KR101076138B1 - Super water- and oil-repellent composite beads, and method for producing the same - Google Patents

Abstract

According to an embodiment of the present invention, a step of synthesizing monodisperse polymer particles by reacting a polymerizable monomer with an acrylamide monomer having a polymerizable unsaturated bond in the presence of an initiator; A surface charge control step of reacting with 1M HCl to give a positive charge to the surface; Coating an inorganic layer on the surface of the monodisperse polymer to produce organic-inorganic composite particles; And it relates to a particle material having a super water-repellent and super oil-repellent surface comprising the step of reacting with the silane compound of Formula 1 to fluorine-modify the surface of the organic-inorganic composite particles.

Organic-inorganic composite particles, inorganic layer, fluorine modified, super water-repellent, oil repellent.

Description

Super water- and oil-repellent composite beads, and method for producing the same

The present invention relates to multiparticulate materials having superhydrophobic and superoil repellent surfaces. More specifically, the present invention relates to a particle material having super water / oil repellency through coating fluorine or silicon fluoride with an inorganic material coated on a surface of mono-dispersed polymer particles having a micro-nano size.

Generally, water repellency refers to a property that is difficult to get wet with water, and super water-repellency / oil repellency in this field is generally defined as a contact angle of water contacting a solid surface of 150 ° or more and an oil contact angle of 100 ° or more. It is becoming.

This water repellency can be observed in the lotus leaf as a natural phenomenon, which is caused by the fact that the surface of the lotus leaf is covered with micro-sized protrusions or cilia and is coated with a wax component. Indicating water repellency is called the Lotus effect. Currently, researches for producing super water-repellent surfaces having improved water repellency using these phenomena are in progress. The technologies that impart water repellency include textile industry (water repellent fiber), civil engineering / building industry (water repellent paint), shipbuilding industry (antifouling paint), metal / machinery / automobile industry (corrosion and anti-frosting paint or coating) and paper industry (inner) Dairy processing) and the like.

Conventional water repellent technology has been to increase the contact angle of water or oil in contact with the surface of the solid by physically chemically modifying the surface of the solid, but the variables that determine the super water repellency is not only the physicochemical properties of the surface but also the geometry of the surface Is also an important factor. Therefore, in the early days, fine control of the spatial structure of the surface was required at the same time in addition to the technique of treating the surface using a material having a low surface energy.

As a technique for maximizing the water repellency by applying such a technology, a surface fine patterning technique for providing water repellency by forming micro to nano size protrusions on the surface has been studied. However, according to the surface fine patterning technique, a high water contact angle of up to 170 ° can be obtained. However, the surface fine patterning technique has a disadvantage in that its compatibility is significantly lowered in a manner that is not suitable for large area products. In addition, studies have been made to maximize the contact angle of water by fine patterning the surface through nanolithography and dry etching through oxygen plasma, but this has been difficult to apply to a large area.

The present invention aims to produce a particulate material having excellent water / oil repelling performance on both sides of water and oil, and excellent durability and water repellency and oil repellency, while solving the problems of the existing technology as described above.

Specifically, the present invention synthesizes a monodisperse polymer core by polymerizing a polymerizable monomer, and then coating an inorganic layer to prepare inorganic-coated organic-inorganic composite particles, and then fluorine-modifies the surface of the composite particle. The present invention relates to a super water / oil repellent particle having excellent water and oil repelling performance and a method of manufacturing the same.

The reason for using the inorganic composite coated polymer composite particles is that these organic-inorganic cores / shells share the physical properties of each core and shell. These composite particles have uniform porosity and surface properties.

According to an embodiment of the present invention, a step of synthesizing monodisperse polymer particles by reacting a polymerizable monomer with an acrylamide monomer having a polymerizable unsaturated bond in the presence of an initiator; A surface charge control step of reacting with 1M HCl to give a positive charge to the surface; Coating an inorganic layer on the surface of the monodisperse polymer to produce organic-inorganic composite particles; And reacting with the silane compound of Formula 1 to fluorine-modify the surface of the organic-inorganic composite particles.

[Formula 1]

R _{1 4-n} -SiX _n

Wherein n is 1-3, R ₁ is fluoroalkyl of the formula -CH ₂ CH ₂ (CF ₂ ) _m CF ₃ (m = 0-17), and X is F, Cl, Br, I Halogen, C ₁ -C ₁₀ selected from the group consisting of Be selected from the group consisting of alkoxy groups, C ₃ -C ₈ aromatic alkoxy groups and C ₂ -C ₇ heteroaromatic alkoxy groups (hetero element is at least one selected from the group consisting of O, N, S, P) Can be).

A. Monodisperse Polymer Particles

In the present invention, as the polymerizable monomer, any monomer having a crosslinkable group capable of forming a polymer of a porous organic core may be used.

