Green solvent extraction of a triblock copolymer from mesoporous silica: Application to the adsorption of carbon dioxide under static and dynamic conditions

Micro/-mesoporous silica was prepared using a triblock copolymer as template. The elimination of the template was successfully carried out by calcination at 550 °C or extraction with water at ∼80 °C. The resulting silicas were characterised with ATR infrared spectroscopy, XPS, nitrogen sorption, TEM and low angle XRD. The extracted silica was characterised by a higher specific surface area, pore volume and microporosity in comparison to the calcined one. However, a similar quantity of surface silanol groups was detected for both samples after activation at 120 °C. Carbon dioxide adsorption was investigated under static conditions using microcalorimetry and under dynamic flow conditions. The extracted silica adsorbed 2.3 times more carbon dioxide than the calcined one which is mainly attributed to a two times higher value of microporous surface. Both silica samples were completely regenerated at 30 °C, which is attributed to weak physisorption interactions (−25 to −32 kJ mol−1) between CO2 and the silica surfaces.