Synthesis of micro-mesoporous materials by pseudomorphic transformations

The porous silica materials with interconnected pore systems were obtained through a pseudomorphic transformation of SBA-15 and SBA-16 using cetyltrimethyl ammonium bromide as a surface-active agent. Such transformations helped in generating hetero porous architectures inside the mesoporous materials while preserving the particle morphology. The obtained materials were characterized by FE-SEM, TEM, BET as well as SAXS studies. In consonance with FE-SEM studies, the structural integrity of the parent material was maintained upon the transformation though, a complete reorganization of the pore structures was observed. In the case of SBA-15, GCMC findings confirmed the change in the pore topology (from cylindrical to narrow slit shape) with the change in the behavior of the hysteresis from H1 to H4 type respectively. In contrast, for SBA-16, the hysteresis changed from type H2(a) to H4 at higher degrees of transformation reflecting a reduction in mesopore size with the simultaneous appearance of microporosity. The original pore size of SBA-15 and SBA-16 was transformed from 7.5 to 3.5 nm and 6.1 to 3.6 nm respectively upon a higher degree of pseudomorphic transformation. It was supported by the SAXS studies that depicted the appearance of new additional phase owing to the formation of newly formed pore architectures. Consequently, pseudomorphic transformation can be attempted to produce new porous materials with intricate pore networks.

Automated summary

Porous silica materials with interconnected pore systems were obtained through a pseudomorphic transformation, preserving the particle morphology. The transformation changed the pore structures and introduced intricate pore networks.