Magneto-optic functionalized thermally enhanced anisotropic conductive film

Abstract

The invention relates to a magneto-optic functionalized thermally enhanced anisotropic conductive film and a preparation technology thereof, and belongs to the technical field of nano material preparation. The method comprises the following five steps: (1) preparing Tb (PABA) 3phen by a precipitation method; (2) preparing VO2 (M) by combining hydrothermal and high-temperature roasting; (3) preparing polymethyl methacrylate (PMMA) by a bulk polymerization method; (4) preparing a spinning solution; and (5) preparing a [PANI / PMMA] / / [VO2 / PMMA] / / [Tb (PABA) 3phen / PMMA] three-color flag type nanobelt array film by adopting a three-axis parallel electrospinning technology, wherein the array film is the magneto-optical functionalized thermally enhanced anisotropic conductive film. The prepared array film has good green fluorescence, thermal enhanced anisotropic conductivity and magnetic multifunctional characteristics. The method disclosed by the invention is simple and easy to implement, batch production can be realized, and the novel nano-structure material has a wide application prospect.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of nanomaterial preparation, in particular to a magneto-optical functional thermal-enhanced anisotropic conductive film and a preparation technology thereof. BACKGROUND

[0002] Anisotropic conductive film is a new type of electronic device interconnection material, which has single-direction conductivity and insulation in other directions. It has been widely used in electronic packaging, chip fixing and electrode bonding, etc. and has attracted much attention. The current anisotropic conductive film can only work and be applied in room temperature environment and has single function. Therefore, developing new anisotropic conductive film suitable for different temperature environments and endowing it with multi-functional properties is of great significance to the development of electronic industry and other related fields.

[0003] The preparation and performance of nanobelt is currently one of the frontiers of research in the fields of chemistry, material science and condensed matter physics. Nanobelt is a kind of nanomaterial with a belt structure synthesized by artificial method. Its cross section is a rectangular structure with a thickness of nanometer level, a width of micron level and a length of several hundred microns or even several millimeters. Nanobelt has attracted much attention due to its novel structure different from that of tube and wire materials and unique optical, electrical and magnetic properties.

[0004] The three colors of the flag represent different meanings, for example, the three colors of the French flag represent freedom, equality and fraternity. Similarly, we will have three chemical compositions in the same nanobelt with a clear three-zone nanobelt structure, each with three properties, such as one side nanobelt with luminescent function, middle nanobelt with electrical conductivity, and the other side nanobelt with magnetic property, i.e. nanobelt / / nanobelt / / nanobelt parallel shoulder-to-shoulder adhesion structure nanobelt. Such one-dimensional nanobelt is called tricolor flag type nanobelt. The nanobelt with such special structure has optical, electrical and magnetic three functions. Using a rotating drum as a receiving device, these tricolor flag type nanobelts can be arranged in a direction to form a tricolor flag type nanobelt array. This array film has good magnetic-fluorescent-anisotropic conductive properties [Chinese invention patent, authorization number: ZL201410795606.9; Materials & Design, 2021, 211, 11012].

[0005] Multifunctional nanomaterials have more extensive application prospects than single functional nanomaterials. Simultaneously having photoelectric and magnetic functions is a typical important multifunctional material, which has attracted much attention of researchers. Previous studies have shown that if directly blending the dark green conductive polyaniline (PANI) and black magnetic cobalt ferrite (CoFe2O4) nanocrystals with rare earth luminescent complexes, the luminescent intensity of the rare earth luminescent complexes will be significantly reduced, and the non-conductive luminescent rare earth complexes and magnetic CoFe2O4 nanocrystals will affect the structural continuity of the conductive substance PANI, thereby affecting the conductivity of PANI. Therefore, if we want to obtain multifunctional materials with good photoelectric and magnetic properties, we must do the following: (1) effectively separate the dark conductive substance and the magnetic substance from the luminescent rare earth complex; (2) form a continuous conductive network of the conductive substance in the matrix. Therefore, for multifunctional materials, it is crucial to design and construct suitable building units. One-dimensional tricolor flag-shaped nanobelt has three independent partitions, and the rare earth complex, conductive polymer and magnetic substance can be assembled into the three regions respectively, thereby realizing the high integration of the three functions in the microcosmic view, and the three functions are independent of each other, reducing the adverse mutual influence among the luminescent, conductive and magnetic properties, thereby obtaining a macroscopic photoelectric and magnetic multifunctional material with good performance. In the current photoelectric and magnetic multifunctional nanomaterials, fluorescence mainly comes from rare earth compounds or dyes, conductive properties mainly come from conductive polymers such as PANI, polypyrrole (PPy) and polythiophene (PTh), and magnetism mainly comes from additional ferromagnetic substances such as CoFe2O4 and Fe3O4.

[0006] Vanadium dioxide VO2 is a metal oxide functional material of electronic strong correlation system, which has first-order reversible phase transition characteristics. Near the critical temperature of 68 DEG C, VO2 undergoes metal-insulator phase transition or semiconductor phase transition, and the resistance of VO2(M) changes by 4-5 orders of magnitude before and after phase transition, i.e. VO2(M) is an insulator or semiconductor at room temperature, and has weak conductivity, while VO2(R) is a metal state tetragonal phase at high temperature (68 DEG C), and has strong metal conductivity, which is a conductive material with thermal induced phase transition characteristics; VO2 also has certain magnetism, and the magnetism increases with the increase of temperature; VO2 has modulation effect on the transmission of infrared light before and after phase transition, i.e. from low temperature high transmittance to high temperature high reflectivity. Due to the electrical and optical mutation properties close to room temperature, VO2 has attracted widespread attention, and has extremely wide application prospects in energy-saving color-changing intelligent windows, photoelectric opening, photoelectric storage, infrared laser radiation protection and non-refrigeration infrared detector, high-performance battery, super capacitor, temperature sensor, gas sensor and other fields. The present application uses PANI as a conductive material, uses VO2 with thermal induced phase transition conductive characteristics as a material to enhance the conductive performance, also as a magnetic material without adding additional magnetic material, uses rare earth complex as a fluorescent material, and constructs a new magnetic and optical functional thermal enhanced anisotropic conductive film. At present, there is no related report.

