| Abstract
| - A systematic study on the structural properties and external morphologies of large-pore mesoporousorganosilicas synthesized using triblock copolymer EO20PO70EO20 as a template under low-acid conditionswas carried out. By employing the characterization techniques of SAXS, FE-SEM, and physical adsorptionof N2 in combination with αs-plot method, the structural properties and external morphologies of large-poremesoporous organosilicas were critically examined and compared with that of their pure-silica counterpartssynthesized under similar conditions. It has been observed that unlike mesoporous pure silicas, the structuraland morphological properties of mesoporous organosilicas are highly acid-sensitive. High-quality mesoporousorganosilicas can only be obtained from synthesis gels with the molar ratios of HCl/H2O between 7.08 ×10-4 and 6.33 × 10-3, whereas mesoporous pure silicas with well-ordered structure can be obtained in awider range of acid concentration. Simply by adjusting the HCl/H2O molar ratios, the micro-, meso-, andmacroporosities of the organosilica materials can be finely tuned without obvious effect on their structuralorder. Such a behavior is closely related to their acid-controlled morphological evolution: from necklacelikefibers to cobweb-supported pearl-like particles and to nanosized particulates.
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