A thermochromic material for filling intelligent insulating glass and its preparation method

Abstract

The invention discloses a preparation method of a thermochromic material for filling intelligent insulating glass. Weigh 0.01 - 0.03 g of cobalt chloride and add it to 20 mL of ethylene glycol solvent, and stir at room temperature until completely dissolved; then add 2 - 4 g of calcium chloride and stir until completely dissolved to obtain the thermochromic material. The material prepared by this method has a relatively low thermochromic temperature (38°C - 53°C), and has a high initial light transmittance at room temperature. At the same time, it can intelligently adjust its light transmittance as the temperature rises, and the light transmittance adjustment range is more than 20%, ultimately achieving the purpose of energy conservation.

Description

Technical Field

[0001] The present invention relates to the technical field of energy-saving materials, and particularly to a thermochromic material for filling intelligent insulating glass and a preparation method thereof. Background Art

[0002] The energy of buildings is mainly consumed by heating, ventilation and air-conditioning systems. The huge energy consumption of air-conditioning systems is mainly caused by the huge heat loss / gain through windows. Especially in modern buildings, the proportion of glass in the outer wall area is increasing. It is estimated that heat transfer through glass windows accounts for 48% and 71% in winter and summer respectively. If the indoor temperature is adjusted by air-conditioning, when the cooling temperature is increased by 2°C, the cooling load is reduced by about 20%; when the heating temperature is lowered by 2°C, the heating load is reduced by about 30%. Insulating glass is a glass product in which two or more pieces of glass are separated by a spacer bar around the perimeter and bonded and sealed to form a dry gas space between the glass layers. Due to this intermediate structure, insulating glass has good heat insulation, sound insulation and energy-saving properties, and is beautiful, safe and practical, and has been widely used in the fields of building facades, doors and windows, trains, ships, electrical products, etc.

[0003] At present, many researchers are committed to developing energy-saving glass technologies. For example, according to the dynamic utilization of solar radiation, electrochromic, thermosensitive, mechanical and photochromic filling materials are used to adjust the light transmittance of intelligent windows to save building energy consumption. Among them, thermochromic intelligent windows are the most widely used. Due to their specific ability to adjust solar radiation between transparent and opaque states in response to the dynamic ambient temperature, this process does not require any energy input. And thermochromic materials play a key role in triggering the color change of the materials. For example, Chinese Patent CN101265374A discloses a vanadium dioxide solar heat intelligent temperature control polymer film, which is prepared by directly adding vanadium dioxide into the polymer film. By pasting a heat insulation film or coating a heat insulation coating on the glass, the energy consumption can be greatly reduced. It has high transparency, smaller haze, and can increase the infrared blocking rate with the increase of temperature, playing the function of intelligent sunshade. However, the high transition temperature (68°C) that triggers the thermochromism of VO2 hinders its wide application.

[0004] Therefore, it is necessary to develop a new thermochromic material for filling intelligent insulating glass and a preparation method thereof. Summary of the Invention

[0005] In view of this, the present invention provides a new thermochromic material for filling intelligent insulating glass, which solves the problem of high transition temperature of the existing thermochromic material for filling intelligent insulating glass.

[0006] On the one hand, the present invention provides a thermochromic material for filling intelligent insulating glass, which is composed of cobalt chloride, calcium chloride and ethylene glycol.

[0007] Preferably, the material includes 0.01 - 0.03 g of cobalt chloride, 2 - 4 g of calcium chloride, and 20 mL of ethylene glycol.

[0008] Preferably, the material includes 0.02 g of cobalt chloride, 3 g of calcium chloride, and 20 mL of ethylene glycol.

[0009] On the other hand, the present invention provides a method for preparing a thermochromic material for filling intelligent insulating glass, comprising the following steps: weighing 0.01 - 0.03 g of cobalt chloride and adding it to 20 mL of ethylene glycol solvent, stirring at room temperature until completely dissolved; then adding 2 - 4 g of calcium chloride and stirring until completely dissolved to obtain the thermochromic material.

[0010] The thermochromic material provided by the present invention is prepared by compounding cobalt chloride and calcium chloride. It not only has a low thermochromic temperature (pink - blue), ranging from 38°C to 53°C, with strong applicability; but also the solution of the present invention has a high initial light transmittance at room temperature, and can intelligently adjust its light transmittance as the temperature rises, with the light transmittance adjustment range being more than 20%. It can intelligently adjust the light transmittance of the window to achieve the purpose of energy saving.

[0011] Furthermore, the preparation method provided by the present invention has a simple process, is easy to implement, and does not require additional glass production. The thermochromic solution of the present invention is directly filled into the existing insulating double - layer glass, saving costs and being suitable for large - scale production. Description of the Drawings

[0012] Figure 1 It is a photo of the heating and color - changing process of the thermochromic material in Example 1 of the present invention, from left to right are light pink, purple, and blue respectively;

[0013] Figure 2 It is the influence result of the compounded mixture of cobalt chloride and calcium chloride with different dosages in Example 2 on the change of its thermochromic temperature;

[0014] Figure 3 It is the influence result of the compounded mixture of cobalt chloride and calcium chloride with different dosages in Example 2 on the change of its light transmittance at room temperature (25°C) and high temperature (60°C);

[0015] Figure 4 It is the influence result of the mixture of different chlorides and cobalt chloride solution in Example 3 on the change of its thermochromic temperature. Detailed Embodiments

[0016] The principles and features of the present invention are described below with reference to the accompanying drawings. The examples given are only used to explain the present invention and are not intended to limit the scope of the present invention.

