KR101189463B1 - Method for coating surface of polymer particle - Google Patents

Abstract

The present invention comprises the steps of dispersing the polymer particles to be coated in a negatively charged poly diaryldimethylammonium chloride solution in an aqueous solution, the step of coating the poly diaryldimethylammonium chloride on the surface of the polymer particles, by centrifugation Precipitating the polymer particles coated with poly diaryldimethylammonium chloride and removing the poly diaryldimethylammonium chloride solution; and polymer particles coated with poly diaryldimethylammonium chloride in a positively charged TiO ₂ precursor solution in aqueous solution. and a TiO ₂ precursor stage and centrifuged to be coated on the step and a poly diallyl dimethyl ammonium chloride-coated polymer particle surface to disperse the method comprising precipitation of the polymer particles coated with the TiO ₂ precursor and eliminating the TiO ₂ precursor solution Polymer particle surface nose containing It relates to a method. According to the present invention, the polydiaryldimethylammonium chloride and TiO ₂ may be uniformly coated on the surface of the polymer particles without aggregation, and the thickness of the thin film coated on the surface of the particles may be easily controlled.

Description

Method for coating surface of polymer particle

The present invention relates to a polymer particle surface coating method, and more specifically, to the surface of the polymer particles can be uniformly coated with poly diaryldimethylammonium chloride and TiO ₂ , there is no aggregation, the thickness of the thin film coated on the particle surface It relates to a polymer particle surface coating method that can easily control.

Research into the technology of producing a functional thin film on the surface of the particles has been actively conducted in recent years. This is because particles coated with functional thin films show various applications such as pharmaceuticals, cosmetics, dyes, inks, fillers and catalysts.

Research using titanium dioxide (TiO ₂ ) as a material for functional thin films is active. This is because TiO ₂ exhibits high refractive index, high dielectric constant, excellent solar energy conversion and photocatalytic properties. The TiO ₂ thin film is manufactured by various methods such as sol-gel method, sputtering method, chemical vapor deposition (CVD) method and liquid phase deposition (LPD) method. .

However, these methods are complicated in the process, it is difficult to uniformly coat the functional thin film on the particle surface, there is a limit in obtaining a thin film of the desired thickness, there is a problem that the particles are aggregated with each other. .

The problem to be solved by the present invention is a polymer particle surface that can uniformly coat poly diaryldimethylammonium chloride and TiO ₂ on the surface of the polymer particles, there is no aggregation, and can easily control the thickness of the thin film coated on the particle surface In providing a coating method.

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The present invention provides a method for preparing a polymer particle comprising (a) dispersing a polymer particle to be coated in a negatively charged poly diaryldimethylammonium chloride solution in an aqueous solution, and (b) allowing the polydiaryldimethylammonium chloride to be coated on the surface of the polymer particle. (C) precipitating the polymer particles coated with poly diaryldimethylammonium chloride by centrifugation and removing the poly diaryldimethylammonium chloride solution; and (d) positively charged TiO ₂ precursor solution in aqueous solution. Dispersing the polymer particles coated with poly diaryldimethylammonium chloride, (e) allowing the TiO ₂ precursor to be coated on the surface of the polymer particles coated with poly diaryldimethylammonium chloride, and (f) centrifuging TiO. _precursor to precipitate the coated polymer particles and pole comprises the step of removing the TiO ₂ precursor solution It provides Murray particles surface coating.

The TiO ₂ precursor solution is preferably an acidic solution having a pH of 0.5 to 6 range.

The dispersing of the polymer particles may be performed by dispersing the polymer particles using ultrasonication, and the ultrasonication may be performed for 1 minute to 2 hours at a frequency ranging from 10 kHz to 5 MHz.

The polymer particle surface coating method may further include a rinsing step after the step (c) and the step (f), water is added to the polymer particles, dispersed by sonication, and then water is removed.

The poly diaryldimethylammonium chloride and TiO ₂ thin film coated on the surface of the polymer particles may be used as one layer, and the steps (a) to (f) may be repeated to form a plurality of layers.

