群青颜料呈色机理的电子顺磁共振研究

A Study on the Electron Paramagnetic Resonance of Coloration Mechanism of Ultramarine Pigment

研究了阿富汗青金石矿石、敦煌石窟青金石颜料、合成群青的呈色机理.实验表明三者均有g=2.029m峰,前两者多一个g=2.047峰.400℃时.g=2.047峰变平.600℃时消失.g=2.029 峰随温度升高而增强,800℃时增强放慢,颜色也随温度变深.在M_0O_3/Si0_2和M_0O_3/Al_2O_3表面上,S_2^-的FPR有g_1=2.047,g_2=2.028,g_3=1.998三个分量.因此,群青、青金石和合成群青的EPR信号应是两种硫自由基信号的重叠.

This paper studies on the coloration mechanism of lapis lazuli ore (I) in Afghanistan, lapis lazuli pigment (I) and artificial ultramarine (III) in Dunhuang Grottoes. The experimental results show that they all have wave of g = 2. 029, and I &.II have g = 2.047 wave value while III does not have. The g=2. 047 wave changes into flat at 400 and disappears at 600. The g=2. 029 wave becomes strong with increasing temperature. At 800, the speed of the strengthening slows down and the color deepens. On the surface of MoO3/SiO2 and MoO3/Al2O3, the EPR spectrum of S2- has g = 2. 047, 2.028, 1.998 branches. The result indicates that the EPR signal of ultramarine, lapis lazuli and artificial ultramarine should be the overlapping signal of two kinds of sulphur free radicals.