KR101467660B1 - Method for making non-spherical colloidal particles - Google Patents

Abstract

The present invention relates to a method for producing non-spherical colloidal particles. The present invention relates to a method for producing non-spherical colloid particles according to the phase separation of the hydrocarbon oil and the polystyrene colloid particles after swelling of dispersed polymer polystyrene colloid particles into hydrocarbon oil.

Description

[0001] METHOD FOR MAKING NON-SPHERICAL COLLOIDAL PARTICLES [0002]

The present invention relates to a method for producing non-spherical colloidal particles. In particular, the present invention relates to a method for producing spherical particles having non-spherical particles having a uniform molecular size distribution. More particularly, the present invention relates to a method for preparing non-spherical particles through the process of swelling, surface tension, and phase separation using spherical particles.

In one aspect, the present invention relates to a method for preparing non-spherical particles whose particle shape and degree of deformation are controlled by controlling the amount of oil and the surface tension.

In another aspect, the present invention relates to a method for producing a dumbbell-like structure in a hydrophilic solvent by selectively binding a surfactant used for assisting absorption of oil to an unmodified portion, thereby making the modified portion hydrophobic in nature, Or other cluster forms, in a variety of ways.

According to another aspect of the present invention, there is provided a method of self-assembling non-spherical particles and spherical particles in the form of a snowman using a depleting force in a solvent in which a polymer is dispersed.

Photonic crystals, a crystalline structure that can control light, are reported to have a periodic structure that reflects light of a specific wavelength in the late 1980s, And the research was begun in earnest.

Recently, various studies have been conducted to extend the wavelength region to the visible light ray region and to utilize the reflection characteristic of a specific wavelength, and application researches such as a display and a fume cell have been conducted.

Although the initial photonic crystal structure is made of isotropic particles, there are structural limitations, and studies on the fabrication of photonic crystal structures using anisotropic particles rather than isotropic particles are underway.

It was also expected that the photonic crystal structure due to anisotropic particles would have better optical properties than the photonic crystal structure due to isotropic particles, and thus some non-isotropic particles have been produced up to now.

Studies on the production of anisotropic particles have been actively carried out in order to obtain better optical properties, and studies on the production of non-spherical particles have been published periodically.

Accordingly, the present inventors have developed a process for producing non-spherical colloidal particles according to the above-mentioned demand; A method of controlling the shape of non-spherical particles; And a method for producing an aspherical particle having an optional coupling surface.

The present invention relates to a method for producing non-spherical colloidal particles. The present invention relates to a method for producing non-spherical colloid particles according to the phase separation of the hydrocarbon oil and the polystyrene colloid particles after swelling of dispersed polymer polystyrene colloid particles into hydrocarbon oil. In one aspect, the present invention provides a method of controlling the shape of non-spherical colloid particles by controlling the interfacial tension between the solvent, polystyrene colloid particles and the hydrocarbon oil. In one aspect, the present invention provides a method for producing non-spherical colloid particles having hydrophilic and hydrophobic surfaces, the method comprising the steps of: preparing a non-spherical colloid particle by self-assembly of the non- And a method of selectively self-assembling the produced non-spherical colloid particles.

The non-spherical particles such as the dumbbell shape or other cluster shape of the present invention manufactured as described above provide a novel crystal structure having optical characteristics superior to those of the spherical particles whose optical properties are limited, And provides properties that can be selectively combined.

The present invention provides a process for preparing a solvent comprising: a) preparing a solvent comprising an alcohol and water; b) adding polystyrene particles and a hydrocarbon oil to the solvent; c) heating the polystyrene at a temperature not lower than the glass transition temperature of the polystyrene in the solvent so that the hydrocarbon oil is dissolved in the solvent and absorbed by the polystyrene particles, thereby swelling the polystyrene particles; d) cooling the hydrocarbon oil to be insoluble in the solvent so that the hydrocarbon oil and the polystyrene particles are phase-separated; And e) removing the phase-separated hydrocarbon oil.

Figure 1 shows a flow diagram of a method of making non-spherical colloidal particles according to one embodiment of the present invention. The method of the present invention comprises: (S10) preparing a solvent comprising an alcohol and water; Adding polystyrene particles and hydrocarbon oil to the solvent (S20); Heating the polystyrene at a temperature not lower than the glass transition temperature of the polystyrene in the solvent so that the hydrocarbon oil is dissolved in the solvent and absorbed by the polystyrene particles to swell the polystyrene particles (S30); (S40) cooling the hydrocarbon oil to become insoluble in the solvent so that the hydrocarbon oil and the polystyrene particles are phase-separated; And removing the phase-separated hydrocarbon oil (S50).

