以沉淀烧结法合成CoCuMnOx粉体,以自制的聚氨酯树脂作为粘合剂,制备了太阳能吸收涂层。采用XRD和SEM表征粉体的成分与形貌,分别采用紫外-可见近红外分光光度计及红外光谱仪测定涂层在200~2000nm和3000~25000nm(中远红外)的光谱反射率,并根据测得的光谱反射率计算涂层太阳能吸收率(αs)和发射率(εT)。研究CoCuMnOx粉体中元素配比对涂料太阳能吸收率的影响,并进一步研究制备工艺(煅烧温度、时间)对粉体的结构、形貌,以及对制得涂层的吸收率、发射率和品质因子的影响。结果表明,Co、Cu、Mn三种元素配比为2∶1∶1时制得的涂层太阳能吸收率最高(92.3%),粉体的物相成分为CoCuMnOx相和Co3O4相。进一步探究制备工艺后发现,随着煅烧温度的升高,粉体形貌由片层状变为块状,表面积减小,太阳能吸收率由92.5%下降至90.3%,发射率由23.1%升高至24.5%,而煅烧时间对粉体的结构与涂层性能并无太大影响。当粉体中Co、Cu、Mn三种元素配比为2∶1∶1,煅烧温度为400℃,时间为4h时,相应的涂层综合性能达到最佳,此时涂层的太阳能吸收率为92.5%,发射率为23.1%,品质因子为4.00。
CoCuMnOx powder was synthesized by precipitation sintering method,and solar energy absorbing coatings were prepared by self-made polyurethane resin and the powder above.The composition and morphology of the powder were characterized by XRD and SEM.The spectral reflectance of the coatings at 200~2000nm and 3000~25000nm (mid-far infrared) were measured by ultraviolet-visible near infrared spectrophotometer and infrared spectroscopy respectively.The solar absorptivity (αs) and emittance (εT) of the coatings were calculated based on the measured spectral reflectance.The influence of the proportion of elements in CoCuMnOx powder on the solar energy absorption of coatings was studied,and the influence of preparation technology (calcination temperature and time) on the structure and morphology of the powder and the absorption,emissivity and quality factors of the coatings were further studied.The results shown that the solar energy absorption rate of the coating was the highest(92.3%) when the ratio of Co,Cu and Mn at 2∶1∶1,and the phase composition of the powder was CoCuMnOx phase and Co3O4 phase.Further investigation of the preparation process shown that with the increasing of calcination temperature,the morphology of the powder changed from lamellar to bulk,the surface area decreased,the solar energy absorptivity (αs) decreased from 92.5% to 90.3%,and the emissivity (εT) increased from 23.1% to 24.5%.The calcination time had little effect on the structure and coating properties.When the ratio of Co,Cu and Mn in the powder at 2∶1∶1,calcination temperature at 400℃ and time at 4h,the comprehensive performance of the coating comes to the best.At this time,the solar energy absorptivity of the coating was 92.5%,the emissivity at 298K was 23.1%,and the quality factor (αs/εT298K) was 4.00.
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