CN110092875B - Preparation method of PDLC (polymer dispersed liquid crystal) film based on liquid crystal/polymer composite material system - Google Patents
Preparation method of PDLC (polymer dispersed liquid crystal) film based on liquid crystal/polymer composite material system Download PDFInfo
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- ISAOCJYIOMOJEB-UHFFFAOYSA-N benzoin Chemical group C=1C=CC=CC=1C(O)C(=O)C1=CC=CC=C1 ISAOCJYIOMOJEB-UHFFFAOYSA-N 0.000 claims description 12
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- C08F—MACROMOLECULAR COMPOUNDS OBTAINED BY REACTIONS ONLY INVOLVING CARBON-TO-CARBON UNSATURATED BONDS
- C08F220/00—Copolymers of compounds having one or more unsaturated aliphatic radicals, each having only one carbon-to-carbon double bond, and only one being terminated by only one carboxyl radical or a salt, anhydride ester, amide, imide or nitrile thereof
- C08F220/02—Monocarboxylic acids having less than ten carbon atoms; Derivatives thereof
- C08F220/10—Esters
- C08F220/12—Esters of monohydric alcohols or phenols
- C08F220/16—Esters of monohydric alcohols or phenols of phenols or of alcohols containing two or more carbon atoms
- C08F220/18—Esters of monohydric alcohols or phenols of phenols or of alcohols containing two or more carbon atoms with acrylic or methacrylic acids
- C08F220/1812—C12-(meth)acrylate, e.g. lauryl (meth)acrylate
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- C08F—MACROMOLECULAR COMPOUNDS OBTAINED BY REACTIONS ONLY INVOLVING CARBON-TO-CARBON UNSATURATED BONDS
- C08F283/00—Macromolecular compounds obtained by polymerising monomers on to polymers provided for in subclass C08G
- C08F283/04—Macromolecular compounds obtained by polymerising monomers on to polymers provided for in subclass C08G on to polycarbonamides, polyesteramides or polyimides
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- G02F—OPTICAL DEVICES OR ARRANGEMENTS FOR THE CONTROL OF LIGHT BY MODIFICATION OF THE OPTICAL PROPERTIES OF THE MEDIA OF THE ELEMENTS INVOLVED THEREIN; NON-LINEAR OPTICS; FREQUENCY-CHANGING OF LIGHT; OPTICAL LOGIC ELEMENTS; OPTICAL ANALOGUE/DIGITAL CONVERTERS
- G02F1/00—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics
- G02F1/01—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour
- G02F1/13—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour based on liquid crystals, e.g. single liquid crystal display cells
- G02F1/133—Constructional arrangements; Operation of liquid crystal cells; Circuit arrangements
- G02F1/1333—Constructional arrangements; Manufacturing methods
- G02F1/1334—Constructional arrangements; Manufacturing methods based on polymer dispersed liquid crystals, e.g. microencapsulated liquid crystals
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- C08J2351/00—Characterised by the use of graft polymers in which the grafted component is obtained by reactions only involving carbon-to-carbon unsaturated bonds; Derivatives of such polymers
- C08J2351/08—Characterised by the use of graft polymers in which the grafted component is obtained by reactions only involving carbon-to-carbon unsaturated bonds; Derivatives of such polymers grafted on to macromolecular compounds obtained otherwise than by reactions only involving carbon-to-carbon unsaturated bonds
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Abstract
本发明提供了一种基于液晶/高分子复合材料体系的PDLC膜的制备方法。具体如下：将液晶、光可聚合单体和光引发剂按照一定的质量比混合均匀后，利用虹吸原理将混合物灌入液晶盒中，液晶盒的厚度由塑料间隔垫控制在10～30μm。然后于室温下经紫外光照射1～5分钟，形成聚合物分散液晶薄膜。然后对形成的聚合物分散液晶膜在电场中进行二次光聚合。本发明引入硫醇单体和乙烯基醚单体大大改善了制备的PDLC薄膜的光电性能；通过调节丙烯酸酯、硫醇、乙烯基醚之间的质量比和聚合条件，调节了聚合物网孔的大小和液晶微滴的大小，制备了驱动电压较小、更节约能源、性能稳定的聚合物分散液晶薄膜。
The invention provides a preparation method of a PDLC film based on a liquid crystal/polymer composite material system. The details are as follows: after the liquid crystal, photopolymerizable monomer and photoinitiator are mixed uniformly according to a certain mass ratio, the mixture is poured into a liquid crystal cell using the siphon principle, and the thickness of the liquid crystal cell is controlled by a plastic spacer at 10-30 μm. and then irradiated with ultraviolet light for 1-5 minutes at room temperature to form a polymer-dispersed liquid crystal film. The resulting polymer dispersed liquid crystal film is then subjected to secondary photopolymerization in an electric field. The introduction of thiol monomer and vinyl ether monomer in the present invention greatly improves the photoelectric properties of the prepared PDLC film; by adjusting the mass ratio and polymerization conditions between acrylate, thiol and vinyl ether, the polymer mesh is adjusted The size of the liquid crystal droplet and the size of the liquid crystal droplet were prepared, and the polymer dispersed liquid crystal film with lower driving voltage, more energy saving and stable performance was prepared.