[0007] The rare earth metal terbium complex Tb(PABA)3phen, Tb 3+ The terbium ion is PABA, and phen is 1,10-phenanthroline. Due to the unique electronic configuration of terbium ion, it becomes a luminescent material with unique properties, such as high luminous intensity, good stability, high fluorescence quantum yield and good monochromaticity, and is a widely used green fluorescent material. Polymethyl methacrylate (PMMA) is a commonly used high polymer material with excellent performance. Therefore, it is an ideal choice to use terbium complex, PANI, VO2 and PMMA to construct photoelectric and magnetic multifunctional materials.

[0008] US Patent No. 1975504 discloses a method of electrospinning, which is an effective method for preparing continuous micro- and nano-fibers with macroscopic length, first proposed by Formhals in 1934. This method is mainly used for preparing polymer nanofibers, and its characteristic is that the charged polymer solution or melt is ejected from the nozzle by the traction of electrostatic force in the electrostatic field, and is thrown to the opposite receiving screen, so as to realize fiber drawing. Then, the solvent is evaporated at room temperature, or the melt is cooled to room temperature to solidify, so as to obtain micro- and nano-fibers. Q.Z. Yu, et al. prepared polyaniline (PANI) nanofibers by using electrospinning technology (also known as electric spinning technology) [Mater. Sci. Eng. B, 2008, 150, 70-76]. It has been reported that polymer nanobelts have been successfully prepared by using electrospinning technology [Materials Letters, 2007, 61: 2325-2328; Journal of Polymer Science: Part B: Polymer Physics, 2001, 39: 2598-2606]. Porous SnO2 nanobelts have been prepared by using tin organic compounds, combining electrospinning technology with metal organic compound decomposition technology [Nanotechnology, 2007, 18: 435704]; porous SnO2 nanobelts have been prepared by first preparing PEO / tin hydroxide composite nanobelts by using electrospinning technology, and then calcining the composite nanobelts [J. Am. Ceram. Soc., 2008, 91(1): 257-262]. Dong Xiangting et al. prepared rare earth trifluoride nanobelts [Chinese Invention Patent, Application No. 201010108039.7], titanium dioxide nanobelts [Chinese Invention Patent, Authorized No. ZL200810050948.2] and Gd3Ga5O 12 :Eu 3+Porous nanobelt [Chemical Journal of Chinese Universities, 2010, 31(7), 1291-1296]. Dong Xiangting et al. used a single spinneret and electrospinning technology to prepare PAN / Eu(BA)3phen composite luminescent nanofibers [New Chemical Materials, 2008, 36(9), 49-52]; Wang Ce et al. used a single spinneret and electrospinning method to prepare polyvinylpyrrolidone / ferroferric oxide magnetic composite nanofibers [Chemical Journal of Chinese Universities, 2006, 27(10), 2002-2004]; Qingbiao Yang, et al. used a single spinneret and electrospinning technology to prepare Fe2O3 nanoparticles / Eu(DBM)3(Bath) composite bifunctional magnetic-optical nanofibers [Journal of Colloid and Interface Science, 2010, 350, 396-401]; Dong Xiangting et al. used electrospinning technology to prepare Fe3O4 / Eu(BA)3phen / PVP magnetic-optical bifunctional composite nanofibers [Journal of Nanoparticle Research, 2012, 14(10):1203-1209] and magnetic-optical bifunctional Fe3O4 / Eu(BA)3phen / PMMA composite nanobelt [National Invention Patent, Application No: 201110303031.0; Optical Materials, 2013, 35(3), 526-530]. Dong Xiangting et al. used a single spinneret and electrospinning technology to prepare Eu(BA)3phen / PANI / PVP optoelectronic bifunctional composite nanofibers [Chemical Journal of Chinese Universities, 2012, 33(8), 1657-1662]; Dong Xiangting et al. used electrospinning technology to prepare Eu(BA)3phen / PVP / / PANI / PVP optoelectronic bifunctional two-strand parallel nanofiber bundle [National Invention Patent, Application No: 201210407369.5]; Dong Xiangting et al. used electrospinning technology to prepare Fe3O4 / PVP / / Eu(BA)3phen / PVP magnetic-optical bifunctional two-strand parallel composite nanofiber bundle [National Invention Patent, Application No: 201110249651.0]. Dong Xiangting et al. used a three-strand parallel spinneret and electrospinning technology to prepare [Tb(BA)3phen / PMMA] / / [PANI / PMMA] / / [Fe3O4 / PMMA] anisotropic conductive magnetic-optical three-functional tri-color flag-shaped nanobelt and its array [Chinese Invention Patent, Authorized No: ZL201410795606.9; Materials & Design, 2021, 211, 11012].Currently, there is no report on the preparation of magneto-optical functionalized thermal enhanced anisotropic conductive [PANI / PMMA] / / [VO2 / PMMA] / / [Tb(PABA)3phen / PMMA] tricolor flag type nanobelt and array film by electrospinning technology.

