Effect of pH in Mesoporous Silica Synthesis

Abstract

Mesoporous silica was tailored by using diluted triblock copolymer F127. The synthesised silica structure was characterized by TEM and N2 sorption isotherm.3D- hexagonal arrangement of 5-30 nm pore sizes obtained. The pore sizes and ordering were affected by pH change in synthesis mixture. Although well-ordered hexagonal arrangement of mesoporous was dominant in acidic conditions, the mesoporous silica synthesized in neutral or basic conditions indicates gel-like structures with no mesoporous. The presence of low pH sol-gel reaction, followed by high pH reaction through addition of alkaline during synthesis, not only produced mesoporous materials, but also provided pore size controlling.