The absence or weakening of the 110 and 200 reflections indicated that some diffusion and any hexagonal structural order of the material did not extend over a long range.
This could be normally observed during modification of mesoporous materials.
Only samples with mildest modification (i.e., modified with only 1% silylating agent for 1 h) and strongest modification (i.e., modified with 9% silylatingagent for 24 h) are shown for comparison in this figure.
The intensity of the strongest peak decreased slightly in the RH-MCM-41 modified with TMCS and PTCS, while no change was observed in the sample modified with DMCS.