Optically anisotropic polymer liquid crystal colloidal particles and preparation method and application thereof

Abstract

The present invention relates to non-spherical optically anisotropic liquid crystal polymer colloid particles, and a preparation method and application thereof. The polymer colloid particles of the present invention include an acrylate polymer containing a liquid crystal unit in its side chain, and the polymer colloid particles have a non-spherical morphology and optical anisotropy. The acrylate polymer containing a liquid crystal unit in its side chain is obtained by dispersion polymerization of an acrylate monomer containing a liquid crystal unit; the liquid crystal unit is selected from at least one of an azobenzene group, a biphenyl group, and a phenyl benzoate group. The present invention uses a liquid crystal unit-containing acrylate monomer to conduct a dispersion polymerization reaction in the presence of a stabilizer and an initiator to prepare the polymer colloid particles. The non-spherical liquid crystal polymer colloid particles of the present invention can be used in optical displays, functional materials, biological imaging, and other fields.

Description

Technical Field

[0001] The invention relates to optically anisotropic polymer liquid crystal colloid particles and a preparation method and application thereof, belonging to the field of colloid synthesis and application. Background Art

[0002] Polymer liquid crystal colloid particles possess unique optical anisotropy, stimulus responsiveness, and controllability, offering broad application prospects in optical displays, functional materials, and bioimaging. In practical applications, the size, shape, and internal structure of polymer liquid crystal colloid particles crucially influence their performance and are important parameters for regulating their properties.

[0003] In recent years, numerous methods have been developed both domestically and internationally to prepare liquid crystal colloidal particles of varying sizes and shapes, but each still has its own shortcomings. For example, the solidification of suspended droplets typically yields liquid crystal colloidal particles larger than 10 microns, making it difficult to prepare liquid crystal colloids in the submicron range. Miniemulsion methods yield smaller liquid crystal colloidal particles, but with a broad distribution. Dispersion polymerization methods produce liquid crystal colloidal particles with a narrow size distribution, adjustable from a few hundred nanometers to a few microns, but are limited to spherical particles, significantly limiting their optical performance. Using acrylate monomers containing tolan groups in dispersion polymerization can produce oblate spherical liquid crystal colloidal particles. Adding chiral compounds to the formulation allows for particle shape adjustment to flat, oblate, and diamond shapes. However, the resulting particles lack a single ordered structure, limiting their optical applications and restricting their applicability to a narrow range of monomer types. Template methods can produce rod-shaped liquid crystal colloidal particles with a single ordered internal structure, but the steps are cumbersome and difficult to scale up for production. Polymerization-induced self-assembly technology can prepare liquid crystal colloidal particles of different shapes and ordered structures in large quantities, but it is often difficult to obtain a single morphology. Moreover, the morphology and structure of the particles are greatly affected by the environment and are easily destroyed, making them difficult to put into practical application.

[0004] Therefore, current preparation methods cannot simply and massively prepare monodisperse non-spherical liquid crystal colloidal particles. Moreover, the obtained particles often do not have a single ordered structure inside and do not have controllable optical anisotropy properties, which cannot meet the needs of practical applications. Summary of the Invention

[0005] In order to solve the above technical problems, the purpose of the present invention is to provide a non-spherical and optically anisotropic polymer liquid crystal colloidal particles and their preparation method and application, so as to solve the problem that monodisperse non-spherical and optically anisotropic polymer liquid crystal colloidal particles are difficult to prepare simply and in large quantities, and to obtain liquid crystal colloidal particles with a single ordered structure inside.

[0006] The present invention is achieved by the following scheme:

[0007] The present invention provides polymer colloid particles. The polymer colloid particles comprise an acrylic ester polymer containing liquid crystal units in the side chains. The polymer colloid particles have a non-spherical morphology and optical anisotropy.

[0008] According to an embodiment of the present invention, the acrylic polymer containing liquid crystal units in the side chain is obtained by dispersion polymerization of acrylic monomers containing liquid crystal units.

[0009] Preferably, the liquid crystal unit is at least one selected from an azobenzene group, a biphenyl group and a phenyl benzoate group.

[0010] Illustratively, the side chain acrylic polymer containing liquid crystal units is obtained by dispersion polymerization of an acrylic monomer containing an azobenzene group, wherein the acrylic monomer containing an azobenzene group has a structure as shown in formula (I):

[0011]

[0012] R1 is selected from hydrogen or methyl;

[0013] X1 is selected from hydrogen, nitro, cyano, hydroxyl, carboxyl, alkyl (-C m H 2m+1 ), alkoxy (-OC m H 2m+1 ) or ester group (-COOC m H 2m+1 ); wherein m is selected from any integer of 1-6, for example, 1, 2, 3, 4, 5, 6;

[0014] n1 is selected from any integer of 3-12, for example, 3, 4, 5, 6, 7, 8, 9, 10, 11, or 12.

