Disclosure of Invention
Aiming at the problems, the invention improves the solution casting method and provides a method for obtaining poly 4-methylpentene and SiO with uniform and controllable thickness by drip injection2The preparation method of the microsphere composite film comprises the following steps:
(1) heating, stirring and dissolving poly-4-methylpentene (TPX) and a solvent at 0-90 ℃ to obtain a poly-4-methylpentene solution;
(2) adding SiO into the obtained poly-4-methylpentene solution2Microspherically to obtain TPX-SiO2Compounding the microsphere with the solution;
(3) dropping the obtained TPX-SiO on the substrate2Placing the microsphere composite solution in a sealed container, and obtaining the poly-4-methylpentene and SiO after the solvent is evaporated2And (3) microsphere composite films.
In the method, a low-boiling-point nonpolar organic substance is used as a solvent of poly 4-methylpentene, the solvent is stirred and dissolved under the heating condition of 0-90 ℃, and inorganic particles SiO are added2Forming composite solution of microsphere by dripping on the pretreated substrateThe substrate coated with the composite solution is then placed in a sealed container for solvent evaporation. The purpose of the sealed container is to control the volatilization rate of the organic solvent, avoid the phenomenon that the solvent in the air is volatilized too fast to cause the uneven surface of the formed film and the lines such as patterns, holes and the like, and obtain the poly-4-methylpentene and SiO with even and controllable thickness and smooth surface2Microsphere composite film (TPX-SiO)2Microsphere composite films).
Preferably, the solvent is a low-boiling point nonpolar organic matter selected from at least one of cyclohexane, cyclohexene, trichloromethane, tetrachloromethane and trichloroethylene; the mass ratio of the poly-4-methylpentene (TPX) to the solvent is 1: (12.5-50).
Preferably, the poly-4-methylpentene and SiO are used2The volume of the microsphere composite film is 100 percent, and the poly-4-methylpentene and SiO are2SiO in microsphere composite film2The volume ratio of the microspheres is 1-20%.
Preferably, the SiO2The particle size of the microspheres is 1-100 mu m; preferably, the SiO2The microsphere has a porous structure, the aperture is 13-15 nm, and the particle size is 1-100 mu m.
Preferably, the heating and stirring time is 1-3 hours.
Preferably, TPX-SiO is dripped2Before the microsphere composite solution, pretreating the substrate; the pretreatment comprises the following steps: sequentially ultrasonically cleaning and drying a substrate in deionized water and ethanol; and then soaking the substrate in a modified solution containing a silane coupling agent for 1-12 hours. The surface of the substrate is modified, so that the bonding force between the film (organic) and the substrate (inorganic) is increased, and the film is prevented from warping and falling off.
Preferably, an adhesive tape with a thickness of 100-1500 μm is attached around the upper surface of the substrate as a baffle to control the poly-4-methylpentene and SiO2Thickness of the microsphere composite film.
Preferably, the size of the dripping area of the substrate is (1-4) cm x (1-3) cm, and the TPX-SiO2The dropping number of the microsphere composite solution is 5-50 drops.
Preferably, the volume of the sealed container is 0.1-0.5L; the solvent is evaporated for 4 to 12 hours, preferably 4 to 8 hours.
Preferably, the substrate is one of a glass slide, a monocrystalline silicon wafer, sapphire, and the like.
On the other hand, the invention also provides poly 4-methylpentene and SiO prepared by the preparation method2A microsphere composite film of poly-4-methylpentene and SiO2The thickness of the microsphere composite film is 20-50 μm.
Preferably, the poly-4-methylpentene and SiO2The emissivity of the microsphere composite film in an atmospheric window of 8-13 mu m (wavelength) is high and can reach more than 0.9.
The invention has the beneficial effects that:
the invention has the beneficial effects that the polymer-inorganic particle composite film with uniform and controllable thickness is prepared by adopting an improved solution casting method, and uniform TPX-SiO is obtained2The microsphere composite film improves the characteristic of poor stability of an organic film, and meanwhile, the composite film is endowed with special functions due to the addition of inorganic particles, and can be used in the fields of radiation refrigeration, infrared heat insulation and the like. Compared with the traditional chemical preparation methods such as sol-gel, in-situ polymerization and the like, the improved solution casting method has the characteristics of simple operation, low equipment requirement and uniform and controllable thickness of the prepared film. The invention takes poly 4-methylpentene as film forming material, and silicon dioxide particles are doped on the basis of a plurality of excellent performances of the film forming material to develop a new function of the polymer-inorganic particle composite film. The preparation method can realize the preparation of TPX-SiO2The thickness and the radiation refrigeration performance of the microsphere composite film can be controllably adjusted; meanwhile, the method has the characteristics of stable and reliable process and simple operation, and is easy to popularize and apply.
