CN101974286B - Near-infrared radiation resistant coating film for energy-saving window - Google Patents

Abstract

The invention discloses a near-infrared radiation resistant coating film for an energy-saving window, which is formed by a gold nano material with infrared absorption function, auxiliary materials and transparent base materials, wherein the mass ratio of gold nano material, auxiliary materials and transparent base materials is 0.001-0.02:0.01-0.2:100-500; the infrared absorption rate is 80-100%; and the visible light absorption rate is 10-40%. A preparation process is characterized by firstly adding the gold nano material to the auxiliary materials and stirring the mixture for 2-24h, and then adding the stirred mixture to the base materials and stirring and mixing the mixture uniformly. The coating film is coated on the outer surface of the glass and the coating times can be increased to increase the thickness, thus the coating film can achieve the effect of absorbing most near-infrared radiation and can not affect the permeability and vision of the visible light.

Description

A kind of anti-near infrared radiation energy-saving window coating film

technical field

The invention relates to the field of nano optics, in particular to a near-infrared light-absorbing coating film containing composite nanomaterials.

Background technique

The wavelength of sunlight reaching the ground (290-4000nm) is mainly divided into three bands: ultraviolet radiation (wavelength λ=290-400nm), visible light (λ=400-760nm), infrared radiation (λ=760nm-1mm); Radiation is further divided into near-infrared IRA (λ=760nm-1440nm), mid-infrared IRB (λ=1440nm-3000nm), and far-infrared IRC (λ=3000nm-1mm). Although the photon energy of infrared light IR is lower than that of ultraviolet light UV, IR accounts for 54% of the total conversion energy of the sun, while UV only accounts for 7%. The most important part of the solar infrared radiant energy is the IRA, because 30% of the solar energy reaching the ground is within the IRA range.

In hot summer, spaces with windows such as buildings, carriages and cabins need to be cooled by air conditioners, which consumes a lot of energy. The consumption of fossil energy pollutes the environment, emits carbon dioxide, and exacerbates the greenhouse effect. In my country's building energy consumption, building energy consumption accounts for 80-90%, of which 65% is used for air conditioning and heating. For this reason, in high temperature weather, being able to effectively block the radiation of sunlight can greatly reduce the utilization rate of the air conditioner, thereby achieving the purpose of energy saving. There are many researches and patents in this area.

Contents of the invention

The object of the present invention is to manufacture a near-infrared radiation-resistant energy-saving window coating film that blocks most of the near-infrared light and does not affect the transmission of visible light.

The present invention adopts following technical scheme:

An anti-near-infrared radiation energy-saving window coating film is composed of infrared-absorbing gold nanomaterials, auxiliary materials and transparent base materials, wherein the mass ratio of gold nanomaterials, auxiliary materials and transparent base materials is 0.001-0.02:0.01- 0.2:100-500, infrared light absorption 80-100%, visible light absorption 10-40%.

The invention uses the absorption function of light in the infrared region of a composite nanometer material, and combines transparent auxiliary materials and base materials to prepare an energy-saving window coating film with specific functions against near-infrared radiation.

The composite nanomaterial is a mixture of one gold nanorod and three gold nanosheets. The excipients are polymers that stabilize nanomaterials, such as polyvinylpyrrolidone, mercaptopolyethylene glycol, and the like. Base materials are polyurethane, epoxy, acrylic paints.

The amount of composite nanomaterials is added on the basis of ensuring most of the infrared light absorption, and the amount of composite nanomaterials is adjusted to control the absorption rate in the visible light region without affecting the visual effect.

The advantages of the present invention are:

1. The product of the present invention can absorb most of the infrared light without affecting the transparency of visible light. Similar patents and products do not have this function: it can block the radiation of sunlight to the greatest extent without affecting the visual effect ;

2. Because the absorption function of the product of the present invention is derived from its nanostructure, there is no problem of photobleaching or long use time, which leads to the decline of its anti-infrared light function, so that the service life can be extended, and the consumption of raw materials and environmental waste can be reduced. generation.

Description of drawings

Figure 1 is an electron micrograph of gold nanorods with an absorption peak at 840nm.

Fig. 2 Electron micrographs of gold nanosheets with absorption peaks at 1100nm, 1400nm and 1800nm respectively.

Figure 3125 micron thick coating film spectrogram (visible light absorption below 760nm is 40%, and infrared light absorption above 760nm is nearly 100%).

Figure 4 Schematic diagram of absorption rate calculation.

Figure 5250 micron thick coating film spectrogram (visible light absorption below 760nm is 40%, and infrared light absorption above 760nm is nearly 100%).

Detailed ways

Embodiment 1, the preparation of gold nanorod

Take 5mL of 0.2M cetyl ammonium bromide (CTAB) aqueous solution and put it into a beaker, and add 5mL of 5×10 ^-4 M chloroauric acid aqueous solution dropwise under stirring. Then quickly add 0.6 mL of freshly prepared 0.01 M sodium borohydride aqueous solution. The solution turned from light yellow to brownish yellow. Stirring was continued for 2 minutes, and the mixture was left to stand at 25° C. for 2 hours as a seed solution for later use.

