CN117447875A - Electronic ink, preparation method thereof and reflective display - Google Patents

Abstract

This application discloses an electronic ink, its preparation method and a reflective display. The electronic ink includes a charged sphere. The charged sphere includes a white hemisphere and a black hemisphere. The white hemisphere and the black hemisphere are connected to form a charged sphere. The white hemisphere and the black hemisphere are electrically opposite. . The preparation method includes preparing black microspheres and dispersing them into a first solvent; transferring the microspheres to a substrate to obtain a film with microspheres; and plating silver on the side of the film away from the substrate to form a silver-coated film on the microspheres. The layers form a white hemisphere and a black hemisphere not covered with silver; the microspheres are modified with surface ligands to make the white hemisphere and black hemisphere electrically opposite to form a charged sphere; the charged sphere is transferred to the second solvent to obtain electronic ink. The single microsphere system of the present application can reduce the complexity of the material system, and can directly change the rotation direction of the microspheres. It does not require the microspheres to move between the upper electrode and the lower electrode, and can effectively reduce the response time of the display.

Description

Electronic ink and preparation method thereof and reflective display

Technical field

The present application belongs to the field of display technology, and specifically relates to an electronic ink, a preparation method thereof, and a reflective display.

Background technique

Reflective display technology is a display technology that has no backlight and directly acts as a screen light source by reflecting ambient light. Under a good ambient light source, it has a better display effect and can also reduce power consumption to save power on the entire product. Electronic paper is a reflective display. It is an ultra-thin, ultra-light display, which is understood as "a paper-thin, soft, erasable display."

At present, the electronic ink of black and white electronic paper displays is mainly composed of black and white microspheres with different electrical properties. When a negative electric field is applied to both ends of the microcapsule, the positively charged white particles move under the action of the electric field. to the negative electrode of the electric field. At the same time, the negatively charged particles move to the bottom of the microcapsule and are "hidden". At this time, the surface will appear white. When a positive electric field is applied to both sides of adjacent microcapsules, the black particles will move to the top of the microcapsules under the action of the electric field, and the surface will appear black. It uses a multi-particle system, which makes the system more complex and prone to agglomeration. During the operation of the display device, electrophoretic particles will move a long distance under the action of the electric field, which will cause the display's response time to slow down.

Contents of the invention

Purpose of the invention: The embodiments of this application provide an electronic ink, a preparation method thereof, and a reflective display, aiming to solve the existing problems of using a multi-particle system, resulting in a complex system, prone to agglomeration, and slow response time of the display. .

Technical solution: an electronic ink described in the embodiment of the present application, including:

Charged spheres, the charged spheres include:

white hemisphere;

A black hemisphere, the white hemisphere and the black hemisphere are connected to form the charged sphere, and the white hemisphere and the black hemisphere have opposite electrical properties;

The second solvent is used to disperse the charged spheres in the second solvent to form the electronic ink.

In some embodiments, the white hemisphere includes a silver film layer and a body. The silver film layer covers the outside of the body. The black hemisphere is made of a transparent material and a black dye. The transparent material is selected from polyethylene. Any one or a combination of styrene, polymethyl methacrylate, silica and titanium dioxide.

In some embodiments, the outer layer of the silver film layer is connected with amino groups, and the outer layer of the black hemisphere is connected with carboxyl groups; or, the outer layer of the white hemisphere is connected with carboxyl groups, and the outer layer of the black hemisphere is connected with carboxyl groups. There are amino groups.

Correspondingly, a method for preparing electronic ink described in the embodiments of this application includes:

Providing black microspheres and dispersing the microspheres into a first solvent;

Transferring the microspheres to a substrate and forming a thin film with the microspheres on the substrate;

Coating the side of the film away from the substrate with silver so that the microspheres form a white hemisphere covered with a silver film layer and a black hemisphere not covered with silver;

Modify the microspheres with surface ligands so that the white hemisphere and the black hemisphere are electrically opposite to form a charged sphere;

The charged spheres are transferred to a second solvent to obtain electronic ink.