Detailed Description
The present invention is further illustrated by the following examples, which are to be understood as merely illustrative and not restrictive.
In the present disclosure, a poly-4-methylpentene film is doped with SiO2Preparation of poly-4-methylpentene and SiO with uniform and controllable thickness from microspheres2The microsphere composite film is applied to the field of radiation refrigeration by regulating and controlling the thickness of the film and the mixing amount of microspheres. Specifically, poly-4-methylpentene and SiO2The structure of the microsphere composite film is shown in figure 1, and comprises a poly-4-methylpentene film and SiO uniformly dispersed in the poly-4-methylpentene film2And (3) microspheres. Wherein, the poly-4-methylpentene and SiO2SiO in microsphere composite film2The volume ratio of the microspheres can be 1-20%.
In an alternative embodiment, SiO2The particle size of the microspheres is 1-100 μm. Preferably, the SiO2The microsphere has a porous structure, the aperture is 13-15 nm, and the particle size is 1-100 mu m.
In an alternative embodiment, poly-4-methylpentene is reacted with SiO2The microsphere composite film has a smooth surface and controllable thickness, and the thickness of the microsphere composite film can be 20-50 mu m.
In the present invention, inorganic particles (SiO) are incorporated in the organic polymer film (poly-4-methylpentene)2Microspheres) to obtain an organic-inorganic composite film having specific properties. For example, the infrared test results show thatThe invention relates to poly-4-methylpentene and SiO with uniform and controllable thickness2The microsphere composite film has radiation refrigeration performance, has high emissivity up to more than 0.9 (shown in figure 4) within an atmospheric window of 8-13 microns, and can be used in various fields of radiation refrigeration, infrared heat insulation and the like.
In one embodiment of the present invention, the thickness of the poly-4-methylpentene and SiO is uniformly controlled2The microsphere composite film is obtained by forming a film on a substrate by a dripping method. Specifically, a low-boiling point nonpolar organic matter is used as a solvent of poly 4-methylpentene, stirred and dissolved under heating, and inorganic particles SiO are added2The microspheres form a composite solution. Spreading the composite solution on the pretreated substrate by adopting a dripping method, and finally placing the substrate coated with the composite solution in a sealed container for solvent evaporation to obtain TPX-SiO with uniform and controllable thickness2And (3) microsphere composite films. The method is simple to operate, low in equipment requirement, high in practicability and high in popularization and application value. The following is an exemplary description of poly-4-methylpentene with SiO2A preparation method of a microsphere composite film.
A non-polar organic solvent is selected as a solvent, and poly 4-methylpentene (TPX) (e.g., poly 4-methylpentene particles) is dissolved under heating and stirring conditions to obtain a poly 4-methylpentene solution. Wherein the heating temperature can be 0-90 ℃, and the stirring time is 1-3 hours, so that the poly-4-methylpentene is completely dissolved in the solvent. The solvent can be selected from low-boiling point nonpolar organic matters selected from at least one of cyclohexane, cyclohexene, trichloromethane, tetrachloromethane, trichloroethylene, etc. Wherein the mass ratio of the poly-4-methylpentene (TPX) to the solvent is 1: (12.5-50).
Adding SiO into poly 4-methylpentene solution2The microspheres are stirred to be uniformly dispersed to obtain TPX-SiO2And (4) microsphere composite solution. Wherein, SiO2The particle size of the microspheres is uniform and is 1-100 mu m, and the shape is regular. SiO is preferred2The microsphere has a porous structure, the aperture is 13-15 nm, and the particle size is 1-100 mu m. With poly-4-methylpentene and SiO2The volume of the microsphere composite film is 100 percent, poly 4-methylpentene andSiO2SiO in microsphere composite film2The volume ratio of the microspheres is 1-20%.