[0015] For example, in the structure shown in formula (I), R1 is selected from methyl, X1 is selected from nitro, and n1=4, that is, the acrylic acid ester monomer containing an azobenzene group is MNAB4;

[0016] Alternatively, in the structure shown in formula (I), R1 is selected from methyl, X1 is selected from nitro, and n1=6, that is, the acrylic acid ester monomer containing an azobenzene group is MNAB6.

[0017] Illustratively, the side chain acrylic polymer containing liquid crystal units is obtained by dispersion polymerization of an acrylic monomer containing a biphenyl group, wherein the acrylic monomer containing a biphenyl group has a structure as shown in formula (II):

[0018]

[0019] R2 is selected from hydrogen or methyl;

[0020] X2 is selected from hydrogen, nitro, cyano, hydroxyl, carboxyl, alkyl (-C m H 2m+1 ), alkoxy (-OC m H 2m+1 ) or ester group (-COOC m H 2m+1 ); wherein m is selected from any integer of 1-6, for example, 1, 2, 3, 4, 5, 6;

[0021] n2 is selected from any integer of 3-12, for example, 3, 4, 5, 6, 7, 8, 9, 10, 11, or 12.

[0022] Illustratively, in the structure shown in formula (II), R2 is selected from a methyl group, X2 is selected from a cyano group, and n2=4, that is, the biphenyl group-containing acrylate monomer is MCB4.

[0023] Illustratively, the side chain acrylic polymer containing liquid crystal units is obtained by dispersion polymerization of an acrylic monomer containing a phenyl benzoate group, wherein the acrylic monomer containing a phenyl benzoate group has at least one of the structures shown in formula (III) or formula (IV):

[0024]

[0025] Among them, in formula (III) and formula (IV):

[0026] R3 or R4 is selected from hydrogen or methyl;

[0027] X3 or X4 is selected from hydrogen, nitro, cyano, hydroxyl, carboxyl, alkyl (-C m H 2m+1 ), alkoxy (-OC m H 2m+1 ) or ester group (-COOC m H 2m+1 ); wherein m is selected from any integer of 1-6, for example, 1, 2, 3, 4, 5, 6;

[0028] n3 or n4 is selected from any integer of 3-12, for example, 3, 4, 5, 6, 7, 8, 9, 10, 11, or 12.

[0029] Illustratively, in the structure shown in formula (III), the substituent group R3 is selected from methyl, the substituent group X3 is selected from methoxy, and n3=4, that is, the acrylic acid ester monomer containing an azobenzene group is MOBzo4.

[0030] According to an embodiment of the present invention, the non-spherical morphology includes cylindrical, mushroom or olive shapes, etc.

[0031] According to an embodiment of the present invention, the polymer colloid particles are micro-nano-scale polymer colloid particles.

[0032] For example, the average size of the cylindrical polymer colloidal particles (referring to the height and / or cross-sectional diameter of the cylinder) is 0.1-10 μm.

[0033] Illustratively, the average size of the mushroom-shaped polymer colloidal particles (referring to the maximum height and / or the maximum length of the cross section) is 0.1-10 μm.

[0034] Illustratively, the average size (referring to the length and / or the maximum length of the cross section) of the olive-shaped polymer colloidal particles is 0.1-10 μm.

[0035] According to an embodiment of the present invention, the interior of the polymer colloid particles has a single ordered structure.

[0036] According to an exemplary embodiment of the present invention, the polymer colloidal particles include an acrylic polymer containing liquid crystal units in the side chains, and the acrylic polymer containing liquid crystal units in the side chains is obtained by a dispersion polymerization reaction of an MNAB4 monomer or an MNAB6 monomer; the polymer colloidal particles are cylindrical colloidal particles with an average size of 0.31-0.38 microns, 0.23-0.26 microns, 0.37-0.48 microns, or 0.28-0.44 microns.

[0037] According to an exemplary embodiment of the present invention, the polymer colloidal particles include an acrylic polymer containing liquid crystal units in the side chains, and the acrylic polymer containing liquid crystal units in the side chains is obtained by a dispersion polymerization reaction of an MNAB4 monomer; the polymer colloidal particles are olive-shaped colloidal particles with an average size of 0.33-0.53 microns.

[0038] According to an exemplary embodiment of the present invention, the polymer colloidal particles include an acrylic polymer containing liquid crystal units in the side chains, and the acrylic polymer containing liquid crystal units in the side chains is obtained by a dispersion polymerization reaction of an MNAB4 monomer; the polymer colloidal particles are mushroom-shaped colloidal particles with an average size of 0.44-0.49 microns.

[0039] The present invention also provides a method for preparing the above-mentioned polymer colloid particles, which comprises subjecting an acrylate monomer containing a liquid crystal unit to a dispersion polymerization reaction in the presence of a stabilizer and an initiator to prepare the polymer colloid particles.