Description
Technical Field
The invention belongs to the technical field of Liquid Crystal application, and relates to a preparation method of a PDLC (Polymer Dispersed Liquid Crystal) film based on a Liquid Crystal/Polymer composite material system, in particular to a method for preparing a PDLC (Polymer Dispersed Liquid Crystal) film material based on an ultraviolet curing system of a Liquid Crystal/Polymer composite material.
Background
The polymer dispersed liquid crystal material is a composite material formed by uniformly dispersing nematic phase liquid crystal microdroplets in a polymer matrix, the optical axis of each liquid crystal microdroplet is in a preferred orientation state, the optical axes of different microdroplets are in a random orientation state, and the dielectric anisotropy is larger than zero (delta epsilon)>0) The nematic liquid crystal material is poured between two substrates coated with ITO (Indium-tin oxide) conductive layers to form a PDLC film with a certain thickness, and liquid crystal droplets with the diameter of about 1-4 μm are randomly distributed in a polymer network and are in uneven arrangement. When no electric field is added, incident light enters the PDLC film, because the difference between the effective refractive index of the light passing through the liquid crystal droplets and the refractive index of the polymer is larger, the directors of a large number of liquid crystal droplets in the system are randomly distributed, so that the light is reflected and refracted for many times on the interface of the liquid crystal and the polymer, the emergent light is in a scattering state, and the appearance of the PDLC film is in a milky opaque state; when a sufficiently strong external electric field is applied between the two substrates, the liquid crystal molecules assume a uniform alignment, changing from a bipolar alignment to a parallel alignment, when the ordinary refractive index (n) of the liquid crystal dropletso) Refractive index (n) with polymer matrixp) When the PDLC film is matched with the PDLC film, the incident light is directly transmitted out without reflection in the PDLC film, so that the conversion of the light from a scattering state to a transmission state can be realized.
In the process of preparing PDLC by the photopolymerization phase-splitting method, photopolymerization is a key step influencing the preparation of PDLC. The photopolymerization reaction is directly related to the micro morphology of the finally prepared polymer network of the PDLC film, so that the electro-optic performance of the PDLC is influenced. Photopolymerization refers to a process in which a compound absorbs light to cause an increase in molecular weight, and includes further photocrosslinking of a pre-formed macromolecule, certain photoinitiated block copolymerization, graft copolymerization, and the like. The initiating species for photopolymerization is generated by photochemical reactions, and the subsequent processes of chain extension and chain termination are the same. Photopolymerization therefore requires absorption of light energy only during the chain initiation stage, and is characterized by low activation energy required for polymerization, so that it can occur over a wide temperature range, especially for low temperature polymerization, which is much superior to polymerization initiated by chemistry. In the laboratory, pure polymers without initiator residues can be obtained by photopolymerization, which provides a convenient means for further research. Photopolymerization has provided a powerful tool for the study of free radical polymerization kinetics and reaction history. In this sense, photopolymerization is a photoreaction with high quantum efficiency, and thus has great practical value.