[0009] When nanomaterials are prepared by electrospinning technology, the type of raw material, the molecular weight of polymer template agent, the composition of spinning solution, the spinning process parameters and the structure of spinneret have important influence on the morphology and size of final product. The invention adopts electrospinning technology, the spinneret is composed of three 12# stainless steel injector needle [single shaft needle] / / [single shaft needle] / / [single shaft needle] special structure of three-axis parallel spinneret, aniline, camphor sulfonic acid, PMMA, N, N-dimethylformamide DMF, chloroform CHCl3 and ammonium persulfate are mixed to form a spinning solution, wherein aniline is polymerized into polyaniline PANI to obtain spinning solution I with conductive function; VO2(M) and PMMA are added to the mixed solvent of DMF and CHCl3 to obtain spinning solution II with magnetic and enhanced conductive function; Tb(PABA)3phen and PMMA are added to the mixed solvent containing DMF and CHCl3 to obtain spinning solution III with fluorescence and insulation function; electrospinning is carried out by applying electrospinning technology, a drum is used as a receiving device, and under the best process conditions, a [PANI / PMMA] / / [VO2 / PMMA] / / [Tb(PABA)3phen / PMMA] three-color flag type nanobelt array film is prepared. In the micro-structural unit three-color flag type nanobelt, the luminescent function Tb(PABA)3phen, the conductive function of dark green PANI and the magnetic and enhanced conductive function of brown VO2 are confined in their own independent space area, effective separation is realized, direct blending of Tb(PABA)3phen and PANI, VO2 is avoided, large-scale and large-area contact is avoided, thus the influence of dark color conductive polymer PANI and magnetic and enhanced conductive material VO2 on the luminescent performance of luminescent material Tb(PABA)3phen can be effectively avoided, the influence of non-conductive luminescent material Tb(PABA)3phen on the conductivity of conductive materials PANI and VO2 can be avoided, good fluorescence and conductivity are obtained.Further, in the construction of the unit [PANI / PMMA] / / [VO2 / PMMA] / / [Tb(PABA)3phen / PMMA] three-color flag type nanobelt structure, one side is the PANI / PMMA conductive nanobelt, which is a conductor at room temperature and high temperature (80℃), has strong conductivity, and the conductivity slightly increases at high temperature (80℃), and the other side is the Tb(PABA)3phen / PMMA luminescent nanobelt, which is an insulator at room temperature and high temperature, has no conductivity, but the middle is the VO2 / PMMA nanobelt, which has weak conductivity at room temperature due to the weak conductivity of VO2, and has strong conductivity at high temperature due to the strong conductivity of VO2, so for a single three-color flag type nanobelt, at room temperature, along the length direction of the three-color flag type nanobelt, due to the existence of the strongly conductive PANI / PMMA nanobelt and the weakly conductive VO2 / PMMA nanobelt, it has strong conductivity, but in the direction perpendicular to the length direction of the three-color flag type nanobelt, i.e. the width direction, due to the insertion of the weakly conductive VO2 / PMMA nanobelt and the non-conductive Tb(PABA)3phen / PMMA nanobelt, it has strong insulation, so that the three-color flag type nanobelt has strong micro anisotropic conductive performance, and since it is arranged as a construction unit, the obtained array film has strong conductivity along the length direction of the three-color flag type nanobelt, and strong insulation along the direction perpendicular to the length direction of the three-color flag type nanobelt, i.e. the width direction, so that the array film has strong anisotropic conductive performance; but at high temperature (80℃), due to the phase transition of VO2 to metal state and the increase in conductivity, the conductivity of PANI also slightly increases, and these two effects make the array film have significantly enhanced conductive performance along the length direction of the three-color flag type nanobelt, and still have strong insulation along the direction perpendicular to the length direction of the three-color flag type nanobelt, i.e. the width direction, so that the array film has significantly enhanced anisotropic conductive performance, i.e. by heating, enhanced anisotropic conductive performance can be obtained, and the array film also has magnetic and fluorescent properties, and as the heating temperature increases, the magnetic property of the array film increases, and the fluorescent intensity decreases, i.e. by adjusting the temperature, the anisotropic conductive degree, magnetic property and fluorescent intensity can be adjusted, and this array film is a magneto-optical functional thermal-enhanced anisotropic conductive film, which is a new type of anisotropic conductive film and a novel optoelectromagnetic multifunctional nanomaterial, and will have important application prospects. There is no related report at present. SUMMARY

[0010] In the background art, polyvinylpyrrolidone / ferroferric oxide composite magnetic nanofiber, PAN / Eu(BA)3phen composite luminescent nanofiber, conductive polyaniline PANI nanofiber, Eu(BA)3phen / PANI / PVP photoelectric dual functional composite nanofiber, Fe3O4 / Eu(BA)3phen / PVP and Fe2O3nanoparticles / Eu(DBM)3(Bath) composite dual functional magnetic-optical nanofiber, Fe3O4 / Eu(BA)3phen / PMMA magnetic-optical dual functional composite nanobelt are prepared by using a single spinneret and adopting electrospinning technology; Eu(BA)3phen / PVP / / PANI / PVP photoelectric dual functional two-parallel nanofiber bundles and Fe3O4 / PVP / / Eu(BA)3phen / PVP magnetic-optical dual functional two-parallel composite nanofiber bundles are prepared by using two-parallel spinnerets and adopting electrospinning technology; [Tb(BA)3phen / PMMA] / / [PANI / PMMA] / / [Fe3O4 / PMMA] anisotropic conductive magnetic-optical trifunctional tricolor flag type nanobelt and array thereof are prepared by using three-parallel spinnerets and adopting electrospinning technology. The raw materials, template agents, solvents and final target products used are different from those of the method of the present application. The present application uses PANI as a conductive substance, uses VO2 with thermotropic phase change conductive properties as a substance for enhancing conductive properties and also as a magnetic substance, does not need to add additional magnetic substances, uses rare earth complexes as fluorescent substances, and uses a special design and manufactured single-axis / single-axis / single-axis structure three-parallel spinneret to prepare a novel [PANI / PMMA] / / [VO2 / PMMA] / / [Tb(PABA)3phen / PMMA] tricolor flag type nanobelt array film by adopting electrospinning technology, which is a magnetic-optical functionalized thermally enhanced anisotropic conductive film, has thermally enhanced anisotropic conductive properties, and is endowed with magnetic and fluorescent properties, and is a new type of anisotropic conductive material and photoelectric-magnetic multifunctional nanomaterial. The present application adds a new type of nanostructured material suitable for the development of the field of materials and devices.