Dripping TPX-SiO on the substrate2And (4) microsphere composite solution. Prior to drop deposition, the substrate is pre-treated, comprising: ultrasonically cleaning a substrate in deionized water and ethanol in sequence, wherein each time is 1-30 minutes, and air-drying in an oven; and soaking the substrate in a modifying solution containing a silane coupling agent (the concentration of the silane coupling agent is 1-2 wt%, and the solvent can be alcohol) for 1-12 hours (the surface of the substrate is modified, and the bonding force between the substrate and the film is improved). Finally, in order to control the thickness of the film, an adhesive tape with the thickness of 100-1500 μm is pasted on the periphery of the upper surface of the substrate to be used as a baffle plate so as to control TPX-SiO2Thickness of the microsphere composite film. The dripping area of the substrate is (1-4) cm x (1-3) cm, TPX-SiO2The dropping number of the dripping of the microsphere composite solution can be 5-50 drops. The substrate is a material with a smooth surface. Wherein the substrate selected includes but is not limited to: glass plate (glass slide), monocrystalline silicon piece, sapphire, aluminum plate, etc.
Will be dripped with TPX-SiO2Placing the substrate of the microsphere composite solution in a container with good sealing property, and evaporating the solvent to obtain a polymer-inorganic particle film (poly-4-methylpentene and SiO)2Microsphere composite films). In order to ensure that the surface of the prepared film is smooth, uniform and controllable, the evaporation rate of the solvent is an important influence factor. The substrate with the compound solution instilled is placed in a sealed container, the sealing degree of different sealed containers is different (the container volume and the sealing performance of the container), and the sealing time is 4-12 hours. The container with good sealing performance comprises a sealing box and the like, and the preferable sealing time is 4-8 hours.
In general, the invention is improved on the basis of the traditional solution casting method, the substrate is pretreated, the composite solution is spread on the substrate by adopting a dripping method, the evaporation rate of the solvent is controlled by a seal box and the like, the uniformity of the composite film is regulated and controlled, and the film with controllable thickness and excellent radiation refrigeration performance is prepared. In particular, the operation and the equipment are simple by the solution casting methodThe method is based on the method of low requirement, and comprises cleaning the substrate, surface modifying, and sticking adhesive tapes with different thicknesses2The microspheres improve the defects of the traditional organic film, and control and adjust the sealing property of the sealed container to control the solvent evaporation rate, so as to finally prepare the TPX-SiO with uniform and controllable thickness and radiation refrigeration performance2And (3) microsphere composite films.
In this disclosure, SiO2The stability of the poly-4-methylpentene (TPX) film is improved by the incorporation of the microspheres, and SiO is improved2The microsphere has high emissivity in an atmospheric window, and a film device which can be used for radiation refrigeration is manufactured by taking the poly 4-methylpentene film as a support.
Compared with the prior art, the invention has the following beneficial effects:
(1) TPX-SiO prepared by the invention2The thickness of the microsphere composite film can be controlled between 20 and 50 mu m, the surface of the film is uniform and smooth, and the organic polymer and inorganic particles (SiO) pass through2Microspheres have a pore structure), so that the stability of the film is improved, the film has radiation refrigeration performance, and the emissivity in an atmospheric window (8-13 mu m) is high and can reach over 0.9;
(2) compared with other chemical preparation methods of polymer-inorganic particle composite films, the chemical preparation method provided by the invention has the characteristics of simple operation, low cost, low equipment requirement and the like.
The present invention will be described in detail by way of examples. It is also to be understood that the following examples are illustrative of the present invention and are not to be construed as limiting the scope of the invention, and that certain insubstantial modifications and adaptations of the invention by those skilled in the art may be made in light of the above teachings. The specific process parameters and the like of the following examples are also only one example of suitable ranges, i.e., those skilled in the art can select the appropriate ranges through the description herein, and are not limited to the specific values exemplified below. The following examples are summarized, and if not otherwise specified, the selected raw materials include: SiO 22Microspheres (Suzhou Zhiyi microsphere science and technology Co., Ltd., silica gel)Chromatographic packing); adhesive tape (3M 4905); silane coupling agent (Hentai chemical, KH-570).