In some embodiments, the method of providing black microspheres includes:

Provide the main material of the microsphere;

Polymerize the main material to form a microsphere matrix;

A black dye is added during the polymerization process of the microsphere matrix to form black microspheres.

In some embodiments, the main material is selected from one or a combination of polystyrene, polymethylmethacrylate, silicon dioxide and titanium dioxide, and the black dye is selected from carbon black and iron oxide black. One or a combination of both.

In some embodiments, a monomer with a carboxyl group or a monomer with an amino group is added to the microsphere during polymerization, so that the formed microsphere has a carboxyl group or an amino group.

In some embodiments, the thickness of the silver film layer is 50 nm to 200 nm, and the diameter of the microsphere is 500 nm to 10 _μm .

In some embodiments, the first solvent is a poor solvent.

In some embodiments, the microspheres are surface modified to make the white hemisphere and the black hemisphere electrically opposite, including:

Provide a third solvent,

Transfer the silver-plated microspheres from the substrate to the third solvent;

Put a ligand into the third solvent to perform surface modification on the microsphere, so that the outer layer of the silver film layer is connected with an amino group, and the outer layer of the black hemisphere is connected with a carboxyl group; or, the outer layer of the white hemisphere is connected with a carboxyl group. Carboxyl groups are connected to the outer layer, and amino groups are connected to the outer layer of the black hemisphere.

In some embodiments, transferring the charged sphere to a second solvent to obtain electronic ink also includes the following steps:

After surface modification of the microsphere, filter out the third solvent containing excess ligand;

The cleaned charged sphere is transferred to the second solvent, and a dispersant is added for dispersion to obtain the electronic ink.

In some embodiments, the second solvent and the third solvent each include one or a combination of propylene glycol methyl ether acetate, propylene glycol methyl ether or ethyl acetate, and the ligand includes an amino acid-containing ligand. terminal ligands and/or ligands with carboxyl terminal groups.

Correspondingly, a reflective display described in the embodiment of this application includes:

An electrode substrate with a thin film transistor;

Microcapsules, the microcapsules are encapsulated with the electronic ink as described in any of the preceding embodiments, or the microcapsules are encapsulated with the electronic ink prepared by the electronic ink preparation method as described in any of the preceding embodiments.

Beneficial effects: Compared with the prior art, an electronic ink according to the embodiment of the present application includes a charged sphere. The charged sphere includes a white hemisphere and a black hemisphere. The white hemisphere and the black hemisphere are connected to form a charged sphere. The electricity between the white hemisphere and the black hemisphere is Sex is the opposite. In the electronic ink of this application, the white hemisphere and the black hemisphere are electrically opposite, that is, they are positively or negatively charged respectively. Under the action of the electric field, the negatively charged hemisphere faces the positive electrode, and the positively charged hemisphere faces the negative electrode. Therefore, by adjusting the direction of the electric field, You can change the orientation of the microspheres, thereby changing the color of the display reflection (black or white). Color adjustment can be achieved through a single charged sphere, reducing the complexity of the material system, and directly changing the rotation of the microsphere by adjusting the direction of the electric field. There is no need for the microsphere to move between the upper and lower electrodes, which can effectively reduce the response of the display. time.

Compared with the prior art, the preparation method of electronic ink in the embodiment of the present application includes: providing black microspheres, and dispersing the microspheres into a first solvent; providing a substrate, and transferring the microspheres to the substrate , to obtain a thin film with microspheres; silver is plated on the side of the film away from the substrate so that half of the microspheres are covered with silver film to form a white hemisphere, and the other half of the microspheres are not covered with silver to form a black hemisphere; the microspheres are The surface ligands are modified to make the white hemisphere and the black hemisphere have opposite electrical properties, thereby forming charged spheres; the charged spheres are transferred to the second solvent to obtain electronic ink. This method achieves dividing the microspheres into white hemispheres and black hemispheres by coating half sides of the black microspheres with a silver film layer. At the same time, the surface of the microspheres is modified with ligands so that the black hemispheres and the white hemispheres are oppositely charged to form a charged sphere. Charged spheres are dispersed in a solvent to form electronic ink. The electronic ink prepared by this method can change the orientation of the microspheres by changing the direction of the electric field, thereby changing the color of the display and reducing the response time of the display.

