反相气相色谱法研究1,3,5-三氨基-2,4,6-三硝基苯的表面特性

采用反相气相色谱技术(IGC)研究了4种不同粒度的1,3,5-三氨基-2,4,6-三硝基苯(TATB)的表面性质。4种不同粒度的TATB表面自由能的色散分量（γds）随着温度的升高而增加;粒度越大的粒子,其色散自由能上升越快；在较高温度下,粗颗粒TATB显示了更强的色散作用(γds=193.2 mJ/m2,353 K)，粒度最小的亚微米TATB显示了最弱的色散作用(γds=64.0 mJ/m2,353 K)。由于制备方法不同和粒子大小的差异,4种TATB的表面酸碱性质显示了明显的差别,细颗粒TATB表面有较强的亲电子特性；而其他3种TATB在极性探针分子的作用下的吸附均表现为吸热吸附,表现出在分子内和分子间具有强烈的相互作用,其Ka和Kb值均为负。

Characterization of Surface Properties of 1,3,5-Triamino-2,4,6-Trinitrobenzene by Inverse Gas Chromatography

The surface properties of 1,3,5-triamino-2,4,6-trinitrobenzene (TATB) with various particle sizes were characterized by inverse gas chromatography (IGC). The disperse component gamma s(d) of surface free energy of TATB samples increased as temperature increased. The larger the particle size is, the quicker the increasing rate of the disperse component will be as the temperature increases. The gamma s(d) of the coarse TATB is the highest (193.2 mJ/m2) and that of the submicron TATB is the smallest (64.0 mJ/m2) at 353 K. Due to the different preparation processes and particle sizes, the samples show obviously different Lewis acid-base properties. Fine TATB can provide positive Lewis acid-base active sites and has higher acidity. The specific components of the adsorption of polar probes on the surface of the other three types of TATB were found to be endothermic owing to the strong hydrogen bond of inter- and intra-TATB molecules. Their surface acidity and basicity constants, K(a) and K(b) are negative.