Example 1
(1) Dissolution of the polymer poly-4-methylpentene (TPX). The specific process is as follows: cyclohexane (0.2g) is selected as a solvent of poly 4-methylpentene (6g), and the mixture is fully stirred under the heating and stirring conditions, the heating temperature is set to be 60 ℃, and the stirring time is 1.5 hours;
(2) and (4) preprocessing the substrate. Wherein the pre-treatment of the substrate comprises: firstly, the substrate is sequentially subjected to ultrasonic cleaning in deionized water and ethanol, the duration time of each time is 10 minutes, and the substrate is dried in an oven. Next, the substrate was immersed in a modification solution (1% wt/alcohol) containing a silane coupling agent for 4 hours. Finally, in order to control the thickness of the film, an adhesive tape with a thickness of 1000 μm is attached to the periphery of the substrate. The substrate is a material with a smooth surface. Wherein the selected substrate is a glass plate;
(3) and (4) preparing a composite solution. Adding SiO into poly 4-methylpentene solution2Microspheres (0.0265g), the particle size of which is 10 μm, are stirred uniformly for 1 hour to obtain a composite solution;
(4) and (4) dripping the composite solution. Dripping the composite solution on a substrate (4 multiplied by 3cm), wherein the dripping number is 25 drops;
(5) control of the solvent evaporation rate. The substrate on which the composite solution was dropped was placed in a sealed container, which was a sealed capsule (0.1L) having a small volume and good sealing properties, for 4 hours. The obtained poly-4-methylpentene and SiO2The thickness of the microsphere composite film is uniform and controllable, and the surface is smooth, as shown in figure 5. Wherein SiO is2The volume ratio of the microspheres is 8%, the thickness of the microspheres is 35 μm, and the emissivity test result is shown in FIG. 4.
Example 2
(1) Dissolution of the polymer poly-4-methylpentene (TPX). The specific process is as follows: selecting trichloroethylene (5g) as a solvent of poly 4-methylpentene (0.3g), and fully stirring under the heating and stirring conditions, wherein the heating temperature is set to be 70 ℃, and the stirring time is 2 hours;
(2) and (4) preprocessing the substrate. Wherein the pre-treatment of the substrate comprises: firstly, the substrate is sequentially subjected to ultrasonic cleaning in deionized water and ethanol, the duration time of each time is 10 minutes, and the substrate is dried in an oven. Next, the substrate was immersed in a modification solution (1% wt/alcohol) containing a silane coupling agent for 4 hours. Finally, in order to control the thickness of the film, an adhesive tape with a thickness of 1000 μm is attached to the periphery of the substrate. The substrate is a material with a smooth surface. Wherein the selected substrate is a monocrystalline silicon wafer;
(3) and (4) preparing a composite solution. Adding SiO into poly 4-methylpentene solution2Microspheres (0.0397g), the particle size of which is 10 μm, are stirred uniformly for 1 hour to obtain a composite solution;
(4) and (4) dripping the composite solution. Dripping the composite solution on a substrate (3 multiplied by 4cm), wherein the dripping number is 25 drops;
(5) control of the solvent evaporation rate. The substrate on which the composite solution was dropped was placed in a sealed container, which was a sealed capsule (0.1L) having a small volume and good sealing properties, and the sealing time was 4 hours. The obtained poly-4-methylpentene and SiO2The thickness of the microsphere composite film is uniform and controllable, the surface is smooth, and SiO is coated on the surface2The microspheres had a volume ratio of 8% and a thickness of 40 μm.
Example 3
(1) Dissolution of the polymer poly-4-methylpentene (TPX). The specific process is as follows: selecting trichloromethane (5.6g) as a solvent of poly (4-methylpentene) (0.2g), and fully stirring under the heating and stirring conditions, wherein the heating temperature is set to be 50 ℃, and the stirring time is 1.5 hours;
(2) and (4) preprocessing the substrate. Wherein the pre-treatment of the substrate comprises: firstly, the substrate is sequentially subjected to ultrasonic cleaning in deionized water and ethanol, the duration time of each time is 10 minutes, and the substrate is dried in an oven. Next, the substrate was immersed in a modification solution (1% wt/alcohol) containing a silane coupling agent for 4 hours. Finally, in order to control the thickness of the film, an adhesive tape with a thickness of 1000 μm is attached to the periphery of the substrate. The substrate is a material with a smooth surface. Wherein the selected substrate is sapphire;
(3) and (4) preparing a composite solution. Adding into poly 4-methyl pentene solutionInto SiO2Microspheres (0.0265g), the particle size of which is 10 μm, are stirred uniformly for 1 hour to obtain a composite solution;
(4) and (4) dripping the composite solution. Dripping the composite solution on a substrate (3 multiplied by 4cm), wherein the dripping number is 25 drops;
(5) control of the solvent evaporation rate. The substrate on which the composite solution was dropped was placed in a sealed container which was a sealed box (0.1L) having good sealing performance and was sealed for 4 hours. The obtained poly-4-methylpentene and SiO2The thickness of the microsphere composite film is uniform and controllable, the surface is smooth, and SiO is coated on the surface2The microspheres had a volume ratio of 8% and a thickness of 35 μm.