Compared with the prior art, a reflective display according to the embodiment of the present application uses the aforementioned electronic ink. Therefore, it can be understood that it has all the functions and effects of the aforementioned electronic ink, which will not be described again here.

Description of the drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings needed to be used in the description of the embodiments will be briefly introduced below. Obviously, the drawings in the following description are only some embodiments of the present application. For those skilled in the art, other drawings can also be obtained based on these drawings without exerting creative efforts.

Figure 1 is a schematic structural diagram of a reflective display of the present application;

Figure 2 is a schematic structural diagram of a charged sphere of the present application;

Figure 3 is an exploded view of a charged sphere of the present application;

Figure 4 is a schematic structural diagram of a charged sphere of the present application before and after ionization;

Figure 5 is a schematic diagram of the production process of a charged sphere according to the present application;

Figure 6 is a schematic structural diagram of a black microsphere of the present application after silver plating;

Figure 7 is a schematic diagram of the working state of a reflective display of the present application.

Reference signs: 1-charged sphere, 11-white hemisphere, 111-silver film layer, 12-black hemisphere, 2-second solvent, 3-microsphere, 4-first solvent, 5-substrate, 6-electrode substrate , 7-Microcapsules.

Detailed ways

The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present application. Obviously, the described embodiments are only some of the embodiments of the present application, but not all of the embodiments. Based on the embodiments in this application, all other embodiments obtained by those skilled in the art without making creative efforts fall within the scope of protection of this application.

In the description of this application, it needs to be understood that the terms "length", "width", "thickness", "upper", "lower", "front", "back", "left", "right", " The orientations or positional relationships indicated by "top", "bottom", "inner", "outside", etc. are based on the orientations or positional relationships shown in the drawings. They are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that The devices or elements referred to must have a specific orientation, be constructed and operate in a specific orientation and therefore should not be construed as limiting the application. In addition, the terms “first” and “second” are used for descriptive purposes only and cannot be understood as indicating or implying relative importance or implicitly indicating the quantity of indicated technical features. Therefore, the features defined as “first” and “second” may explicitly or implicitly include one or more features. In the description of this application, "plurality" means two or more, and at least one means one, two, or more than two, unless otherwise clearly and specifically limited. In the description of this application, "vertical" means completely vertical to 90° or almost completely vertical. For example, any angle within the range of 80° to 100° is considered vertical. Similarly, "parallel" means completely vertical. Parallel or almost perfectly parallel, for example, within 10° of perfectly parallel is considered parallel.

The applicant noticed that the current electronic ink in the black and white electronic paper display area mainly consists of black and white microspheres with different electrical properties. When a negative electric field is applied to both ends of the microcapsules, the white ones with positive charges will The particles move to the negative electrode of the electric field under the action of the electric field. At the same time, the negatively charged particles move to the bottom of the microcapsule and are "hidden". At this time, the surface will appear white. When a positive electric field is applied to both sides of adjacent microcapsules, the black particles will move to the top of the microcapsules under the action of the electric field, and the surface will appear black. It uses a multi-particle system, which makes the system more complex and prone to agglomeration. And during the operation of the display device, the electrophoretic particles will move a long distance under the action of the electric field, which will cause the display's response time to slow down.

In view of this, embodiments of the present application provide an electronic ink, a preparation method thereof, and a reflective display to solve at least one of the above problems.

Please refer to Figure 1, Figure 2 and Figure 3. An electronic ink according to the embodiment of the present application includes a charged sphere 1 and a second solvent 2. The charged sphere 1 includes a white hemisphere 11 and a black hemisphere 12. The white The hemisphere 11 and the black hemisphere 12 are connected to form the charged sphere 1. The white hemisphere 11 and the black hemisphere 12 have opposite electrical properties; the second solvent 2 is used to disperse the charged sphere 1 in the second The electronic ink is formed in solvent 2.

