Mesoporous silica molecular sieves prepared by ionic and neutral surfactant templating : A comparison of physical properties

摘要: A series of mesoporous MCM-41 and HMS silica molecular sieves have been prepared by electrostatic neutral assembly pathways, respectively, their properties compared a variety physical techniques. Direct S+I- charge matching between cationic quaternary ammonium ion surfactants (S+) the anionic silicate precursors (I-) affords long-range hexagonal structures under hydrothermal synthesis conditions (100 °C), but order is greatly reduced when conducted at ambient temperature. Conversely, owing to weaker forces, counterion-mediated S+X-I+ S0I0 pathways (where X- halide S0 primary amine) provide calcined products with best syntheses are In general, silicas formed or exhibit greater than analogues assembly. However, framework-confined pore structures, though depend...