Polar nanorod quantum dot-based electronic paper display and preparation method thereof

Abstract

The application relates to a polar nanorod quantum dot-based electronic paper display and a preparation method thereof, and belongs to the field of display devices. The method relates to a polar nanorod, polarization of which is realized by performing an electret treatment on an electret material. Different color quantum dots or black and white particles are added to the two ends of the electret material. The structure can respond to different applied electric fields, trigger changes in flip angles, and thus cause changes in the degree of reflection of external ambient light. Thanks to the core electret material, the application can guarantee the stability of display and significantly improve the picture contrast. Under the action of an electric field, the charged quantum dots and black and white particles located at the two ends of the electret material can flip under the driving of the electric field, and the mechanism not only reduces the flip time of the polar nanorod, but also improves the response speed. With the application of different voltages, the application technology can realize color display.

Description

TECHNICAL FIELD

[0001] The application belongs to the field of display devices, and particularly relates to an electronic paper display based on polar nanorod quantum dots and a preparation method thereof. BACKGROUND

[0002] Electronic paper is a kind of paper-like display with memory function and reflection type, and can repeatedly change the content, which has great development prospects in electronic reading, personal electronics and product media.

[0003] The display principle of electronic paper includes microcapsulated electronic ink, rotating ball display, toner display, micro-cup type electrophoretic display, electrochromic display, electrophoretic deposition display, electrowetting display, cholesteric liquid crystal display and micro-electro-mechanical system display.

[0004] Electronic paper display technology based on electrophoretic ink material can keep the electrophoretic particles stable for a long time after power-off, so that the picture can be normally displayed. The black and white colors are commonly seen. However, the existing electrophoretic particles have slow response speed and large power consumption, which leads to the delay of electronic paper display. In order to realize colorization, a color filter film needs to be added, which reduces the light transmittance. SUMMARY

[0005] The application aims at the problems in the prior art, and provides an electronic paper display based on polar nanorod quantum dots and a preparation method thereof, which can realize colorization of electronic paper, greatly shorten the response time of electronic paper and improve the display effect.

[0006] In order to achieve the above-mentioned purpose, the technical scheme of the application is as follows: an electronic paper display based on polar nanorod quantum dots, in which the polar nanorod quantum dots in the display layer of the electronic paper display are subjected to a poling treatment to realize polarization.

[0007] In an embodiment of the application, different color quantum dots or black and white particles are added to the two ends of the poling material, so as to respond to different electric fields and cause the change of flip angle, thereby causing the change of the reflection degree of external ambient light.

[0008] In an embodiment of the application, the electronic paper display further includes a first substrate and a second substrate, the display layer is located between the first substrate and the second substrate, a first electrode is arranged on the side of the first substrate away from the display layer, a color filter film is arranged on the first electrode, and a second electrode is arranged on the side of the second substrate away from the display layer.

[0009] The application further provides a preparation method of the electronic paper display based on polar nanorod quantum dots, which includes the following steps:

[0010] Step 1, hydrophobic / hydrophilic treatment is performed on one end surface of the electret material, and hydrophilic / hydrophobic treatment is performed on the other end surface of the electret material;

[0011] Step 2, electret treatment is performed on the electret material after step 1, so that the electret material has different electrical properties at both ends;

[0012] Step 3, black particles or white particles and an anionic surfactant are added to IsoparL to obtain negatively charged black particles or negatively charged white particles;

[0013] Step 4, quantum dots and a cationic surfactant are mixed, ion exchange is realized by ultrasonic or stirring, and after standing, filtration is performed, so that the cation is adsorbed on the surface of the quantum dots by physical adsorption to make the quantum dots positively charged, and positively charged quantum dots are obtained;

[0014] Step 5, the electret material, the negatively charged black particles or the negatively charged white particles, and the positively charged quantum dots are placed in a dispersion medium to obtain a polar nanorod.