[0040] According to an embodiment of the present invention, the mesogen-containing acrylate monomer is at least one selected from an azobenzene-containing acrylate monomer, a biphenyl-containing acrylate monomer, and a phenyl benzoate-containing acrylate monomer.

[0041] Preferably, the azobenzene group-containing acrylic acid ester monomer is selected from at least one monomer having a structure as represented by formula (I), for example, MNAB4 or MNAB6.

[0042] Preferably, the biphenyl group-containing acrylate monomer is selected from at least one monomer having a structure as represented by formula (II), for example, MCB4.

[0043] Preferably, the acrylic acid ester monomer containing a phenyl benzoate group is selected from at least one monomer having a structure represented by formula (III) or formula (IV).

[0044] According to an embodiment of the present invention, the dispersion polymerization reaction is carried out in a reaction medium.

[0045] According to an embodiment of the present invention, the reaction medium is selected from an organic solvent or a mixed solvent of an organic solvent and water. Preferably, the organic solvent accounts for 10-90% of the total mass of the mixed solvent, for example, 20-85%, and illustratively 25%, 30%, 40%, 50%, 60%, 70%, 80%, or 85%.

[0046] According to an embodiment of the present invention, the organic solvent is selected from at least one of alcohol, acetonitrile, acetic acid, ethyl acetate, propyl acetate, butyl acetate, acetone, methyl ethyl ketone, dimethyl sulfoxide, dioxane, toluene, xylene, chlorobenzene, N,N-dimethylformamide and tetrahydrofuran.

[0047] In the present invention, there is no specific requirement for the selection of alcohol. Exemplarily, the alcohol is selected from at least one of the following alcohols: methanol, ethanol, ethylene glycol, propanol, isopropanol, butanol, isobutanol, pentanol, isopentanol, hexanol, octanol, and isooctyl alcohol.

[0048] According to an exemplary embodiment of the present invention, the reaction medium is selected from at least one of ethanol, a mixed solvent of ethanol and N,N-dimethylformamide, a mixed solvent of ethanol and water, a mixed solvent of N,N-dimethylformamide and water, and a mixed solvent of tetrahydrofuran and water.

[0049] According to an embodiment of the present invention, the stabilizer is selected from at least one of the following compounds: polyvinyl pyrrolidone, polymethacrylic acid, polyacrylic acid, poly-2-hydroxyethyl methacrylate, and hydroxypropyl cellulose.

[0050] According to an embodiment of the present invention, the initiator is selected from at least one of an azo initiator, a peroxide initiator and a persulfate initiator.

[0051] Preferably, the azo initiator is at least one selected from azobisisobutyronitrile, azobisisovaleronitrile, azobisisoheptanenitrile, azobiscyclohexanecarbonitrile, azobisisocyanovaleric acid, azobisisobutylamidine hydrochloride, and the like.

[0052] Preferably, the peroxide initiator is at least one selected from dibenzoyl peroxide, dodecyl peroxide, tert-butyl pervalerate, diisopropyl peroxydicarbonate, dicyclohexyl peroxydicarbonate, tert-butyl peroxybenzoate, and the like.

[0053] Preferably, the persulfate initiator is selected from at least one of ammonium persulfate, potassium persulfate, and the like.

[0054] According to an embodiment of the present invention, the mass ratio of the acrylic acid ester monomer containing liquid crystal elements, the initiator, the stabilizer and the reaction medium is (0.1-20):(0.001-10):(0.01-30):(40-99.889), for example, (0.1-10):(0.01-5):(1-20):(50-98), preferably (0.1-1):(0.01-0.2):(1-20):(70-98), and exemplarily 0.5:0.16:2:97.34, 0.7:0.12:20:79.18, and 0.8:0.04:2:97.16.

[0055] According to an embodiment of the present invention, the dispersion polymerization reaction is carried out at 30-100°C, preferably 50-80°C, for example, 30°C, 35°C, 40°C, 45°C, 50°C, 55°C, 60°C, 65°C, 67°C, 70°C, 75°C, 76°C or 80°C.

[0056] In the present invention, there is no specific requirement for the time of the dispersion polymerization reaction. Exemplarily, the dispersion polymerization reaction time is 0.1-48h, for example, 1h, 2h, 3h, 4h, 5h, 6h, 7h, 8h, 9h, 10h, 20h, 30h, 40h, or 48h.

[0057] According to a preferred embodiment of the present invention, the method for preparing the polymer colloidal particles comprises: subjecting an acrylate monomer containing a liquid crystal unit to a dispersion polymerization reaction in the presence of a stabilizer and an initiator to prepare the polymer colloidal particles;

[0058] The acrylate monomer containing liquid crystal elements is selected from acrylate monomers containing azobenzene groups with a structure represented by formula (I), for example, MNAB4 or MNAB6, or acrylate monomers containing biphenyl groups with a structure represented by formula (II), for example, MCB4, or acrylate monomers containing phenyl benzoate groups with a structure represented by formula (III) or formula (IV), for example, MOBzo4.

