In summer, the sun is strong, and the sunlight enters the room through the glass, causing the temperature in the car to rise sharply, which seriously affects the comfort of living and vehicle riding. Among them, the energy in the infrared band accounts for the largest proportion, and it is also the main source of energy for the temperature increase in the place where the sunlight is irradiated. By blocking infrared rays and maintaining a high visible light transmittance through the method of glass film, it can avoid the substantial rise of indoor and car temperature, and provide people with a comfortable living, working and riding environment. Cesium tungsten oxide nanoparticles are used in transportation vehicles. And building energy saving has a good application prospect.

The dispersion of cesium tungsten bronze nanoparticles directly affects the performance of the final product. The author explored the method of dispersing cesium tungsten bronze powder by ball milling, and studied the influence of the type and amount of dispersant, grinding time and other factors on the dispersibility of cesium tungsten bronze powder, and used it to prepare polyvinyl chloride (PVC) thermal insulation film. It can provide theoretical guidance for the preparation of thermal insulation products for doors and windows with excellent infrared blocking performance and high visible light transmittance.

1. Main raw materials:
Cesium tungsten oxide nano powder: particle size <100nm, 99.9%
Acrylate copolymer: M325
PVC powder: S–70, degree of polymerization 1300
Plasticizer: HM–828
Heat Stabilizer: HW–303
Dispersant: PVPK–20
Super dispersant: D626
Dispersants: K–80, K–92, K–61



2. Main instruments and equipment
ball mill
Torque Rheometer
Hot press forming machine
Thermal insulation film temperature tester
Solar Film Tester



3. Sample preparation

(1) Preparation of cesium tungsten bronze slurry.
Weigh the cesium tungsten bronze nano-powder, dispersant and acrylate copolymer according to the formula, and then use a ball mill to grind with zirconia balls at a speed of 200 r/min. min is a cycle, and the grinding is continuously cycled. According to the formula and research needs, the total grinding time is set to 4-72 h.
(2) Preparation of cesium tungsten bronze modified PVC film.
Weigh the ingredients according to the formula, first mix HM-828 with the ground cesium tungsten bronze slurry evenly, then add PVC powder and heat stabilizer HM-W303 to premix evenly, and then feed them to a torque rheometer for melt blending , melt and blend for 5 min at a temperature of 180 ° C and a rotational speed of 50 r/min.
Weigh 10 g of the melt-blended sample, and use a hot-pressing machine to prepare a film sample with a thickness of 150 μm. The specific parameters of the hot-pressing process are: temperature 190 ° C, preheating for 5 min, hot pressing for 1 min, and cooling to Take out at 37°C.



4. Performance test
(1) Dispersion stability test of cesium tungsten bronze slurry.
After grinding the cesium tungsten bronze slurry for the set time, use a plastic centrifuge tube to sample 6-7 mL, and after standing for a period of time, observe whether the solution is stratified and record it by taking pictures.
(2) Thermal insulation performance test.
Put the PVC thermal insulation film sample on the test glass plate of the thermal insulation film temperature tester, plug in the power supply, and press the red "reset/test" button to start the test. The test time is 1 min. After the 1 min test is completed, the instrument will Automatically turn off the infrared light, and record the temperature difference between the start of the test and the infrared light irradiation for 1 min. The smaller the temperature difference value, the better the thermal insulation performance of the film. Press the "Reset/Test" button again to start the instrument reset, and after the temperature on both sides is basically the same, carry out the second test. Repeat the test 3 times and take the average value.
(3) Barrier performance test.
Turn on the switch of the solar film tester, place the film sample in the test tank, and immediately display the total solar transmittance, infrared blocking rate and visible light transmittance of the tested object. Select the DIP switch, and test the infrared blocking rate with a wavelength of 950 and 1 400 nm. Repeat the test 3 times and take the average value.

Five, performance summary
(1) The type of dispersant has the greatest influence on the dispersion stability of cesium tungsten bronze nano-powder in acrylate copolymer, and the dispersion stability of dispersant K-61 is the best.
(2) Under the same grinding time, as the amount of dispersant K-61 increases, the homogeneity and stability of the cesium tungsten bronze slurry are gradually improved. When the amount of the cesium tungsten bronze slurry is greater than or equal to 4%, a good dispersion stability effect can be obtained. .
(3) The infrared blocking rate of the PVC film prepared by adding the slurry with the same grinding time increases with the increase of the amount of K-61 in the slurry, and the temperature difference, total solar transmittance and visible light transmittance decrease accordingly.
(4) Add 1.3% slurry to the PVC film (the dosage of K-61 is 4%, grinding for 72h), the infrared blocking rate of 950 nm is 52.4%, the infrared blocking rate of 1 400 nm is 60.1%, the whole infrared band The infrared blocking rate is 58.4%, the temperature rises by 6.3 ℃ for 1 min of infrared lamp irradiation, the visible light transmittance is 68.5%, and the total solar transmittance is 0.531. The slurry has a good application prospect in the field of thermal insulation and energy saving of glass doors and windows.