绿色植被近红外光谱模拟材料的设计及应用

Design and Application of Simulation Material of Green Vegetation Spectrum in NIR Interval

通过对绿色植被近红外区反射光谱的系统分析,充分证明O-H决定植被在1450nm和1940nm附近的光谱特征,在此基础上,设计并制备了4种层间含O-H的新型光谱模拟材料Mg-Al-X-LDH(X为NO_3-、Cl-、CO_3^(2-)、SO_4^(2-)),并对其进行了X射线衍射、红外光谱、热重分析及拉曼光谱表征。依据光谱相关系数和光谱角度匹配模型计算,4种层状双金属氢氧化物(LDH)与植物叶片近红外反射光谱两种计算模型的相似度分别超过0.9600和0.9700;以Mg-Al-Cl-LDH为模拟材料,初步与聚氨酯复合,制备了与植被在近红外区光谱高度相似的涂层,两种计算模型的相似度分别达到0.9702和0.9924;Mg-Al-Cl-LDH在紫外可见光区的高度透明性,有利于各个波段光谱材料的复合;经180℃高温处理前后的Mg-Al-Cl-LDH,两种计算模型的相似度依然能达到0.9888和0.9959,说明Mg-Al-LDH有良好的热稳定性,不易失水。

those vegetation′s spectral characteristics at about 1450 nm and 1940 nm. Based on the knowledge, Mg-Al-X-LDH （X represents NO3-, Cl-, CO32-, SO42-）, four types of novel spectral simulation materials containing interlayed O-H, were designed and prepared, and their X-ray diffraction patterns, infrared spectra, thermogravimetric curves and Raman spectra were characterized. The model calculation results of spectral correlation mapper and spectral angle mapper show similarities more than 0.9600 and 0.9700 between four types of layered double hydroxides （LDHs） and plant leaves in near infrared reflectance spectrum. The polyurethane coating with Mg-Al-Cl-LDHs as a simulation material exhibits a highly coincided spectrum with that of plant leaves, and similarities of two calculation models are up to 0.9702 and 0.9924, respectively. The similarities calculation of reflectance spectra for Mg-Al-Cl-LDHs before and after calcining at 180 ℃ are still up to 0.9888 and 0.9959, indicating high thermo stability of Mg-Al-LDHs.