In one embodiment, the black hemisphere 12 and the white hemisphere 11 have different charges respectively, and the white hemisphere 11 is white and the black hemisphere 12 is black. Under the action of the electric field, the white hemisphere 11 and the black hemisphere 12 face different directions respectively. direction, and all the white hemispheres 11 under the action of the same electric field have the same orientation, and the black hemispheres 12 have the same orientation. As the direction of the electric field changes, it displays black or white.

It should be noted that the charged sphere 1 of the electronic ink of the present application directly sets the charged sphere 1 to be half white and half black. Therefore, the corresponding electronic ink is black and white electronic ink. According to the adjustment of the direction of the electric field, the direction of the corresponding charged sphere 1 is rotated and adjusted, thereby adjusting the black and white display.

Specifically, for example, the white hemisphere 11 is positively charged, and the black hemisphere 12 is negatively charged. When an electric field is applied, the positively charged white hemisphere 11 faces the negative electrode and is arranged in a white array, and the negatively charged black hemisphere 12 faces the positive electrode and is arranged in a white array. It forms a black array. At this time, if the positive electrode is at the top, the black hemisphere 12 faces upward, showing black. When the direction of the electric field is changed, the white hemisphere 11 faces upward, thereby reflecting the ambient light. When the ambient light is white, white is displayed.

It should also be noted that in the embodiment of the present application, the black hemisphere 12 and the white hemisphere 11 are connected to form the charged sphere 1. The connection method between the black hemisphere 12 and the white hemisphere 11 can be splicing connection or integrated connection.

In some embodiments, the white hemisphere 11 includes a silver film layer 111 and a body 112. The silver film layer 111 covers the outside of the body 112, making the white hemisphere 11 appear white. The material of the black hemisphere 12 includes black dye and transparent material, the transparent material is selected from one or a combination of polystyrene, polymethyl methacrylate, silicon dioxide, and titanium dioxide. The black dye and the transparent material are mixed to dye the transparent material black, so that the black hemisphere 12 appears black. The white hemisphere 11 appears white and the black hemisphere 12 appears black, and the two are oppositely charged, so that under the action of the electric field, the charged sphere 1 rotates, thereby appearing black or white.

It should be noted that the charged sphere 1 of the present application may initially be a black microsphere 3 that is partially covered with silver to form a white hemisphere 11 and a black hemisphere 12 . Black microspheres 3 are mainly made of black dye added during the polymerization process to turn them black. Half of the surface of the black microsphere 3 is coated with a silver film layer 111 to turn it into silver white, so that the white hemisphere 11 and the black hemisphere 12 appear. That is, the body 112 of the white hemisphere 11 is black, and forms the black microsphere 3 with the black hemisphere 12. The microsphere 3 is silver-plated and half of the silver film layer 111 is covered, so that the white hemisphere 11 and the black hemisphere appear. 12.

In addition, it should be noted that the raw material of the black microsphere 3 of the present application is a transparent material, which can be selected from non-soluble transparent materials such as polystyrene, polymethyl methacrylate, silica and titanium dioxide, and is light in weight. , and after being mixed with black dye, the color of the black dye can be revealed. This can ensure that the black microspheres appear black as a whole when the amount of black dye is small, thereby preventing the overall weight of the black microspheres from being heavier and affecting their performance. Rotate and move under the influence of electric field.

In some embodiments, the outer layer of the silver film layer 111 is connected with amino groups, and the outer layer of the black hemisphere 12 is connected with carboxyl groups; or the outer layer of the white hemisphere 11 is connected with carboxyl groups, and the outer layer of the black hemisphere 12 is connected with carboxyl groups. The outer layer has amino groups attached to it.

It should be noted that this application uses different ligands to modify the white hemisphere 11 and the black hemisphere 12 based on the surface differences of the white hemisphere 11 and the black hemisphere 12, so that the two hemispheres are respectively positively and negatively charged. The ligands include ligands with amino end groups and ligands with carboxyl end groups.