[0015] In an embodiment of the present application, in step 1, the hydrophobic / hydrophilic treatment is performed on the single end surface of the electret material in the following manner:

[0016] (1) The hydrophilic treatment method for the single end surface of the electret material

[0017] (1.1) Chemical modification using chemicals with hydrophilic functional groups (such as hydroxyl, carboxyl, amino, etc.) to chemically graft the single end surface of the electret material or copolymerization of hydrophilic monomers on the single end surface of the electret material to improve the hydrophilic property, and then plasma treatment (oxygen, water vapor, etc.) or high-temperature oxidation, chemical oxidation to form an oxide film with hydrophilic properties on the single end surface of the electret material, or using a surfactant (silane, sulfonate, etc.) to reduce the surface energy of the electret material to make the single end surface of the electret material hydrophilic;

[0018] (1.2) Coating a hydrophilic material (fluorocarbon polymer, polyvinyl alcohol, etc.) on the single end surface of the electret material by a physical method, and then using physical vapor deposition, electrochemical deposition, or solution immersion method for coating;

[0019] (1.3) Changing the morphology of the single end surface of the electret material by laser etching to form a microstructure to make the single end surface of the electret material hydrophilic;

[0020] (1.4) Preparing a nanostructure by a method including sputtering, electrodeposition, and anodic oxidation to make the single end surface of the electret material hydrophilic;

[0021] (2) The hydrophobic treatment method for the single end surface of the electret material

[0022] (2.1) through chemical modification of the single end surface of the electret material using chemicals with hydrophobic functional groups (such as alkyl, fluorocarbon chains, etc.) for chemical grafting or copolymerization of hydrophobic monomers on the electret material to improve the hydrophobic properties, and then forming a hydrophobic fluorocarbon film through plasma treatment with fluorinated gas;

[0023] (2.2) coating a hydrophobic material (such as fluorocarbon polymer, polyvinyl alcohol, etc.) on the single end surface of the electret material through a physical method, and then using plasma to chemically react with the surface to enhance the hydrophobic properties;

[0024] (2.3) changing the morphology of the single end surface of the electret material through laser etching to form a microstructure to make the single end surface of the electret material hydrophobic;

[0025] (2.4) making the single end surface of the electret material hydrophobic through methods including sputtering, electrodeposition, anodic oxidation, etc. to prepare nanostructures.

[0026] In an embodiment of the present application, step 2 is implemented as follows:

[0027] The electret material to be treated for hydrophilicity or hydrophobicity is placed in a polar solution or a non-polar solution. The electret material treated for hydrophilicity or hydrophobicity has different single end densities and different hydrophilicity or hydrophobicity, resulting in vertical orientation of the electret material. At this time, one end of the electret material treated for hydrophilicity or hydrophobicity is placed in a polar solution, and the electret material is treated for electret through methods including corona electret, thermal electret, and light electret. Then, one end of the electret material not treated for hydrophilicity or hydrophobicity is placed in a non-polar solution, and the electret material is treated for electret through methods including corona electret, thermal electret, and light electret, so that the two ends of the electret material have different electrical properties.

[0028] In an embodiment of the present application, step 3 is implemented as follows:

[0029] Black particles or white particles and anionic surfactants are added to Isopar L, stirred at 80°C for 6h, centrifuged to remove supernatant, washed with anhydrous ethanol multiple times, centrifuged at 8000r / min, and vacuum dried for 24h to obtain negatively charged black particles or negatively charged white particles.

[0030] In an embodiment of the present application, the electret material is made of materials including Brazilian brown wax, K-1 polycarbonate, polymethyl methacrylate, polytetrafluoroethylene, polyvinylidene fluoride, polyperfluoroethylene propylene, polypropylene, polyethylene, barium titanate (BaTiO3), lead zirconium titanate, zinc oxide, tantalum oxide, aluminum oxide, and titanium oxide, or silicon nitride, etc.

[0031] In an embodiment of the present application, the black particles comprise carbon black particles; the white particles comprise TiO2 particles; the quantum dots adopt materials comprising II-VI compounds, III-V compounds, inorganic compounds, organic compounds, etc., preferably silicon quantum dots, germanium quantum dots, cadmium sulfide quantum dots, cadmium selenide quantum dots, cadmium telluride quantum dots, zinc selenide quantum dots, lead sulfide quantum dots, lead selenide quantum dots, indium phosphide quantum dots, and indium arsenide quantum dots; the quantum dots comprise red, green, and blue quantum dots, and the particle sizes are 8-10 nm, 6-8 nm, and 4-6 nm, respectively.