[0011] The present application is implemented in the following way: firstly, Tb(PABA)3phen is prepared by using the precipitation method, VO2(M) is prepared by using the combination of hydrothermal and high-temperature calcination, and polymethyl methacrylate PMMA is prepared by using the bulk polymerization method; aniline, camphor sulfonic acid, PMMA, N,N-dimethylformamide DMF, chloroform CHCl3 and ammonium persulfate are mixed to form a spinning solution, wherein aniline is polymerized into polyaniline PANI to obtain spinning solution I, which has a conductive function; VO2(M) and PMMA are added into a mixed solvent of DMF and CHCl3 to obtain spinning solution II, which has a magnetic and enhanced conductive function; Tb(PABA)3phen and PMMA are added into a mixed solvent containing DMF and CHCl3 to obtain spinning solution III, which has a fluorescent and insulating function; electrospinning is performed by using electrostatic spinning technology, a special designed and manufactured single-shaft / single-shaft / single-shaft structure three-shaft parallel spinneret is used, a rotating drum is used as a receiving device, and under the optimal process conditions, a [PANI / PMMA] / / [VO2 / PMMA] / / [Tb(PABA)3phen / PMMA] tricolor flag type nanobelt array film is prepared, which is a magneto-optical functionalized thermal enhanced anisotropic conductive film, and the steps are as follows:

[0012] (1) Preparation of Tb(PABA)3phen by precipitation method

[0013] 3.7338g of terbium trichloride hexahydrate TbCl3·6H2O, 4.1142g of p-aminobenzoic acid PABA and 1.8021g of 1,10-phenanthroline are dissolved in anhydrous ethanol respectively; the ethanol solution of TbCl3·6H2O and the ethanol solution of PABA are uniformly mixed, the pH value is adjusted to 6.8 by using a dilute sodium hydroxide solution, the ethanol solution of 1,10-phenanthroline is added and uniformly stirred, and the obtained precipitate is centrifuged and washed with anhydrous ethanol for three times, and then dried at 55℃ for 24h to obtain Tb(PABA)3phen;

[0014] (2) Preparation of VO2(M) by combining hydrothermal and high-temperature calcination

[0015] 0.91g of vanadium pentoxide V2O5 and 1.26g of oxalic acid dihydrate C2H2O4·2H2O are added into a 100mL polytetrafluoroethylene lined high-pressure reaction kettle, hydrothermal treatment is carried out at 200℃ for 48h, the precipitate is centrifuged after cooling to room temperature, washed with deionized water and anhydrous ethanol for three times, and then vacuum dried at 60℃ for 12h to obtain VO2(B), the obtained VO2(B) is placed in a tube furnace, heated to 500℃ at a heating rate of 2℃ / min with nitrogen as the protective gas, and then kept for 2h, and then cooled to room temperature at a cooling rate of 5℃ / min to obtain VO2(M);

[0016] (3) Preparation of polymethyl methacrylate PMMA by bulk polymerization

[0017] Weigh 100 g of methyl methacrylate MMA and 0.1 g of dibenzoyl peroxide BPO, add them to a 250 mL three-necked bottle with reflux device and stir them evenly, stir the above solution vigorously at a temperature of 90-95℃ and reflux until the solution has a certain viscosity, when its viscosity is similar to that of glycerol, continue stirring while stopping heating and naturally cool to room temperature, then pour the above solution into a test tube with a pouring height of 5-7 cm, after pouring, let it stand for 2 h until there is no bubble in the solution in the test tube, then transfer the above test tube to a 50℃ drying oven and place it for 48 h, the liquid in the test tube hardens into a transparent solid, finally increase the temperature of the drying oven to 110℃ and keep it for 2 h to end the polymerization reaction, then naturally cool to room temperature to obtain polymethyl methacrylate PMMA;

[0018] (4) Preparation of spinning solution

[0019] Add 0.45 g of camphor sulfonic acid CSA, 0.18 g of aniline ANI and 1.00 g of PMMA to 15.00 g of CHCl3, stir at room temperature for 24 h to obtain solution A; add 0.44 g of ammonium persulfate APS to 3.00 g of DMF, stir at room temperature for 2 h to obtain solution B; place solution A and solution B in a refrigerator at 0℃ for 20 min, then pour solution B into solution A, stir in an ice water bath for 3 h, then place the mixture in a refrigerator for 24 h to obtain spinning solution I; add 2.00 g of VO2(M) and 1.00 g of PMMA to a mixed solvent of 3.00 g of DMF and 15.00 g of CHCl3, stir at room temperature for 20 h to obtain spinning solution II; dissolve 0.20 g of Tb(PABA)3phen and 1.00 g of PMMA in a mixed solvent of 3.00 g of DMF and 15.00 g of CHCl3, stir at room temperature for 20 h to obtain spinning solution III;

[0020] (5) Preparation of [PANI / PMMA] / / [VO2 / PMMA] / / [Tb(PABA)3phen / PMMA] tricolor flag type nanobelt array film by using three-axis parallel electrospinning technology

[0021] The special structure of the spinneret is composed of three 12# stainless steel syringe needles which are cut off at the needle tip. Two 12# stainless steel needles are bent to 155°, and then the two bent 12# needles and one 12# needle are fixed together in parallel by copper wire, with the unbent 12# needle between the two bent 12# needles, and further fixed by ethylene-vinyl acetate hot melt adhesive to ensure that the bottoms of the three needles are parallel. A yellow plastic spray gun head is then sleeved on the bottom of the needle to obtain a triaxial parallel spinneret with a single-axis / single-axis / single-axis structure. The spinning solution I, the spinning solution II and the spinning solution III are respectively injected into three 5 mL syringes connected to the three stainless steel needles, and the amount of each spinning solution is 4 mL. The vertical spraying mode is adopted, and the receiving device is a horizontally placed cylindrical aluminum drum with a length of 20 cm and a diameter of 7 cm. The rotation speed is 1250 r / min, the spinning voltage is 7.5 kV, the distance between the needle tip and the collecting drum is 17 cm, the environmental temperature is 22-26°C, and the relative humidity is 25-35%. After the spinning solution is completely consumed, the [PANI / PMMA] / / [VO2 / PMMA] / / [Tb(PABA)3phen / PMMA] tricolor flag type nanobelt array film is collected on the drum.

