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 dispersive components γsd of surface free energy of TATB samples increase as the temperature increases. The larger the particle size, the faster the increasing rate of the disperse component as the temperature increases. The γsd of the coarse TATB is the largest (193.2 mJ/m2) and that of the submicron TATB is the smallest (64.0 mJ/m2) at 353 K. Because of different preparation processes and particle sizes, the samples show obviously different Lewis acid-base properties. The fine TATB can provide positive Lewis acid-base active sites and have higher acidity. But the other three types of TATB with the specific components of the adsorption of polar probes on the surface were found to be endothermic because the strong hydrogen bond of inter- and intra-TATB molecules. Hence, their surface acidity and basicity constants, Ka and Kb, are negative.