It should be noted that the amino group is ionized in the second solvent 2 to generate positively charged ammonium ions, thereby making the corresponding hemisphere with the amino group positively charged, and the carboxyl group is ionized in the second solvent 2 to generate carboxylate radicals, thus corresponding to The hemisphere with the carboxyl group is negatively charged, so that under the action of the electric field, the charged sphere 1 can adjust its orientation according to the direction of the electric field.

According to this application, the surface modification ligands of the black hemisphere 12 and the white hemisphere 11 are different, and the charging of the corresponding hemispheres is also different. Specifically, in this embodiment, the outer surface of the silver film layer 111 is modified with a ligand with an amino terminal group, so that the surface of the black hemisphere 12 has an amino group, and the corresponding white hemisphere 11 is positively charged, and the black hemisphere 12 has an amino group. The outer surface is modified with a ligand with a carboxyl end group, so that the surface of the black hemisphere 12 has carboxyl groups, and the corresponding black hemisphere 12 is negatively charged; or, the outer layer of the white hemisphere 11 is connected with carboxyl groups, and the corresponding white hemisphere 11 It is negatively charged. If the outer layer of the black hemisphere 12 is connected with an amino group, the corresponding black hemisphere 12 is positively charged.

Correspondingly, please refer to Figure 5. A method for preparing electronic ink according to the embodiment of the present application includes:

Provide black microspheres 3, and disperse the microspheres 3 into the first solvent 4;

Provide a substrate 5, transfer the microspheres 3 to the substrate 5, and form a thin film with the microspheres 3 on the substrate 5;

Silver is plated on the side of the film away from the substrate 5, so that the microsphere 3 forms a white hemisphere 11 covering the silver film layer 111, and the other half of the microsphere 3 is not covered with silver to form a black hemisphere 12;

The microsphere 3 is modified with surface ligands to make the white hemisphere 11 and the black hemisphere 12 electrically opposite, thereby forming a charged sphere 1;

The charged sphere 1 is transferred to the second solvent 2 to obtain electronic ink.

In the embodiment of the present application, black microspheres 3 are first prepared. After the black microspheres 3 are dispersed into the first solvent 4, the microspheres 3 float on the surface of the solvent to form a single-layer array of microspheres 3. The microspheres 3 are transferred to the substrate 5 by the pull method or LBL (layer-by-layer) molecular deposition method to obtain a thin film with black microspheres 3, and then metallic silver is deposited on the microspheres 3 using the vapor deposition method. , half of the black microspheres 3 were covered with silver, thereby obtaining microspheres 3 that were half covered with silver and half black (as shown in Figure 2). Then the microspheres 3 on the substrate 5 are transferred to the second solvent 2 using methods such as ultrasound. Because of the surface differences between the black microspheres 3 and silver, different ligands can be used to modify the surface of the microspheres 3. As a result, the two hemispheres are positively and negatively charged respectively, and a charged sphere 1 is obtained. Then transfer the charged sphere 1 to a new second solvent 2 to obtain electronic ink.

It should be noted that the substrate 5 in the embodiment of the present application is usually a glass substrate, which facilitates subsequent peeling off of the microspheres 3 . At the same time, the first solvent 4 in this application is usually a poor solvent such as water to prevent the microspheres 3 from dissolving.

It should be noted that the half in the embodiment of the present application is not a half sphere in the absolute sense, but a partial surface of the microsphere.

In some embodiments, the preparation of black microspheres 3 includes:

Provide the main material of the microsphere 3;

Polymerize the main material to form a microsphere matrix;

A black dye is added during the polymerization process of the microsphere matrix to form black microspheres 3 .

Wherein, the main material includes polystyrene, polymethyl methacrylate, silicon dioxide or titanium dioxide, and the black dye is carbon black or iron oxide black.

In the embodiment of the present application, during the polymerization process of black microspheres 3, black dyes such as carbon black or iron oxide black can be added to obtain black microspheres 3. Furthermore, this application can optionally use styrene to polymerize to obtain polystyrene microspheres 3, or PMMA (polymethyl methacrylate), SiO2 (silicon dioxide), TiO2 (titanium dioxide) and other materials for microspheres. Ball 3. The above-mentioned materials are all colorless and transparent materials, which are easily dyed black by black dye and the black color is revealed to obtain black microspheres 3.