Step S10 is a step of preparing a solvent containing alcohol and water. The alcohol used for the solvent may be ethanol and / or methanol. On the other hand, the solvent may further include a surfactant.

Step S20 is a step of adding polystyrene particles and hydrocarbon oil to the solvent. The polystyrene particles used in the dispersion polymerization method are polystyrene particles, which will be described in detail in the following examples.

In addition, the polystyrene particles preferably have a high molecular weight distribution. As the hydrocarbon oil, decane may be used.

In step S30, the polystyrene in the solvent is heated to a temperature higher than the glass transition temperature, and by this warming process, the hydrocarbon oil can be dissolved in the solvent and absorbed into the polystyrene particles. As the hydrocarbon oil is absorbed into the polystyrene particles, the polystyrene particles swell.

At this time, it is possible to control the shape of the non-spherical colloidal particle product by controlling the absorption amount of the hydrocarbon oil absorbed in the polystyrene by varying the heating temperature in the heating process.

Step S40 is a cooling step, in which the hydrocarbon oil becomes insoluble in the solvent, resulting in phase separation of the hydrocarbon oil and the polystyrene particles. In this case, it is possible to control the shape of the non-spherical colloidal particle product by varying the cooling rate. If the cooling rate is made slow, many dimples are formed on the surface of the non-spherical colloidal particle product, and when the cooling rate is fast, one dimple is formed.

Finally, step S50 is a step of removing the phase-separated hydrocarbon oil. By removing the phase-separated hydrocarbon oil, non-spherical colloidal particle products can be formed.

Meanwhile, according to one embodiment of the present invention, by controlling the type of alcohol, the surface tension between polystyrene, hydrocarbon oil, and solvent can be controlled, thereby controlling the shape of the non-spherical colloidal particle product.

According to a further embodiment of the present invention, the surface tension between polystyrene, hydrocarbon oil and solvent can be controlled, thereby controlling the shape of the non-spherical colloidal particle product.

Depending on the control of the surface tension between the polystyrene, the hydrocarbon oil and the solvent, the shape of the non-spherical colloidal particle product may be a volcanic crater, a flat surface or a disk.

The ratio of the surface tension (Tac) acting on the polystyrene (a) and the solvent (c) to the surface tension (Tab) acting on the polystyrene (a) and the hydrocarbon oil (b) The ratio of the surface tension Tbc acting on the hydrocarbon oil (b) to the solvent (c) and the surface tension Tab acting on the polystyrene (a) and the hydrocarbon oil (b) Tbc / Tab) is defined as B. By controlling the size of A and B to A <B, the morphology of the non spherical colloidal particle product is transformed into a volcanic crater shape, and when A> B, the shape of the non spherical colloidal particle product is transformed into a flat surface or disk shape.

The shape of the non-spherical colloidal particle product made by the present invention may be a shape having one dimple, a shape having a plurality of dimples, a shape having a flat surface, a shape having a disc-shaped surface, .

On the other hand, as mentioned above, the solvent may contain a surfactant, and when the solvent contains a surfactant, the surface of the polystyrene particles having the hydrocarbon oil removed after the step S50 is hydrophobic, and the other surface is hydrophilic . When the surface of the polystyrene particles has both hydrophobic and hydrophilic surfaces, non-spherical colloidal particles having a hydrophobic surface can self-assemble hydrophobic surfaces in a solvent. The shape may represent a shape such as a dumbbell shape, a snowman shape, or the like.

FIG. 1 is a flow chart of a method for producing non-spherical colloidal particles according to an embodiment of the present invention.
2 is a scanning electron micrograph of synthesized polystyrene particles.
FIG. 3 shows the result of gel chromatography measurement to confirm the molecular weight of the particles by size.

The following description provides a simplified description of one or more embodiments in order to provide a basic understanding of embodiments of the invention. This section is not a comprehensive overview of all possible embodiments and is not intended to identify key elements or to cover the scope of all embodiments of all elements. Its sole purpose is to present the concept of one or more embodiments in a simplified form as a prelude to the more detailed description that is presented later.

Hereinafter, the contents of the present invention will be further described based on actual experimental examples.