[0032] In an embodiment of the present application, the polar nanorod has an aspect ratio in the range of 50:1-200:1.

[0033] Compared with the prior art, the present application has the following beneficial effects: the present application designs a polar nanorod, compared with electrophoretic particles, the rotation angle of the polar nanorod is realized by controlling the voltage change of the upper and lower plates, different display effects are realized, a faster response speed than the migration of electrophoretic particles can be obtained, and the power consumption is greatly reduced to realize more efficient full-color display. BRIEF DESCRIPTION OF DRAWINGS

[0034] Figure 1 It is a schematic diagram of the polar black and white nanorod of the embodiment of the present application;

[0035] Figure 2 It is a schematic diagram of the polar black and white nanorod electronic paper display of the embodiment of the present application without voltage;

[0036] Figure 3 It is a schematic diagram of the polar black and white nanorod electronic paper display of the embodiment of the present application with voltage;

[0037] Figure 4 It is a schematic diagram of the polar black and white nanorod electronic paper display of the embodiment of the present application without voltage;

[0038] Figure 5 It is a schematic diagram of the polar black and white nanorod electronic paper display of the embodiment of the present application with voltage again;

[0039] Figure 6 It is a schematic diagram of the polar color nanorod of the embodiment of the present application;

[0040] Figure 7 It is a schematic diagram of the polar nanorod quantum dot electronic paper display of the embodiment of the present application without voltage;

[0041] Figure 8 It is a schematic diagram of the polar nanorod quantum dot electronic paper display of the embodiment of the present application with voltage;

[0042] Figure 9 It is a schematic diagram of the polar nanorod quantum dot electronic paper display of the embodiment of the present application without voltage;

[0043] Figure 10 Schematic diagram of applying voltage again for the polar nanorod quantum dot electronic paper display of the embodiment of the present application;

[0044] 1-black particles, 2-white particles, 3-electret material, 4-glass substrate, 5-color filter film, 6-first electrode, 7-first substrate, 8-display layer, 9-second substrate, 10-second electrode, 11-red quantum dots, 12-green quantum dots, 13-blue quantum dots. DETAILED DESCRIPTION

[0045] The technical solutions of the present application will be specifically described below with reference to the drawings.

[0046] The present application provides a polar nanorod quantum dot-based electronic paper display, which realizes polarization by performing electret treatment on the electret material of the polar nanorods in the display layer of the electronic paper display. Different color quantum dots or black and white particles are added to both ends of the electret material, so as to be able to respond to different electric fields applied and cause the change of flip angle, thereby causing the change of the degree of reflection of external ambient light. The electronic paper display further comprises a first substrate and a second substrate, and the display layer is located between the first substrate and the second substrate. A first electrode is arranged on the side of the first substrate away from the display layer, and a color filter film is arranged on the first electrode. A second electrode is arranged on the side of the second substrate away from the display layer.

[0047] The present application also provides a preparation method of the polar nanorod quantum dot-based electronic paper display as described above, which comprises the following steps:

[0048] Step 1: performing hydrophobic / hydrophilic treatment on one end surface of the electret material and performing hydrophilic / hydrophobic treatment on the other end surface of the electret material;

[0049] Step 2: performing electret treatment on the electret material treated in step 1, so that the electret material has different electric properties at both ends;

[0050] Step 3: adding black particles or white particles and anionic surfactant into Isopar L to obtain negatively charged black particles or negatively charged white particles;

[0051] Step 4: mixing quantum dots and cationic surfactant, realizing ion exchange through ultrasonic or stirring, and then filtering after standing. The cations are adsorbed on the surface of the quantum dots through physical adsorption, so that the quantum dots are positively charged, and positively charged quantum dots are obtained.

