiator, TBPO (tert-butyl peroxide, Aldrich 168521, 250 ml, 98%) was placed in the initiator bottle and kept at room temperature.

The monomer and initiator were flowed in the iCVD reactor at a 1: 1 ratio (weight ratio). The temperature of the filament in the reactor was maintained at 180 占 폚. The circular substrate PAN350 (polyacrylonitrile, Sepro M-PA350-SPET 5 m ² ) substrate cut to a diameter of 6 cm was fixed to the bottom without bubbles while the substrate temperature in the reactor was maintained at 40 ° C. The pressure in the chamber was also constantly maintained at 300 mTorr. After 160 minutes, PAN substrate deposited with 400 nm thick pV3D3 (poly (1,3,5-trivinyl-1,3,5-trimethylcyclotrisiloxane) was obtained.

The gas permeability test was performed using the apparatus of FIG. The prepared gas separation membrane was cut into a diameter of 6 cm and then placed in a measuring device and allowed to flow for 1 minute so as to wash the membrane with N ₂ gas. Thereafter, a pressure of 5 bar was applied to the membrane. The pressure difference between both phases of the membrane becomes the driving force of gas separation. The gas permeability was measured five times and the average of the values was used as data. The same procedure was performed on CO ₂ gas to obtain gas permeability data.

Example 2: Preparation of pV4D4 deposited PAN substrate

First, 25 g of liquid monomer V4D4 (2,4,6,8-Tetramethyl-2,4,6,8-tetravinylcyclotetrasiloxane, TCI T2523) was added to the monomer vessel of the iCVD reactor and heated to 38 ° C. As an initiator, TBPO (tert-butyl peroxide, Aldrich 168521, 250 ml, 98%) was placed in the initiator bottle and kept at room temperature.

The monomer and initiator were flowed in the iCVD reactor at a 1: 1 ratio (weight ratio). The temperature of the filament in the reactor was maintained at 180 占 폚. The circular substrate PAN350 (polyacrylonitrile, Sepro M-PA350-SPET 5 m ² ) substrate cut to a diameter of 6 cm was fixed to the bottom without bubbles while the substrate temperature in the reactor was kept at 30. The pressure in the chamber was also constantly maintained at 300 mTorr. After 300 minutes, PAN substrate deposited with pV4D4 (2,4,6,8-Tetramethyl-2,4,6,8-tetravinylcyclotetrasiloxane) having a thickness of 510 nm was obtained.

The prepared gas separation membrane was cut into a diameter of 6 cm and then placed in a measuring device and allowed to flow for 1 minute so as to wash the membrane with N ₂ gas. Thereafter, a pressure of 5 bar was applied to the membrane. The pressure difference between both phases of the membrane becomes the driving force of gas separation. Gas permeabilities were measured five times and the average of the values was used as data. The same procedure was performed on CO ₂ gas to obtain gas permeability data.

Example 3: Preparation of pV4D4 deposited PAN substrate

The procedure of Example 2 was repeated except that the deposition time was changed to 600 minutes in Example 2 to obtain a 1.1-thickness pV4D4 (poly V4D4 (2,4,6,8-Tetramethyl-2,4,6,8-tetravinylcyclotetrasiloxane ) Was deposited on the PAN substrate.

Example 4: Preparation of PDMS substrate deposited with pGMA

In order to show that it can be applied to substrates other than PAN350, the PDMS (polydimethylsiloxane) substrate was also coated with a polymer to conduct a gas permeability test.

A method of making a PDMS substrate is as follows.

A silicone elastomer base (sylgard 184) and a silicone curing agent (sylgard 184) were mixed in a mass ratio of 10: 1. The well-mixed solution was placed in a circular patterned dish having a diameter of 14 cm and then spread on a spin-coating machine at 300 rpm for 30 seconds to flatten it. The PDMS (Polydimethylsiloxane) solution was annealed in an oven at 70 ° C for 1 hour to allow crosslinking to proceed. Thereafter, a PDMS substrate was completed by cutting into a circle having a diameter of 6 cm.