[Example]

1. Preparation process of polystyrene particles by dispersion polymerization

1.1 Samples and structures

As monomers and initiators, styrene (99.9%, Aldrich) and 2,2-azobisisobutyronitrile (AIBN, 99.9%, Aldrich) were used. Ethanol (Aldrich, 99.9% Respectively. Polyvinylpyrrolidone (PVP, MW = 3x105 g / mol, Junsei) was used as the stabilizer, and the structure of the reagent is shown in Table 1 below.

Styrene monomer

2,2'-Azobis (isobutyronitrile)

Ethanol

Water

Polyvinylpyrrolidone

1.2 Manufacturing

In order to synthesize spherical fine particles composed of homogeneous polymer, dispersion polymerization method using alcohol and organic solvent as a dispersion medium was used.

As a specific synthesis method, polyvinylpyrrolidone (PVP, molecular weight: 3.0 105 g / mol), which is a stabilizer, is first dispersed in ethanol and distilled water as a solvent, and then a mixed solution in which polyvinylpyrrolidone is dispersed is dispersed And placed in a flask. Thereafter, the polymerization inhibitor present in the styrene monomer was removed through a commercial filling column (inhibitor remover, Aldrich), and the mixture was stirred at a speed of 500 rpm under a nitrogen stream to mix the mixture in a three-neck flask. After the reaction temperature was fixed at 70 占 폚, 2,2'-azobis (isobutyronitrile), AIBN, which is an initiator, was added and the polymerization time was adjusted to 12 hours. And then washed several times with distilled water using a centrifuge at 4500 rpm for 3 minutes.

The particle size was adjusted by adjusting the amount of ethanol and water, and the amount of reagent used is shown in Table 2.

Type Styrene Ethanol Water PVP AIBN 1PS 2.0 g 32.0 g 3.6 g 0.600g 0.080g 2PS 6.0g 30.2 g 3.4 g 0.288 g 0.288 g 3PS 6.0g 33.6 g 0.0 g 0.300 g 0.048g

1.3 Analysis

The swelling is caused by the osmotic pressure difference in the continuously dispersed state. Water-soluble materials such as styrene, for example, migrate from small to large due to differences in interfacial potentials caused by differences in size. Insoluble, low molecular weight polymers also help to form stable emulsions. A low molecular weight polymer has a higher entropy than a high molecular weight polymer. And the higher entropy lowers the Gibbs free energy and hence the swelling of the particles. Because this swelling process is relatively slow, it absorbs the same amount of oil to maintain the same chemical potential in all polymer particles. Likewise, particles may be allowed to grow when they absorb the monomers instead of the oil in the particles. In most emulsion polymerization, the molecular weight of the polymer contained in the particles is high and the distribution is also narrow. Therefore, the amount of the oil or the polymer monomer swelling in the monomer is relatively low. However, in the case of dispersion polymerization, since the distribution of molecular weight is relatively large, a low molecular weight polymer such as an oligomer existing inside the particle is used as an agent for improving the swelling.

For this reason, the present invention synthesizes spherical polystyrene particles composed of a polymer having a uniform size (dispersion of less than 5%), which is a basis for producing non-spherical particles through dispersion polymerization.

The morphology of the synthesized polystyrene particles was confirmed by scanning electron microscope. 2 is a scanning electron micrograph of synthesized polystyrene particles. FIG. 2A shows that spherical polystyrene particles having a size of 1 micrometer are synthesized by mixing water and ethanol as a solvent. In FIGS. 2B and 2C, only ethanol was used, and it was confirmed that spherical polystyrene particles each having a size of 2 micrometers and 3 micrometers were synthesized.

On the other hand, in the present invention, the molecular weight of the particles is very important for producing the non-spherical particles. In this case, the polystyrene particles preferably have a high molecular weight distribution. Gel chromatography was performed to confirm the molecular weight of the particles, and FIG. 3 shows the result of measuring the molecular weight of the particles by size. As can be seen from the measurement results, it was confirmed that the molecular weight distribution of the particles is broad. The distribution of the molecular weight was wide. As a result, it was presumed that the 1 micrometer size polystyrene particles having the broadest distribution showed the largest amount of oil swelling in proportion to the volume when producing the non-spherical particles. On the contrary, it is presumed that the amount of oil in proportion to the volume of the 3-micrometer-sized polystyrene particles having the narrowest molecular weight distribution is the smallest.

