KR102096023B1 - Coating method for membrane contactor surface modification - Google Patents

Abstract

The present invention relates to a coating method for surface modification of a membrane contactor, and more particularly, to a coating method capable of reducing the wetting and flatness of the CO ₂ absorbing solution through the implementation of superhydrophobicity on the surface of the membrane contactor. Provided is a method for coating a surface of a membrane contactor capable of forming a high-density film and coating a surface of the film contactor to form a film having excellent water-repellent, anti-fouling, and durable effects.

Description

Coating method for membrane contactor surface modification

The present invention relates to a coating method for surface modification of a membrane contactor, and more particularly, to a coating method capable of reducing the wetting and flatness of the CO ₂ absorbing solution through the implementation of superhydrophobicity on the surface of the membrane contactor.

Liquid-gas contactors are used to transport one or more water-soluble materials from one phase to another. Conventional contactors include packed towers, single towers, wet wall towers, and the like, and in these systems, gas absorption of one or more components from the gas stream is achieved by dispersing the gas in the packed column and the single column during countercurrent to the liquid stream. The absorption efficiency is controlled by the effective surface area of the gas flow bubbles and the solubility by the relative proportions of the flow. In wetwall contactors, the gas stream flows in contact with the surface of the liquid flowing along the inner wall of the vertical tube.

Conventional contactors have several deficiencies, the main of which is the fact that individual gas and liquid flows cannot be varied independently over a wide range. The tower has problems such as whipping at low gas flow and overflow at high liquid flow. Filling towers can overflow at high flow rates, and the use of low liquid flow rates not only has channeling and reduced effective surface area, but excessive bubble or foam formation leads to inefficient processes. Wet wall contactors can also overflow at high gas flow rates. To overcome these deficiencies. Membrane contactors have been actively developed.

The membrane contactor is a device that is separated by a membrane having permeability to the gas being transported. When a microporous membrane is used, it is transported depending on the non-wetting properties of the membrane material and the pore size to prevent liquid from entering and filling the pores. The specific components in the gas to be separated are separated. On the other hand, if a non-porous membrane is used, the movement of the gas is controlled by the diffusion rate in the non-porous layer of the membrane.

The porous membrane can be used in various forms, such as a flat plate, spiral-wound module, tubular type module, hollow fiber module, and the like. Among them, the hollow fiber porous membrane is a tubular filament including an outer diameter, an inner diameter, and a porous wall thickness between them, and the inner diameter defines a hollow portion of the fiber.

For limited tube contact, the liquid phase flows through the hollow portion, often referred to as the lumen, and remains independent from the gas phase surrounding the fiber. In cell face contact, the liquid phase surrounds the outer diameter and surface of the fiber, and the gas phase flows through the lumen.

The separation membrane used in the membrane contactor is subjected to chemical and thermal shock to the separation membrane during a long period of operation, whereby the absorbent liquid penetrates the separation membrane. When the separator is in continuous contact with the absorbent, the porosity of the separator, the shape of the pores, and the structure and properties of the surface are changed by chemical action. In addition, when the separation membrane is heated by an absorption process in which an exothermic reaction occurs, and operation is performed near the glass transition temperature or melting temperature, decomposition of the polymer, which is the material of the separation membrane, is caused, and the performance of the separation membrane is rapidly reduced. Therefore, in order for the separator of the membrane contactor to stably maintain its performance for a long period of time, it is required that the separator has chemical and thermal stability.

In addition, during the membrane contactor process, when the pores of the separation membrane are wetted by the absorbent liquid, the mass transfer resistance is greatly increased, and the performance of the membrane contactor decreases rapidly. It is important to allow the pores to remain non-wetting during operation.

The wetting properties of the separator pores are determined by the properties of the separator and absorbent. If the surface tension is low, the absorbent wets the pores of the separator relatively easily. Therefore, in order to maintain the pores of the separator in a non-wet state, increasing the surface tension of the absorbent to the surface of the separator, that is, increasing the water repellency of the separator, can increase the long-term performance stability of the membrane contactor.

