Low viscous aminoalkyl-phenyl-silane with π–π interaction and its optimal SO2 capture condition

The high viscosity of ionic liquids (ILs) limits their practical application in SO 2 capture. In this work, the low viscous aminoalkyl-phenyl-silanes were synthesized to capture SO 2 . The π – π interaction between phenyl groups reduced the volatility of aminoalkyl-phenyl-silanes greatly, but it did not increase their viscosity significantly. Among them, N-[(dimethylphenylsilyl)methyl]-N-methylbenzenemethanamine (DPSA) containing two phenyl groups exhibited the strongest π – π interaction. Therefore, the thermal decomposition temperature reached 150°C, while its viscosity was only 8.45 mPa·s at 25°C, which is much lower than that of ILs. The absorption enthalpy and entropy change of DPSA absorption reaction were −79.284 kJ/mol and −224 J/mol/K, respectively. These values are more negative than those of SO 2 capture reaction with ILs. An objective function was proposed to obtain the optimal absorption and desorption temperature. Furthermore, five cycles of regeneration experiments indicated that DPSA possessed good regeneration ability.