Table 3 shows the results of the gel chromatography in numerical values. It can be seen that the molecular weight distribution diagrams of the synthesized particles are all 3 or more.

Styrene Ethanol Water AIBN PVP Size Mn Mw Polydispersity (= Mw / Mn) 2.0 g 32.0 g 3.6 g 0.080g 0.600g 1mm 13291 49309 3.7099 6.0g 30.2 g 3.4 g 0.048g 0.288 g 2mm 50422 174193 3.4547 6.0g 33.6 g 0.0 g 0.048g 0.300 g 3mm 36935 117364 3.1776

2. Process for manufacturing non-spherical particles through temperature control

2.1. Samples and structures

As the spherical particles used for producing the non-spherical particles, polystyrene particles (3 μm, 25 wt%) prepared in the dispersion polymerization were used and ethanol (Aldrich, 99.9%) and methanol (Aldrich, 99.9% ) And distilled water were used. Blocking poly (ethylene glycol) (Pluronic F108, BASF Corp.) was used as the surfactant and swelling oil rode decane (Aldrich) was used. The structures of the reagents are shown in Table 4.

Polystyrene particles

Ethanol

Methanol

Water

Decane

F108

2.2. Produce

Fig. 4 is a schematic view showing a process for producing non-spherical particles. Usually, 0.05 g of poly (ethylene glycol) -block-poly (propylene glycol) -block-poly (ethylene glycol), which is a surfactant, is added to 5 g of a mixture of methanol and water or a mixture of ethanol and water (60 wt%) Lt; / RTI &gt; After that, 1 g of polystyrene particles (3 μm, 25 wt%) synthesized by dispersion polymerization and 1 g of decane were added, followed by a closed system. The stirring speed was fixed at 600 rpm and heat was applied to swell the decane in polystyrene, followed by phase separation through cooling. The amount of absorption of decane was controlled by adjusting the heating temperature (60 to 80 ° C) and the cooling temperature (10 to 30 ° C), and the heating time and the cooling time were fixed to 6 hours and 3 hours, respectively. After the reaction was completed for 9 hours, the particles were separated using a centrifuge and washed several times with ethanol at 4500 rpm for 3 minutes to remove decane and the surfactant.

2.2 Analysis

Figure 5 shows the shape of particles by quantity in the oil being absorbed. The shape of particles is controlled by controlling the reaction temperature in ethanol and distilled water. 5A and 5B are an optical microscope photograph and a scanning electron microscope photograph at a reaction temperature of 60 deg. FIGS. 5C and 5D are optical micrographs and scanning electron micrographs at a reaction temperature of 80 deg. In FIGS. 5A and 5C, which are optical microscope photographs, the amount of oil absorbed in the particles is different. It can be seen that when the reaction was carried out at 80 ° C, the amount of oil absorbed in the particles was larger than that in the case of 60 ° C. 5B and 5C show the results of measurement using a scanning electron microscope after removing the oil at 10 degrees through a centrifugal separator. As shown in the optical microscope picture, it can be confirmed that the shapes are deformed into spherical particles and disk-shaped particles each having a flat surface depending on the amount of absorbed oil. It can be confirmed that the same result as the simulation picture shown in Fig. 6 has come out.

When the polystyrene particles become oil, the shape of the particles is deformed by the surface tension between the particles and the oil. In the case of the prepared polystyrene particles, the glass transition temperature is 29 ° C in the mixture of alcohol and distilled water.

Fig. 6 shows a simulation of the shape of particles according to the surface tension of particles and oil. In Fig. 6, a represents polystyrene and b represents oil. c is a solvent in which particles are dispersed. The ratio of the surface tension acting on a and c to the surface tension acting on a and b (Tac / Tab) is assumed to be A, the ratio of the surface tension acting on b and c and the surface tension acting on a and b Tbc / Tab) is assumed to be B, the shape of the particle is transformed into a volcanic crater shape when A <B. On the other hand, in the case of A> B, the particle shape has a flat surface or deforms into a disc shape. This is because the larger the surface tension acting, the greater the force of maintaining the spherical shape.

In the case of A <B, since the surface tension of B is large, the shape of the particle is transformed into a volcanic crater. Conversely, when A> B, A has a large surface tension, . When the volume of a is constant and the volume of b is different, the larger the volume of b is, the wider the range of surface tension between a and b becomes, and the morphological deformation of the particle becomes larger than when the volume of b is smaller.