[0022] The [PANI / PMMA] / / [VO2 / PMMA] / / [Tb(PABA)3phen / PMMA] tricolor flag type nanobelt array film prepared in the above process is composed of aligned tricolor flag type nanobelts, the thickness of the tricolor flag type nanobelt is 940 nm, and the average width is 7.12±0.15 μm. Under the excitation of ultraviolet light at 274 nm, the array film emits bright green light, and the luminescence intensity of the array film at room temperature 25°C is significantly higher than that at 80°C. The array film has paramagnetism, the magnetization at 25°C is 0.0158 emu·g -1 , and the magnetization at 80°C is 0.1007 emu·g -1 , which is increased by 6.37 times, and the magnetic property is obviously increased. When not heated, i.e. at room temperature 25°C, the electrical conductivity of the array film along the length direction of the tricolor flag type nanobelt is 3.63×10 -5 S, and the electrical conductivity along the width direction of the tricolor flag type nanobelt is 2.06×10 -10 S, and the ratio of the electrical conductivities in the two directions is 1.76×10 5 . The array film has strong anisotropic conductive properties. When heated to 80°C, the electrical conductivity of the array film along the length direction of the tricolor flag type nanobelt is 9.54×10 -5 S, which has a heat-enhanced conductive property, and the electrical conductivity along the width direction of the tricolor flag type nanobelt is 2.64×10 -10 S, which still remains insulating, and the ratio of the electrical conductivities in the two directions is 3.61×10 5, the array film has enhanced anisotropic conductive properties, the conductive anisotropy is increased by 2.05 times compared with room temperature, that is, the array film has strong anisotropic conductive properties when no heating, the array film has enhanced anisotropic conductive properties when heating, the thermal enhanced anisotropic conductive properties are realized by heating, the [PANI / PMMA] / / [VO2 / PMMA] / / [Tb(PABA)3phen / PMMA] tricolor flag type nanobelt array film is a magneto-optical functional thermal enhanced anisotropic conductive film, and the purpose is realized. BRIEF DESCRIPTION OF DRAWINGS

[0023] Figure 1 is an XRD spectrum of the [PANI / PMMA] / / [VO2 / PMMA] / / [Tb(PABA)3phen / PMMA] tricolor flag type nanobelt array film;

[0024] Figure 2 is an SEM photo of the [PANI / PMMA] / / [VO2 / PMMA] / / [Tb(PABA)3phen / PMMA] tricolor flag type nanobelt array film, and the figure also serves as an abstract drawing;

[0025] Figure 3 is a width distribution histogram of the [PANI / PMMA] / / [VO2 / PMMA] / / [Tb(PABA)3phen / PMMA] tricolor flag type nanobelt;

[0026] Figure 4 is an EDS line analysis diagram of a single [PANI / PMMA] / / [VO2 / PMMA] / / [Tb(PABA)3phen / PMMA] tricolor flag type nanobelt;

[0027] Figure 5 is a DSC curve of the [PANI / PMMA] / / [VO2 / PMMA] / / [Tb(PABA)3phen / PMMA] tricolor flag type nanobelt array film;

[0028] Figure 6 is an excitation spectrum diagram of the [PANI / PMMA] / / [VO2 / PMMA] / / [Tb(PABA)3phen / PMMA] tricolor flag type nanobelt array film;

[0029] Figure 7 is an emission spectrum diagram of the [PANI / PMMA] / / [VO2 / PMMA] / / [Tb(PABA)3phen / PMMA] tricolor flag type nanobelt array film;

[0030] Figure 8is a CIE chromaticity coordinate diagram of the [PANI / PMMA] / / [VO2 / PMMA] / / [Tb(PABA)3phen / PMMA] tricolor flag type nanobelt array film;

[0031] Figure 9 is a hysteresis loop diagram of the [PANI / PMMA] / / [VO2 / PMMA] / / [Tb(PABA)3phen / PMMA] tricolor flag type nanobelt array film;

[0032] Figure 10 is a ring curve diagram of the conductance of the [PANI / PMMA] / / [VO2 / PMMA] / / [Tb(PABA)3phen / PMMA] tricolor flag type nanobelt array film along the length direction of the tricolor flag type nanobelt along with temperature change. DETAILED DESCRIPTION

[0033] The terbium trichloride hexahydrate TbCl3·6H2O, para-aminobenzoic acid PABA, 1,10-phenanthroline Phen, vanadium pentoxide V2O5, sodium hydroxide NaOH, oxalic acid dihydrate C2H2O4·2H2O, dibenzoyl peroxide BPO, methyl methacrylate MMA, anhydrous ethanol, nitrogen, N,N-dimethylformamide DMF, chloroform CHCl3, camphor sulfonic acid CSA, aniline ANI, ammonium persulfate APS used in the application are all commercially available analytical pure products; the deionized water is laboratory self-made; the glass instruments and equipment used are the commonly used instruments and equipment in the laboratory.