[0052] Step 5: placing the electret material, the negatively charged black particles or the negatively charged white particles, and the positively charged quantum dots into a dispersion medium to obtain polar nanorods.

[0053] The following is the specific implementation process of the present application.

[0054] As Figure 1 , the polar black and white nanorods are prepared from black particles and white particles and an electret material.

[0055] The present application provides a polar black and white nanorod preparation method, comprising the following steps:

[0056] Step 1, hydrophobic / hydrophilic treatment is performed on one end surface of the electret material, and hydrophilic / hydrophobic treatment is performed on the other end surface of the electret material;

[0057] Step 2, electret treatment is performed on the electret material after step 1, so that the two ends of the electret material have different electrical properties;

[0058] Step 3, black particles or white particles and an anionic surfactant are added to Isopar L to obtain negatively charged black particles or negatively charged white particles;

[0059] Step 4, the electret material, the negatively charged black particles, and the negatively charged white particles are placed in a dispersion medium to obtain polar black and white nanorods.

[0060] Figure 1 The black particles in the polar black and white nanorods described in the above-mentioned embodiment include but are not limited to carbon black particles, carbon black, aniline black, lamp black, vine black, natural graphite black, star black, manganese black, perylene black, etc.

[0061] The carbon black particles in the above-mentioned polar black and white nanorods are modified with oxygen plasma in a vacuum to hydroxylize the surface of the carbon black; the hydroxylated carbon black is dispersed in a formaldehyde solution, and after being heated, an appropriate amount of sodium hydroxide solution is added, and a reaction is performed to obtain hydroxymethylated carbon black; the hydroxymethylated carbon black obtained by the reaction is washed, centrifuged, and then dried and ground to obtain carbon black particles; methyl methacrylate and methacrylic acid are dispersed in ethanol, nitrogen is introduced, and at a temperature of 60-70°C, potassium persulfate is added, and a reaction is performed to obtain a polymethyl methacrylate copolymer solution; the carbon black particles after drying and grinding are dispersed in ethanol, and the polymethyl methacrylate copolymer solution is added, stirred, and then dried and ground to obtain electrically neutral black particles.

[0062] The above-mentioned black particles and a surfactant are added to Isopar L to obtain charged black particles. The surfactant includes but is not limited to alkyl benzene sulfonate, alkyl sulfonate, alkyl succinate sulfonate, alcohol amine alkyl benzene sulfonate, naphthenate, alkyl phenol sulfonate, polyoxyethylene monolaurate, etc.

[0063] The white particles in the above-mentioned polar black and white nanorods include but are not limited to white titanium dioxide particles, white lead, zinc white, etc.

[0064] The white particles in the polar black and white nanorods above are grafted with KH560 to graft TiO2 nanoparticles. 0.1 g of KH560 is dissolved in 150 ml of toluene and placed in a 500 ml round bottom flask with a magnetic stirrer and a nitrogen reflux condenser. When methylbenzene begins to reflux, 0.8 g of hydrophilic TiO2 nanoparticles are added to the KH560 toluene solution. The stirring speed is fixed at 400 rpm. The reaction mixture is kept at 110 °C for 12 h by purging with nitrogen. The grafted KH560 TiO2 particles are obtained by washing with methanol and ethanol and centrifugation.

[0065] The white particles and surfactants above are added to Isopar L to obtain charged white particles. The surfactants include but are not limited to alkyl benzene sulfonate, alkyl sulfonate, alkyl succinate sulfonate, alcohol amine alkyl benzene sulfonate, naphthenate, alkyl phenol sulfonate, polyoxyethylene monolaurate, etc.

[0066] The electret material in the polar black and white nanorods above includes but is not limited to Brazil brown wax, K-1 polycarbonate, polymethyl methacrylate, polytetrafluoroethylene, polyvinylidene fluoride, polyperfluoroethylene propylene, polypropylene, polyethylene, etc. The electret material is subjected to electret treatment by corona electret, thermal electret, light electret, etc. to form an electret.