In some embodiments, a monomer with a carboxyl group or a monomer with an amino group is added to the microsphere 3 during polymerization, so that the formed microsphere 3 has a carboxyl group or an amino group.

It should be noted that in this embodiment, by adding carboxyl derivatives or amino derivatives during the initial polymerization of microspheres 3, microspheres 3 can be directly equipped with carboxyl or amino groups after polymerization of microspheres 3. In this way, only one ligand needs to be modified when modifying the surface of microsphere 3, simplifying the surface ligand modification process.

Specifically, in some embodiments, polystyrene microspheres 3 can first be obtained by emulsion polymerization of styrene derivatives with carboxyl groups. Because the styrene carboxyl groups used are derivatized as monomers, the polystyrene microspheres 3 obtained are The surface has carboxyl groups. At this time, there is no need to modify it with ligands with carboxyl end groups.

In some embodiments, the thickness of the silver film layer 111 is 50 nm to 200 nm, and the diameter of the microsphere 3 is 500 nm to 10 μm. The size of the black microspheres 3 obtained by polymerization in the above embodiment is between 500 nanometers and 10 micrometers, and the thickness of the silver film layer 111 is between 50 nanometers and 200 nanometers, ensuring that the size of the microspheres 3 is much larger than the silver film layer 111 The thickness of the glass substrate is such that when silver is plated on a vertical glass substrate, the side of the microsphere 3 close to the substrate is blocked by the side of the microsphere 3 away from the substrate, so that the silver film cannot be plated on the side of the microsphere 3 close to the substrate. , and the plated silver film layer 111 is very thin, very small compared to the distance between the center of the microsphere 3 and the substrate, which can prevent the silver film attached to the body 112 from falling adjacent to the silver film when plating the silver film. The silver film on the substrate between the two microspheres 3 is adhered, thereby avoiding the situation where the entire silver film is directly formed on the substrate during silver plating and the microspheres 3 cannot be removed from the substrate. The details are shown in Figure 6.

In some embodiments, surface modification is performed on the microsphere 3 to make the white hemisphere 11 and the black hemisphere 12 electrically opposite, including:

Provide a third solvent,

Transfer the silver-plated microspheres 3 from the substrate 5 to a third solvent;

Put a ligand into the third solvent to perform surface modification on the microsphere 3, wherein the ligand includes a ligand with an amino end group and/or a ligand with a carboxyl end group; so that the The outer layer of the silver film layer 111 is connected with amino groups, and the outer layer of the black hemisphere 12 is connected with carboxyl groups; or the outer layer of the white hemisphere 11 is connected with carboxyl groups, and the outer layer of the black hemisphere 12 is connected with amino groups;

The carboxyl group is ionized in the second solvent 2, so that the corresponding hemisphere is negatively charged, and the amino group is ionized in the second solvent 2, so that the corresponding hemisphere is positively charged.

Specifically, the following situations occur when surface ligand modification is performed on microsphere 3:

1) When monomers with carboxyl groups are added to polymerize into black microspheres 3, it is only necessary to modify the outer surface of the black hemisphere 12 with ligands with amino end groups on the outside of the black hemisphere 12 to achieve positive alignment of the white hemisphere 11. Electricity, black hemisphere 12 is negatively charged;

2) When monomers with amino groups are added to polymerize into black microspheres 3, it is only necessary to modify the outer surface of the black hemisphere 12 with ligands with carboxyl end groups on the outside of the black hemisphere 12 to make the white hemisphere 11 negatively charged. , the black hemisphere 12 is positively charged;

3) When black microspheres 3 are directly polymerized with monomers without added carboxyl or amino groups, there are two situations at this time;

(1) Modify the surface of the black hemisphere 12 with a ligand with an amino end group, and modify the surface of the black hemisphere 12 with a ligand with a carboxyl end group; realize that the white hemisphere 11 is positively charged and the black hemisphere 12 is negatively charged;

(2) Modify the surface of the black hemisphere 12 with a ligand with a carboxyl end group, and modify the surface of the black hemisphere 12 with a ligand with an amino end group; realize that the white hemisphere 11 is negatively charged and the black hemisphere 12 is positively charged.