By adjusting the number of the bilayers in a range of 10 to 100, the thickness of the polydiaryldimethylammonium chloride and TiO ₂ thin film coated on the surface of the polymer particles may be controlled.

The polymer may be polymethylmethacrylate.

TiO ₂ precursor may be the titanium (IV) bis ammonium lactoto dihydroxide.

In addition, the present invention provides a polymer particle coated with a functional thin film coated by a polymer particle surface coating method and forming a structure in which polydiaryldimethylammonium chloride and a TiO ₂ thin film are sequentially stacked.

According to the present invention, the polydiaryldimethylammonium chloride and the TiO ₂ thin film can be uniformly coated on the surface of the polymer particles.

In addition, the polymer particles coated with the polydiaryldimethylammonium chloride and the TiO ₂ thin film by the surface coating method of the present invention are uniformly dispersed and there is no aggregation.

In addition, the thickness of the thin film coated on the surface of the polymer particles may be controlled by adjusting the pH of the TiO ₂ precursor solution.

In addition, the polydiaryldimethylammonium chloride and TiO ₂ thin film coated on the surface of the polymer particle may be used as one layer, and the thickness of the thin layer may be adjusted by controlling the number of layers.

1 is a diagram showing the molecular structure of PDDA having a positive charge after dissociation in an aqueous solution.
2 is a diagram showing the molecular structure of TALH having a negative charge in an aqueous solution state.
3 is a view showing the adsorption characteristics according to the pH of the TALH solution.
FIG. 4 is a field emission transmission electron microscope (FE-TEM) photograph of TiO ₂ crystal particles formed in a manufactured PDDA / TALH thin film.
5a to 5d are field emission scanning electron microscope (FE-SEM) images showing PMMA particles, and TALH titrated with PDDA, pH 5.5, pH 4.5, and pH 2.5 on PMMA particles surface with an average particle size of 760 nm. (PDDA / TALH) ₃₀ FE-SEM image showing the surface structure and size of particles coated with a thin film.
6A to 6F are graphs showing the surface structure and size of particles according to the number of bilayers (n) of a thin film prepared using PDDA and TALH titrated at pH 3.5.
FIG. 7 is a view showing the change of particle size according to the change of the number of bilayers of (PDDA / TALH) _n thin film coated on the surface of PMMA particles.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. However, the following embodiments are provided to those skilled in the art to fully understand the present invention, and may be modified in various forms, and the scope of the present invention is limited to the embodiments described below. It doesn't happen.

The present invention provides a method of forming a functional thin film on the surface of a polymer particle by using a layer-by-layer (hereinafter, referred to as LBL) method, which is a wet process method.

The LBL method has a simple thin film manufacturing process, easy to control the film thickness on a nano scale, and has an advantage in large area coating. The LBL method is a technique for manufacturing a thin film using electrostatic forces of materials having different charges by alternately depositing a substrate in a solution having electrolyte polymers or nanoparticles having positive or negative charges dissolved or dispersed in water at room temperature and atmospheric pressure. By controlling the concentration, pH, and deposition time of the electrolyte solution by the LBL method, a thin film having a surface having various structures can be produced.

Titanium (IV) bis ammonium lactato dihydroxide (hereinafter referred to as 'TALH') is used as a TiO ₂ precursor for preparing a TiO ₂ thin film. TALH is stable in aqueous solution and is a negatively charged TiO ₂ precursor because it has the advantage of easily controlling the structure and thickness of the thin film by hydrolysis and condensation reaction according to temperature and pH.

In the present invention, polydimethyl dimethylammonium chloride having a positive charge (hereinafter referred to as' PDDA ') and a negative charge TALH using the LBL method is a polymer polymethylmethacrylate (polymethylmethacrylate; below' PMMA) To form a functional thin film on the particle surface.

Hereinafter, a method of forming a functional thin film on the polymer particle surface will be described in more detail.

The polymer particles to be coated are dispersed in a negatively charged poly diaryldimethylammonium chloride solution in aqueous solution. The polymer may be polymethylmethacrylate. Dispersion of the polymer particles, using an ultrasonic treatment, the ultrasonic treatment is preferably performed for 1 minute to 2 hours at a frequency in the range of 10kHz to 5MHz.

