Controlling the primary particle evolution process towards silica monoliths with tunable hierarchical structure

Hierarchical mesoporous silica monoliths with high mechanical intensity, tunable 3D net-liked framework and textural properties were synthesized in hydroxyl carboxylic acids route. [Display omitted] ► Using hydroxyl carboxylic acids to create a weak acidic synthetic condition. ► Adjusting the resembling process of micro-morphology to mesostructure. ► Hierarchical monoliths exhibit a high mechanical strength up to 25Ncm−2. ► Efficiently eliminate particulate matters and tobacco special nitrosamines in smoke. In order to establish the hierarchical structure in multiple levels on mesoporous silica, this article reports a new strategy to prepare the monolith with the pore configuration in nanometer scale, micro-morphology in micrometer level and macroscopic shape in millimeter or larger grade. These hierarchical monoliths are synthesized in a weak acidic condition by using triblock copolymer P123, hydroxyl carboxylic acid and tetramethyl orthosilicate (TMOS), and the textural properties of the mesostructure can be facilely adjusted by simply controlling the synthesis condition without any additive. During the synthesis, the primary particles can be selectively synthesized as monodispersed sphere, noodle, prism, straight rods with different size or irregular bars, and their connection plus arrangement in 3D directions can be also regulated. Therefore, various textural properties of mesopore are able to be altered including pore size (5.5–10.6nm), total pore volume (0.48–1.2cm3g−1), micropore surface area (47–334m2g−1), and pore shape (from 2D or 3D straight channel to plugged channel). Moreover, these monoliths exhibit a considerable mechanical strength; they are also applied in eliminating particulate matters and tobacco special nitrosamines (TSNA) in tobacco smoke, exhibiting various morphology-assisted functions.