Taking the black hemisphere 12 with carboxyl groups as an example, SH-PEG-NH2 ligands can be used to modify the surface of the silver film layer 111. Due to the strong interaction between sulfhydryl groups and silver, the ligands are adsorbed to the silver surface. This modification occurs at room temperature. , so NH2 will not react with the carboxyl group of the black hemisphere 12. Thus, white hemispheres 11 with NH2 and black hemispheres 12 with carboxyl groups were obtained. As shown in Figure 4.

In some embodiments, the charged sphere 1 is transferred to the second solvent 2 to obtain the electronic ink, and the charged sphere 1 also needs to be cleaned, which specifically includes: surface modification of the microsphere 3 After obtaining the charged sphere 1, filter out the third solvent containing excess ligand, and use the third solvent to wash away the residual ligand; transfer the washed charged sphere 1 to the second solvent 2, and A dispersant is added for dispersion to obtain the electronic ink.

In some embodiments, both the second solvent 2 and the third solvent include one or a combination of several lipid solvents such as propylene glycol methyl ether acetate, propylene glycol methyl ether or ethyl acetate, or are other suitable lipid solvents. After the propylene glycol methyl ether acetate liquid is modified with ligands, the charged sphere 1 can be cleaned to remove residual liquid and excess ligands. In addition, when forming the electronic ink, propylene glycol methyl ether acetate liquid is used as a solvent to disperse the charged spheres 1 in it, thereby facilitating the steering and movement of the charged spheres 1 .

Correspondingly, please refer to Figures 1 and 7 in combination. A reflective display according to an embodiment of the present application includes: an electrode substrate 6 and a microcapsule 7. The electrode substrate 6 is equipped with a thin film transistor; the microcapsule 7 The electronic ink as described in any of the preceding embodiments is encapsulated inside, and/or the electronic ink prepared by the electronic ink preparation method as described in any of the preceding embodiments. Microcapsules 7 are located between two adjacent electrode substrates 6 .

The reflective display of the embodiment of the present application includes the black and white electronic ink of the aforementioned embodiment. This embodiment uses the charged sphere 1 in which the white hemisphere 11 is positively charged and the black hemisphere 12 is negatively charged as an example to describe the working process of the reflective display. As shown in Figure 7.

Specifically, when no electric field is initially added, the charged spheres 1 are randomly distributed in the second solvent 2. When an electric field is applied to them, under the action of the electric field, the negatively charged black hemisphere 12 faces the positive electrode and is positively charged. The silver hemisphere faces the negative pole. The upper electrode substrate is the positive electrode, and the black hemisphere 12 faces the positive electrode and upward. At this time, an array of black microspheres 3 facing upward is obtained, showing black. When the direction of the electric field is changed, the white hemisphere 11 faces upward, thereby reflecting the ambient light. When the ambient light is white, white is displayed. When the positive electricity of the charged sphere 1 is greater than the negative electricity, the charged sphere 1 moves toward the negative electrode under the action of the electric field force, and will move to the negative electrode. On the contrary, when the negative electricity is greater than the positive electricity, the charged sphere 1 will move to the positive electrode. When the difference between positive electricity and negative electricity is not big, the charged sphere 1 will only rotate and there will be no obvious movement.

In the above embodiments, each embodiment is described with its own emphasis. For parts that are not described in detail in a certain embodiment, please refer to the relevant descriptions of other embodiments.

The electronic ink, its preparation method and the reflective display provided by the embodiments of the present application have been introduced in detail, and specific examples have been used to illustrate the principles and implementation methods of the present application. The description of the above embodiments is only for To help understand the technical solutions and core ideas of this application; those of ordinary skill in the art should understand that they can still modify the technical solutions recorded in the foregoing embodiments, or make equivalent substitutions for some of the technical features; and these modifications Or substitution does not cause the essence of the corresponding technical solution to depart from the scope of the technical solution of each embodiment of the present application.

