Hierarchical Macro-Mesoporous Silica Monolith

摘要

Monolithic pure silica gels with hierarchical macro-mesoporous structure have been synthesized via spontaneous sol-gel process from silicon alkoxide using a structure-directing agent and a micelle-swelling agent.Monolithic body with well-defined co-continuous macropores is a result of concurrent phase separation and sol-gel transition induced by the polymerization reaction,whereas the mesopores are templated by the cooperative self-assembly of inorganic species,a structure-directing agent and a micelle-swelling agent.The following removal of surfactants by heat-treatment gives silica gels with hierarchical and fully accessible pores in discrete size ranges of micrometers and nanometers.The highly ordered 2D-hexagonal arrays of mesopores have been confirmed by X-ray diffraction measurements and FE-SEM observations.Furthermore,by further additions of the micelle-swelling agent,the mesostructural transition from well-ordered 2D-hexagonal arrays to mesostructured cellular foams(MCF)have been induced accompanied by minor modifications of the micrometer-range structure.