At 25°C, 2.5mL of 0.2M CTAB aqueous solution was placed in a beaker, and 0.125mL of 4×10 ⁻³ M silver nitrate aqueous solution was added. Then add 2.5mL of 1×10 ^-3 M chloroauric acid aqueous solution, mix well, then add 30μL of 0.0788M ascorbic acid aqueous solution, the solution turns from dark brown to colorless, then add 10μL of 1M hydrochloric acid, and add 14μL of the above of seed liquid. Stand still for 30 minutes to obtain the gold nanorod suspension. The electron microscope and spectrum of the obtained gold nanorods are shown in accompanying drawing 1.

Embodiment 2, the preparation of gold nanosheet

0.2ml of 1% chloroauric acid aqueous solution, 0.6ml of 100mM sodium borohydride aqueous solution, and 0.5ml of 10mM sodium citrate were added to 19ml of water in turn. The solution turned orange-red after stirring for 2 minutes. After standing for 2 hours, take a certain amount of orange-red solution and add it to the following solutions: 0.103ml of 1% chloroauric acid aqueous solution, 0.2ml of 100mM ascorbic acid solution, 5ml of 0.2M CTAB solution, 1.5ml of 0.5mM potassium iodide solution and 10ml of water. Stand for reaction for 4 hours, add a certain concentration of NaCl, and naturally settle in the round bottom flask for 12 hours, pour out the supernatant, then add pure water into the flask, ultrasonicate for 5 minutes, add pure water from transparent to green, that is A suspension of gold nanosheets was obtained. Adding 80, 60 and 40 ul of the orange-red solution can obtain gold nanosheet suspensions with absorption peaks at 1100, 1400 and 1800 nm, respectively. The electron microscope and spectrum of the obtained gold nanosheets are shown in accompanying drawing 2.

Example 3, an energy-saving window coating film with visible light absorption of 20% and infrared light absorption of 90%

Add 100ml of the gold nanorod suspension prepared above with an absorption peak at 840nm and an absorption intensity of 1.0 to 100ml of 1mg/ml polyvinylpyrrolidone, stir at room temperature (20-25°C) for 24 hours, and centrifuge at 2000 rpm for 20 Minutes, remove the supernatant, resuspend the precipitate with polyurethane paint, and adjust the absorbance to 6.0 to form a gold nanorod polyurethane suspension.

Add 100ml of the gold nanosheet suspension prepared above with an absorption peak at 1100nm and an absorption intensity of 1.0 to 100ml of 1mg/ml polyvinylpyrrolidone, stir at room temperature (20-25°C) for 24 hours, and centrifuge at 1500 rpm for 20 Minutes, remove the supernatant, resuspend the precipitate with polyurethane paint, and adjust the absorbance to 6.0 to form a polyurethane suspension of gold nanosheets.

Add 100ml of the gold nanosheet suspension prepared above with an absorption peak at 1400nm and an absorption intensity of 1.0 to 100ml of 1mg/ml polyvinylpyrrolidone, stir at room temperature (20-25°C) for 24 hours, and centrifuge at 1200 rpm for 20 Minutes, remove the supernatant, resuspend the precipitate with polyurethane paint, and adjust the absorbance to 6.0 to form a polyurethane suspension of gold nanosheets.

Add 100ml of the gold nanosheet suspension prepared above with an absorption peak at 1800nm and an absorption intensity of 1.0 to 100ml of 1mg/ml polyvinylpyrrolidone, stir at room temperature (20-25°C) for 24 hours, and centrifuge at 1200 rpm for 20 Minutes, remove the supernatant, resuspend the precipitate with polyurethane paint, and adjust the absorbance to 6.0 to form a polyurethane suspension of gold nanosheets.

The polyurethane suspensions of the above four gold nanomaterials are mixed in equal volumes. When the thickness of the coated film reaches 125 microns, it can reach the index of 20% visible light absorption and 80% infrared light absorption (see Figure 3, where the abscissa is the wavelength, the ordinate is the transmittance, the visible light below 760nm absorbs 20%, Infrared light above 760nm absorbs 80%.Absorptivity calculation method: measure the spectrum of the transmission mode of the coating film with a full-wavelength spectrophotometer, and the percentage of the area above the spectral curve is the absorptivity. The calculation diagram is shown in the attached Figure 4. The following calculations involving the absorption rate follow this method).

Example 4, a coating film with visible light absorption of 40% and almost total absorption of infrared light

Add 100ml of the gold nanorod suspension prepared above with an absorption peak at 840nm and an absorption intensity of 1.0 to 100ml of 1mg/ml mercaptopolyethylene glycol aqueous solution and stir at room temperature (20-25°C) for 24 hours. Centrifuge for 20 minutes, remove the supernatant, resuspend the precipitate with acrylic paint, and adjust the absorbance to 6.0 to form a gold nanorod acrylic paint suspension.