Current liquid crystal displays use polarizing plates for light transmission and refraction, but the polarizing plates reduce the brightness and contrast of the display device. PDLC has incomparable advantages as an electro-optic display material over conventional LCDs: no need of polarizer, high brightness, wide viewing angle, and flexibility; the substrate does not need to be subjected to surface treatment in the manufacturing process, and the yield is greatly improved when the method is applied to the manufacturing of a TFT display; and it is the solid film, has solved the problem that the liquid crystal reveals, and the display device that makes is thinner and thickness is changeed the control, does benefit to the display of preparation large tracts of land or flexibility. Therefore, the PDLC has wide application prospects in the aspects of mobile phone display screens, large-area display advertising boards, wearable liquid crystal display screens, electric control intelligent glass and the like, and has become a very active research front in the liquid crystal field.
Disclosure of Invention
The invention aims to provide a preparation method of a PDLC film based on a liquid crystal/polymer composite material system, and the PDLC film with excellent electro-optic performance is prepared.
The invention relates to a preparation method of a PDLC film based on a liquid crystal/polymer composite material system, which comprises the following steps:
1) uniformly mixing a liquid crystal material, a photopolymerizable monomer and a photoinitiator, and enabling the mixture to be in a clear state at room temperature;
2) pouring the mixture in the clear state in the step 1) into a liquid crystal box by a siphon principle, and irradiating the mixture in the liquid crystal box by ultraviolet light to form a polymer dispersed liquid crystal film;
3) placing the polymer dispersed liquid crystal film formed in the step 2) in an electric field for secondary ultraviolet irradiation, and polymerizing to form a PDLC film of a liquid crystal/polymer composite material system.
According to the preparation method of the PDLC film, the photopolymerizable monomer comprises acrylic esters, thiols and vinyl ethers, preferably, the mass ratio of the acrylic esters to the thiols to the vinyl ethers is 27-32: 0-8: 0-8.
The acrylates include lauryl methacrylate (abbreviated as LMA) as a diluent and trimethylolpropane triacrylate (abbreviated as TMPTA) as a crosslinking agent; the mercaptan is pentaerythritol tetra (3-mercaptopropionate) (PETMP for short), and the vinyl ether (C4V for short) can be purchased or synthesized by a laboratory.
Further, the mass ratio of the diluent to the cross-linking agent is 1: 1-6: 1, preferably 4: 1. the mass of the photoinitiator is 3-5% of the total mass of the photopolymerizable monomers; the mass ratio of the liquid crystal material to the photopolymerizable monomer is 70: 30-50: 50.
the liquid crystal material according to the present invention may be any liquid crystal material known in the art, preferably nematic liquid crystal SLC1717 is used. The photoinitiator according to the invention is preferably benzoin dimethyl ether (651).
The PDLC film manufacturing method according to the present invention, wherein the clearing point in the clear state in step 2) is a critical temperature at which a homogeneous mixture of the liquid crystal material and the photopolymerizable monomer material is transformed from an anisotropic state to an isotropic state.
According to the preparation method of the PDLC film, the thickness of the liquid crystal box is preferably 10-30 μm, wherein the liquid crystal box is made of glass plated with indium tin oxide transparent electrodes, and the thickness of the liquid crystal box is controlled by a plastic spacer.
Preferably, the first step ultraviolet irradiation conditions in step 2) are as follows: the light intensity is 1-5 mw/cm2The wavelength is 365nm, and the irradiation time is 5-10 minutes; step 3) the second step of ultraviolet irradiation conditions are as follows: the light intensity is 10-30 mw/cm2The wavelength is 365nm, and the irradiation time is 30-60 minutes. The electric field condition of the ultraviolet irradiation polymerization in the second step is as follows: the field intensity is 100-200V, and the frequency of the electric field is 100-1000 HZ.