Fig. 7 shows the shape of particles by the phase separation time. FIG. 7A is an optical microscope image after phase separation at room temperature without cooling reaction resulting from the natural lowering of the temperature of the solvent after completion of the heating reaction. Two drops of oil appear on the surface of the particle. In the case of FIG. 7C, after the heating reaction, the temperature of the solvent was slowly lowered for 3 hours by circulating water at 30 degrees. One oil droplet can be seen on the surface of the particle.

As shown in Figure 8, oil is absorbed throughout the particle as it is absorbed by the particle. Therefore, when the phase separation is performed without a cooling reaction after the heating reaction, the temperature drops below Tg in the state where the oil is not incorporated, and two oil droplets appear in one particle as shown in FIG. 8A. On the contrary, when the cooling reaction is carried out after the heating reaction, the phase separation is made slowly, and the oil and the oil which are outside are merged, and one oil droplet is observed in one particle as shown in FIG.

8B and 8D are scanning electron micrographs obtained after removal of oil droplets through washing using a centrifugal separator. In FIG. 8B, it can be seen that two oils are observed on one particle, and that when the oil is removed, there are two deformed portions of the particle. In FIG. 8D, one oil is observed in one particle. As shown in FIG. 8C, when the oil is removed, it can be confirmed that the deformed portion of the particle is one. Controlling the amount of time that the same amount of oil is absorbed into the particles and adjusting the phase separation time will reveal phase separation of several oils in one particle.

In order to control the particle shape, it is necessary to control the amount of oil absorbed by the temperature and to control the surface tension by changing the solvent in addition to adjusting the phase separation rate and the phenomenon that the absorbed oil is dissolved in the solvent Method.

First, the control of the ratio of the water to the alcohol by the solvent of the particles used in the reaction has already been reported. In this study, the surface tension acting on particles and oil was controlled according to the kind of solvent. In FIG. 6, by controlling the surface tension acting on the particles, oil, and solvent of the particles, it is explained that the particle shape can be controlled by the volcanic crater-shaped particles, the particles having the flat surface, and the disk-shaped particles.

FIGS. 9A and 9C are scanning electron micrographs of reactions in a mixture of ethanol and water and a mixture of methanol and water. FIG. In the case of FIG. 9A, it can be seen that the particle shape has a flat surface as shown in FIG. 5 and FIG. However, in the case of FIG. 9c, it can be seen that the shape of the particle is a volcanic crater-like shape. In the case of the mixture of methanol and water, the surface tension acting on the solvent and the particles or on the solvent and the oil is higher than that of the mixture of ethanol and water. However, the surface tension acting between the particles and the oil relatively decreases. For this reason, the shape of the particles is a volcanic crater-like shape.

FIG. 10 is a photograph taken through an atomic force microscope, and it can be confirmed that the shape of the particle is a shape of a volcanic crater or a particle having a flat portion. 9B and 9D are graphs showing the sizes of deformed portions. By slowly increasing the heating temperature, the absorption of the oil was slowed so that all the particles could absorb the same amount of oil. (b) and (d) confirm that the amount of oil absorbed is similar.

Next, in the case of using a phenomenon in which the absorbed oil is dissolved in the solvent, the shape deformation of the particles can be controlled by controlling the temperature at which the solvent is cooled.

When the oil is decane, it is dissolved in a mixture of methanol and water or a mixture of ethanol and water when the temperature is high. This phenomenon also occurs in the decane absorbed in the particles.

8A, when the cooling temperature is fixed at 10 degrees, it can be seen that the size of the absorbed oil is the largest. On the other hand, the oil absorbed at 40 ° C is the smallest. This can be confirmed by Figure 11. 11A, the size of the flat surface is the largest. On the other hand, Figs. 11B and 11C show that the size of the flat surface is smaller than that of Fig. 11A, and the case of Fig. 11C is the smallest. FIG. 11A shows the result at 10 degrees in FIG. 8A, and FIG. 11B and FIG. 11C show the results at 30 degrees and 40 degrees, respectively. In the heating reaction, stirring is carried out together, but stirring is not performed in the cooling reaction. When the oil is agitated, the size of the oil becomes small, so that the oil is absorbed by the particles. However, if the oil is not stirred, the surface area of the oil is reduced in order to maintain a stable state, and thereby the oil is merged with each other. Since the solvent is a mixture of water and alcohol, the oil is phase-separated from the solvent. For this reason, the amount of oil absorbed in the particles is reduced, and the oil existing in the particles is dissolved in the solvent. In this case, since the diffusion speed of the oil increases as the temperature increases, the flat surface of FIG. 11c is the smallest. The reaction in the mixture of methanol and water also has the same result. As shown in Fig. 15B, the oil is absorbed most at 10 degrees and the least at 40 degrees.