[0034] Example: 3.7338 g of TbCl3.6H2O, 4.1142 g of p-aminobenzoic acid PABA and 1.8021 g of 1,10-phenanthroline were dissolved in anhydrous ethanol respectively; the ethanol solution of TbCl3.6H2O and the ethanol solution of PABA were uniformly mixed, the pH value was adjusted to 6.8 with dilute sodium hydroxide solution, the ethanol solution of 1,10-phenanthroline was added and uniformly stirred, and then the stirring reflux was continued at 60℃ for 12 h; the obtained precipitate was centrifuged and washed with anhydrous ethanol for three times, and then dried at 55℃ for 24 h to obtain Tb(PABA)3phen; 0.91 g of vanadic oxide V2O5 and 1.26 g of oxalic acid dihydrate C2H2O4.2H2O were added into a 100 mL polytetrafluoroethylene-lined high-pressure reaction kettle, and then hydrothermal reaction was carried out at 200℃ for 48 h; after cooling to room temperature, the precipitate was centrifuged, washed with deionized water and anhydrous ethanol for three times respectively, and then vacuum dried at 60℃ for 12 h to obtain VO2(B); the obtained VO2(B) was placed in a tube furnace, heated to 500℃ at a heating rate of 2℃ / min with nitrogen as the protective gas, and then kept at 500℃ for 2 h; after that, the temperature was decreased to room temperature at a cooling rate of 5℃ / min to obtain VO2(M); 100 g of methyl methacrylate MMA and 0.1 g of benzoyl peroxide BPO were weighed and added into a 250 mL three-necked bottle with reflux device and stirred uniformly; the above solution was stirred vigorously and refluxed at a temperature of 90-95℃ until the solution had a certain viscosity; when the viscosity was similar to that of glycerol, the heating was stopped and the solution was naturally cooled to room temperature while continuing to stir; then the above solution was poured into a test tube with a pouring height of 5-7 cm; after pouring, the solution in the test tube was left to stand for 2 h until no bubbles were observed; then the test tube was transferred to a 50℃ drying oven and left to stand for 48 h; the liquid in the test tube hardened into a transparent solid; finally, the temperature of the drying oven was increased to 110℃ and kept for 2 h to complete the polymerization reaction, and then naturally cooled to room temperature to obtain polymethyl methacrylate PMMA; 0.45 g of camphor sulfonic acid CSA, 0.18 g of aniline ANI and 1.00 g of PMMA were added into 15.00 g of CHCl3, and stirred at room temperature for 24 h to obtain solution A; 0.44 g of ammonium persulfate APS was added into 3.00 g of DMF, and stirred at room temperature for 2 h to obtain solution B; solution A and solution B were placed in a refrigerator at 0℃ for 20 min, and then solution B was poured into solution A; after stirring in an ice water bath for 3 h, the mixture was placed in a refrigerator for 24 h to obtain spinning solution I; 2.00 g of VO2(M) and 1.00 g of PMMA were added into a mixed solvent of 3.00 g of DMF and 15.00 g of CHCl3, and stirred at room temperature for 20 h to obtain spinning solution II; 0.20 g of Tb(PABA)3phen and 1.00 g of PMMA were dissolved in 3.00 g of DMF and 15.The mixture solvent of 00 g CHCl3is stirred at room temperature for 20 h to obtain spinning solution III; the special structure spinneret is composed of three 12# stainless steel syringe needles which are cut flat at the needle tip, two 12# stainless steel needles are bent to 155°, and the two bent 12# needles and one 12# needle are fixed together in parallel by copper wire, the un-bent 12# needle is located between the two bent 12# needles, and is further fixed by using ethylene-vinyl acetate hot melt adhesive to ensure that the bottoms of the three needles are parallel, and then a yellow plastic spray gun head is sleeved on the bottom of the needle to obtain a triaxial parallel spinneret with the structure of single shaft / single shaft / single shaft, the spinning solution I, the spinning solution II and the spinning solution III are respectively injected into three 5 mL syringes connected with the three stainless steel needles, the amount of each spinning solution is 4 mL, the vertical spraying mode is adopted, the receiving device is a horizontally placed cylindrical aluminum drum with a length of 20 cm and a diameter of 7 cm, the rotating speed is 1250 r / min, the spinning voltage is 7.5 kV, the distance between the needle tip and the collecting drum is 17 cm, the environmental temperature is 22-26 ℃, and the relative humidity is 25%-35%, after the spinning solution is completely consumed, the [PANI / PMMA] / / [VO2 / PMMA] / / [Tb(PABA)3phen / PMMA] tricolor flag type nanobelt array film is collected on the drum. Figure 1 The [PANI / PMMA] / / [VO2 / PMMA] / / [Tb(PABA)3phen / PMMA] tricolor flag type nanobelt array film is shown in FIG. 1; the tricolor flag type nanobelt is arranged in an array film in a directional arrangement, and the thickness of the tricolor flag type nanobelt is 940 nm, as shown in FIG. 2. Figure 2 The average width of the [PANI / PMMA] / / [VO2 / PMMA] / / [Tb(PABA)3phen / PMMA] tricolor flag type nanobelt is 7.12±0.15 μm, as shown in FIG. 3. Figure 3 The