According to the invention, by introducing the diluent lauryl methacrylate, the molecular chain is longer, the flexibility is good, and the functionality is 1, so that the density of polymer network meshes can be reduced to a certain extent, the size of the meshes is increased, liquid crystal microdroplets are enlarged, the anchoring effect of the polymer network on liquid crystals is reduced, and the driving voltage of the PDLC is reduced. The first polymerization step involves self-polymerization of trimethylolpropane triacrylate and copolymerization between trimethylolpropane triacrylate and thiol, and the second polymerization step involves copolymerization between vinyl ether (C4V) and thiol, allowing the PDLC film to form a vertical network. Due to the mismatch of refractive index between the polymer matrix and the liquid crystal droplets in the film and between the randomly oriented liquid crystal molecules in the liquid crystal droplets, the film is in a strongly light scattering state, thereby increasing the contrast. The polymer liquid crystal dispersion film with high contrast and low driving voltage is formed by self-polymerization between acrylate monomers, copolymerization between acrylate and thiol, and polymerization between vinyl ether and thiol. Meanwhile, the phase separation process of the PDLC film material is controlled by utilizing the compatibility of the monomer and the liquid crystal, so that the PDLC film material with a proper polymer network is formed, and the comprehensive electro-optic performance of the PDLC film material is greatly improved while the stability of the PDLC film material is ensured.
The invention has the advantages that functional mercaptan monomer and vinyl ether are introduced, a mercapto-acrylate system formed by one-step polymerization has the advantages of higher refractive index, more excellent water resistance, more excellent heat insulation effect, strong oxidation resistance, small initiator dosage and the like compared with a common ultraviolet system, and meanwhile, the driving voltage of the PDLC film is greatly reduced by the vertical anchoring formed by two-step polymerization, so that the polymer dispersed liquid crystal film with low driving voltage, high contrast and stable performance can be obtained by regulating the mass ratio of the acrylate, the mass ratio of the mercaptan to the vinyl ether and selecting proper polymerization conditions.
Drawings
FIG. 1 is a molecular structural formula of an ultraviolet polymerizable monomer according to the present invention;
FIG. 2 is a scanning electron micrograph of a polymer network of the polymer dispersed liquid crystal thin film material prepared in example 1;
FIG. 3 is a voltage-transmittance curve of the polymer dispersed liquid crystal thin film material prepared in example 1;
FIG. 4 is a graph showing a comparison of saturation voltages after one-step polymerization and two-step polymerization of the polymer dispersed liquid crystal thin film material prepared in example 1;
FIG. 5 is a scanning electron micrograph of a polymer network of the polymer dispersed liquid crystal thin film material prepared in example 2;
FIG. 6 is a voltage-transmittance curve of a polymer dispersed liquid crystal thin film material prepared in example 2;
FIG. 7 is a graph showing a comparison of saturation voltages after one-step polymerization and two-step polymerization of the polymer dispersed liquid crystal thin film material prepared in example 2;
FIG. 8 is a scanning electron micrograph of a polymer network of the polymer dispersed liquid crystal thin film material prepared in example 3;
FIG. 9 is a voltage-transmittance curve of a polymer dispersed liquid crystal thin film material prepared in example 3;
FIG. 10 is a comparison graph of saturation voltages after one-step polymerization and two-step polymerization of the polymer dispersed liquid crystal thin film material prepared in example 3;
FIG. 11 is a scanning electron micrograph of a polymer network of a polymer dispersed liquid crystal thin film material prepared in example 4;
FIG. 12 is a voltage-transmittance curve of a polymer dispersed liquid crystal thin film material prepared in example 4;
FIG. 13 is a graph showing a comparison of saturation voltages after one-step polymerization and two-step polymerization of the polymer dispersed liquid crystal film material prepared in example 4.