A predetermined time (eg, 1 minute to 6 hours) is maintained in a state where the polymer particles are dispersed in the poly diaryldimethylammonium chloride solution so that the poly diaryldimethylammonium chloride is coated on the surface of the polymer particles.

When poly diaryldimethylammonium chloride is coated on the surface of the polymer particles, centrifugation separates the polymer particles coated with poly diaryldimethylammonium chloride and removes the poly diaryldimethylammonium chloride solution.

After removing the poly diaryldimethylammonium chloride solution, water may be added to the polymer particles, dispersed by sonication, and then rinsed to remove water.

The polymer particles coated with poly diaryldimethylammonium chloride are then dispersed in a positively charged TiO ₂ precursor solution in aqueous solution. TiO ₂ precursor may be the titanium (IV) bis ammonium lactoto dihydroxide. Dispersion of the polymer particles, using an ultrasonic treatment, the ultrasonic treatment is preferably performed for 1 minute to 2 hours at a frequency in the range of 10kHz to 5MHz. The TiO ₂ precursor solution is preferably an acidic solution having a pH of 0.5 to 6 range. The thickness of the thin film coated on the surface of the polymer particle may be controlled by adjusting the pH of the TiO ₂ precursor solution. A detailed description thereof will be described later.

The polymer particles are dispersed in the TiO ₂ precursor solution for a predetermined time (eg, 1 minute to 6 hours) to allow the TiO ₂ precursor to be coated on the surface of the polymer particles coated with poly diaryldimethylammonium chloride.

When poly diallyl dimethyl ammonium chloride, the TiO ₂ precursor is coated on the coated polymer particle surface, and centrifuged to precipitate the TiO ₂ precursor is coated polymer particles and to remove the TiO ₂ precursor solution.

After removing the TiO ₂ precursor solution, water may be added to the polymer particles, dispersed by sonication, and then rinsed to remove water.

As described above, the polydiaryldimethylammonium chloride and TiO ₂ thin film coated on the surface of the polymer particles are used as one layer, and the polymer particles to be coated in the polydiaryldimethylammonium chloride solution are dispersed to form a plurality of layers. removing the TiO ₂ precursor solution can be carried out repeatedly up to (or after removal of the TiO ₂ precursor solution, rinsing). By making the number of the bilayers in the range of 10 to 100, the thickness of the polydiaryldimethylammonium chloride and TiO ₂ thin film coated on the surface of the polymer particles may be adjusted, and a detailed description thereof will be described later.

Hereinafter, examples according to the present invention will be presented in more detail, and the present invention is not limited to the following examples.

In the embodiment of the present invention, it was confirmed that the surface structure of the thin film and the size of the coated particles could be controlled by adjusting the pH of the TALH solution, and thus the color change by the interference light of the prepared particles was confirmed.

PMMA with an average particle size of 760 nm was used as a template for coating a functional thin film on the surface of the particles. PMMA particles were dispersed in water to prepare a 1.0 wt% colloidal solution. A positively charged PDDA (20 wt% in water) and a negative charge TALH (50 wt% in water) were used to prepare a functional thin film using the LBL method.

The concentration of PDDA was adjusted to 0.01 M by using an ultra-pure water. The concentration of TALH was adjusted to 1.0% by weight using ultrapure water, and the pH of the solution was titrated to pH 5.5, pH 4.5, pH 3.5, and pH 2.5 using HCl, respectively.

PMMA (1.0 wt%) colloidal solution was centrifuged to coat the positively charged PDDA on the surface of PMMA particles, water was removed from the centrifuge tube, PDDA solution was added and sonicated to remove PMMA particles deposited under the centrifuge tube. Dispersed. After 5 minutes in the dispersed state, the PDDA was coated on the surface of the PMMA particles and centrifuged to precipitate the particles and remove the PDDA solution. After rinsing the super purified water and dispersing it by ultrasonic wave and centrifuging to remove the super purified water, it was repeated twice.