[0059] The dispersion polymerization reaction is carried out in a reaction medium, wherein the reaction medium is selected from an organic solvent or a mixed solvent of an organic solvent and water, wherein the organic solvent accounts for 10-90% of the total mass of the mixed solvent, and the organic solvent is selected from at least one of alcohol, acetonitrile, acetic acid, ethyl acetate, propyl acetate, butyl acetate, acetone, methyl ethyl ketone, dimethyl sulfoxide, dioxane, toluene, xylene, chlorobenzene, N,N-dimethylformamide and tetrahydrofuran;

[0060] The mass ratio of the mesogen-containing acrylic acid ester monomer, the initiator, the stabilizer and the reaction medium is (0.1-20):(0.001-10):(0.01-30):(40-99.889);

[0061] The dispersion polymerization reaction temperature is 50-80° C. and the reaction time is 2-6 hours.

[0062] The present invention also provides applications of the polymer colloid particles in the fields of optical display, functional materials, or bio-imaging. Preferably, the polymer colloid particles are applied in the field of optical display, for example, as liquid crystal materials.

[0063] The present invention also provides a liquid crystal material comprising the above polymer colloid particles.

[0064] Beneficial effects

[0065] The present invention adopts acrylate monomers containing specific liquid crystal units, and prepares monodisperse polymer liquid crystal colloid particles with both shape and optical anisotropy in one step through dispersion polymerization, and obtains liquid crystal colloid particles with a single ordered structure inside.

[0066] 1) The present invention can precisely control the size and shape of micro-nano-scale non-spherical optically anisotropic polymer liquid crystal colloidal particles by adjusting parameters such as reaction temperature, reaction medium, and material ratio in the dispersion polymerization reaction.

[0067] 2) The preparation method provided by the present invention has a simple process, is applicable to a wide range of monomer types, can be scaled up for production, and has the conditions for large-scale production in batches.

[0068] 3) The polymer liquid crystal colloidal particles provided by the present invention have a stable shape and an ordered internal structure, and have optical anisotropy, and can be directly applied to fields such as optical display, functional materials and biological imaging. BRIEF DESCRIPTION OF THE DRAWINGS

[0069] Figure 1 This is a SEM image of the colloidal particles prepared in Example 1, with a magnification of 30,000 times;

[0070] Figure 2 This is a SEM image of the colloidal particles prepared in Example 2, with a magnification of 30,000 times;

[0071] Figure 3 This is a SEM image of the colloidal particles prepared in Example 3, with a magnification of 30,000 times;

[0072] Figure 4 This is a SEM image of the colloidal particles prepared in Example 4, with a magnification of 30,000 times;

[0073] Figure 5 This is a SEM image of the colloidal particles prepared in Example 5, with a magnification of 30,000 times;

[0074] Figure 6 This is a SEM image of the colloidal particles prepared in Example 6, with a magnification of 30,000 times;

[0075] Figure 7 This is a SEM image of the colloidal particles prepared in Example 7, with a magnification of 25,000 times;

[0076] Figure 8 This is a SEM image of the colloidal particles prepared in Example 8, with a magnification of 30,000 times;

[0077] Figure 9 This is the SEM image of the colloidal particles prepared in Comparative Example 1, with a magnification of 30,000 times;

[0078] Figure 10 This is an optical microscope photograph of the colloidal particles prepared in Comparative Example 1;

[0079] Figure 11 This is the SEM image of the colloidal particles prepared in Comparative Example 2, with a magnification of 10,000 times;

[0080] Figure 12 This is an optical microscope photograph of the colloidal particles prepared in Comparative Example 2;

[0081] Figure 13 Optical microscope photos (a and b) and SEM images (d1-d4) of the colloidal film prepared in Application Example 1. DETAILED DESCRIPTION

[0082] The technical solutions of the present invention will be described in further detail below with reference to specific embodiments. It should be understood that the following embodiments are merely illustrative and explanations of the present invention and should not be construed as limiting the scope of protection of the present invention. All technologies implemented based on the above content of the present invention are encompassed within the scope of protection that the present invention is intended to protect.

[0083] Unless otherwise specified, the raw materials and reagents used in the following examples are commercially available or can be prepared by known methods.

[0084] The monomers used in the following embodiments are acrylic acid ester monomers containing an azobenzene group having a structure as shown in formula (I), or acrylic acid ester monomers containing a biphenyl group having a structure as shown in formula (II), or acrylic acid ester monomers containing a phenyl benzoate group having a structure as shown in formula (III); wherein MNAB2 represents: in the structure shown in formula (I), the substituent R is a methyl group, the substituent X is a nitro group, and the number of methylene groups n=2; MNAB4 represents: in the structure shown in formula (I), the substituent R is a methyl group, the substituent X is a nitro group, and the number of methylene groups n=4; MNAB6 represents: in the structure shown in formula (I), the substituent R is a methyl group, the substituent X is a nitro group, and the number of methylene groups n=6; MCB4 represents: in the structure shown in formula (II), the substituent R is a methyl group, the substituent X is a cyano group, and the number of methylene groups n=4; MOBzo4 represents: in the structure shown in formula (III), the substituent R is a methyl group, the substituent X is a methoxy group, and the number of methylene groups n=4.

