KR101321803B1 - Multi-channel microreactor, method of producing the same, and photosensitized oxygenation using the same - Google Patents

Abstract

A microreactor, a preparation method thereof, and a photooxidation reaction method using the same are disclosed. The present invention is a microreactor comprising an upper channel, a lower channel, and a gas permeable membrane bonded to them, and includes a coating layer coated with a chemical-resistant material on the inner upper surface of the upper channel. In addition, in the photooxidation reaction method using the microreactor of the present invention, at least one liquid solution is added to the upper channel, oxygen gas is introduced into the lower channel, and then irradiated with a light source to chemically react inside the upper channel. Characterized in obtaining.

Description

Multi-channel microreactor, method of producing the same, and photosensitized oxygenation using the same

The present invention relates to a dual channel microreactor, and more particularly, to a microreactor coated with a chemical resistant material on an inner wall of a parallel dual channel separated by a gas permeable membrane, and using the same to perform a photooxidation reaction of a product. The present invention relates to a dual channel microreactor capable of maximizing yield, a method for preparing the same, and a method for photooxidation using the same.

Micro reactors are commonly referred to in microchemical engineering as reactors consisting of channels of several hundred microns or less in width and width, allowing the fluids to mix as they pass through the microchannels, and the reactors capable of discharging the mixed fluids. Say. Microreactor fabrication techniques range from electronic engineering to micro-etching techniques to the latest ultra-precision processing technologies. This variety of choices allowed the fabrication of various shapes such as three-dimensional structures. Materials used in the conventional reactors include silicon, glass, and polymer materials, including metals. In particular, silicon is mainly used in semiconductor processes using dry or wet etching.

The technique for manufacturing a microreactor is disclosed in the present applicant's Patent Publication No. 10-2011-0024992 "Micro reactor using a polymer film and a method for manufacturing the same." This patent is made up of a fluid input part into which the fluid to be mixed is introduced, a fluid mixing part into which the injected fluid is mixed, and a fluid discharge part from which the mixed fluid is discharged, and the properties of the thermoplastic polymer film used as the base film of the fluid mixing part. Therefore, it is a technique for a microreactor for chemical reaction having characteristics such as resistance to a specific fluid, heat resistance, light transmittance, and the like.

In addition, the applicant's registered patent No. 10-0837829 (2008.06.05) discloses a method for producing fine, nanofluidic devices and MEMS microstructures using inorganic polymers and hydrophilic polymers.

In addition, the article "Dual Channel Microreactor for Gas-Liquid Syntheses (Journal of the American Chemical Society, 132, 10102-10106, 2010)" published in 2010 by the present inventor discloses a dual channel microreactor for gas-liquid mixing. It is. (See Figs. 1 and 2)

According to this paper, as shown in Fig. 1, a microreactor having a dual channel separated by a gas permeable membrane is composed of an upper channel and a lower channel, respectively, with a gas permeable membrane therebetween. At this time, by using a high light-transmitting polymer material (polydimethylsiloxane (PDMS), Dow corning., USA) to form a fine upper layer of 300 ㎛ width and 200 ㎛ depth, to form a fine lower channel of the same width and depth, A gas permeable membrane having a thickness of 45 μm is formed using a polymer material having good gas permeability (polydimethylsiloxane (PDMS), Dow corning., USA), and then each of the upper and lower channels is laminated with the gas permeable membrane interposed therebetween and over 200 g. The metal weight was put up and left to allow the microfilm to be bonded to each channel at a temperature of 70 ° C. for 3 hours, and then cooled.

FIG. 2 schematically illustrates an oxidative heck reaction, which is a mixture of gas and liquid, using a microreactor having a dual channel.

In addition, the photooxidation reaction is a reaction using light and oxygen gas, and is known as one of the most meaningful reactions among natural friendly reactions. In terms of organic synthesis, active single anti-oxygen has been successfully characterized in a variety of fields, such as medicine, fine chemistry, in addition to research in the singlet oxygen phase. This reaction was conventionally carried out in a conventional flask reactor, in which the reaction was accomplished by constantly supplying gaseous oxygen to the liquid reactant in the presence of light. These reactions show very low photon absorption due to volume to low abnormal contact area, resulting in long reaction times. Furthermore, there is a disadvantage in that the reaction efficiency is lowered due to the short lifetime and the long diffusion distance between the molecules in the organic solvent of the active singlet oxygen. Attempts have been made to use a single capillary microreactor to overcome this drawback. The optical clarity of the microreactor and the short distance of light provide the reactant with a sufficient amount of light, unlike the flask reactor. However, the gas and liquid double phases in a single microreactor show low reaction rates due to the lack of gas transport in the oxygenation reaction.