Example 4
(1) Dissolution of the polymer poly-4-methylpentene (TPX). The specific process is as follows: selecting cyclohexene (5.6g) as a solvent of poly 4-methylpentene (0.2g), and fully stirring under the heating and stirring conditions, wherein the heating temperature is set to 70 ℃, and the stirring time is 1.5 hours;
(2) and (4) preprocessing the substrate. Wherein the pre-treatment of the substrate comprises: firstly, the substrate is sequentially subjected to ultrasonic cleaning in deionized water and ethanol, the duration time of each time is 10 minutes, and the substrate is dried in an oven. Next, the substrate was immersed in a modification solution (1% wt/alcohol) containing a silane coupling agent for 4 hours. Finally, in order to control the thickness of the film, an adhesive tape with a thickness of 1000 μm is attached to the periphery of the substrate. The substrate is a material with a smooth surface. Wherein the selected substrate is an aluminum plate;
(3) and (4) preparing a composite solution. Adding SiO into poly 4-methylpentene solution2Microspheres (0.0265g), the particle size of which is 10 μm, are stirred uniformly for 1 hour to obtain a composite solution;
(4) and (4) dripping the composite solution. Dripping the composite solution on a substrate (3 multiplied by 4cm), wherein the dripping number is 25 drops;
(5) control of the solvent evaporation rate. The substrate on which the composite solution was dropped was placed in a sealed container, which was a sealed capsule (0.1L) having a small volume and good sealing properties, and the sealing time was 4 hours. The obtained poly-4-methylpentene and SiO2The thickness of the microsphere composite film is uniformControllable, smooth surface, SiO2The microspheres had a volume ratio of 8% and a thickness of 35 μm.
Example 5
(1) Dissolution of the polymer poly-4-methylpentene (TPX). The specific process is as follows: selecting a mixed solution (volume ratio is 1: 1, total 6g) of cyclohexane and trichloromethane as a solvent of poly 4-methylpentene (0.2g), and fully stirring under the heating and stirring conditions, wherein the heating temperature is set to be 50 ℃, and the stirring time is 1.5 hours;
(2) and (4) preprocessing the substrate. Wherein the pre-treatment of the substrate comprises: firstly, the substrate is sequentially subjected to ultrasonic cleaning in deionized water and ethanol, the duration time of each time is 10 minutes, and the substrate is dried in an oven. Next, the substrate was immersed in a modification solution (1% wt/alcohol) containing a silane coupling agent for 4 hours. Finally, in order to control the thickness of the film, an adhesive tape with a thickness of 1000 μm is attached to the periphery of the substrate. The substrate is a material with a smooth surface. Wherein the selected substrate is a glass plate;
(3) and (4) preparing a composite solution. Adding SiO into poly 4-methylpentene solution2Microspheres (0.0265g), the particle size of which is 10 μm, are stirred uniformly for 1 hour to obtain a composite solution;
(4) and (4) dripping the composite solution. Dripping the composite solution on a substrate (3 multiplied by 4cm), wherein the dripping number is 25 drops;
(5) control of the solvent evaporation rate. The substrate on which the composite solution was dropped was placed in a sealed container, which was a sealed capsule (0.1L) having a small volume and good sealing properties, and the sealing time was 4 hours. The obtained poly-4-methylpentene and SiO2The thickness of the microsphere composite film is uniform and controllable, the surface is smooth, and SiO is coated on the surface2The microspheres had a volume ratio of 8% and a thickness of 35 μm.
Comparative example 1
Poly 4-methylpentene and SiO2See example 1 for the preparation parameters of the microsphere composite film, except that the sealing vessel is not used for sealing. The composite solution in the air completes the volatilization process of the solvent within ten minutes, and the obtained poly-4-methylpentene and SiO2Obvious naked eyes appear on the surface of the microsphere composite filmThe holes and patterns visible are quite uneven as shown in fig. 6.
The invention adopts an improved solution casting method to prepare poly 4-methylpentene (TPX) -SiO with controllable thickness2And (3) microsphere composite films. The invention can ensure the uniformity of the composite film, improves the characteristic of poor stability of the organic film, and simultaneously, the addition of the inorganic particles endows the composite film with special functions and can be used in the field of radiation refrigeration. Compared with the traditional chemical preparation methods such as sol-gel, in-situ polymerization and the like, the improved solution casting method has the characteristics of simple operation, low equipment requirement, stable and reliable process and easy popularization and application.