S, V and Tb elements represent PANI, VO2 and Tb(PABA)3phen respectively, the S element is only distributed on the left side of the tricolor flag type nanobelt, the V element is only distributed in the middle region of the tricolor flag type nanobelt, and the Tb element is only distributed on the right side of the tricolor flag type nanobelt, which is consistent with the overall structure of the tricolor flag type nanobelt, as shown in FIG. 4. Figure 4As shown; the tricolor flag-shaped nanobelt array film of [PANI / PMMA] / / [VO2 / PMMA] / / [Tb(PABA)3phen / PMMA] exhibits an endothermic phase transition peak at 67.11℃ upon heating, which is basically consistent with the phase transition temperature of pure VO2. Upon cooling, it exhibits an exothermic phase transition peak at 60.38℃, showing a temperature hysteresis phenomenon. (See...) Figure 5 As shown; using 546 nm as the monitoring wavelength, the [PANI / PMMA] / / [VO2 / PMMA] / / [Tb(PABA)3phen / PMMA] tricolor flag-shaped nanoribbon array film exhibits a broad excitation band between 225 and 425 nm, with an optimal excitation wavelength of 274 nm, which can be attributed to the π→π* transition of the ligands. The excitation spectral intensity of the array film at room temperature (25℃) is significantly higher than that at 80℃, see... Figure 6 As shown, under 274 nm ultraviolet light excitation, the [PANI / PMMA] / / [VO2 / PMMA] / / [Tb(PABA)3phen / PMMA] tricolor flag-shaped nanoribbon array film exhibits four emission peaks at 491, 546, 585, and 623 nm, corresponding to Tb, respectively. 3+ of 5 D4→ 7 F6, 5 D4→ 7 F5, 5 D4→ 7 F4 and 5 D4→ 7 The F3 level transition is observed, with the strongest emission peak at 546 nm. The emission intensity of the array film at room temperature (25℃) is significantly higher than that at 80℃. (See...) Figure 7 As shown; under 274 nm UV excitation, at room temperature (25℃) and 80℃, the [PANI / PMMA] / / [VO2 / PMMA] / / [Tb(PABA)3phen / PMMA] tricolor flag-shaped nanoribbon array film emitted green fluorescence, with chromaticity coordinates of (0.2367, 0.4923) and (0.2383, 0.4994), respectively. Figure 8 As shown, the [PANI / PMMA] / / [VO2 / PMMA] / / [Tb(PABA)3phen / PMMA] tricolor flag-shaped nanoribbon array film exhibits paramagnetism, with a magnetization of 0.0158 emu·g at 25°C. -1 The magnetization at 80℃ is 0.1007 emu·g. -1 The magnetization increased by 6.37 times, and the magnetism increased significantly. This is due to V 4+ This is due to the transformation of ions from a low-temperature dimer state to a high-temperature bubble paramagnetic state, see […]. Figure 9As shown; the [PANI / PMMA] / / [VO2 / PMMA] / / [Tb(PABA)3phen / PMMA] tricolor flag-shaped nanoribbon array film exhibits abrupt changes in conductivity along the length of the tricolor flag-shaped nanoribbons near the phase transition temperature during heating, followed by a slight increase with rising temperature. When the temperature exceeds 80℃, the conductivity remains essentially constant, indicating that the strongest conductivity has been reached. Therefore, the thermally induced anisotropic conductivity test temperature was set to 80℃. During cooling, the conductivity recovers to its initial level as the temperature decreases, and the conductivity at the beginning and end of the heating / cooling curves remains consistent, indicating that the VO2 phase transition in the thermally enhanced anisotropic conductive film is completely reversible. See Figure 10 As shown; the [PANI / PMMA] / / [VO2 / PMMA] / / [Tb(PABA)3phen / PMMA] tricolor flag-shaped nanoribbon array film, when not heated (i.e., at room temperature of 25°C), exhibits a conductivity of 3.63 × 10⁻⁶ along the length of the tricolor flag-shaped nanoribbons. -5 S, while the conductivity along the width direction of the tricolor nanoribbon is 2.06 × 10⁻⁶. -10 The ratio of the conductivities in the two directions is 1.76 × 10⁻⁶. 5 The array film exhibits strong anisotropic conductivity; when heated to 80℃, the conductivity along the length of the tricolor flag-shaped nanoribbons is 9.54 × 10⁻⁶. - 5 S exhibits thermally enhanced conductivity, with a conductivity of 2.64 × 10⁻⁶ along the width direction of the tricolor flag-shaped nanoribbon. -10 S remains insulating, and the ratio of its conductivities in the two directions is 3.61 × 10⁻⁶. 5 The array film exhibits enhanced anisotropic conductivity, with a 2.05-fold increase in conductivity anisotropy compared to room temperature. This means that the array film possesses strong anisotropic conductivity even without heating, and its anisotropic conductivity is further enhanced upon heating. Heating achieves thermally enhanced anisotropic conductivity. The constructed [PANI / PMMA] / / [VO2 / PMMA] / / [Tb(PABA)3phen / PMMA] tricolor flag-shaped nanoribbon array film is a magneto-optically functionalized thermally enhanced anisotropic conductive film. The [PANI / PMMA] / / [VO2 / PMMA] / / [Tb(PABA)3phen / PMMA] tricolor flag-shaped nanoribbon array film possesses excellent green fluorescence, thermally enhanced anisotropic conductivity, and magnetic multifunctionality.