Detailed Description
The following sets forth preferred embodiments of the invention, which are intended to be illustrative of the invention and not limiting.
Example 1
The selected photo-polymerizable monomers are lauryl methacrylate, trimethylolpropane triacrylate and pentaerythritol tetrakis (3-mercaptopropionate). Mixing a polymerizable monomer and a nematic liquid crystal SLC1717 according to the mass ratio of 35.0: and 65.0 mixing. Wherein the mass ratio of lauryl methacrylate, trimethylolpropane triacrylate, pentaerythritol tetrakis (3-mercaptopropionate) and vinyl ether is 24.0: 6.0: 2.0: 3.0. the mass of the photoinitiator benzoin dimethyl ether (651) is 3.0 percent of the total mass of the photopolymerizable monomers. Stirring, keeping the mixture in clear state at room temperature, filling the mixture into a liquid crystal box with thickness of 20 μm by siphoning, and irradiating at room temperature with light intensity of 2mw/cm2Irradiating for 5 minutes under 365nm ultraviolet light, and then performing two-step polymerization at room temperature under the conditions that the electric field intensity is 100V and the electric field frequency is 100HZ, wherein the ultraviolet light intensity is 15mw/cm2The polymer dispersed liquid crystal film of example 1 was formed by irradiating the film at 365nm for 30 minutes.
The microscopic morphology of the polymer network of the PDLC film was observed by scanning electron microscopy (as shown in fig. 2), and the electro-optic performance curve and saturation voltage of the PDLC film prepared above were measured by a liquid crystal comprehensive parameter tester (as shown in fig. 3 and 4).
Experimental results show that the prepared PDLC film has low driving voltage, high contrast, short on-state response time, uniform and compact polymer meshes and good stability. The driving voltage of the film after the two-step polymerization is significantly reduced compared to the PDLC film formed by the one-step polymerization and the two-step polymerization.
Example 2
The selected photopolymerizable monomers are lauryl methacrylate, trimethylolpropane triacrylate, pentaerythritol tetrakis (3-mercaptopropionate) and vinyl ether. Mixing a polymerizable monomer and a nematic liquid crystal SLC1717 according to the mass ratio of 35.0: and 65.0 mixing. Wherein the methacrylic acid lauryl ester and the trimethylolpropaneThe mass ratio of the alkane triacrylate, the pentaerythritol tetrakis (3-mercaptopropionate) and the vinyl ether was 20.0: 10.0: 2.0: 3.0. the mass of the photoinitiator benzoin dimethyl ether (651) is 3.0 percent of the total mass of the photopolymerizable monomers. Stirring, keeping the mixture in clear state at room temperature, filling the mixture into a liquid crystal box with thickness of 20 μm by siphoning, and irradiating at room temperature with light intensity of 2mw/cm2Irradiating for 8 minutes under 365nm ultraviolet light, and then performing two-step polymerization at room temperature under the conditions that the electric field intensity is 100V and the electric field frequency is 100HZ, wherein the ultraviolet light intensity is 15mw/cm2The polymer dispersed liquid crystal film of example 2 was formed by irradiating the film at 365nm for 30 minutes.
The microscopic morphology of the polymer network of the PDLC film was observed by scanning electron microscopy (as shown in fig. 5), and the electro-optic performance curve and saturation voltage of the PDLC film prepared above were measured by a liquid crystal comprehensive parameter tester (as shown in fig. 6 and 7).
The experimental results show that as the content of the trimethylolpropane triacrylate having three functional groups increases, the reaction rate increases, and the liquid crystal is more likely to phase separate to form droplets having a smaller size. Compared with the embodiment 1, the driving voltage of the polymer dispersed liquid crystal film material prepared in the embodiment 2 is increased, the contrast is correspondingly increased, the response time is reduced, the meshes of the polymer network are more compact and uniform, and the polymer dispersed liquid crystal film material has good electro-optical performance. Compared with the driving voltage of the PDLC film formed by one-step polymerization, the driving voltage of the PDLC film formed by two-step polymerization is obviously reduced.