However, since the solubility of decane at the same temperature is lower than that of a mixture of ethanol and water, the deformation of the particles is large as shown in Fig. 12C. However, due to the small amount of decane absorbed for the same reason, it takes a long time for the decane bubbles to merge into one, and the temperature drops below Tg before merging, and the shape of the particles appears as shown in FIG.

3. Self-assembly of non-spherical particles by selective interaction

3.1. Samples and structures

Non - spherical polystyrene particles prepared by the above process and spherical polystyrene particles prepared by dispersion polymerization were used for self - assembly of non - spherical particles, and ethanol and distilled water were used as solvents.

3.2. Manufacturing and Analysis

3.2.1. Self-assembly of non-spherical particles with flat faces

13 is a schematic view showing a self-assembly process of non-spherical particles having a flat surface. The non-spherical polystyrene particles having the flat surface prepared above were separated through a centrifuge and washed several times at 4500 rpm for 3 minutes through distilled water.

Surfactants were used to reduce the surface tension of the particles when manufacturing non-spherical particles. When the surfactant becomes a particle, a hydrophobic part is attached to the surface, and the temperature is lowered to Tg or less and bonded to the particle surface. However, the surfactant does not bind to the portion where the surface tension with decane acts. When the residual surfactant is removed by centrifugal separation and the surfactant is removed in the hydrophilic solvent, the particles are hydrophilic in the portion having the surfactant, but the hydrophobic portion is self-assembled because the surfactant is not present in the portion where the oil exists.

Thus, the reaction was carried out using a hydrophobic iron oxide particle instead of a surfactant such that a surfactant was indirectly bonded. As a result, it was confirmed that the iron oxide particles were bonded to the remaining portions except for the oil-phase separated portion as shown in Fig.

3.2.2. Self-assembly of non-spherical and spherical particles with volcanic crater-like shapes

15 is a schematic view showing a self-assembly process of non-spherical particles and spherical particles having a volcanic crater shape. The spherical polystyrene particles synthesized by the above-described volcanic crater-shaped particles and the spherical polystyrene particles synthesized by the dispersion polymerization were separated and separated by centrifugal separation, and then washed several times with ethanol at 4500 rpm for 3 minutes. Then, non-spherical particles and spherical particles were mixed at a ratio of 2: 1, separated through a centrifuge, and washed several times with distilled water.

16 is a photograph showing the result of self-assembly of particles by selective interaction. FIGS. 16A and 16B are optical micrographs and scanning electron micrographs showing that particles having a flat surface are self-assembled in a reaction mixture of ethanol and water, respectively. As described above, since the deformed portions of the particles are hydrophobic, the flat portions of the particles are selectively self-assembled in the hydrophilic solvent. Finally, it can be confirmed that the shape of the particles becomes dumbbell shape. Figure 24 shows that particles with multiple deformed parts self-assemble in various forms in a hydrophilic solvent by lowering the temperature below Tg before the oil is merged into one.

The reaction was carried out in a mixture of methanol and water, and particles having a volcanic crater shape can be self-assembled with spherical particles. FIGS. 16C and 16D are photomicrographs and scanning electron microscope photographs showing that the reaction proceeds in a mixture of methanol and water, respectively, and self-assembled particles of a volcanic crater-shaped particle and a spherical particle. FIG. Polvinylpyrrolidone (PVP) used as a stabilizer of polystyrene particles initially acts as a stabilizer in ethanol, but when dispersed in a hydrophilic solvent together with the hydrophobic particles produced, it can not act as a stabilizer, And the spherical particles are self-assembled. Finally, it can be confirmed that self-assembly is performed in the form of a trimmer.

3.2.3. Interaction between non-spherical particles with a flat surface and a hydrophobic substrate

7 is a schematic diagram showing the interaction between a non-spherical particle having a flat surface and a hydrophobic substrate. First, a polystyrene-dissolved solution on a silicon substrate was spin-coated at 2000 rpm for 1 minute to form a film, which was then placed in a beaker containing distilled water. Thereafter, the non-spherical polystyrene particles having flat faces separated from each other at 4500 rpm for 3 minutes through a centrifuge were put into a beaker containing the substrate and reacted for a long time.

