Development and spectral reflectance analysis of thermochromic coatings for buildings

doi:10.11949/0438-1157.20190311

Abstract

Abstract:

Thermochromic coatings have great application potential in reducing the building’s heating and cooling load and improving the urban thermal environment. In order to investigate the factors influencing the optical properties of thermochromic coatings and optimize the material formulation, 12 different thermochromic coatings with the color-changing temperature of 31°C were prepared by incorporating thermochromic powder with other assistant components. The effects of rutile TiO₂ content on the spectral reflectance of the coatings were analyzed. The results show that the spectral reflectance of coatings increases with the content of TiO₂. The optimum mass fraction for thermochromic powder is 5%, and for TiO₂ is about 5%—10%, in which the solar reflectance of colorless phase is higher than that of colored phase by more than 0.2. At the same time, the effects of the particle size of TiO₂ on the reflectivity of the coatings in different bands were investigated. The results show that the reflectivity of the thermochromic coatings decreases with the increase of TiO₂ particle size in ultraviolet and visible light bands except red band. In the red and near-infrared bands, the reflectivity of the thermochromic coatings increases with the increase of TiO₂ ^{particle size.}

Key words: thermochromic coatings, spectral reflectance, solar energy, building energy saving

摘要：

感温变色建筑涂料在降低建筑冷热负荷、改善城市热环境方面具有很大的应用潜力。为了探究感温变色材料光学性能的影响因素，优化材料配方，首先制备了12种不同配方，变色温度为31℃的感温变色涂料，并分析了金红石型TiO₂质量百分含量对涂料光谱反射率和太阳光反射比的影响，研究表明涂料光谱反射率均随着TiO₂含量的增加而提高，感温变色粉最佳质量分数5%，TiO₂的最佳质量分数应在5%~10%之间，此时浅色态的反射比比深色态高0.2以上。同时探究了TiO₂粒径对涂料在不同波段反射率的影响，结果表明，在紫外和除红光外的可见光波段，感温变色涂料的反射率基本上随TiO₂粒径的增大而减小；在红光和近红外波段，感温变色涂料反射率基本上随TiO₂粒径的增大而增大。

关键词: 感温变色涂料, 光谱反射率, 太阳能, 建筑节能

CLC Number:

TU 56

Yuxuan ZHANG, Xiaoqiang ZHAI. Development and spectral reflectance analysis of thermochromic coatings for buildings[J]. CIESC Journal, 2019, 70(9): 3537-3544.

张宇轩, 翟晓强. 感温变色建筑涂料的制备及光谱反射性能实验研究[J]. 化工学报, 2019, 70(9): 3537-3544.

Figures/Tables 7

References 30

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样品	5%TCM		10%TCM		15%TCM
样品	深色态	浅色态	深色态	浅色态	深色态	浅色态
0%TiO₂
5%TiO₂
10%TiO₂
15%TiO₂

样品	5%TCM		10%TCM		15%TCM
样品	深色态	浅色态	深色态	浅色态	深色态	浅色态
0%TiO₂
5%TiO₂
10%TiO₂
15%TiO₂

样品		太阳反射比		反射比变化
样品		深色态	浅色态	反射比变化
5%TCM	0%TiO₂	0.43	0.55	0.12
	5%TiO₂	0.51	0.72	0.21
	10%TiO₂	0.55	0.77	0.22
	15%TiO₂	0.62	0.78	0.16
10%TCM	0%TiO₂	0.41	0.54	0.13
	5%TiO₂	0.51	0.72	0.21
	10%TiO₂	0.53	0.75	0.22
	15%TiO₂	0.65	0.81	0.16
15%TCM	0%TiO₂	0.43	0.56	0.13
	5%TiO₂	0.50	0.72	0.22
	10%TiO₂	0.53	0.75	0.22
	15%TiO₂	0.64	0.82	0.18

样品		太阳反射比		反射比变化
样品		深色态	浅色态	反射比变化
5%TCM	0%TiO₂	0.43	0.55	0.12
	5%TiO₂	0.51	0.72	0.21
	10%TiO₂	0.55	0.77	0.22
	15%TiO₂	0.62	0.78	0.16
10%TCM	0%TiO₂	0.41	0.54	0.13
	5%TiO₂	0.51	0.72	0.21
	10%TiO₂	0.53	0.75	0.22
	15%TiO₂	0.65	0.81	0.16
15%TCM	0%TiO₂	0.43	0.56	0.13
	5%TiO₂	0.50	0.72	0.22
	10%TiO₂	0.53	0.75	0.22
	15%TiO₂	0.64	0.82	0.18

样品	全光谱波段太阳反射比		全光谱波段太阳反射比变化	紫外波段太阳反射比		紫外波段太阳反射比变化	可见光波段太阳反射比		可见光波段太阳反射比变化	近红外波段太阳反射比		近红外波段太阳反射比变化
样品	深色态	浅色态	全光谱波段太阳反射比变化	深色态	浅色态	紫外波段太阳反射比变化	深色态	浅色态	可见光波段太阳反射比变化	深色态	浅色态	近红外波段太阳反射比变化
25 nm TiO₂	0.59	0.77	0.18	0.1	0.15	0.05	0.48	0.82	0.34	0.77	0.78	0.01
60 nm TiO₂	0.55	0.77	0.22	0.07	0.19	0.12	0.4	0.81	0.41	0.77	0.78	0.01
100 nm TiO₂	0.56	0.74	0.18	0.06	0.2	0.14	0.4	0.74	0.34	0.79	0.8	0.01
200 nm TiO₂	0.56	0.7	0.14	0.06	0.2	0.14	0.4	0.66	0.26	0.8	0.81	0.01
400 nm TiO₂	0.57	0.7	0.13	0.08	0.18	0.1	0.41	0.66	0.25	0.8	0.81	0.01