For this reason, the reaction often must be carried out at dilute reactant conditions or at high pressures in extreme conditions. In another way, the reaction solution was sufficiently infiltrated with oxygen and reacted to continuously supply oxygen during the reaction. However, this still shows unsatisfactory results on the side of traditional microreactors due to long reaction times and excess solvent waste to introduce oxygen gas into the liquid.

In addition, metal and glass, which are used as the main materials of current microreactors, have a disadvantage of costly and time-consuming processing as a microreactor, and are generally used materials that are inexpensive and have a simple manufacturing process. Phosphorus polydimethylsiloxane (PDMS) has a physical property that is vulnerable to organic solvents, thereby limiting various organic synthesis application reactions.

Due to these factors, the reaction in the conventional microreactor still shows a problem, and it is necessary to introduce a new microreactor that can be easily and quickly manufactured through a low-cost simple process and compensates for the disadvantages of the conventional flask reaction and the microreactor. Do.

In addition, the conventional flask reactor and the single capillary microreactor have low contact area between gas and liquid and pressure control of each droplet due to the low contact volume per volume, and have low light transmittance to provide a light source for photooxidation reaction. It could not be effectively supplied into the reactor, and as a result, the operating conditions of the microreactor are limited due to a long reaction time and waste of a solvent for a sufficient supply of oxygen gas.

SUMMARY OF THE INVENTION An object of the present invention is to provide a photooxidation reaction method in which a microchannel reactor having a double channel and a gas permeable membrane made of a material having high light transmittance and chemical resistance is used to obtain a high yield by high efficiency photooxidation reaction. To provide.

Another object of the present invention is to provide a microreactor and a method of manufacturing the same, which ensures safety against toxicity of a fluid by coating an inner wall of a parallel dual channel separated by a gas permeable membrane with a chemical resistant material.

In order to achieve the above object, the microreactor according to the present invention,

In a microreactor comprising an upper channel, a lower channel, and a gas permeable membrane bonded to and installed therebetween,

It characterized in that it comprises a coating layer coated with a chemical resistant material on the inner upper surface of the upper channel.

In a microreactor comprising an upper channel, a lower channel, and a gas permeable membrane bonded to and installed therebetween,

The upper channel or the lower channel is characterized in that made of glass or quartz excellent in light transmittance.

The chemical resistant material is polyvinylsilazane (PVSZ), polycarbosilane (PCS), and polyethylene glycol (PEG), tetraethyl orthosilicate (TEOS) It is characterized in that any one material selected from transparent fluoropolymer.

Method for producing a microreactor according to the present invention,

Forming an upper channel and a lower channel from a polymer material, glass or quartz; Forming a gas permeable membrane from a polymer material or a porous material; Preparing a mixture of a photoinitiator and a thermal initiator with chemical resistance; Oxygen plasma treatment on the upper channel surface; Spin coating the prepared chemical resistant mixture on the upper channel; Wiping the portion other than the channel with the flat glass using the flat upper channel; Curing the upper channel; And placing and bonding a gas permeable membrane between the upper and lower channels, which are completely cured.

The polymer material is polydimethylsiloxane (PDMS), and the chemical resistant material is polyvinyl silazane (PVSZ).

In the spin coating step, the thickness of the coating is adjusted by changing the rpm of the spin coater.

The curing step is characterized in that it comprises a step of performing a thermal curing at a temperature of 120 to 180 degrees immediately after curing using an ultraviolet curing machine.

The bonding step is characterized in that it comprises a step of cooling after leaving for 4 to 12 hours in an oven of 110 to 150 degrees.

Photooxidation reaction method using a microreactor according to the present invention,

A photooxidation reaction method using the microreactor according to any one of claims 1 to 3, wherein at least one liquid solution is introduced into the upper channel, oxygen gas is introduced into the lower channel, and the upper layer is irradiated with light. It is characterized by obtaining a product by chemical reaction inside the channel.

The oxygen gas is introduced into the lower channel and is supplied to the upper channel through the gas permeable membrane.

Light is introduced into the upper layer, characterized in that to generate a chemical reaction with the liquid solution and oxygen in the upper channel.

