室温固-固反应初期动力学的粉末紫外-可见漫反射光谱研究

以丁二酮肟和水合醋酸镍及无水醋酸镍的反应为模板, 利用反应物与产物之间的颜色差异, 通过粉末紫外-可见漫反射光谱对反应初期产物生成量的变化进行测定, 从而研究其反应动力学. 由于光谱性质与产物的晶型无关, 并且如果反应物与某一产物之间的光谱性质(如颜色)差异较大, 即使在微量产物的情况下也很容易跟踪到产物量的变化. 因此, 该方法对于固-固反应初期的动力学响应非常灵敏, 但当反应进行到一定程度后则不适用.

Studies on Initial Kinetics of Room-temperature Solid-solid Reaction by UV-visible Reflection Spectrum

In this paper, the method of UV-visible reflection spectrum(UV method) was theoretically and experimentally proposed to investigate the initial kinetic characters of the solid-solid reaction with the mixture of dimethylglyoxime and Ni(Ac)2·4H2O, and the mixture of dimethylglyoxime and anhydrous Ni(Ac)2 as the modeling reaction examples. The results indicated that the UV method was very sensitive in the initial period of solid-solid reaction. The reactive rates for above two reaction systems were varied non-linearly with the change of reaction time. The fastest reaction rates can be reasonably explained by the formation of the cold-melting layer or cold-dissolving-melting layer.