Add 100ml of the gold nanosheet suspension prepared above with an absorption peak at 1100nm and an absorption intensity of 1.0 to 100ml of 1mg/ml mercaptopolyethylene glycol aqueous solution and stir at room temperature (20-25°C) for 24 hours. Centrifuge for 20 minutes, remove the supernatant, resuspend the precipitate with acrylic paint, and adjust the absorbance to 6.0 to form a gold nanosheet acrylic paint suspension.

Add 100ml of the gold nanosheet suspension prepared above with an absorption peak at 1400nm and an absorption intensity of 1.0 to 100ml of 1mg/ml mercaptopolyethylene glycol aqueous solution and stir at room temperature (20-25°C) for 24 hours. Centrifuge for 20 minutes, remove the supernatant, resuspend the precipitate with acrylic paint, and adjust the absorbance to 6.0 to form a gold nanosheet acrylic paint suspension.

Add 100ml of the gold nanosheet suspension prepared above with an absorption peak at 1800nm and an absorption intensity of 1.0 to 100ml of 1mg/ml mercaptopolyethylene glycol aqueous solution and stir at room temperature (20-25°C) for 24 hours. Centrifuge for 20 minutes, remove the supernatant, resuspend the precipitate with acrylic paint, and adjust the absorbance to 6.0 to form a gold nanosheet acrylic paint suspension.

Mix the above four acrylic paint suspensions in equal volumes. When the thickness of the coated film reaches 250 microns, the visible light absorption is 40%, and the index of infrared light total absorption (see Figure 5, wherein the abscissa is the wavelength, the ordinate is the transmittance, the visible light below 760nm absorbs 40%, and the infrared light above 760nm absorbs 40%. Infrared light absorption is nearly 100%).

Example 5, a coating film with visible light absorption of 40% and almost total absorption of infrared light

Add 100ml of the gold nanorod suspension prepared above with an absorption peak at 840nm and an absorption intensity of 1.0 to 100ml of 1mg/ml cysteine aqueous solution and stir at room temperature (20-25°C) for 24 hours. Centrifuge for 20 minutes, remove the supernatant, add epoxy resin to the precipitate, and adjust the absorbance to 6.0 to form a gold nanorod epoxy resin suspension.

Add 100ml of the gold nanosheet suspension prepared above with an absorption peak at 1100nm and an absorption intensity of 1.0 to 100ml of 1mg/ml cysteine aqueous solution and stir at room temperature (20-25°C) for 24 hours. Centrifuge for 20 minutes, remove the supernatant, resuspend the precipitate with epoxy resin, and adjust the absorbance to 6.0 to form a gold nanosheet epoxy resin suspension.

Add 100ml of the gold nanosheet suspension prepared above with an absorption peak at 1400nm and an absorption intensity of 1.0 to 100ml of 1mg/ml cysteine aqueous solution and stir at room temperature (20-25°C) for 24 hours. Centrifuge for 20 minutes, remove the supernatant, resuspend the precipitate with epoxy resin, and adjust the absorbance to 6.0 to form a gold nanosheet epoxy resin suspension.

Add 100ml of the gold nanosheet suspension prepared above with an absorption peak at 1800nm and an absorption intensity of 1.0 to 100ml of 1mg/ml cysteine aqueous solution and stir at room temperature (20-25°C) for 24 hours. Centrifuge for 20 minutes, remove the supernatant, resuspend the precipitate with epoxy resin, and adjust the absorbance to 6.0 to form a gold nanosheet epoxy resin suspension.

Mix the above four epoxy resin suspensions in equal volumes. When the thickness of the coated film reaches 250 microns, the visible light absorption is 40%, and the infrared light is fully absorbed.

Claims (1)

1. An anti-near-infrared radiation energy-saving coating film for windows is characterized in that it is made up of gold nanomaterials, auxiliary materials and transparent base materials with infrared absorption, wherein the mass ratio of gold nanomaterials, auxiliary materials and transparent base materials is 0.001-0.02:0.01-0.2:100-500, infrared light absorption 80-100%, visible light absorption 10-40%, The auxiliary material is polyvinylpyrrolidone, mercapto polyethylene glycol or cysteine, The gold nanomaterial is composed of a gold nanorod and three kinds of gold nanosheets, the extinction peak of the gold nanorod is at 850±50 nm, and the absorption peaks of the three kinds of gold nanosheets are respectively at 1100±100 nm and 1400±100 nm , 1700±100 nm, the ratio of the absorption peak intensities between the gold nanorods and the three gold nanosheets is 1:1:1:1, The transparent base material is polyurethane, epoxy resin or acrylic paint.

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