[0035] Of course, the present invention may have other various embodiments. Without departing from the spirit and essence of the present invention, those skilled in the art can make various corresponding changes and modifications according to the present invention, but these corresponding changes and modifications should all fall within the protection scope of the appended claims.

Claims

1. A magneto-optically functionalized thermally enhanced anisotropic conductive film, characterized in that, Composed of tricolor flag-shaped nanoribbons arranged in an oriented manner to form an array structure film, it has multifunctional properties such as magnetism, green fluorescence, and thermally enhanced anisotropic conductivity. The average width of the tricolor flag-shaped nanoribbons is 7.12±0.15μm and the thickness is 940nm.

2. A fabrication technique for a magneto-optically functionalized thermally enhanced anisotropic conductive film as described in claim 1, characterized in that, Using a triaxial parallel spinneret with a uniaxial / / uniaxial / / uniaxial structure, and employing triaxial parallel electrospinning technology with N,N-dimethylformamide (DMF) and chloroform (CHCl3) as a mixed solvent, a tricolor flag-shaped nanoribbon array film was prepared. The steps were as follows: (1) Preparation of Tb(PABA)3phen by precipitation method 3.7338 g of terbium trichloride hexahydrate (TbCl3·6H2O), 4.1142 g of p-aminobenzoic acid (PABA), and 1.8021 g of 1,10-o-phenanthroline were dissolved in anhydrous ethanol. The ethanol solutions of TbCl3·6H2O and PABA were mixed evenly, and the pH was adjusted to 6.8 with dilute sodium hydroxide solution. The ethanol solution of 1,10-o-phenanthroline was added and stirred evenly. The mixture was stirred and refluxed at 60 °C for 12 h. The resulting precipitate was centrifuged and washed three times with anhydrous ethanol. The precipitate was then dried at 55 °C for 24 h to obtain Tb(PABA)3phen. (2) Preparation of VO2(M) by combining hydrothermal treatment with high-temperature calcination 0.91 g of vanadium pentoxide (V₂O₅) and 1.26 g of oxalic acid dihydrate (C₂H₂O₄·2H₂O) were added to a 100 mL polytetrafluoroethylene-lined high-pressure reactor. The reactor was hydrothermally heated at 200 °C for 48 h. After cooling to room temperature, the precipitate was separated by centrifugation and washed three times each with deionized water and anhydrous ethanol. After vacuum drying at 60 °C for 12 h, VO₂(B) was obtained. The obtained VO₂(B) was placed in a tube furnace and heated to 500 °C with nitrogen as a protective gas at a heating rate of 2 °C / min and held for 2 h. Then, it was cooled to room temperature at a cooling rate of 5 °C / min to obtain VO₂(M). (3) Preparation of polymethyl methacrylate (PMMA) by bulk polymerization Weigh 100g of methyl methacrylate (MMA) and 0.1g of benzoyl peroxide (BPO), add them to a 250mL three-necked flask equipped with a reflux device and stir well. The solution is then vigorously stirred and refluxed at 90-95℃ until it reaches a certain viscosity. When the viscosity is similar to that of glycerol, heating is stopped while continuing to stir, and the solution is allowed to cool naturally to room temperature. The solution is then poured into test tubes to a height of 5-7cm. After pouring, the solution is allowed to stand for 2 hours until no air bubbles remain in the test tubes. The test tubes are then transferred to a 50℃ drying oven and placed for 48 hours. The liquid in the test tubes hardens into a transparent solid. Finally, the temperature of the drying oven is increased to 110℃ and maintained for 2 hours to complete the polymerization reaction. The solution is then allowed to cool naturally to room temperature to obtain polymethyl methacrylate (PMMA). (4) Preparation of spinning solution 0.45 g camphorsulfonic acid (CSA), 0.18 g aniline (ANI), and 1.00 g PMMA were added to 15.00 g CHCl3 and stirred at room temperature for 24 h to obtain solution A. 0.44 g ammonium persulfate (APS) was added to 3.00 g DMF and stirred at room temperature for 2 h to obtain solution B. Solutions A and B were placed in a 0°C refrigerator for 20 min, then solution B was poured into solution A. The mixture was stirred in an ice-water bath for 3 h, and then placed in a refrigerator for 24 h to obtain spinning solution I. 2.00 g VO2(M) and 1.00 g PMMA were added to a mixed solvent of 3.00 g DMF and 15.00 g CHCl3 and stirred at room temperature for 20 h to obtain spinning solution II. 0.20 g Tb(PABA)3phen and 1.00 g PMMA were dissolved in a mixed solvent of 3.00 g DMF and 15.00 g CHCl3 and stirred at room temperature for 20 h to obtain spinning solution III. (5) Preparation of [PANI / PMMA] / / [VO2 / PMMA] / / [Tb(PABA)3phen / PMMA] tricolor flag-shaped nanoribbon array film by triaxial parallel electrospinning technology The specially structured spinneret consists of three 12# stainless steel syringe needles with their tips flattened. First, two 12# stainless steel needles are bent to 155°. The two bent needles and one other 12# needle are then fixed side-by-side together with copper wire. The unbent 12# needle is positioned between the two bent needles and further secured with ethylene-vinyl acetate hot melt adhesive to ensure the bottoms of the three needles are parallel. A yellow plastic spray gun head is then fitted onto the bottom of the needles, resulting in a single-axis / / single-axis / / single-axis structure three-axis parallel spinneret. Spinning solution I, spinning solution II, and spinning solution III are injected into three 5mL syringes connected to the three stainless steel needles, with 4mL of each solution used. A vertical spray method is employed, and the receiving device is a horizontally placed 20cm long... A cylindrical aluminum rotating drum with a diameter of 7 cm was used, rotating at 1250 r / min. The spinning voltage was 7.5 kV, the distance between the needle tip and the collecting drum was 17 cm, the ambient temperature was 22℃-26℃, and the relative humidity was 25%-35%. After the spinning solution was completely consumed, a tricolor flag-shaped nanoribbon array film of [PANI / PMMA] / / [VO2 / PMMA] / / [Tb(PABA)3phen / PMMA] was collected on the rotating drum. The film consisted of oriented tricolor flag-shaped nanoribbons with a thickness of 940 nm and an average width of 7.12 ± 0.15 μm. Under 274 nm ultraviolet light excitation, the array film emitted bright green light, and the luminescence intensity of the array film at room temperature (25℃) was significantly higher than that at 80℃. The array film is paramagnetic, with a magnetization of 0.0158 emu·g at 25℃. -1 When the temperature is increased to 80℃, the magnetization is 0.1007 emu·g. -1 The magnetization increased by 6.37 times, and the magnetism significantly increased; when there was no heating (i.e., at room temperature of 25°C), the conductivity of the array film along the length of the tricolor flag-shaped nanoribbons was 3.63 × 10⁻⁶. -5 S, while the conductivity along the width direction of the tricolor nanoribbon is 2.06 × 10⁻⁶. -10 The ratio of the conductivities in the two directions is 1.76 × 10⁻⁶. 5 The array film exhibits strong anisotropic conductivity; when heated to 80℃, the conductivity along the length of the tricolor flag-shaped nanoribbons is 9.54 × 10⁻⁶. -5 S exhibits thermally enhanced conductivity, with a conductivity of 2.64 × 10⁻⁶ along the width direction of the tricolor flag-shaped nanoribbon. -10 S remains insulating, and the ratio of its conductivities in the two directions is 3.61 × 10⁻⁶. 5 The array film exhibits enhanced anisotropic conductivity, with a 2.05-fold increase in conductivity anisotropy compared to room temperature. This means that the array film possesses strong anisotropic conductivity even without heating, and enhanced anisotropic conductivity upon heating. Heating achieves thermally enhanced anisotropic conductivity. The constructed [PANI / PMMA] / / [VO2 / PMMA] / / [Tb(PABA)3phen / PMMA] tricolor flag-shaped nanoribbon array film is a magneto-optically functionalized thermally enhanced anisotropic conductive film, possessing excellent magnetic properties, green fluorescence, and thermally enhanced anisotropic conductivity.

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