Microreactors having a dual channel separated by a gas permeable membrane made of the present invention and composed of chemically resistant materials have a feature of having a large contact area of gas and liquid per unit area due to the gas permeable membrane, and a series of reactions are continuously performed. In addition, the present invention can be expected to be applied to a microreactor to be used for photocatalytic reactions such as recycling and photooxidation of various catalysts and mixed reactions of highly toxic and explosive gases with various organic solvents. .

According to the microreactor according to the present invention, there is an advantage in that a variety of gases having explosiveness and toxicity can be used stably.

A microreactor having a dual channel separated by a gas permeable membrane prepared by the present invention and composed of a chemically resistant material has a higher contact area of gas and liquid per unit area than a conventional single channel by separating two channels with a gas permeable membrane. Therefore, there is an advantage that can obtain a high yield reaction product.

1 is a cross-sectional view showing a conventional microreactor.
Figure 2 shows a schematic diagram of the oxidative Heck reaction (oxidative Heck reaction) which is a mixture reaction of gas and liquid using a conventional microreactor.
Figure 3 is a schematic diagram showing the photooxidation reaction in a dual channel microreactor separated by a gas permeable membrane and coated with a chemical resistant material according to the present invention.
4 is a cross-sectional view of the microreactor of FIG. 3.
5 is a view schematically showing a photooxidation reaction using a microreactor according to the present invention.
6 is a schematic view showing a photooxidation reaction according to the present invention.
7 is an optical image showing a microreactor having a dual channel structure according to the present invention.
FIG. 8 is a graph showing the performance of PDMS, glass and PVSZ coated PDMS chips in the transmission of light within the ultraviolet-visible range.

Hereinafter, with reference to the accompanying drawings will be described in detail with respect to a microreactor according to various embodiments of the present invention, a manufacturing method and a photooxidation reaction method using the same.

The microreactor according to the present invention is composed of a dual channel separated by a gas permeable membrane, and the dual channel is coated with a chemical resistant material.

The gas permeable membrane of the microreactor may be prepared by spin coating a polymer material having gas permeability on a flat plastic material or include a conventional commercially available porous thin film, and has a gas permeability polydimethylsiloxane (polydimethylsiloxane). (PDMS)), a ceramic permeable membrane consisting of fluorine polymer, gore sheet and aluminia, zirconia, titania, and silicon carbide (SiC), or cathodic oxidation This includes materials consisting of metals such as aluminum (anodic aluminum oxide (AAO)).

The joining process of the dual microchannels and the gas permeable membrane includes a process of integrally joining two channels based on the gas permeable membrane or bonding them by physical force by heating and pressing to a temperature below the melting point of the polymer material.

In addition, the dual microchannels form a fluid inlet through which the fluid is introduced, a microchannel unit through which the introduced fluid flows, or a fluid outlet through which the introduced fluid is discharged, and includes glass, polydimethylsiloxane (PDMS), and light. It is made of a material with good permeability.

The microchannels can be prepared by adjusting the depth and width of the microchannels according to the purpose of use with a thickness of several hundred microns from several microns and a width of several millimeters from several microns.

In addition, the photooxidation reaction using a micro-reactor having a dual channel separated by the gas permeation membrane dramatically reduces the reaction yield due to the low gas and liquid contact area and the low photon supply in the conventional flask reactor. It can be raised.

Chemical resistant material coated on the microchannel of the microreactor according to the present invention is a material having excellent chemical resistance and light transmittance, polyvinylsilazane (PVSZ), polycarbosilane (PCS), and polyethylene It is preferable that the substance is any one selected from a polyethylene glycol (PEG), tetraethyl orthosilicate (TEOS), and a transparent fluoropolymer. However, the chemical resistant material is not limited thereto and can be selectively used from various organic and inorganic composite materials.

A microreactor having a dual channel separated by a gas permeable membrane prepared by the present invention and composed of a chemically resistant material has a higher contact area of gas and liquid per unit area than a conventional single channel by separating two channels with a gas permeable membrane. Therefore, there is an advantage to obtain a high yield of the reaction result, in particular the chemical resistance is used has the advantage that can be used stably in toxic or organic chemical reactions.

In particular, the photooxidation reaction can be expected not only to continuously perform a series of reactions, but also to the recycling reaction to enable the application of various microreactors.

As shown in Figures 3 and 4, the microreactor according to the present invention is composed of an upper channel (1), a lower channel (2), and a gas permeable membrane (3) bonded and installed therebetween, the upper layer A coating layer 5 coated with a chemical resistant material may be introduced into the inner upper surface of the channel 1.

The chemical resistant material 5 as described above may be coated on the lower channel 2 according to the application.