[0067] The electret prepared above is dissolved in 300 ml of Isopar L with 0.8 g of black carbon particles, 0.8 g of white TiO2 particles, 1 g of KH560, 0.100 g of T-151, 0.075 g of CH-5, and 0.075 g of Span 85, and placed in a 500 ml three-necked flask with a magnetic stirrer and a nitrogen reflux condenser. The stirring speed is fixed at 400 rpm. The reaction mixture is kept at 400 rpm for 7 h by purging with nitrogen. The reaction mixture is rotated at 6000 rpm for 10 minutes to obtain a display solution of polar black and white nanorods with grafted black and white particles and dispersion medium.

[0068] Example 1

[0069] As Figure 2 The prepared electronic paper display is not powered, the polar black and white nanorods are perpendicular to the substrate, and the nanorods do not flip, and are arranged in parallel with each other, with the black particles at one end facing up, absorbing external ambient light, at which time the polar black and white nanorod electronic paper display presents pure black. If the white particles in the polar black and white nanorods are at one end facing up, reflecting external ambient light, at which time the polar black and white nanorod electronic paper display presents pure white.

[0070] Example 2

[0071] As Figure 3After the polar black and white nanorod electronic paper display is powered on, the polar black and white nanorod is flipped, and according to different driving voltages, the angle of the polar black and white nanorod is changed, at this time, the polar black and white nanorod reflects the external environment light, the angle of the flip is changed, the light reflected is changed, and the red, green and blue three-color light with different light emission amounts is emitted through the color filter film, and full-color display is realized.

[0072] Example 3

[0073] As Figure 4 After the polar black and white nanorod electronic paper display is powered on, the polar black and white nanorod is flipped, and according to different driving voltages, the angle of the polar black and white nanorod is changed, at this time, the polar black and white nanorod reflects the external environment light, the angle of the flip is changed, the light reflected is changed, and the red, green and blue three-color light with different light emission amounts is emitted through the color filter film, and full-color display is realized.

[0074] Example 4

[0075] As Figure 5 After the polar black and white nanorod electronic paper display is powered on, the polar black and white nanorod is flipped, and according to different driving voltages, the angle of the polar black and white nanorod is changed, at this time, the polar black and white nanorod reflects the external environment light, the angle of the flip is changed, the light reflected is changed, and the red, green and blue three-color light with different light emission amounts is emitted through the color filter film, and full-color display is realized.

[0076] As Figure 6 The polar color nanorod is prepared from quantum dots, black particles or white particles and an electret material, and the specific implementation is as follows.

[0077] The embodiment of the application provides a polar color nanorod quantum dot preparation method, which comprises the following steps:

[0078] Step 1, first, the electret material is subjected to electret treatment, and the electret material is subjected to electret treatment through corona electret, thermal electret, light electret and the like, so that the electret material has different electric properties at both ends.

[0079] Step 2, the surface of the electret material is subjected to hydrophobic / hydrophilic treatment.

[0080] Step 3, the black particles or white particles and an anionic surfactant are added into Isopar L and stirred at 80 DEG C for 6h, the supernatant is removed through centrifugation, anhydrous ethanol is added for multiple times of washing, centrifugal treatment is carried out at 8000r / min, and vacuum drying is carried out for 24h to obtain negative black or white particles.

[0081] Step 4, the quantum dots and a cationic surfactant are mixed, ion exchange is realized through ultrasonic or stirring, and the quantum dots are positively charged after standing and filtering.

[0082] Step 5, the electret material, charged black or white particles, charged quantum dots are put into the dispersion medium, simple test polarity nanorod flip situation, performance meet the requirements, vacuum drying 48h, get the required polarity color nanorod.

[0083] The quantum dots include but are not limited to II-VI compounds, and can also be selected from III-V compounds, can be inorganic compounds, or can be organic compounds, preferably silicon quantum dots, germanium quantum dots, cadmium sulfide quantum dots, cadmium selenide quantum dots, cadmium telluride quantum dots, zinc selenide quantum dots, lead sulfide quantum dots, lead selenide quantum dots, indium phosphide quantum dots and indium arsenide quantum dot materials.