1 ~ 25 g of liquid monomer GMA (glycidyl methacrylate, Aldrich 151238-500G 97%) was added to the monomer vessel of the iCVD reactor and heated to 35 ° C. As an initiator, TBPO (tert-butyl peroxide, Aldrich 168521, 250 ml, 98%) was placed in the initiator bottle and kept at room temperature.

The monomer and initiator were flowed into the iCVD reactor at a flow rate ratio of 1: 1. The temperature of the filament in the reactor was maintained at 180 占 폚. The circular substrate PAN350 (polyacrylonitrile, Sepro M-PA350-SPET 5 m ² ) substrate cut to a diameter of 6 cm was fixed to the bottom without bubbles while maintaining the substrate temperature at 25 in the reactor. The pressure in the chamber was also kept constant at 200 mTorr. After 20 minutes, a PDMS substrate having a thickness of 200 nm deposited with polyglycidyl methacrylate (pGMA) was obtained.

The prepared gas separation membrane was cut into a diameter of 6 cm and then placed in a measuring device and allowed to flow for 1 minute so as to wash the membrane with N ₂ gas. Thereafter, a pressure of 5 bar was applied to the membrane. The pressure difference between both phases of the membrane becomes the driving force of gas separation. Gas permeabilities were measured five times and the average of the values was used as data. The same procedure was performed on CO ₂ gas to obtain gas permeability data.

Example 5: Preparation of PDMS substrate deposited with pHVDS

1 to 25 g of HVDS (hexavinyldisiloxane, Gelest SIH6162.0) was used as a monomer in Example 4, the monomer bottle was heated to a temperature of 40 占 폚, the temperature of the substrate was maintained at 30 占 폚 and the pressure of the chamber was maintained at 220 mTorr for 20 minutes , A PDMS substrate on which a pHVDS (polyhexavinyldisiloxane) having a thickness of 100 nm was deposited was obtained. A gas permeability test was carried out in the same manner as in Example 4.

Example 6: Preparation of PDMS substrate on which pV4D4 is deposited

The procedure of Example 2 was repeated except that the substrate was PDMS in Example 2 to prepare a 100 nm-thick pV4D4 (poly (V4D4) (2,4,6,8-Tetramethyl-2,4,6,8-tetravinylcyclotetrasiloxane) To obtain a deposited PDMS substrate. A gas permeability test was carried out in the same manner as in Example 2.

Example 7: Preparation of pV4D4 deposited PDMS substrate

The procedure of Example 6 was repeated except that the deposition time was changed to 40 minutes in Example 6 to prepare a 200 nm thick pV4D4 (poly V4D4 (2,4,6,8-Tetramethyl-2,4,6,8-tetravinylcyclotetrasiloxane ) Was deposited on the PDMS substrate. A gas permeability test was carried out in the same manner as in Example 6.

Example 8: Preparation of PDMS substrate on which pV4D4 was deposited

The procedure of Example 6 was repeated except that the deposition time was changed to 80 minutes in Example 6 to prepare a 400 nm thick pV4D4 (poly V4D4 (2,4,6,8-Tetramethyl-2,4,6,8-tetravinylcyclotetrasiloxane ) Was deposited on the PDMS substrate. A gas permeability test was carried out in the same manner as in Example 6.

Example 9: Preparation of pV4D4 deposited PDMS substrate

The procedure of Example 6 was repeated except that the deposition time was changed to 100 minutes in Example 6 to prepare a 500 nm-thick pV4D4 (poly V4D4 (2,4,6,8-Tetramethyl-2,4,6,8-tetravinylcyclotetrasiloxane ) Was deposited on the PDMS substrate. A gas permeability test was carried out in the same manner as in Example 6.

Comparative Example

The gas permeability test was carried out on the PDMS substrate prepared in Example 4 without performing the deposition process.

The selectivity and the permeability of the polymer-deposited substrate prepared in Examples 1 to 9 and the gas separation membrane of the comparative example are shown in Table 1, Fig. 1 and Fig. 3.