[0085] The names of the initiators and stabilizers used in the following examples are abbreviated as shown in Table 1:

[0086] Table 1 Abbreviations of initiators and stabilizers

[0087]

[0088] Example 1 Preparation of cylindrical polymer colloidal particles

[0089] 75 mg MNAB4 monomer, 24 mg AIBN, 300 mg PMAA (M w =60k) and 14.6g EtOH were added to a 25ml single-necked flask, and then nitrogen was bubbled through for 25 minutes to remove oxygen. The flask was then placed in a 66°C constant temperature water bath and reacted with magnetic stirring for 6 hours. The resulting reaction solution was naturally cooled to room temperature, and the colloidal particles were collected by centrifugal sedimentation. The colloidal particles were then washed four times with anhydrous ethanol by repeated ultrasonic dispersion and centrifugal sedimentation to obtain the following: Figure 1 The cylindrical colloidal particles shown have an average size of: column height 372 nm ± 13 nm, and cross-sectional diameter 318 nm ± 9 nm.

[0090] Example 2 Preparation of Olive-Shaped Polymer Colloidal Particles

[0091] 75 mg MNAB4 monomer, 24 mg AIBN, 300 mg PMAA (M w=60k) and 14.6g EtOH were added to a 25ml single-necked flask, and then nitrogen was bubbled through for 25 minutes to remove oxygen. The flask was then placed in a 60°C constant temperature water bath and reacted with magnetic stirring for 6 hours. The resulting reaction solution was naturally cooled to room temperature, and the colloidal particles were collected by centrifugal sedimentation. The colloidal particles were then repeatedly ultrasonically dispersed and centrifuged, and washed with anhydrous ethanol four times to obtain the following: Figure 2 The olive-shaped colloidal particles shown have an average size of 503 nm ± 21 nm in length and a maximum cross-sectional length of 343 nm ± 12 nm.

[0092] Example 3 Preparation of Mushroom-Shaped Polymer Colloidal Particles

[0093] 120 mg MNAB4 monomer, 6.0 mg AIBN, 300 mg PMAA (M w =60k) and 14.6g EtOH were added to a 25ml single-necked flask, and then nitrogen was bubbled through for 25 minutes to remove oxygen. The flask was then placed in a 76°C constant temperature water bath and reacted with magnetic stirring for 4 hours. The resulting reaction solution was naturally cooled to room temperature, and the colloidal particles were collected by centrifugal sedimentation. The colloidal particles were then washed four times with anhydrous ethanol by repeated ultrasonic dispersion and centrifugal sedimentation to obtain the following: Figure 3 The mushroom-shaped colloidal particles shown have average dimensions of a maximum height of 461 nm ± 18 nm and a maximum cross-sectional length of 468 nm ± 21 nm.

[0094] Example 4 Preparation of cylindrical polymer colloidal particles

[0095] 105 mg MNAB4 monomer, 18 mg AIBN, 3.0 g PVP (M w =40k) and 11.9g EtOH were added to a 25ml single-necked flask, and then nitrogen was bubbled for 25min to remove oxygen. The mixture was then placed in a 67°C constant temperature water bath and reacted with magnetic stirring for 4h. After the reaction solution was naturally cooled, the colloidal particles were collected by centrifugal sedimentation, and then washed with anhydrous ethanol 4 times by repeated ultrasonic dispersion and centrifugal sedimentation to obtain the following: Figure 4 The cylindrical colloidal particles shown have an average size of: column height 243 nm ± 9 nm, and cross-sectional diameter 253 nm ± 6 nm.

[0096] Example 5 Preparation of cylindrical polymer colloidal particles

[0097] 120 mg MNAB6 monomer, 6.0 mg ABVN, 300 mg PHEMA (M w=50k) and 14.6g EtOH were added to a 25ml single-necked flask, and then nitrogen was bubbled for 25 minutes to remove oxygen. Then, the mixture was placed in a 60°C constant temperature water bath and reacted with magnetic stirring for 6 hours. After the reaction solution was cooled naturally, the colloidal particles were collected by centrifugal sedimentation, and then washed with anhydrous ethanol four times by repeated ultrasonic dispersion and centrifugal sedimentation to obtain the following: Figure 5 The cylindrical colloidal particles shown have an average size of: column height 299 nm ± 14 nm, and cross-sectional diameter 419 nm ± 17 nm.

