As expected, these characteristic peaks of MCX, that of the IL and that of MS, 3700–3200 cm−1 for the`Si–OH vibration, 1088 cm−1 for the Si– O–Si asymmetrical stretching vibration and 1000–1200, 780–820 and 430–460 cm−1 for the `Si–O–Si` strain vibrations, are all observed without shift in Fig. 1(e). After the extraction process, the characteristic peaks of the IL disappeared as shown in Fig. 1(f), indicating that the IL was successfully removed. The results confirm that MCX was successfully encapsulated in the mesoporous silica network without chemical bonding with the silica network. Besides, the similar solid state 29Si NMR spectra of MS and MCX-MS (not shown) also support the result.