On the other hand, Fig. 2(d) reveals that about 40 wt.% of MCX was adsorbed in MCX-MSA, which was about 1/3 lesser than that in MCX-MS. The result indicates that the encapsulation method is a better way to include MCX in the mesoporous silica than the direct absorption method. The TEM images of MS and MCX-MS (not shown) exhibit the disordered and interconnected mesopores in both the SiO2 networks, confirming that both MS and MCX-MS had the mesoporous structure. Besides, it also shows that the pore volume of MCX-MS was significantly less than that of MS due to the presence of MCX.