Conventional prior art WO 9853894 discloses contacting one side of a microporous substrate with a dilute coating solution of an amorphous copolymer of a polymer, preferably hydrophobic and oleophobic perfluoro-2,2-dimethyl-1,3-dioxole. The process of forming a compact, high flow, fouling resistant gas filter by a continuous ultrathin layer of porous gas permeable polymer on the surface of the filter paper is disclosed.

As a conventional prior art, Korean Patent Registration No. 10-1122569 (2012.03.16.) Relates to a gas separation membrane and a coating treatment method for increasing the separation ability of the gas separation membrane, in a gas separation membrane having a coating layer on the membrane surface, the membrane Characterized by a gas separation membrane comprising a coating layer formed on a surface of a two-liquid silicone elastomer and a one-liquid silicone for room temperature curing mixed with a 1: 1 weight ratio or volume ratio.

Although the prior arts have modified the surface including the process of coating the surface of the separator, the separation performance of the gas is improved by the surface modification, but since the water-repellent property of the membrane surface is not modified, the performance is still stable for a long time in the membrane contactor. There is a problem that cannot be shown.

WO 98/53894 (1998.05.12.) Korean Registered Patent No. 10-1123271 (2012.03.20.)

The present invention is to solve the above problems, to form a high-density film, and by coating the surface of the film contactor to provide a method for coating the surface of the film contactor to form a film having excellent water-repellent, anti-fouling, and durable effects will be.

The present invention is a method of coating the surface of the membrane contactor membrane, the first step of coating an alkylsilane silicone polymer coating solution containing 20 to 80 parts by weight of an alkylsilane silicone polymer on 100 parts by weight of a solvent; Membrane characterized in that it comprises a; second coating the surface of the first nano-coated membrane with a silica nanoparticle coating solution containing 0.5 to 10 parts by weight of silica nanoparticles whose surface is modified with alkylsilane in 100 parts by weight of solvent; Provided is a method of coating a surface modification of a contactor membrane.

In the present invention, in the first coating step and the second coating step, the solvent is acetone, butanone, methyl isobutanone, cyclohexanone, benzene, toluene, xylene, methyl acetate, ethyl acetate, butyl Acetyl, diethyl ether, tetrachloromethane, petroleum ether, tetrahydrofuran, diisopropylamine, triethylamine, pentane, chloroform, ether, hexane, heptane, dimethoxyethane, butyl alcohol, propyl alcohol It provides a method for coating a surface modification of a membrane contactor membrane, characterized in that at least one selected from.

In the present invention, the alkylsilane of the solution containing the alkylsilane silicone polymer is characterized in that at least one is selected from the group consisting of one alkyl group and three alkoxy groups, or two alkyl groups and two alkoxy groups. Provides a method for coating a surface modification of a membrane contactor membrane.

In the present invention, the alkylsilane of the silica nanoparticles whose surface is modified with the alkylsilane is selected from one or more groups of one alkyl group and three alkoxy groups, or two alkyl groups and two alkoxy groups. It provides a method of coating the surface modification of the membrane contactor membrane characterized in.

In the membrane contactor membrane having a surface-modified surface of the present invention, an alkylsilane silicone polymer coating solution containing 20 to 80 parts by weight of an alkylsilane silicone polymer in 100 parts by weight of a solvent is coated on the surface of the membrane; Provides a membrane-contacted membrane contactor membrane comprising a secondary coating film coated on top of the primary coating film with a silica nanoparticle coating solution containing 0.5 to 10 parts by weight of silica nanoparticles whose surface is modified with alkylsilane in 100 parts by weight of solvent do.

The surface modification coating method of the membrane contactor membrane according to the present invention can more easily coat the membrane contactor membrane, and has an effect of realizing oxidation resistance and super water repellency by forming a high-density coating layer.

In addition, the membrane contactor surface modification coating composition according to the present invention has an economical effect by increasing the replacement cycle of the membrane of the membrane contactor as the hydrophobicity lasts longer.