Example 3
The selected photopolymerizable monomers are lauryl methacrylate, trimethylolpropane triacrylate, pentaerythritol tetrakis (3-mercaptopropionate) and vinyl ether. Mixing a polymerizable monomer and a nematic liquid crystal SLC1717 according to the mass ratio of 35.0: and 65.0 mixing. Wherein the mass ratio of lauryl methacrylate, trimethylolpropane triacrylate, pentaerythritol tetrakis (3-mercaptopropionate) and vinyl ether is 23.0: 5.0: 2.0: 5.0. the mass of the photoinitiator benzoin dimethyl ether (651) is 3.0 percent of the total mass of the photopolymerizable monomers. After being stirred evenly, the mixture is in a clear state at room temperature,the mixture was poured into a liquid crystal cell having a cell thickness of 20 μm by the siphon principle and then passed through a light intensity of 2mw/cm at room temperature2Irradiating for 5 minutes under 365nm ultraviolet light, and then performing two-step polymerization at room temperature under the conditions that the electric field intensity is 100V and the electric field frequency is 100HZ, wherein the ultraviolet light intensity is 15mw/cm2The polymer dispersed liquid crystal film of example 3 was formed by irradiating the film at 365nm for 30 minutes.
The microscopic morphology of the polymer network of the PDLC film was observed by scanning electron microscopy (as shown in fig. 8), and the electro-optic performance curve and saturation voltage of the PDLC film prepared above were measured by a liquid crystal comprehensive parameter tester (as shown in fig. 9 and 10).
The experimental result shows that as the C4V is a molecule with a rigid structure, when the content of vinyl ether is increased, the mesh of the polymer network of the formed PDLC film is more compact, the vertical anchoring energy is larger, and the liquid crystal molecules are easier to arrange along the direction of an electric field, compared with the embodiment 1 and the embodiment 2, the driving voltage of the embodiment 3 is more obviously reduced compared with the voltage of the PDLC film formed by one-time polymerization, and the purposes of energy conservation and environmental protection are achieved.
Example 4
The selected photopolymerizable monomers are lauryl methacrylate, trimethylolpropane triacrylate, pentaerythritol tetrakis (3-mercaptopropionate) and vinyl ether. Mixing a polymerizable monomer and a nematic liquid crystal SLC1717 according to the mass ratio of 35.0: and 65.0 mixing. Wherein the mass ratio of lauryl methacrylate, trimethylolpropane triacrylate, pentaerythritol tetrakis (3-mercaptopropionate) and vinyl ether is 24.0: 6.0: 2.0: 3.0. the mass of the photoinitiator benzoin dimethyl ether (651) is 3.0 percent of the total mass of the photopolymerizable monomers. Stirring, keeping the mixture in clear state at room temperature, filling the mixture into a liquid crystal box with thickness of 20 μm by siphoning, and irradiating at room temperature with light intensity of 2mw/cm2Irradiating for 10 minutes under 365nm ultraviolet light, and then performing two-step polymerization at room temperature under the conditions that the electric field intensity is 100V and the electric field frequency is 100HZ, wherein the ultraviolet light intensity is 15mw/cm2The polymer dispersed liquid crystal film of example 4 was formed by irradiating the film at 365nm for 30 minutesAnd (3) a membrane.
The microscopic morphology of the polymer network of the PDLC film was observed by scanning electron microscopy (as shown in fig. 11), and the electro-optic performance curve of the PDLC film prepared above was measured by a liquid crystal comprehensive parameter tester (as shown in fig. 12 and 13).
The experimental results showed that, since the PDLC film aligned in the vertical electric field direction was formed by one-step polymerization, when the time for one-step polymerization was increased, the density of the polymer network aligned in the vertical electric field direction was increased, and the density of the polymer network aligned in the electric field direction was decreased, resulting in an increase in the driving voltage of the PDLC film, and the voltage drop of the PDLC film subjected to two-step polymerization was not significant as compared to example 1.