Fig. 18 shows a state in which particles having a flat surface are selectively placed on a substrate coated with a hydrophobic substance. By reducing the concentration of the dispersion of particles, the particles can be selectively placed on the substrate by reducing self-assembly among the particles.

Self-assembly of non-spherical particles and spherical particles by depletion force

The self-assembly method of volcanic crater-shaped particles and spherical particles prepared from a mixture of methanol and water can be self-assembled by using a depletion force in addition to a method using hydrophobic properties. When the colloidal particles are dispersed in the solvent in which the polymer is dissolved, each particle is surrounded by the polymer molecules in a certain space. For this reason, the particles are not assembled together but are independent of each other. However, if these spaces are overlapped by the flow of the particles, the remaining space except the overlapping space is surrounded by the polymer molecules, and the particles are bonded by a specific force. In order to increase the entropy of the polymer molecules, the binding of the colloidal particles is induced. Here, the force due to the entropy is referred to as the depletion force. When volcanic crater-shaped particles and spherical particles are dispersed in the polymer dissolved solvent, volcanic crater-shaped and spherical particles self-assemble. The combination of volcanic crater and spherical particles, which is a specific part of the volcanic crater, combines with spherical particles because the spherical parts have less space for overlapping, resulting in lower depletion potential. However, since the volcanic crater shape has a larger overlapping space, will be. 19 is an optical micrograph showing the self-assembly of particles with time. Although it overlaps with the crater boundary of the initial volcanic crater, it can be confirmed that the particles move and self-assemble as a part that has a high depletion force with time.

The description of the disclosed embodiments is provided to enable any person skilled in the art to make or use the present invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the generic principles defined herein may be applied to other embodiments without departing from the scope of the invention. Thus, the present invention is not intended to be limited to the embodiments shown herein but is to be accorded the widest scope consistent with the principles and novel features presented herein.

Claims (18)