Hereinafter, with reference to the accompanying drawings will be described in detail with respect to the method for coating the surface modification of the membrane contactor membrane according to the present invention so that those skilled in the art to easily carry out the present invention.

In the detailed description of the principles of the preferred embodiment of the present invention, when it is determined that detailed descriptions of related known functions or configurations may unnecessarily obscure the subject matter of the present invention, detailed descriptions thereof will be omitted.

In addition, the configurations shown in the embodiments and drawings described in this specification are only the most preferred embodiments of the present invention, and do not represent all of the technical spirit of the present invention. It should be understood that there may be equivalents and variations.

The present invention is a method of coating the surface of the membrane contactor membrane, the first step of coating an alkylsilane silicone polymer coating solution containing 20 to 80 parts by weight of an alkylsilane silicone polymer on 100 parts by weight of a solvent; Coating the silica nanoparticle coating solution containing 0.5 to 10 parts by weight of the silica nanoparticles whose surface is modified with alkylsilane by 100 parts by weight of the solvent on the surface of the first coated membrane; It relates to a method for coating a surface modification of a membrane contactor membrane, characterized in that it comprises a.

The present invention comprises the steps of first coating the alkylsilane silicone polymer coating solution, and secondly coating the surface-modified silica nanoparticle coating solution with an alkylsilane. In addition, the present invention may further include curing the coated membrane.

First, the surface of the membrane contactor membrane is coated with an alkylsilane silicone polymer coating solution. The alkylsilane silicone polymer coating solution is prepared by mixing 20 to 80 parts by weight of an alkylsilane silicone polymer with 100 parts by weight of a solvent to prepare an alkylsilane silicone polymer coating solution.

The alkylsilane silicone polymer is prepared by synthesizing an alkylsilane silicone polymer by utilizing an alkylsilane. The alkylsilane may be selected from one or more of the group consisting of one alkyl group and three alkoxy groups, or two alkyl groups and two alkoxy groups, for example, methyl trimethoxysilane and ethyl trimethoxy. These include silane, propyltrimethoxysilane and dimethyldiethoxysilane.

The solvent of the alkylsilane silicone polymer coating solution is acetone, butanone, methyl isobutanone, cyclohexanone, benzene, toluene, xylene, methyl acetate, ethyl acetate, butyl acetate, diethyl ether, tetrachloromethane, petroleum ether , Tetrahydrofuran, diisopropylamine, triethylamine, pentane, chloroform, ether, hexane, heptane, dimethoxyethane, butyl alcohol, propyl alcohol, one or more selected from the group consisting of, toluene, hexane And it is more preferable to use xylene.

The alkylsilane silicone polymer coating solution may be prepared by containing 20 to 80 parts by weight of an alkylsilane silicone polymer in 100 parts by weight of a solvent, and more preferably, an alkylsilane silicone polymer containing 40 to 80 parts by weight in 100 parts by weight of a solvent. It is preferred. When the content of the alkylsilane silicone polymer is less than 20 parts by weight, it is difficult to uniformly coat the entire area, and when it exceeds 80 parts by weight, it is difficult to implement super water repellency.

In the present invention, the coating solution of silica nanoparticles whose surface is modified with alkylsilane is prepared by including 0.5 to 10 parts by weight of silica nanoparticles surface-modified with alkylsilane in 100 parts by weight of the solvent. More preferably, it is preferable to include 1 to 5 parts by weight of silica nanoparticles surface-modified with an alkylsilane in 100 parts by weight of the solvent. This disperses the silica nanoparticles surface-modified with an alkylsilane in a solvent. When the content of the silica nanoparticles surface-modified with an alkylsilane is less than 0.5 part by weight, the effect of water repellency is negligible, and when it exceeds 10 parts by weight It is preferable to use the above range because the viscosity of the coating solution containing silica nanoparticles surface-modified with an alkylsilane increases, and some aggregation and sedimentation occurs, resulting in problems in which coating is not easy.

