Mesoporous silica with Ia3d structure has been successfully prepared utilizing a triblock copolymer
(EO20PO70EO20)−acetate mixture for structure direction in aqueous solution over a wide pH range, even
above the isoelectric point of silica, where the pH value could be finely tuned by varying the concentration
of HCl and/or acetate. Characterization by XRD, TEM, and N2 sorption measurements show that the
cubic Ia3d materials possess high surface areas (about 900 m2/g), large pore volumes (about 1.2 cm3/g),
and uniform pore diameters (about 9.2 nm). Further, the phase diagram in the SiO2−P123−ZnAc2−H2O−HCl system is drawn to map the range of cubic mesophase. Salt effect has been investigated during
the phase transformation process, which reveals that the nature and concentration of cations can also
determine the mesostructure. In addition, when two different acetates are introduced into the solution at
one time, metal oxides-modified cubic mesoporous silica can be directly synthesized. Among others,
copper-modified cubic samples, prepared by this direct method, display superior properties in the NO2-TPD experiments. The lower acid concentration in the acetate-modulated synthetic system favors the
direct incorporation of metal oxide species and this discovery may offer us a new perspective to better
understand the formation mechanism of ordered mesoporous materials.
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