delete delete a) preparing a solvent comprising an alcohol and water;
b) adding polystyrene particles and a hydrocarbon oil to the solvent;
c) heating the polystyrene particles above the glass transition temperature of the polystyrene in the solvent to swell the polystyrene particles;
d) cooling the hydrocarbon oil and the polystyrene particles to phase-separate; And
e) removing the phase-separated hydrocarbon oil, comprising the steps of:
The hydrocarbon oil is a hydrocarbon compound which is dissolved in a solvent by heating the solvent and absorbed into the polystyrene particles to swell the polystyrene particles and insoluble in the solvent by cooling to cause phase separation with the polystyrene particles.
Controlling the shape of the non-spherical colloidal particle product by varying the cooling rate,
A method of making non-spherical colloidal particles. The method of claim 3,
Slowing the cooling rate to form a plurality of dimples on the surface of the non-spherical colloidal particle product,
A method of making non-spherical colloidal particles.
The method of claim 3,
Wherein the cooling rate is increased to form a dimple on the surface of the non-spherical colloidal particle product,
A method of making non-spherical colloidal particles.
a) preparing a solvent comprising an alcohol and water;
b) adding polystyrene particles and a hydrocarbon oil to the solvent;
c) heating the polystyrene particles above the glass transition temperature of the polystyrene in the solvent to swell the polystyrene particles;
d) cooling the hydrocarbon oil and the polystyrene particles to phase-separate; And
e) removing the phase-separated hydrocarbon oil, comprising the steps of:
The hydrocarbon oil is a hydrocarbon compound which is dissolved in a solvent by heating the solvent and absorbed into the polystyrene particles to swell the polystyrene particles and insoluble in the solvent by cooling to cause phase separation with the polystyrene particles.
Controlling the type of the alcohol to control the shape of the non-spherical colloidal particle product,
A method of making non-spherical colloidal particles. delete a) preparing a solvent comprising an alcohol and water;
b) adding polystyrene particles and a hydrocarbon oil to the solvent;
c) heating the polystyrene particles above the glass transition temperature of the polystyrene in the solvent to swell the polystyrene particles;
d) cooling the hydrocarbon oil and the polystyrene particles to phase-separate; And
e) removing the phase-separated hydrocarbon oil, comprising the steps of:
The hydrocarbon oil is a hydrocarbon compound which is dissolved in a solvent by heating the solvent and absorbed into the polystyrene particles to swell the polystyrene particles and insoluble in the solvent by cooling to cause phase separation with the polystyrene particles.
Controlling the surface tension between the polystyrene, the hydrocarbon oil and the solvent to control the shape of the non-spherical colloidal particle product,
(Tac / Tab) of the surface tension (Tac) acting on the polystyrene (a) and the solvent (c) and the surface tension (Tab) acting on the polystyrene (a) and the hydrocarbon oil Define,
(Tbc / Tab) of the surface tension (Tbc) acting on the hydrocarbon oil (b) and the solvent (c) and the surface tension (Tab) acting on the polystyrene (a) and the hydrocarbon oil In this case,
A < B to transform the shape of the non-spherical colloidal particle product into a volcanic crater shape,
A method of making non-spherical colloidal particles. a) preparing a solvent comprising an alcohol and water;
b) adding polystyrene particles and a hydrocarbon oil to the solvent;
c) heating the polystyrene particles above the glass transition temperature of the polystyrene in the solvent to swell the polystyrene particles;
d) cooling the hydrocarbon oil and the polystyrene particles to phase-separate; And
e) removing the phase-separated hydrocarbon oil, comprising the steps of:
The hydrocarbon oil is a hydrocarbon compound which is dissolved in a solvent by heating the solvent and absorbed into the polystyrene particles to swell the polystyrene particles and insoluble in the solvent by cooling to cause phase separation with the polystyrene particles.
Controlling the surface tension between the polystyrene, the hydrocarbon oil and the solvent to control the shape of the non-spherical colloidal particle product,
(Tac / Tab) of the surface tension (Tac) acting on the polystyrene (a) and the solvent (c) and the surface tension (Tab) acting on the polystyrene (a) and the hydrocarbon oil Define,
(Tbc / Tab) of the surface tension (Tbc) acting on the hydrocarbon oil (b) and the solvent (c) and the surface tension (Tab) acting on the polystyrene (a) and the hydrocarbon oil In this case,
A> B to transform the shape of the non-spherical colloidal particle product into a flat surface or disk shape,
A method of making non-spherical colloidal particles. a) preparing a solvent comprising an alcohol and water;
b) adding polystyrene particles and a hydrocarbon oil to the solvent;
c) heating the polystyrene particles above the glass transition temperature of the polystyrene in the solvent to swell the polystyrene particles;
d) cooling the hydrocarbon oil and the polystyrene particles to phase-separate; And
e) removing the phase-separated hydrocarbon oil, comprising the steps of:
The hydrocarbon oil is a hydrocarbon compound which is dissolved in a solvent by heating the solvent and absorbed into the polystyrene particles to swell the polystyrene particles and insoluble in the solvent by cooling to cause phase separation with the polystyrene particles.
Controlling the cooling temperature to control the shape of the non-spherical colloidal particle product,
A method of making non-spherical colloidal particles. 10. The method according to any one of claims 3 to 6, 8, and 9,
The shape of the non-spherical colloidal particle product may be any shape including a shape having one dimple, a shape having a plurality of dimples, a shape having a flat surface, a shape having a disc-shaped surface,
A method of making non-spherical colloidal particles. a) preparing a solvent comprising an alcohol and water;
b) adding polystyrene particles and a hydrocarbon oil to the solvent;
c) heating the polystyrene particles above the glass transition temperature of the polystyrene in the solvent to swell the polystyrene particles;
d) cooling the hydrocarbon oil and the polystyrene particles to phase-separate; And
e) removing the phase-separated hydrocarbon oil, comprising the steps of:
The hydrocarbon oil is a hydrocarbon compound which is dissolved in a solvent by heating the solvent and absorbed into the polystyrene particles to swell the polystyrene particles and insoluble in the solvent by cooling to cause phase separation with the polystyrene particles.
Wherein the solvent comprises a surfactant,
Wherein the surface of the polystyrene particles from which the hydrocarbon oil has been removed is hydrophobic after the removal of the hydrocarbon oil,
A method of making non-spherical colloidal particles. 13. The method of claim 12,
Wherein the non-spherical colloid particles having the hydrophobic surface are self assembled with the hydrophobic surfaces in the solvent to form non-spherical colloidal particles,
A method of making non-spherical colloidal particles.
delete delete 13. A method of selectively self-assembling non-spherical colloidal particles made according to claim 12 or 13 on hydrophobic or hydrophilic surfaces.
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