In addition, the alkylsilane of the silica nanoparticles whose surface has been modified with an alkylsilane may be selected from one or more of the group consisting of one alkyl group and three alkoxy groups, or two alkyl groups and two alkoxy groups. Examples include methyltrimethoxysilane, ethyltrimethoxysilane, propyltrimethoxysilane and dimethyldiethoxysilane.

The solvent is acetone, butanone, methyl isobutanone, cyclohexanone, benzene, toluene, xylene, methyl acetate, ethyl acetate, butyl acetate, diethyl ether, tetrachloromethane, petroleum ether, tetrahydrofuran, diiso One or more may be selected from the group consisting of propylamine, triethylamine, pentane, chloroform, ether, hexane, heptane, dimethoxyethane, butyl alcohol, and propyl alcohol, and using toluene, hexane and xylene It is more preferable.

The surface of the membrane of the membrane contactor is coated by using the alkylsilane silicone polymer coating solution prepared as described above and the silica nanoparticle coating solution whose surface is modified with alkylsilane.

The coating method is primarily by coating the membrane with a membrane contactor membrane in an alkylsilane silicone polymer coating solution. First, after coating the surface of the membrane contactor membrane, the surface of the membrane is coated with the alkylsilane in the present invention in a silica nanoparticle coating solution whose surface is modified.

After the primary coating, the membrane contactor membrane is coated with an alkylsilane and the secondary coating is performed with a silica nanoparticle coating solution, so that the primary coated alkylsilane silicone polymer and the surface modified silica nanoparticles are commercially available. It is possible to realize effective super water repellency by forming the chemical properties and surface structure of the surface by utilizing the properties.

The membrane contactor membrane having the primary and secondary coatings may be thermally cured in a temperature range of 50 to 150 ° C. The heat curing time may be performed for 30 minutes to 30 hours, which may be performed by changing the heat curing time according to the characteristics of the membrane of the membrane contactor and the type and composition of the silicone polymer.

Hereinafter, details of the process of the present invention will be described through examples.

This is a representative example related to the present invention, and it is revealed that this alone can never limit the scope of application of the present invention.

<Example>

Preparation of alkylsilane silicone polymer coating solution

1. After adding Dimethoxydimethylsilane 0.05 mol, Methyltromethoxy silane 0.05 mol, H ₂ O 10 mol, HCl 0.003 mol to 30 ml of Tetrahydrofuran solvent, react for 24 hours at a temperature of 60 ℃. After the reaction, HCl contained in the solution is removed to obtain the resulting silicone polymer, and then dried at a temperature of 25 ° C. for 12 hours to obtain an alkylsilane silicone polymer.

2. The synthesized alkylsilane silicone polymer is mixed with a solvent such as hexane, toluene, or xylene, and 20 to 100 wt% (2O wt%, 4O wt%, 6O wt%, 8O wt%, 100 wt%) of alkylsilane silicone polymer Prepare a coating solution.

Preparation of silica nanoparticle coating solution whose surface is modified with alkylsilane

1. After adding 5wt% Dimethoxydimethylsilane to Silica particles, stirring for 24 hours at pH 2-3, and centrifuging to prepare silica nanoparticles whose surface is modified with alkylsilane.

2. Mixing 5 parts by weight of silica nanoparticles whose surface has been modified with alkylsilane by 100 parts by weight of hexane, toluene, and xylene as solvents, thereby preparing a silica nanoparticle coating solution with surface modification with alkylsilane.

Membrane contactor coating method for surface modification of membrane

Polypropylene (PP), a membrane contactor membrane of 5 x 2 cm, is supported on 50 ml of an alkylsilane silicone polymer coating solution, and the primary coating is performed with a pulling speed of 0.03 to 50 cm / sec. The primary coated polypropylene (PP) is supported on a silica nanoparticle coating solution surface-modified with an alkylsilane to perform a secondary coating at a rate of 10 to 50 cm / sec.

The second coated polypropylene (PP) is cured at a temperature of 100 ° C. for about 1 hour to prepare a surface-modified membrane contactor membrane.