In order to coat TALH on the surface of PDDA-coated PMMA particles, TALH solution was added to the centrifuge tube, and ultrasonic waves were used to disperse the PMDA-coated PMMA particles, and then maintained for 5 minutes. After allowing to be coated, centrifugation removed the TALH solution. After rinsing the super purified water and dispersing with ultrasonic wave and centrifuging to remove the super purified water, it was repeated twice.

Hereinafter, PDAA / TALH is used to mean that the PDDA coated on the surface of the PMMA particles, and TALH coated on the top. In addition, when PDDA and TALH are laminated once, it is 1 bilayer, and when the number of bilayers is n, it shows as (PDDA / TALH) n. For example, (PDDA / TALH) ₃₀ means that 30 processes of coating PDDA and coating TALH are performed. That is, as described above, it means that the process of dispersing PMMA particles in the PDDA solution to the process of repeating the rinsing process twice after removing the TALH solution is repeated 30 times.

In order to monitor the self-assembly properties of TALH in aqueous solution, quartz crystal microbalance (hereinafter referred to as 'QCM') is used to measure the change in frequency as the TALH is deposited on the surface of the crystal oscillator. Confirmed. Field emission transmission electron microscope (hereinafter referred to as 'FE-TEM'), in order to check the surface microstructure of the prepared thin film and TiO ₂ crystal particles formed on the PDDA / TALH thin film coated on the PMMA surface, A field emission transmission electron microscope (hereinafter referred to as FE-SEM) was used.

Figure 1 shows the molecular structure of the PDDA having a positive charge after dissociation in an aqueous solution state, Figure 2 shows the molecular structure of TALH with a negative charge in an aqueous solution state.

In order to confirm the adsorption characteristics according to pH of the TALH solution, PDDA was coated on the electrode surface of the hydrophilized QCM, and then the frequency change of the QCM was confirmed after immersion in the TALH solution titrated with pH 5.5, pH 4.5, and pH 2.5, respectively.

3 is a view showing the adsorption characteristics according to the pH of the TALH solution. In FIG. 3, (a) shows a case where the pH of the TALH solution is 5.5, (b) shows a case where the pH of the TALH solution is 4.5, and (c) shows a case where the pH of the TALH solution is 2.5. As shown in FIG. 3, the lower the pH of the TALH solution, the greater the change in frequency. This result means that as the pH of the TALH solution is lowered, the hydrolysis and condensation reactions become active, thereby increasing the amount of adsorption on the QCM electrode. Therefore, using a low pH titrated TALH will be able to produce a thick thin film.

FIG. 4 is a FE-TEM photograph of TiO ₂ crystal particles formed in a manufactured PDDA / TALH thin film. As shown in FIG. 4, it can be seen that TiO ₂ nanoparticles having a particle size of about 5 nm are formed and dispersed in the PDDA / TALH thin film.

5A to 5D show FE-SEM images showing PMMA particles having an average particle size of 760 nm, and TALH titrated with PDDA, pH 5.5, pH 4.5, and pH 2.5 on the surface of PMMA particles having an average particle size of 760 nm. FE-SEM image showing the surface structure and size of particles coated with (PDDA / TALH) ₃₀ thin film. FIG. 5A is a photograph showing PMMA particles, FIG. 5B is a photograph showing the formation of a (PDDA / TALH) ₃₀ thin film using PDDA and pH 5.5 appropriately deposited on the surface of PMMA particles, and FIG. (PDDA / TALH) ₃₀ thin film using TALH suitable for pH 4.5 is formed, Figure 5d is a (PDDA / TALH) ₃₀ thin film using PDDA and pH 2.5 suitable for TALH formed on the surface of PMMA particles It is a photograph.

PMMA particles coated with the PDDA / TALH film on the surface by the LBL method are uniformly coated with a thin film on the surface of the particles as compared with the initial state, and even after the film is coated, the particles are uniformly dispersed without aggregation of the particles. This is because when the PDDA or TALH solution is sufficiently coated on the surface of the PMMA particles, the surface of the particles is charged with the same charge and thus a repulsion force is generated between the particles. The particle size was determined as the average value of the particle size calculated from the measured FE-SEM image. When the pH of the TALH solution used was pH 5.5, pH 4.5, pH 2.5, the actual size of the particles identified in Figures 5a to 5d increased to about 0.92, 0.935, 1.05mm as the pH of the solution was lowered. This result means that the thickness of the (PDDA / TALH) thin film coated on the surface of the PMMA particles increases as the frequency change increases as confirmed in FIG. 3.