[0084] The cationic surfactant added before preparing the polarity color nanorod includes but is not limited to one or more of hexadecyl trimethyl ammonium bromide, tetra-n-butyl ammonium bromide, benzyl trimethyl ammonium chloride, fatty amine salt, ethanolamine salt, polyethylene polyammonium salt, cetyl pyridinium bromide, etc., ion exchange is achieved by ultrasonic or stirring, and the quantum dots are positively charged after standing and filtering.

[0085] The black particles in the above nanorod include but are not limited to carbon black particles, carbon black, aniline black, lamp black, vine black, natural graphite black, Mars black, manganese black, perylene black, etc.

[0086] The carbon black particles in the above nanorod are modified with oxygen plasma to hydroxylize the surface of the carbon black in vacuum; the hydroxylated carbon black is dispersed in formaldehyde solution, and after heating, an appropriate amount of sodium hydroxide solution is added, and the reaction obtains hydroxymethylated carbon black; the hydroxymethylated carbon black obtained by reaction is washed, centrifuged and dried and ground to obtain carbon black particles; methyl methacrylate and methacrylic acid are dispersed in ethanol, nitrogen is introduced, potassium persulfate is added at a temperature of 60-70°C, and a polymethyl methacrylate copolymer solution is obtained by reaction; the carbon black particles after drying and grinding are dispersed in ethanol, the polymethyl methacrylate copolymer solution is added, stirred and dried, and ground to obtain electrically neutral black particles.

[0087] The above black particles and anionic surfactants are added to Isopar L to obtain charged black particles. The surfactant includes but is not limited to one or more of fatty acid salt, sulfate salt, sulfonate salt, phosphate salt, amino acid salt, phenol salt, enol salt, ketone sulfonamide salt, sodium dodecyl benzene ring acid, etc., ion exchange is achieved by ultrasonic or stirring, and the black particles are negatively charged after standing and filtering.

[0088] The white particles in the above polarity color nanorod include but are not limited to white titanium dioxide particles, white lead, zinc white, etc.

[0089] The white particles in the above polar color nanorods are grafted with KH560 to graft TiO2 nanoparticles. 0.1 g of KH560 is dissolved in 150 ml of toluene and placed in a 500 ml round bottom flask with a magnetic stirrer and a nitrogen reflux condenser. When methylbenzene begins to reflux, 0.8 g of hydrophilic TiO2 nanoparticles are added to the KH560 toluene solution. The stirring speed is fixed at 400 rpm. The reaction mixture is kept at 110°C for 12 h by nitrogen purging. The grafted KH560 TiO2 particles are obtained by washing with methanol and ethanol and centrifugation.

[0090] The above white particles and anionic surfactants are added to Isopar L to obtain charged white particles. The surfactants include, but are not limited to, one or more of fatty acid salts, sulfate salts, sulfonate salts, phosphate salts, amino acid salts, phenol salts, enol salts, ketone sulfonamide salts, sodium dodecylbenzenesulfonate, etc. Ion exchange is achieved by ultrasonic or stirring, and after standing, the white particles are filtered to be negatively charged.

[0091] The electret material in the above nanorods includes, but is not limited to, Brazilian brown waxes, K-1 polycarbonate, polymethyl methacrylate, polytetrafluoroethylene, polyvinylidene fluoride, polyperfluoroethylene propylene, polypropylene, polyethylene, etc. The electret material is subjected to electret treatment by corona electret, thermal electret, light electret, etc. to form an electret.

[0092] The above prepared electret is dissolved in 300 ml of Isopar L with 0.8 g of positively charged quantum dots, 0.8 g of negatively charged black carbon particles or 0.8 g of negatively charged white TiO2 particles, 1 g of KH560, 0.100 g of T-151, 0.075 g of CH-5 and 0.075 g of Span85, and placed in a 500 ml three-necked flask with a magnetic stirrer and a nitrogen reflux condenser. The stirring speed is fixed at 400 rpm. The reaction mixture is kept at 400 rpm for 7 h by nitrogen purging. The reaction mixture is rotated at 6000 rpm for 10 minutes to obtain a display solution of polar color nanorods with grafted black and white particles and dispersion medium.