Claims (13)

1. An electronic ink, characterized in that it includes: a charged sphere, and the charged sphere includes: white hemisphere; Black hemisphere, the white hemisphere and the black hemisphere are connected to form the charged sphere, and the white hemisphere and the black hemisphere have opposite electrical properties. 2. The electronic ink according to claim 1, wherein the white hemisphere includes a silver film layer and a body, the silver film layer covers the outside of the body, and the black hemisphere is made of a transparent material and Black dye, the transparent material is selected from any one or a combination of polystyrene, polymethylmethacrylate, silicon dioxide and titanium dioxide. 3. The electronic ink of claim 2, wherein the outer layer of the white hemisphere is connected to an amino group, and the outer layer of the black hemisphere is connected to a carboxyl group; or, the outer layer of the white hemisphere is connected to a carboxyl group. , the outer layer of the black hemisphere is connected with amino groups. 4. An electronic ink preparation method, characterized by comprising: Providing black microspheres and dispersing the microspheres into a first solvent; Transferring the microspheres to a substrate and forming a thin film with the microspheres on the substrate; Coating the side of the film away from the substrate with silver so that the microspheres form a white hemisphere covered with a silver film layer and a black hemisphere not covered with silver; Modify the microspheres with surface ligands to make the white hemisphere and the black hemisphere electrically opposite to form a charged sphere; The charged sphere is transferred to a second solvent to obtain the electronic ink. 5. The electronic ink preparation method according to claim 4, characterized in that said providing black microspheres includes: Provide the main material of the microsphere; Polymerize the main material to form a microsphere matrix; A black dye is added during the polymerization process of the microsphere matrix to form black microspheres. 6. The electronic ink preparation method according to claim 5, characterized in that the main material is selected from one or a combination of polystyrene, polymethylmethacrylate, silicon dioxide and titanium dioxide, so The black dye is selected from one or a combination of carbon black and iron oxide black. 7. The electronic ink preparation method according to claim 5, characterized in that, during polymerization of the microspheres, a monomer with a carboxyl group or a monomer with an amino group is added, so that the formed microspheres have a carboxyl group. or amino. 8. The electronic ink preparation method according to claim 4, characterized in that the thickness of the silver film layer is 50nm~200nm, and the diameter of the microsphere is 500nm~10 _μm . 9. The electronic ink preparation method according to claim 4, wherein the first solvent is a poor solvent. 10. The electronic ink preparation method according to claim 4, characterized in that surface modification is performed on the microsphere to make the white hemisphere and the black hemisphere electrically opposite, including: Provide a third solvent; Transfer the silver-plated microspheres from the substrate to the third solvent; Ligands are added to the third solvent to perform surface modification on the microspheres, so that the outer layer of the white hemisphere is connected with amino groups, the outer layer of the black hemisphere is connected with carboxyl groups, or the outer layer of the white hemisphere is connected with carboxyl groups. The layer has carboxyl groups attached, and the outer layer of the black hemisphere has amino groups attached. 11. The electronic ink preparation method according to claim 10, characterized in that transferring the charged sphere to a second solvent to obtain the electronic ink further includes the following steps: After surface modification of the microsphere, filter out the third solvent containing excess ligand; The cleaned charged sphere is transferred to the second solvent, and a dispersant is added for dispersion to obtain the electronic ink. 12. The electronic ink preparation method according to claim 11, characterized in that the second solvent and the third solvent are selected from one of propylene glycol methyl ether acetate, propylene glycol methyl ether or ethyl acetate, or A combination of several, the ligand includes a ligand with an amino end group and/or a ligand with a carboxyl end group. 13. A reflective display, characterized by comprising: An electrode substrate with a thin film transistor; Microcapsules, the electronic ink as described in any one of claims 1-3 is encapsulated in the microcapsules, or the electronic ink preparation method as described in any one of claims 4-12 is encapsulated in the microcapsules Prepared electronic ink.