6A to 6F show the surface structure and size of particles according to the number of bilayers (n) of a thin film prepared using PDDA and TALH titrated at pH 3.5. Figure 6a is a photograph showing the PMMA particles, Figure 6b (PDDA / TALH) and when the bi-layer count (n) 10 from the _n thin film, and Figure 6c is a water by-layer in the (PDDA / TALH) _n thin film (n) Is 20, FIG. 6D is a case where the number of bilayers _n is 30 in the (PDDA / TALH) _n thin film, and FIG. 6E is a case where the number of bilayers n is 40 in the (PDDA / TALH) _n thin film. 6F illustrates the case where the number of bilayers n is 50 in the (PDDA / TALH) _n thin film.

As can be seen in Figures 6a to 6b, the (PDDA / TALH) _n thin film is uniformly coated on the surface of the particles can be confirmed that there is no aggregation between the particles, the size of the particle as the number of bilayers (bilayer) increases It can be seen that the roughness of the particle surface increases with the increase.

The change in particle size according to the bilayer number of bilayer of the (PDDA / TALH) _n thin film coated on the surface of PMMA particles is shown in FIG. 7. It was confirmed that the particle size also increased linearly as the number of Bilayers was increased up to n = 50, and it was judged that the LBL method was appropriate as a method for uniformly coating the surface of the particles. As a result of calculating the average value by measuring the sizes of the particles shown in FIGS. 6A to 6F, when the bilayer number n is 10, 20, 30, 40, 50, the (PDDA / TALH) _n thin film was The size of the coated PMMA particles was found to be 0.84, 0.91, 0.99, 1.07 and 1.18 μm, respectively.

As mentioned above, although preferred embodiment of this invention was described in detail, this invention is not limited to the said embodiment, A various deformation | transformation by a person of ordinary skill in the art within the scope of the technical idea of this invention is carried out. This is possible.

Claims (9)

(a) dispersing polymer particles to be coated in a negatively charged poly diaryldimethylammonium chloride solution in an aqueous solution;
(b) coating poly diaryldimethylammonium chloride on the surface of the polymer particles;
(c) centrifuging to precipitate the polymer particles coated with poly diaryldimethylammonium chloride and remove the poly diaryldimethylammonium chloride solution;
(d) dispersing the polymer particles coated with poly diaryldimethylammonium chloride in a positively charged TiO ₂ precursor solution in an aqueous solution;
(e) allowing the TiO ₂ precursor to be coated on the surface of the polymer particles coated with poly diaryldimethylammonium chloride; And
(f) by centrifugation, and TiO ₂ precursor is precipitated coated polymer particles and removing a TiO ₂ precursor solution,
The TiO ₂ precursor solution is an acid solution having a pH in the range of 0.5 to 4.5,
The polymer is polymethylmethacrylate,
The TiO ₂ precursor is titanium (IV) bis ammonium lactoto dihydroxide,
Dispersing the polymer particles, dispersing the polymer particles by using an ultrasonic treatment, the ultrasonic treatment is performed for 1 minute to 2 hours at a frequency in the range of 10kHz ~ 5MHz.
delete delete The method of claim 1, wherein after step (c) and step (f),
The polymer particle surface coating method further comprises a rinsing step of removing water after putting water in the polymer particles and dispersed by ultrasonication.
The method of claim 1, wherein the polydiaryldimethylammonium chloride and TiO ₂ thin film coated on the surface of the polymer particles are used as one layer, and the steps (a) to (f) are performed so that the number of layers is formed in multiple layers. Polymer particle surface coating method characterized in that it is carried out repeatedly.
The method of claim 5, wherein the number of the bilayers is in the range of 10 to 100 to control the thickness of the polydiaryldimethylammonium chloride and TiO ₂ thin films coated on the surface of the polymer particles.
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