Looking at the cross-sectional picture of the microreactor of Figure 4, the coating layer 5 coated on the upper channel 1 is preferably in the range of 5 to 15㎛ at the top and 20 to 150㎛ at the corner.

In the present invention, polyvinylsilazane (PVSZ) having excellent chemical resistance is mainly used for coating in the microchannel of the microreactor, but as mentioned above, various chemical resistant materials have a dual channel structure. It can be utilized in reactor manufacturing.

Referring to Figure 5, looking at the manufacturing method of the microreactor for photo-oxidation reaction according to the present invention.

1. Form the upper and lower channels.

Using a high light-transmitting polymer material (polydimethylsiloxane (PDMS), Dow corning., USA), glass or quartz to form a fine upper layer 300 μm wide and 200 μm deep, and to form a lower fine channel of the same width and depth do.

2. Form a gas permeable membrane.

A gas permeable membrane having a thickness of 45 μm is formed using a polymer material having good gas permeability (polydimethylsiloxane (PDMS), Dow corning, USA) or a porous material.

3. A photoinitiator and a thermal initiator are prepared by mixing polyvinylsilazane (PVSZ (KiON-VL20)), claiant, USA, which is a chemical resistant material. This is to allow the chemical resistant material to be easily cured by light or heat.

4. Oxygen plasma treatment is applied to the upper channel surface.

5. Coat the prepared polyvinylsilazane mixture on the upper channel.

The polyvinylsilazane mixture is spin coated using a spin coater at 1000 to 2000 rpm for 40 to 60 seconds. At this time, the thickness of the coating can be adjusted to a thickness of 10 to 40㎛ by changing the rpm of the spin coater.

6. Wipe the non-channel areas with flat glass on the top layer channels that have been coated.

7. Cure the upper channel.

After curing for 30 minutes using an ultraviolet curing machine (λ = 250-400nm), the thermal curing is performed at a temperature of 120 to 180 degrees immediately. At this time, after curing for 3 hours at 120 to 180 degrees gradually lower the temperature to cool the temperature of the channel.

8. A gas permeable membrane is placed between the upper and lower channels which are cured and bonded.

After placing the upper channel, the gas permeable membrane and the lower channel in place, put a metal weight of 200g or more and leave each channel and the gas permeable membrane bonded for 3 hours at a temperature of 70 ℃, then complete the bonding process In order to produce it for 4 to 12 hours in an oven at 110 to 150 degrees, it is cooled and manufactured.

Since the microreactor manufactured by the above method is coated with chemically resistant polyvinylsilazane (PVSZ), diffusion through the wall is hardly achieved or diffusion for a long time than in the channel of the uncoated microreactor. Can be prevented.

Hereinafter, the present invention will be described in more detail with reference to various embodiments. At this time, the following embodiments are for the purpose of explanation, the present invention is not limited thereto.

Example 1

Using a high light-transmitting polymer material (polydimethylsiloxane (PDMS), Dow corning, USA) to form a fine upper layer of 300 ㎛ width and 200 ㎛ depth, and to form a lower micro channel of the same width and depth. A 45 μm thick gas permeable membrane is formed using a polymer material having good gas permeability (polydimethylsiloxane (PDMS), Dow corning., USA). After oxygen plasma treatment on the prepared upper channel surface, polyvinylsilazane (PVSZ (KiON-VL20)), claiant, USA), in which a photoinitiator and a thermal initiator were mixed in advance, was used for 60 seconds at 2000 rpm using a spin coater. Spin coating. The coated channel is wiped with the prepared flat glass, and the part other than the channel is wiped and cured by using an ultraviolet curing machine (250-400 nm) for 30 minutes, followed by thermal curing at a temperature of 180 degrees. At this time, after curing for 3 hours at 180 degrees gradually cools the temperature of the channel by gradually decreasing the temperature. After placing the gas permeable membrane between the upper and lower channels where the hardening is completed, put a metal weight of 200g or more and leave each channel and the gas permeable membrane bonded for 3 hours at a temperature of 70 ° C. After cooling for 4 hours in an oven at 150 degrees it was produced by cooling.

