TiO_2@CoAl_2O_4复合颜料的制备及其近红外反射性能研究

Preparation and near-infrared reflectance properties of TiO_2@CoAl_2O_4 complex pigments

以TiO_2微球为模板,采用化学共沉淀法制备了一种具有核壳结构的TiO_2@CoAl_2O_4复合颜料.利用XRD、SEM、TEM和紫外可见分光光度计等分析测试手段对其晶体结构、微观形貌、可见吸光度和近红外反射率进行了表征.结果表明:TiO_2@CoAl_2O_4复合颜料是由金红石型TiO_2核和尖晶石型CoAl_2O_4壳组成,TiO_2微球模板保证了复合颜料具有较好的球形形貌和颗粒均匀性.复合颜料分别在547、584和624nm处有三个吸收峰,这与CoAl_2O_4颜料的吸收峰一致,因此复合颜料呈现CoAl_2O_4壳层的蓝色色调.复合颜料的平均近红外反射率为65.92%,较商业CoAl_2O_4颜料提高了16.4%.利用复合颜料制得的近红外反射涂层与空白聚氨酯涂层比较,使其玻璃基板温度下降了3.09℃,具有显著的隔热效果.

The TiO2@CoAl2O4 complex pigments with core-shell structure were fabricated by chemical coprecipitation methods,using TiO2 microspheres as template.The crystal structure,micromorphology,absorbance in visible light and near-infrared reflectance properties were characterized by XRD,SEM,TEM and UV-Vis spectrometer.The results show that TiO2@ CoAl2O4 complex pigments were consisted of rutile TiO2 core and outer spinel CoAl2O4 shell.Since the uniform TiO2 microspheres used as template,the complex pigments present good spherical morphology and particle distribution uniformity.Three absorbance bands at 547,584 and 624 nm in the Uv-Vis absorption spectra of the TiO2@CoAl2O4 complex pigments were corresponded to the characteristic absorption bands of the spinel CoAl2O4,which resulted in the pigments with a bright blue hue.The average near infrared reflectivity of the complex pigments is 65.92%,and 16.4% higher than commercial CoAl2O4 pigments.Compared to blank coating,the coating colored by the complex pigments made glass state temperature reduce by approximately 3.09 ℃,which has obvious heat insulation effect.