Selectivity and permeability of gas separation membrane The substrate (the thickness of the polymer) CO ₂ permeability
(barrer) CO ₂ / N ₂ selectivity Example 1 PAN350 + pV3D3 (400 nm) 63.289 20.193 Example 2 PAN350 + pV4D4 (510 nm) 94.740 18.330 Example 3 PAN350 + pV4D4 (1.1 占 퐉) 30.503 18.652 Comparative Example PDMS 962.447 13.523 Example 4 PDMS + pGMA (200 nm) 2060.350 10.819 Example 5 PDMS + pHVDS (100 nm) 2117.871 18.871 Example 6 PDMS + pV4D4 (100 nm) 1837.197 13.839 Example 7 PDMS + pV4D4 (200 nm) 3786.862 10.465 Example 8 PDMS + pV4D4 (400 nm) 3825.473 14.341 Example 9 PDMS + pV4D4 (500 nm) 2718.043 13.295

As a result, it was confirmed that the CO ₂ permeability and the CO ₂ / N ₂ selectivity of the gas separation membrane coated with the polymer were much higher than that of the PDMS substrate alone (Comparative Example).

As shown in FIG. 1, the PAN substrate gas separation membrane on which the polymer was deposited exhibited CO ₂ / N ₂ selectivity of about 18 to 20, and CO ₂ permeability of about 30 to 90 barrer. Also, as shown in FIG. 3, the PDMS substrate gas separation membrane on which the polymer was deposited exhibited CO ₂ / N ₂ selectivity of about 10 to 19, and CO ₂ permeability of about 900 to 3800 barrer.

While the present invention has been particularly shown and described with reference to specific embodiments thereof, those skilled in the art will appreciate that such specific embodiments are merely preferred embodiments and that the scope of the present invention is not limited thereto will be. Accordingly, the actual scope of the present invention will be defined by the appended claims and their equivalents.

Claims (11)

A method for preparing a gas separation membrane using a chemical vapor deposition reactor (iCVD) using an initiator comprising the steps of:
(a) injecting a monomer and an initiator into an iCVD reactor;
(b) fixing the porous substrate to the bottom of the reactor; And
(c) depositing a polymer on the porous substrate.
The method according to claim 1, wherein the gas separation is performed at a temperature of 25 to 45 ° C and a pressure of 150 to 350 mTorr for 10 minutes to 12 hours.
The method of claim 1, wherein the porous substrate is selected from the group consisting of polyacrylonitrile, polydimethylsiloxane, polyethersulfone (PES), polysulfone (PSF), and polyvinylidene fluoride vinylidene fluoride, vinylidenedifluoride, PVDF).
The method for producing a gas separation membrane according to claim 1, wherein the monomer is a compound containing a vinyl group.
The method of claim 4, wherein the vinyl group-containing compound is 2,4,6,8-tetramethyl-2,4,6,8-tetravinylcyclotetrasiloxane, 1,3,5-trimethyl 1,3,5-trivinylcyclotrisiloxane, hexavinyldisiloxane, glycidyl methacrylate, divinylbenzene, diethylene glycol divinyl ether, diethylene glycol diacrylate, ethylene glycol dimethacrylate, and 1,3-diethenyl-1,1,3,3-tetramethyl-disiloxane. ≪ / RTI >
The method according to claim 1, wherein the flow ratio of the monomer to the initiator in the step (a) is 1: 1 to 4: 1.
The method according to claim 1, further comprising the step of adding monomers to the monomer vessel of the iCVD reactor before the step (a), heating the mixture to 30 to 45 ° C, and holding the initiator in the initiator vessel of the iCVD reactor at room temperature ≪ / RTI >
The method for producing a gas separation membrane according to claim 1, wherein the initiator is tert-butyl peroxide.
The method according to claim 1, wherein the polymer has a thickness of 50 to 1200 nm.
A CO ₂ separator prepared by the method of claims 1 or 3, wherein the substrate is polyacrylonitrile, the CO ₂ permeability is from 30 to 90 barrer, and the CO ₂ / N ₂ selectivity is from 18 to 20.
A CO ₂ separator produced by the method of claims 1 or 3, wherein the substrate is polydimethylsiloxane, the CO ₂ permeability is from 900 to 3800 barrer, and the CO ₂ / N ₂ selectivity is from 10 to 19.

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