[0098] Example 6 Preparation of cylindrical polymer colloidal particles

[0099] 120 mg MNAB6 monomer, 6.0 mg ABVN, 300 mg PMAA (M w =60k) and 14.6g EtOH were added to a 25ml single-necked flask, and then nitrogen was bubbled for 25min to remove oxygen. Then, the mixture was placed in a 60°C constant temperature water bath and reacted with magnetic stirring for 6h. After the reaction solution was naturally cooled, the colloidal particles were collected by centrifugal sedimentation, and then washed with anhydrous ethanol 4 times by repeated ultrasonic dispersion and centrifugal sedimentation to obtain the following: Figure 6 The cylindrical colloidal particles shown have an average size of: column height 398 nm ± 19 nm, and cross-sectional diameter 455 nm ± 16 nm.

[0100] Example 7 Preparation of Mushroom-Shaped Polymer Colloidal Particles

[0101] 120 mg MNAB6 monomer, 6.0 mg AIBN, 600 mg PVP (M w =40k) and 14.3g of a mixed solvent of N,N-dimethylformamide and water were added to a 25ml single-necked flask, wherein the mass of N,N-dimethylformamide accounted for 85% of the total mass of the mixed solvent. Then, nitrogen was bubbled through for 25min to deoxygenate the mixture. The mixture was then placed in a 60°C constant temperature water bath and reacted with magnetic stirring for 4h. The reaction solution was poured into 36g of ethanol and the colloidal particles were collected by centrifugal sedimentation. The colloidal particles were then washed with anhydrous ethanol 4 times by repeated ultrasonic dispersion and centrifugal sedimentation to obtain the following: Figure 7 Mushroom-shaped colloidal particles shown.

[0102] Example 8 Preparation of non-spherical colloidal particles containing biphenyl groups

[0103] 75 mg MCB4 monomer, 24 mg AIBN, 300 mg PMAA (M w=60k) and 14.6g EtOH were added to a 25ml single-necked flask, and then nitrogen was bubbled through for 25 minutes to remove oxygen. The flask was then placed in a 56°C constant temperature water bath and reacted with magnetic stirring for 6 hours. The resulting reaction solution was naturally cooled to room temperature, and the colloidal particles were collected by centrifugal sedimentation. The colloidal particles were then repeatedly ultrasonically dispersed and centrifuged, and washed with anhydrous ethanol four times to obtain the following: Figure 8 Olive-shaped colloidal particles are shown.

[0104] Example 9 Preparation of non-spherical colloidal particles containing phenyl benzoate groups

[0105] According to the method of Example 8, the MCB4 monomer was replaced by the MOBzo4 monomer, and other conditions remained unchanged, to obtain polymer colloidal particles with non-spherical morphology similar to that in Example 8.

[0106] Comparative Example 1

[0107] 120 mg MNAB2 monomer, 6.0 mg AIBN, 300 mg PMAA (M w =60k) and 14.6g EtOH were added to a 25ml single-necked flask, and then nitrogen was bubbled for 25min to remove oxygen. The mixture was then placed in a 76°C constant temperature water bath and stirred with magnetic stirring for 4h. After the reaction solution was cooled naturally, the colloidal particles were collected by centrifugal sedimentation, and then washed with anhydrous ethanol 4 times by repeated ultrasonic dispersion and centrifugal sedimentation to obtain the following: Figure 9 The spherical colloidal particles shown, Figure 10 This is an optical microscope photo of the spherical colloidal particles ( Figure 10 a) and polarizing microscope photograph ( Figure 10 b), the scale bar in the figure is 10 μm.

[0108] from Figure 9 It can be seen that when the number of methylene groups n in the acrylic acid ester monomer MNAB is less than 3 (n=2), the obtained colloidal particles are spherical. Figure 10 It can be seen that spherical colloidal particles do not have optical anisotropy and cannot be used in the field of optical displays. This is because when n is less than 3, the polymer inside the colloidal particles cannot form a liquid crystal ordered structure.

[0109] Comparative Example 2

[0110] 120 mg MNAB6 monomer, 6.0 mg AIBN, 600 mg PVP (M w=40k) and 14.3g of a mixed solvent of N,N-dimethylformamide and water were added to a 25ml single-necked flask, wherein the mass of N,N-dimethylformamide accounted for 92% of the total mass of the mixed solvent. Then, nitrogen was bubbled through for 25min to remove oxygen. The mixture was then placed in a 60°C constant temperature water bath and reacted with magnetic stirring for 4h. The reaction solution was poured into 36g of ethanol and the colloidal particles were collected by centrifugal sedimentation. The colloidal particles were then washed with anhydrous ethanol 4 times by repeated ultrasonic dispersion and centrifugal sedimentation to obtain the following: Figure 11 The spherical colloidal particles shown in the SEM morphology are Figure 12 This is an optical microscope photo of the spherical colloidal particles ( Figure 12 a) and polarizing microscope photograph ( Figure 12 b), the scale bar in the figure is 10 μm.