The present invention may be embodied in many different forms and modifications may be effected therein by one skilled in the art without departing from the spirit and scope of the invention as defined in the appended claims.
Claims (7)
1. A preparation method of a PDLC film based on a liquid crystal/polymer composite material system comprises the following steps:
1) uniformly mixing a liquid crystal material, a photopolymerizable monomer and a photoinitiator, and enabling the mixture to be in a clear state at room temperature; the photopolymerizable monomers comprise acrylates, thiols and vinyl ethers, and the acrylates comprise lauryl methacrylate as a diluent and trimethylolpropane triacrylate as a crosslinking agent; the mass ratio of the diluent to the cross-linking agent is 1: 1-6: 1; the mercaptan is pentaerythritol tetrakis (3-mercaptopropionate); the vinyl ethers are C4V and have the following chemical formula:
2) pouring the mixture in the clear state in the step 1) into a liquid crystal box by a siphon principle, and irradiating the mixture in the liquid crystal box by first ultraviolet light to form a polymer dispersed liquid crystal film;
3) placing the polymer dispersed liquid crystal film formed in the step 2) in an electric field for secondary ultraviolet irradiation, and polymerizing to form a PDLC film of a liquid crystal/polymer composite material system.
2. The PDLC film preparation method of claim 1, wherein: the mass ratio of the acrylic esters to the thiols to the vinyl ethers is 27-32: 0-8: 0 to 8.
3. The PDLC film preparation method of claim 1 or 2, wherein: the liquid crystal material is nematic liquid crystal SLC1717, and the photoinitiator is benzoin dimethyl ether.
4. The PDLC film preparation method of claim 1 or 2, wherein: the mass of the photoinitiator is 3-5% of the total mass of the photopolymerizable monomers; the mass ratio of the liquid crystal material to the photopolymerizable monomer is 70: 30-50: 50.
5. the PDLC film preparation method of claim 1 or 2, wherein: the clearing point in the clearing state in the step 2) is the critical temperature at which the homogeneous mixture of the liquid crystal material and the photopolymerizable monomer material is converted from the anisotropic state to the isotropic state.
6. The PDLC film preparation method of claim 1 or 2, wherein: the thickness of the liquid crystal box is 10-30 mu m, wherein the liquid crystal box is made of glass plated with indium tin oxide transparent electrodes, and the thickness of the liquid crystal box is controlled by a plastic spacer.
7. The PDLC film preparation method of claim 1 or 2, wherein: step 2) the first ultraviolet irradiation conditions are as follows: the light intensity is 1-5 mw/cm2The wavelength is 365nm, and the irradiation time is 5-10 minutes; step 3) the electric field intensity is 100-200V, and the electric field frequency is100 to 1000HZ, and the ultraviolet irradiation intensity of the second step in the step 3) is 10 to 30mw/cm2，The wavelength is 365nm, and the irradiation time is 30-60 minutes.
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| CN111690159A (en) * | 2020-06-10 | 2020-09-22 | 北京大学 | Preparation method of liquid crystal/high-molecular full-polymerization quantum dot film based on vinyl ether |
| CN114456415A (en) * | 2022-01-08 | 2022-05-10 | 北京大学 | A kind of preparation method of liquid crystal/polymer film |
| CN115220267B (en) * | 2022-08-01 | 2023-07-25 | 南京大学 | Construction method of liquid crystal injection porous smooth surface and microfluidic application thereof |
| US12055810B2 (en) | 2022-08-30 | 2024-08-06 | Orbotech Ltd. | Enhanced defect detection with planar macrocycle dyes in liquid-crystal films |
| CN115639706B (en) * | 2022-09-21 | 2023-04-11 | 杭州兵智科技有限公司 | Polymer dispersed liquid crystal device based on zwitterion and preparation method thereof |
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