[0017] Example 1: A method for preparing a thermochromic material for filling intelligent insulating glass, comprising the following steps:

[0018] Weigh 0.02 g of cobalt chloride (CoCl₂) and add it to 20 mL of ethylene glycol (EG) solvent. Stir at room temperature for 20 min until completely dissolved. Then add 2 g of calcium chloride (CaCl₂) and stir for 3 h until completely dissolved to obtain the filling solution material. Pour the filling solution material into a test tube, heat it, and observe the color change. It is found that when calcium chloride is added, the filling solution material changes from light pink to purple and finally to blue after heating. When the temperature returns to room temperature, the solution will change back to its original light pink color (as Figure 1 ).

[0019] Example 2: The difference between Example 2 and Example 1 is that different amounts of cobalt chloride (0.01 - 0.03 g) are dissolved in 20 mL of ethylene glycol solvent respectively, and stirred at room temperature for 20 min until completely dissolved. Then add calcium chloride (0.5 - 4 g) and stir for 3 h until completely dissolved to obtain the filling solution material. Then pour the solution into a cuvette with a 10 mm optical path length to observe its room temperature transmittance. Subsequently, pour it into a test tube, heat it, and observe the transition temperature during the color change, and measure the transmittance of the solution at high temperature at the same time. From Figure 2 and the results in Table 1, it can be seen that when the solvent is ethylene glycol and the content of cobalt chloride added is 0.01 - 0.03 g, as the mass of calcium chloride increases, the color transition temperature of the mixture becomes lower and lower. And in the same calcium chloride, as the content of cobalt chloride increases, the color transition temperature also decreases.

[0020] Table 1 Influence of the mixture of cobalt chloride and calcium chloride with different dosages on the change of thermochromic temperature

[0021]

[0022] From Figure 3 and the results in Table 2, it can be seen that when the addition amount of cobalt chloride increases and the mass of calcium chloride increases from 0 g to 4 g in sequence, the change range of the transmittance at room temperature is small, and the corresponding transmittance range at high temperature is larger. When the added calcium chloride reaches a certain amount, the difference in transmittance at room temperature and high temperature shows a trend of decreasing from large to small. When the content of cobalt chloride added is 0.01 g and the content of calcium chloride is 4 g, the difference is the largest. The transmittance at room temperature is 79.16%, and the transmittance at high temperature is 49.27%. Referring to Figure 2 it can be known that its transition temperature is 40.1°C. When the content of cobalt chloride added is 0.02 g and the content of calcium chloride is 3 g, the difference is the largest. The transmittance at room temperature is 70.99%, and the transmittance at high temperature is 47.27%. Referring to Figure 2 it can be known that its transition temperature is 38.7°C. When the content of cobalt chloride added is 0.03 g and the content of calcium chloride is 2 g, the difference is the largest. The transmittance at room temperature is 74.66%, and the transmittance at high temperature is 49.43%. Referring to Figure 2It can be known that its transition temperature is 45.6 °C. Therefore, the best formula is the compounding of 0.01 g - 0.03 g of cobalt chloride and 2 - 4 g of calcium chloride, which has a lower color transition temperature, and has a higher light transmittance at room temperature and can adjust its light transmittance as the temperature rises. The maximum light transmittance adjustment range is more than 20%, so as to achieve the purpose of energy saving.

[0023] Table 2 Light transmittance of mixed solutions of different amounts of cobalt chloride and calcium chloride at room temperature (25 °C) and high temperature (60 °C)

[0024]

[0025] Example 3: The difference between Example 3 and Example 1 is the effect of the transition temperature during color change of the mixed solutions obtained by compounding different amounts of sodium chloride, potassium chloride, manganese dichloride or magnesium chloride and 0.01 g of cobalt chloride respectively. From Figure 4 It can be seen from Table 3 that as the amount of chloride added increases, its transition temperature becomes lower and lower. However, compared with the high transition temperatures of sodium chloride, potassium chloride, manganese chloride, and magnesium chloride, the filling solution prepared by compounding calcium chloride and cobalt chloride has a color transition temperature of 38 °C - 53 °C, and has potential application prospects in building thermochromic materials.

[0026] Table 3 Transition temperatures of mixed solutions of different chlorides and cobalt chloride

[0027]

[0028] In summary, the thermochromic material provided by the present invention, which is prepared by compounding cobalt chloride and calcium chloride, not only has a low thermochromic temperature (pink - blue), ranging from 38 °C to 53 °C, and has strong applicability; but also filling the thermochromic solution of the present invention into the existing hollow double - layer glass can save costs, intelligently adjust the light transmittance of the window, and save some energy consumption. Further, the preparation method provided by the present invention has a simple process, is easy to implement, and does not require additional glass production, and is suitable for large - scale production.

[0029] The above are only the preferred embodiments of the present invention, and are not intended to limit the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present invention shall be included within the scope of protection of the present invention.

Claims

1. A thermochromic material for filling intelligent insulating glass, characterized in that, The material consists of cobalt chloride, calcium chloride and ethylene glycol. The dosage of cobalt chloride is 0.01 - 0.03 g, the dosage of calcium chloride is 2 - 4 g, and the dosage of ethylene glycol is 20 mL.

2. The thermochromic material for filling intelligent insulating glass according to claim 1, wherein The material includes 0.02 g of cobalt chloride, 3 g of calcium chloride and 20 mL of ethylene glycol.

3. Preparation method of a thermochromic material for filling intelligent insulating glass, characterized in that It includes the following steps: Weigh 0.01 - 0.03 g of cobalt chloride and add it to 20 mL of ethylene glycol solvent, stir at room temperature until completely dissolved; then add 2 - 4 g of calcium chloride and stir until completely dissolved to obtain the thermochromic material.

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