[0111] from Figure 11 It can be seen that when the mass of N,N-dimethylformamide in the mixed solvent accounts for too high a proportion of the total mass of the mixed solvent (e.g. 92%), colloidal particles with stable shape and size, non-spherical morphology, and a single ordered structure inside cannot be prepared. Figure 12 It can be seen that the colloidal particles prepared in Comparative Example 2 have optical anisotropy. However, since the particles do not have a single ordered structure, their optical anisotropy cannot be manipulated by particle orientation, and therefore their application in the field of optical display is greatly limited.

[0112] Application Example 1: Optical Display Application of Polymer Colloidal Particles

[0113] The cylindrical polymer colloidal particles obtained in Example 6 were coated on the surface of a glass sheet to obtain a layer of Figure 13 The colloidal film shown in a is then placed between crossed polarizers, as shown in Figure 13 When light passes through orthogonal polarizers, due to the optical anisotropy of the liquid crystal polymer colloid particles and the different orientations of the particles in the colloid film, different areas of the colloid film show different brightness. With the help of such brightness differences, the optical display of the pattern is achieved (such as Figure 13 The area with different brightness on the colloidal film (i.e. Figure 13 The area within the dotted box in middle b) was magnified step by step by scanning electron microscopy (see Figure 13 In the middle d1-d4), it can be observed that in the bright area (i.e. Figure 13 The colloidal particles in the area marked by the arrow in b are in a downturned orientation, and the colloidal particles in the dark area are in an upright orientation. The above observation results show that the cylindrical liquid crystal polymer colloidal particles have different optical properties in the axial and radial directions (such as Figure 13As shown in c), it is illustrated that the non-spherical liquid crystal polymer colloidal particles prepared by the present invention have significant optical anisotropy and can be applied in the field of optical display.

[0114] about Figure 13 Description: Figure 13 A and Figure 13 b is an optical microscope photograph, in which the dotted box represents the same area; Figure 13 In the middle, d1-d4 are Figure 13 A and Figure 13 SEM micrographs of the area within the dotted box in middle b are magnified step by step; Figure 13 A and Figure 13 The scale bars in middle b are all 10 μm. Figure 13 The scale bars in d1-d4 are all 5 μm.

[0115] The exemplary embodiments of the present invention have been described above. However, the present invention is not limited to the aforementioned embodiments. Any modifications, equivalent substitutions, improvements, etc. made by those skilled in the art within the spirit and principles of the present invention shall be included within the scope of protection of the present invention.

Claims

1. A polymer colloidal particle, characterized in that: The polymer colloidal particles include an acrylic polymer containing liquid crystal units in the side chains, and the polymer colloidal particles have a non-spherical morphology and optical anisotropy; the non-spherical morphology includes a cylindrical shape, a mushroom shape, or an olive shape; The side chain acrylic polymer containing liquid crystal units is obtained by dispersion polymerization of acrylic monomers containing liquid crystal units in the presence of a stabilizer and an initiator, wherein the dispersion polymerization reaction is carried out in a reaction medium; the acrylic monomer containing liquid crystal units is selected from at least one of acrylic monomers containing azobenzene groups, acrylic monomers containing biphenyl groups, and acrylic monomers containing phenyl benzoate groups; the stabilizer is selected from at least one of the following compounds: polyvinyl pyrrolidone, polymethacrylic acid, polyacrylic acid, poly(2-hydroxyethyl methacrylate), and hydroxypropyl cellulose; the acrylic monomer containing liquid crystal units is selected from at least one of the following compounds: polyvinyl pyrrolidone, polymethacrylic acid, polyacrylic acid, poly(2-hydroxyethyl methacrylate), and hydroxypropyl cellulose; the side chain acrylic polymer containing liquid crystal units is obtained by dispersion polymerization of acrylic monomers containing liquid crystal units in the presence of a stabilizer and an initiator, wherein the dispersion polymerization reaction is carried out in a reaction medium ... The mass ratio of the acrylate monomer, the initiator, the stabilizer, and the reaction medium is 0.1-20:0.001-10:0.01-30:40-99.889; the reaction medium is selected from alcohol, or a mixed solvent of an organic solvent excluding alcohol and water; when the reaction medium is a mixed solvent, the organic solvent excluding alcohol accounts for 10-90% of the total mass of the mixed solvent; the organic solvent excluding alcohol is selected from at least one of acetonitrile, acetic acid, ethyl acetate, propyl acetate, butyl acetate, acetone, methyl ethyl ketone, dimethyl sulfoxide, dioxane, toluene, xylene, chlorobenzene, N,N-dimethylformamide, and tetrahydrofuran; The azobenzene-containing acrylate monomer has a structure as shown in formula (I): Formula (I) R1 is selected from hydrogen or methyl; X1 is selected from hydrogen, nitro, cyano, hydroxyl, carboxyl, alkyl-C m H 2m+1 , alkoxy-OC m H 2m+1 or ester-COOC m H 2m+1 ; wherein m is selected from any integer of 1-6; n1 is selected from any integer of 3-12; The biphenyl group-containing acrylate monomer has a structure as shown in formula (II): Formula (II) R2 is selected from hydrogen or methyl; X2 is selected from hydrogen, nitro, cyano, hydroxyl, carboxyl, alkyl-C m H 2m+1 , alkoxy-OC m H 2m+1 or ester-COOC m H 2m+1 ; wherein m is selected from any integer of 1-6; n2 is selected from any integer of 3-12; The acrylic acid ester monomer containing a phenyl benzoate group has at least one of the structures shown in formula (III) or formula (IV): Formula (III) Formula (IV) Wherein, in formula (III) and formula (IV): R3 or R4 is selected from hydrogen or methyl; X3 or X4 is selected from hydrogen, nitro, cyano, hydroxyl, carboxyl, alkyl C m H 2m+1 , alkoxy-OC m H 2m+1 or ester-COOC m H 2m+1 ; wherein, m is selected from any integer of 1-6; n3 or n4 is selected from any integer of 3-12.

