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The energies of combustion of single-walled and multi-walled carbon nanotubes were measured by using an isoperibolic micro-combustion calorimeter. The values of the massic energy of combustion in oxygen at T = 298.15 K and pº = 0.1 MPa of the compounds under study were obtained as: (− 27,635.0 ± 9.5) and (− 32,347.3 ± 15.3) J g−1, respectively. The corresponding standard molar enthalpies of formation were derived as: (4.7 ± 1.3) and (0.8 ± 0.9) kJ mol−1, respectively. The used calorimeter to test the compounds was calibrated previously with benzoic acid NIST 39j, salicylic acid and 1,2,4-triazole. [ABSTRACT FROM AUTHOR]

The thermochemical study of the 1,3-bis(N-carbazolyl)benzene (NCB) and 1,4-bis(diphenylamino)benzene (DAB) involved the combination of combustion calorimetric (CC) and thermogravimetric techniques. The molar heat capacities over the temperature range of (274.15 to 332.15) K, as well as the melting temperatures and enthalpies of fusion were measured for both compounds by differential scanning calorimetry (DSC). The standard molar enthalpies of formation in the crystalline phase were calculated from the values of combustion energy, which in turn were measured using a semi-micro combustion calorimeter. From the thermogravimetric analysis (TGA), the rate of mass loss as a function of the temperature was measured, which was then correlated with Langmuir's equation to derive the vaporization enthalpies for both compounds. From the combination of experimental thermodynamic parameters, it was possible to derive the enthalpy of formation in the gaseous state of each of the title compounds. This parameter was also estimated from computational studies using the G3MP2B3 composite method. To prove the identity of the compounds, the 1H and 13C spectra were determined by nuclear magnetic resonance (NMR), and the Raman spectra of the study compounds of this work were obtained. [ABSTRACT FROM AUTHOR]