[0093] Example 5

[0094] As Figure 7 The prepared polar nanorod quantum dot electronic paper display is not powered, the polar color nanorods are perpendicular to the substrate, and the polar color nanorods do not flip, and are arranged in parallel with each other, with the black particles at one end facing up, absorbing external ambient light, at which time the polar nanorod quantum dot electronic paper display presents pure black. If the white particles in the polar black and white nanorods are at one end facing up, reflecting external ambient light, at which time the polar black and white nanorod electronic paper display presents pure white.

[0095] Example 6

[0096] As Figure 8 After the polar nanorod quantum dot electronic paper display is powered on, the polar color nanorods are reversed, and according to different driving voltages, the angles of the polar color nanorods are changed, at this time, the polar color nanorods reflect the external environment light, the angles of the reversed polar color nanorods are changed, the reflected light is changed, and red, green and blue three-color lights with different light emission amounts are emitted, and full-color display is realized by controlling different voltages.

[0097] Example 7

[0098] As Figure 9 After the polar color nanorod electronic paper display is powered on, the polar color nanorods are reversed, and according to different driving voltages, the angles of the polar color nanorods are changed, at this time, the polar color nanorods reflect the external environment light, the angles of the reversed polar color nanorods are changed, the reflected light is changed, and red, green and blue three-color lights with different light emission amounts are emitted, and full-color display is realized by controlling different voltages.

[0099] Example 8

[0100] As Figure 10 , the polar nanorod quantum dot electronic paper display is powered on again, the polar color nanorods continue to reverse, and according to different driving voltages, the angles of the polar color nanorods are changed, at this time, the polar color nanorods reflect the external environment light, the angles of the reversed polar color nanorods are changed, the reflected light is changed, and red, green and blue three-color lights with different light emission amounts are emitted, and full-color display is realized by controlling different voltages.

[0101] The above is the preferred embodiment of the present application, any changes made according to the technical solutions of the present application, as long as the generated function does not exceed the scope of the technical solutions of the present application, belongs to the protection scope of the present application.

Claims

1. A method for fabricating an electronic paper display based on polar nanorod quantum dots, characterized in that, Polarization is achieved by electret treatment of the electret material of polar nanorods in the display layer of an electronic paper display; the method includes: Step 1: Perform hydrophobic / hydrophilic treatment on one end of the electret material and hydrophilic / hydrophobic treatment on the other end of the electret material. Step 2: Perform electret treatment on the electret material after Step 1 to make the two ends of the electret material have different charges; Step 3: Add black or white particles and anionic surfactant to Isopar L to obtain negatively charged black or negatively charged white particles. Step 4: Mix quantum dots and cationic surfactants, achieve ion exchange by ultrasound or stirring, filter after standing, and make the quantum dots positively charged by physical adsorption to adsorb cations on the surface of quantum dots. Step 5: Place electret material, negatively charged black particles or negatively charged white particles, and positively charged quantum dots into a dispersion medium to obtain polar nanorods.

2. The method for fabricating an electronic paper display based on polar nanorod quantum dots according to claim 1, characterized in that, Quantum dots of different colors or black and white particles are added to both ends of the electret material to respond to different applied electric fields, causing changes in the flip angle, which in turn changes the degree of reflection of ambient light.

3. A method for preparing an electronic paper display based on polar nanorod quantum dots according to claim 1 or 2, characterized in that, It also includes a first substrate and a second substrate, the display layer is located between the first substrate and the second substrate, a first electrode is provided on the side of the first substrate opposite to the display layer, a color filter film is provided on the first electrode, and a second electrode is provided on the side of the second substrate opposite to the display layer.