<How to measure contact angle>

The contact angle is 1.5 μL of distilled water dropped on the surfaces of the primary and secondary coated surface-modified membrane contactor membranes, and then images are taken with a CCD camera. The contact angle between the surface of the membrane and the water droplet of the membrane is measured through image analysis obtained through a CCD camera.

Table 1 to Table 4 are the contact angle test results of the membrane contactor membrane surface-modified polypropylene (PP) according to the embodiment.

Looking at the results of coating using the primary coating solvent of Table 1, it was confirmed to have water repellency as having a result value of 100 or more. Looking in more detail, most of the contact angle is 100 ° to 127 °, it was confirmed to have an average contact angle of 118 °. The above results show that the contact angle of the general polypropylene (PP) before coating is somewhat increased compared to that of 97 ° to 103 ° to realize excellent water repellency, but this is somewhat insufficient to realize super water repellency.

In Table 2, the primary coating solvent is hexane, and the contact angle is measured using toluene, hexane and xylene as the solvent of silica nanoparticles whose surface is modified with alkylsilane.

In addition, Table 3 used toluene as a solvent for the primary coating, and Table 4 used toluene, hexane, and a solvent of silica nanoparticles whose surface was modified with an alkylsilane after using xylene as a solvent for the primary coating. The contact angle was measured using xylene.

Looking at the results of Tables 2 to 4, looking at the results of Table 2 when hexane was used as a solvent for the primary coating, the contact angle was found to be 109 ° to 169 ° and 142.6 ° on average.

Looking at the results of Table 3, in which the solvent used for the primary coating was toluene, the contact angle was found to be 112 ° to 170 °, and on average, it was confirmed to have excellent super water repellency as it was confirmed to have a contact angle of 158.3 °.

In addition, according to the results of Table 4, which is xylene as a solvent for the primary coating, the contact angle is 128 ° to 169 °, and as a result, it is confirmed that the average has a contact angle of 161.2 °. It can be seen that the best water repellency is realized.

As described above, the present invention has been described with reference to examples, but this is only exemplary, and those skilled in the art to which the art belongs will understand that various modifications and other equivalent examples are possible therefrom. . Therefore, it can be said that the technical protection scope of the present invention is defined by the appended claims and their equivalents.

Claims (5)

As a method of coating the surface of the membrane contactor membrane,
First coating an alkylsilane silicone polymer coating solution containing 20 to 80 parts by weight of an alkylsilane silicone polymer on 100 parts by weight of a solvent on the surface of the membrane;
Coating the silica nanoparticle coating solution containing 0.5 to 10 parts by weight of the silica nanoparticles whose surface is modified with alkylsilane by 100 parts by weight of the solvent on the surface of the first coated membrane; Including,
In the first coating step and the second coating step, the solvent is one or more selected from the group consisting of toluene, hexane, and xylene, the surface modification coating method of the membrane contactor membrane. delete According to claim 1,
The alkylsilane of the solution containing the alkylsilane silicone polymer is selected from the group consisting of one alkyl group and three alkoxy groups, or two alkyl groups and two alkoxy groups. Surface modification coating method. According to claim 1,
The alkylsilane of the silica nanoparticles whose surface is modified with the alkylsilane is a membrane contactor, characterized in that at least one is selected from the group consisting of one alkyl group and three alkoxy groups, or two alkyl groups and two alkoxy groups. Method for coating surface modification of membrane. In the surface-modified membrane contactor membrane,
A primary coating film coated with an alkylsilane silicone polymer coating solution containing 20 to 80 parts by weight of an alkylsilane silicone polymer on 100 parts by weight of a solvent;
A silica nanoparticle coating solution containing 0.5 to 10 parts by weight of silica nanoparticles whose surface is modified with an alkylsilane in 100 parts by weight of a solvent includes a secondary coating film coated on top of the primary coating film,
The solvent is toluene, hexane, xylene is one or more surface-modified membrane contactor membrane selected from the group consisting of xylene.