[Example 2]

The photooxidation reaction was carried out using a microreactor having a dual channel coated with a chemical resistant material prepared by the method of Example 1. 3.5 mmol (-)-citrinellol solution is placed in a glass bottle containing 3 ml of acetonitrile, mixed using a stirrer and placed in a glass syringe to provide fluid at the top of the dual channel. Put it in the slot. In the same way, 0.035 mmol of methylene blue solution is placed in a glass bottle containing 7 ml of acetonitrile, and then put in a glass syringe into the second fluid inlet at the top of the dual channel. Oxygen gas was placed in a plastic syringe into the lower fluid inlet of the dual channel. After irradiating the 16W LED light source on the microreactor, the reaction was stored in a brown glass bottle. The stored reaction was purified by NaBH 4 in methanol and analyzed by 1H NMR. (See Fig. 6)

The reaction formula for the photooxidation reaction in Example 2 is as follows.

[Reaction Scheme 1]

Table 1 shows the results showing the yield of the product in Example 2.

As shown in Table 1 above, the product yield in the dual channel is significantly higher than in one channel. This is possible by having a channel structure excellent in light transmittance while being coated with a chemical resistant material.

In particular, the yield of Entry 1 is about 10 times higher than that of Entry 2, and the yield of Entry 4 is 50 times higher than the yield of Entry 5.

FIG. 8 is a graph showing a comparison of PDMS, glass, and PVSZ coated PDMS chips (PDMS-Kion; 10 μm PVSZ thickness) for transmitting light within the ultraviolet-visible range.

As shown in FIG. 8, the PVSZ-coated chip shows excellent transmittance of 90% or more in the measurement range.

In addition, the conventional micro-reactor not coated with a chemical resistant material shown in Figure 1 has a problem that can not be used for more than one day because of the expansion problem of the channel when used in the photooxidation reaction, PVSZ-coated microreactor according to the present invention Since it is possible to prevent diffusion through PDMS, there is an advantage that the problem of expansion does not occur even if used for a long time in the photo-oxidation reaction.

That is, the photooxidation reaction according to the present invention uses a dual channel microreactor to maximize the yield of the product.

At this time, PVSZ is coated on the upper inner surface of the upper channel to overcome the expansion problem caused by the solvents supplied and reacted to the upper channel while allowing oxygen to be supplied to the lower channel to be sufficiently supplied to the upper channel. It is a main feature to do. In this case, the light transmittance in the upper layer channel coated with PVSZ should be excellent, but in the present invention, there is an advantage that it can be overcome.

As a result, the photooxidation reaction using the microreactor according to the present invention is greatly reduced than the reaction time performed in a general batch reactor, for example, the reaction takes place if it takes several hours.

1: upper channel 2: lower channel
3: gas permeable membrane 5: coating layer

Claims (11)

delete delete delete Forming an upper channel and a lower channel from a polymer material, glass or quartz;
Forming a gas permeable membrane from a polymer material or a porous material;
Preparing a mixture of a photoinitiator and a thermal initiator with chemical resistance;
Oxygen plasma treatment on the upper channel surface;
Spin coating the prepared chemical resistant mixture on the upper channel;
Wiping the portion other than the channel with the flat glass using the flat upper channel;
Curing the upper channel; And
And placing and bonding a gas permeable membrane between the upper and lower channels, where the hardening is completed, to bond the gas permeable membrane. 5. The method of claim 4,
The polymer material is polydimethylsiloxane (PDMS), and the chemical resistant material is polyvinyl silazane (PVSZ). 5. The method of claim 4,
In the spin coating step,
The thickness of the coating is controlled by varying the rpm of the spin coater manufacturing method of the microreactor. 5. The method of claim 4,
Wherein the curing step comprises:
A method for producing a microreactor comprising thermally curing at a temperature of 120 to 180 degrees immediately after curing using an ultraviolet curing machine. 5. The method of claim 4,
In the joining step,
Method of producing a microreactor comprising the step of cooling for 4 to 12 hours in an oven of 110 to 150 degrees. Comprising an upper channel, a lower channel and a gas permeable membrane bonded to them, a coating layer coated with a chemical resistant material is provided on the inner upper surface of the upper channel, the upper channel or the lower channel is excellent in light transmission A photooxidation method using a microreactor made of glass or quartz,
A method of photooxidation using a microreactor, wherein at least one liquid solution is added to an upper channel, oxygen gas is introduced to a lower channel, and a light source is irradiated to perform a chemical reaction inside the upper channel to obtain a product. The method of claim 9,
The oxygen gas is introduced into the lower channel and supplied to the upper channel through a gas permeable membrane. 11. The method according to claim 9 or 10,
Light is injected into the upper portion of the upper channel, the photooxidation reaction method characterized in that to generate a chemical reaction with the liquid solution and oxygen in the upper channel.

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