静电纺丝法制备La0.67Ba0.33MnO3微纳米纤维及其红外发射率研究

采用静电纺丝法结合溶胶-凝胶技术制备了钙钛矿型La_0.67Ba_0.33MnO₃微纳米纤维, 并利用差示扫描量热-热失重分析(DSC-TGA)、 X射线衍射(XRD)、 傅里叶变换红外光谱(FTIR)和扫描电子显微镜(SEM)等技术对产物进行了表征, 利用IR-2红外发射率测试仪测试了La_0.67Ba_0.33MnO₃在280~370 K范围内的红外发射率. 结果表明, La_0.67Ba_0.33MnO₃在600 ℃时已形成钙钛矿结构. 随着煅烧温度的升高, La_0.67Ba_0.33MnO₃的形貌由纤维状向三维网络状转变, 并最终失去纤维形态. 在280~370 K范围内, La_0.67Ba_0.33MnO₃微纳米纤维的红外发射率随温度升高而升高, 由0.564增加至0.689. 利用钙钛矿材料双交换理论解释了这一现象, 并进一步探讨了其在红外发射率可变材料中的应用前景.

Electrospinning Preparation and Infrared-emissivity Properties of La0.67Ba0.33MnO3 Micro/nanofibers

Perovskite-type La0.67Ba0.33MnO3 micro/nanofibers were fabricated through electrospinning technology.The fibers were characterized by means of differential scanning calorimetry-thermogravimetric analysis(DSC-TGA), X-ray diffraction(XRD), Fourier transform infrared spectroscopy(FTIR) and scanning electron microscopy(SEM).The infrared emissivity of the fibers in the temperature range of 280-370 K was tested by IR-2 infrared-emissivity analyzer.The results show that perovskite structure is formed at 600 ℃.As the temperature increases, the morphology of samples changes from fiber to three-dimensional network structure, and eventually loses the fiber morphology.The infrared emissivity of La0.67Ba0.33MnO3 fibers calcined at 600 ℃ rises from 0.564 to 0.689 with the increase of temperature, which can be explained by the theory of double-exchange.The prospect of La0.67Ba0.33MnO3 fibers in variable infrared-emissivity materials is promising in the future.