2. The polymer colloidal particles according to claim 1, characterized in that The polymer colloid particles are micro-nano-scale polymer colloid particles; The interior of the polymer colloid particles has a single ordered structure.

3. The polymer colloidal particles according to claim 1, wherein The average size of the cylindrical polymer colloidal particles is 0.1-10 microns; The average size of the mushroom-shaped polymer colloidal particles is 0.1-10 microns; The average size of the olive-shaped polymer colloid particles is 0.1-10 microns.

4. The method for preparing the polymer colloidal particles according to any one of claims 1 to 3, characterized in that: The preparation method comprises the steps of subjecting an acrylic acid ester monomer containing a liquid crystal unit to a dispersion polymerization reaction in the presence of a stabilizer and an initiator to prepare the polymer colloidal particles; The dispersion polymerization reaction is carried out in a reaction medium; the mass ratio of the mesogen-containing acrylic acid ester monomer, the initiator, the stabilizer and the reaction medium is 0.1-20:0.001-10:0.01-30:40-99.889; The reaction medium is selected from alcohol, or a mixed solvent of an organic solvent excluding alcohol and water; when the reaction medium is a mixed solvent, the organic solvent excluding alcohol accounts for 10-90% of the total mass of the mixed solvent; the organic solvent excluding alcohol is selected from at least one of acetonitrile, acetic acid, ethyl acetate, propyl acetate, butyl acetate, acetone, methyl ethyl ketone, dimethyl sulfoxide, dioxane, toluene, xylene, chlorobenzene, N,N-dimethylformamide and tetrahydrofuran.

5. The preparation method according to claim 4, characterized in that The mesogen-containing acrylate monomer is selected from at least one of an azobenzene-containing acrylate monomer, a biphenyl-containing acrylate monomer, and a phenyl benzoate-containing acrylate monomer; The azobenzene group-containing acrylic acid ester monomer is selected from at least one monomer having a structure as shown in formula (I); The biphenyl group-containing acrylate monomer is selected from at least one monomer having a structure as shown in formula (II); The acrylic acid ester monomer containing a phenyl benzoate group is selected from at least one monomer having a structure represented by formula (III) or formula (IV).

6. The preparation method according to claim 4, characterized in that The alcohol is selected from at least one of the following alcohols: methanol, ethanol, ethylene glycol, propanol, isopropanol, butanol, isobutanol, pentanol, isopentanol, hexanol, octanol, and isooctyl alcohol; The mass ratio of the acrylic acid ester monomer containing liquid crystal unit, the initiator, the stabilizer and the reaction medium is 0.1-10:0.01-5:1-20:50-98.

7. The preparation method according to claim 4, characterized in that The initiator is selected from at least one of an azo initiator, a peroxide initiator and a persulfate initiator; The azo initiator is selected from at least one of azobisisobutyronitrile, azobisisovaleronitrile, azobisisoheptanenitrile, azobiscyclohexanecarbonitrile, azobisisocyanovaleric acid, and azobisisobutylamidine hydrochloride; The peroxide initiator is at least one selected from dibenzoyl peroxide, dodecyl peroxide, tert-butyl pervalerate, diisopropyl peroxydicarbonate, dicyclohexyl peroxydicarbonate, and tert-butyl peroxybenzoate; The persulfate initiator is selected from at least one of ammonium persulfate and potassium persulfate.

8. The preparation method according to claim 4, characterized in that The dispersion polymerization reaction is carried out at 30-100°C; The dispersion polymerization reaction time is 0.1-48 h.

9. The preparation method according to claim 4, characterized in that The dispersion polymerization reaction is carried out at 50-80°C; The dispersion polymerization reaction time is 2-6 h.

10. Use of the polymer colloidal particles according to any one of claims 1 to 3 in the fields of optical display, functional materials or bioimaging.

11. A liquid crystal material, characterized in that: The liquid crystal material comprises the polymer colloid particles according to any one of claims 1 to 3.

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