Specifically, ethylene, styrene, vinyl chloride, (meth) acrylic acid, methyl (meth) acrylate, ethyl (meth) acrylate, butyl (meth) acrylate, hexyl (meth) acrylate, dodecyl (meth) acrylic Vinyl monomers such as acrylate, stearyl (meth) acrylate, benzyl (meth) acrylate, cyclohexyl (meth) acrylate, acrylonitrile, acrylamide and vinyl acetate; N-methylol (meth) acrylamide, N- [3- (dimethylamino) propyl] (meth) acrylamide, N-methylol acrylamide butylether, N-butoxy (meth) acrylamide, 2-hydroxy Acrylic monomer containing crosslinkable groups, such as (meth) acrylate and 2-hydroxypropyl (meth) acrylate; And one or more monomers selected from thermosetting monomers such as divinylbenzene.

Among the above monomers, styrene, methyl (meth) acrylate, divinylbenzene and N- [3- (dimethylamino) propyl] (meth) acrylamide are preferable, and N- [3- (dimethylamino) propyl] ( It is more preferable to copolymerize with meta) acrylamide. When copolymerized with N- [3- (dimethylamino) propyl] (meth) acrylamide, an amine group including nitrogen is present on the surface of the polymer particles, so that the control of surface charge is easily performed by hydrochloric acid treatment. have.

According to one embodiment of the invention, the monomers are neutral initiators such as 2,2'-azobisisobutyronitrile (AIBN) or 2,2'-azobis (2-methylpropionamidine) dihydrochloride ( It can be prepared into monodisperse polymer particles by surfactant-free polymerization in the presence of a cationic initiator such as AIBA). The addition of AIBA is particularly preferred because the surface of the synthesized monodisperse polymer particles is positively charged.

According to one embodiment of the present invention, when copolymerizing the acrylamide monomer having a polymerizable unsaturated bond with the polymerizable monomer, the initiator is preferably a neutral initiator.

The polymerization reaction can be carried out through a generally known polymer polymerization reaction, and emulsion polymerization and precipitation polymerization are more preferable.

According to one embodiment of the present invention, a curing agent may be added to a polymerization reaction of monodisperse polymer particles, and the curing agent is generally used which includes two or more of the same functional groups capable of reacting with a polymer such as divinylbenzene. There is no limitation as long as it is a curing agent.

The size of the monodisperse polymer particles according to the invention is preferably about 200 nm to about 5 μm.

B. Polymer composite particles coated with inorganic layer

To coat the inorganic layer on the surface of the monodisperse polymer particles, a layer-by-layer technique can be applied (see F. Caruso et al., Science 202, 1111 (1998)). According to the above method, the thickness of the silica layer coated as the inorganic layer is easily controlled. As a material for forming the inorganic layer, silica (SiO ₂ ), alumina (Al ₂ O ₃ ), aluminosilicate or titanium dioxide (TiO ₂ ) is preferable. In order to be coated as an inorganic layer on the surface of the curved polymer particles, amorphous silica is particularly preferable.

According to one embodiment of the present invention, silica coated composite particles may be prepared through a technique of reacting tetraethylorthosilicate (TEOS) after surface charge control of the polymer particles.

According to one embodiment of the present invention, the surface amine control is carried out by ammonization of the terminal amine groups of the monodisperse polymer particles obtained by copolymerization of the polymerizable monomer with the acrylamide monomer having a polymerizable unsaturated bond through the reaction with hydrochloric acid. Thereafter, the silica inorganic layer may be coated by reacting with TEOS in an acidic or basic atmosphere. The process is shown in FIG. The amount of TEOS is preferably 20 to 80% by weight relative to the total mass of monodisperse polymer particles.

The concentration of TEOS is closely related to the thickness of the silica layer coated on the surface of the monodisperse polymer particles. The higher the concentration, the greater the thickness of the coating layer.

According to one embodiment of the present invention, when AIBA is added as an initiator in the synthesis step of the monodisperse polymer particles, it is possible to impart a positive charge to the surface of the monodisperse polymer particles.

C. Surface Fluorine Modification of Organic-Inorganic Composite Particles

When the inorganic layer-coated organic-inorganic composite particles react with the fluorine compound to introduce fluorine terminal groups on the surface of the composite particles, the water and oil repellency is maximized due to the physicochemical properties of fluorine having extremely low surface energy. Indicates. As a fluorine compound, it is preferable to select from the silane compound in which hydrogen of the alkyl chain was substituted with fluorine, as shown in following General formula (1).

[Formula 1]

R _{1 4-n} -SiX _n

Wherein n is 1-3, R ₁ is fluoroalkyl of the formula -CH ₂ CH ₂ (CF ₂ ) _m CF ₃ (m = 0-17), and X is F, Cl, Br, I Halogen, C ₁ -C ₁₀ selected from the group consisting of It may be selected from the group consisting of an alkoxy group, a C ₃ -C ₈ aromatic alkoxy group and a C ₂ -C ₇ heteroaromatic alkoxy group (hetero element is at least one selected from the group consisting of O, N, S, P). have).

The fluorine compound is more preferably 3,3,3-trifluoropropyltrimethoxysilane or nonafluorohexyltrimethoxysilane.

The amount of fluorine compound added is preferably 5 to 60 mol% of TEOS added to form a silica layer.

According to the present invention, super water-repellent / super-oil repellent particles can be obtained that maintain super water repellency and oil repellency continuously and free control of surface functionality.