4. The method for fabricating an electronic paper display based on polar nanorod quantum dots according to claim 1, characterized in that, In step 1, the specific methods for hydrophobic / hydrophilic treatment of the single-end surface of the electret material are as follows: (1) Hydrophilic treatment of the single-end surface of the electret material (1.1) By chemical modification, chemical grafting of hydrophilic functional groups is used to the single-end surface of the electret material, or the copolymerization reaction of hydrophilic monomers on the single-end surface of the electret material is carried out to improve the hydrophilicity. Then, by plasma treatment or high-temperature oxidation or chemical oxidation, a hydrophilic oxide film is formed on the single-end surface of the electret material, or surfactants are used to reduce the energy of the single-end surface of the electret material to make the single-end surface of the electret material hydrophilic. (1.2) A hydrophilic material is coated on one end of the electret material by physical methods, and then a coating is applied by physical vapor deposition, electrochemical deposition, or solution impregnation. (1.3) Laser etching is used to change the surface morphology of the single end of the electret material to form a microstructure, making the single end surface of the electret material hydrophilic; (1.4) Nanostructures are prepared by methods including sputtering, electrodeposition, and anodic oxidation to make the single-end surface of the electret material hydrophilic; (2) Method of hydrophobic treatment on the single-end surface of electret materials (2.1) By chemical modification, chemical substances with hydrophobic functional groups are used to chemically graft onto the single-end surface of the electret material or hydrophobic monomers are copolymerized in the electret material to improve the hydrophobic properties, and then hydrophobic fluorocarbon film is formed by plasma treatment with fluorinated gas. (2.2) A hydrophobic material is coated on one end of the electret material by physical methods, and then a plasma method is used to make the surface chemically react to enhance the hydrophobic properties. (2.3) The surface morphology of the electret material at one end is changed by laser etching to form a microstructure, making the surface of the electret material at one end hydrophobic; (2.4) Nanostructures are prepared by methods including sputtering, electrodeposition and anodic oxidation to make the single-end surface of the electret material hydrophobic.

5. The method for fabricating an electronic paper display based on polar nanorod quantum dots according to claim 1, characterized in that, The specific implementation method for step 2 is as follows: Electret materials that have undergone hydrophilic or hydrophobic treatment are placed in polar or non-polar solutions. The treated electret materials have different densities and different hydrophilic or hydrophobic properties at their single ends, resulting in vertical orientation of the electret materials. At this point, one end of the hydrophilic or hydrophobic electret material is placed in a polar solution and electret treatment is performed on the electret material using methods including corona electret, thermal electret, and photoelectret. Then, the other end of the electret material that has not undergone hydrophilic or hydrophobic treatment is placed in a non-polar solution and electret treatment is performed on the electret material using methods including corona electret, thermal electret, and photoelectret, so that the two ends of the electret material carry different charges.

6. The method for fabricating an electronic paper display based on polar nanorod quantum dots according to claim 1, characterized in that, The specific implementation method for step 3 is as follows: Black or white particles and anionic surfactant were added to Isopar L and stirred at 80°C for 6 hours. The supernatant was removed by centrifugation, and the mixture was washed multiple times with anhydrous ethanol. After centrifugation at 8000 r / min, the mixture was vacuum dried for 24 hours to obtain negatively charged black or negatively charged white particles.

7. The method for fabricating an electronic paper display based on polar nanorod quantum dots according to claim 1, characterized in that, The electret material used includes Brazilian brown wax, K-1 polycarbonate, polymethyl methacrylate, polytetrafluoroethylene, polyvinylidene fluoride, perfluoroethylene propylene, polypropylene, polyethylene, barium titanate (BaTiO3), lead zirconate titanate, zinc oxide, tantalum oxide, aluminum oxide, and oxides of titanium oxide or silicon nitride.

8. The method for fabricating an electronic paper display based on polar nanorod quantum dots according to claim 1, characterized in that, The black particles include carbon black particles; the white particles include TiO2 particles; the quantum dots are made of materials including group II-VI compounds, group III-V compounds, inorganic compounds, and organic compounds; the quantum dots include red, green, and blue quantum dots with particle sizes of 8-10 nm, 6-8 nm, and 4-6 nm, respectively.

9. The method for fabricating an electronic paper display based on polar nanorod quantum dots according to claim 1, characterized in that, The aspect ratio of the polar nanorods is in the range of 50:1 to 200:1.

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