PH sensitive structural uniformity of rice husk ash-derived MCM-41 silica

In this study, highly uniform MCM‐41 mesoporous silica was synthesised from rice husk ash‐derived sodium silicate using cetyltrimethyl ammonium chloride (CTAC) as a template. The chemical composition of the gel mixture was based on a SiO2:CTAC:H2O molar ratio of 1:0.5:75. When the pH value was initially controlled at ranges of 5.0–10.5 for 5 h and then immediately adjusted to 11.25 for the next 1 h, the structural uniformity of MCM‐41 was abruptly increased by 3.3–7.5 times of the single pH value at 11.25, respectively. Moreover, thermal and hydrothermal stabilities at 900 and 250°C were clearly observed. © 2012 Canadian Society for Chemical Engineering