Hereinafter, specific examples will be presented to help clearly understand the present invention, but the present invention is not limited to the embodiments.

Example

Poly (Divinylbenzene- [N- [3- (Dimethylamino propyl) methacryamide]]) Particle Silica Coating and Modification Method

① poly ( Divinylbenzene- [N- [3- ( Dimethylamino propyl ) methacryamide ]]) Particle Synthesis (P ( DVB - co - DMAPMA ))

Add 63 g of acetonitrile to a 100 mL flask and add 1.6 g of divinylbenzene (DVB) and 0.4 g of [N- [3- (Dimethylamino propyl) methacryamide]] (DMAPMA). Thereafter, 0.1 g of initiator 2,2'-Azobis (isobutyronitrile) (AIBN) was added thereto, followed by nitrogen purge for 10 minutes. Place in 70 ℃ oil bath and react for 24 hours without stirring. The particles after the reaction were centrifuged five times for 10 minutes at 6000 rpm using tetrahydrofuran (THF) to remove impurities. The obtained particles were vacuum dried overnight at 70 ° C.

② Preparation of P (DVB- co -DMAPMA) / SiO2 Particles

In order to ionize P (DVB- co- DMAPMA) particles and disperse them in 38 g of 1M HCl for 10 minutes, the mixture was centrifuged for 5 minutes at 6000 rpm for 7 minutes to remove HCl. The particles thus prepared were dispersed in a 30 mL glass bottle by mixing 1.5 g of distilled water and 7.5 g of ethanol, and then 3 g of tetraethyl orthosilicate (TEOS, 98%) was added thereto and stirred at 150 rpm and 70 ° C. for 24 hours in a water bath. . The reaction product was centrifuged five times for 10 minutes at 6000 rpm using ethanol to remove impurities, and the obtained particles were dried overnight in a 50 ℃ vacuum oven.

③ P (DVB- co -DMAPMA) / SiO ₂ / R _f 4

In a 50 mL flask, 0.3 g of P (DVB- co- DMAPMA) / SiO ₂ particles were added to 24 g of ethanol and dispersed for 5 minutes. After adjusting the pH to 11.8 using ammonia water, 0.6g of a silane coupling agent Nonafluorohexyltriethoxysilane was added and stirred at 150 rpm for 18 hours in a water bath of 40 ° C. The reaction product was centrifuged five times for 10 minutes at 6000 rpm using ethanol to remove impurities, and the obtained particles were dried overnight in a 50 ℃ vacuum oven.

As a result of measuring the contact angle with respect to the water and the oil of the Example, it was determined that the water contact angle is up to 153 ° and the oil contact angle is up to 101 °. The results are shown in FIG.

1 is a schematic diagram showing an example of a step of synthesizing monodisperse polymer particles by copolymerizing divinylbenzene and N- [3- (dimethylamino) propyl] (meth) acrylamide under AIBN.

2 is a schematic view showing an example of surface charge control and inorganic layer coating process of monodisperse polymer particles.

3 is an electron micrograph of an inorganic layer coated monodisperse polymer particles.

4 is a schematic diagram showing an example of a step of fluorine-modifying the surface of an organic-inorganic composite particle.

5 is an electron micrograph of a surface-fluorinated organic-inorganic composite particle.

6 is an electron micrograph showing a state in which the super water-repellent / oil-repellent particles according to the present invention are applied to a solid surface.

7 shows the contact angles for water and oil in the examples.

Claims (6)

Monodisperse polymer is obtained by copolymerizing 1 to 10% by volume of a polymerizable monomer with a solvent and an acrylamide monomer having a polymerizable unsaturated bond of 10 to 20% by weight with respect to the total mass of the reactants except the solvent in the presence of a neutral initiator. Synthesizing particles; A surface charge control step of reacting with 1M HCl to give a positive charge to the surface; Coating an inorganic layer on the surface of the monodisperse polymer to produce organic-inorganic composite particles; And Reacting with 3,3,3-trifluoropropyltrimethoxysilane or nonafluorohexyltrimethoxysilane to fluorine modify the surface of the organic-inorganic composite particles, The polymerizable monomer is selected from styrene, divinylbenzene, methyl (meth) acrylate, and N- [3- (dimethylamino) propyl] (meth) acrylamide, The inorganic layer is formed of silica (SiO ₂ ), alumina (Al ₂ O ₃ ), aluminosilicate or titanium dioxide (TiO ₂ ), Wherein said polymer particles are monodisperse polymer particles having a particle size of 200 nm to 5 μm. delete The method of claim 1, The polymerizable monomer is divinyl benzene. The method of claim 1, The acrylamide monomer having a polymerizable unsaturated bond is N- [3- (dimethylamino) propyl] (meth) acrylamide. The method of claim 1, Coating the inorganic layer is carried out by reacting 20 to 80% by weight of TEOS with respect to the monodisperse polymer mass in an acidic or basic atmosphere. Particle material having a super water-repellent and super oil-repellent surface produced by the method according to any one of claims 1 and 3.

Images