Synthesis and inclusion chemistry of mesoporous silicate SBA-15 and related materials.

摘要

Nature has evolved over the years to optimize the process of biomineralization for fabricating intricately shaped organisms, such as diatoms and radiolarians. The outer shells of these intricate organisms are composed of inorganic materials, such as silica (SiO₂) and calcium carbonates (CaCO₃). arranged by the organisms by producing organic molecules, which serve as biomineralization templates.; The mesoporous silicates synthesized in the early 1990s utilized ionic surfactants to assemble inorganic molecules (SiO₂) to fabricate intricately patterned inorganic-organic hybrid materials.; The discovery of original mesoporous silicates led to numerous other mesoporous silicates, namely HMS, MSU, KIT and SBA. These mesoporous materials were synthesized with organic templates, including cationic, anionic, nonionic, bolaamphiphile and gemini surfactants. Nonionic polymers were also used to synthesize mesoporous silicates.; One of the most promising mesoporous silicates for applications in various fields of research is SBA-15. With a tunable pore diameter in the range of 5–30 nm, and a large surface area (ca. 1000 m 2/g), this material shows excellent potentials for many applications for which tunable pore size and surface chemistry are key traits.; Described in this these are some examples of how mesoporous SBA-15 may be used in some of these applications. For its first practical application, SBA-15 was used as a medium for protein separation. By tailoring the pore size and surface properties of this mesoporous material, it was possible to selectively isolate a protein from a pool of proteins.; SBA-15 and its related mesoporous material MCF were also used as hosts for enzyme immobilization and as grafting substrates of transition metals. The immobilization of enzymes and transition metal functionalization on these mesoporous silicates showed excellent promises for potential applications as bio-sensors and as heterogeneous catalysts.; Mesoporous SBA-15 has also been used as a template for nanostructured materials. Due to the highly ordered pore-structure, nano-structured materials were fabricated using SBA-15. Namely, gold, silver, and platinum nanowires were fabricated by loading the pores of SBA-15 with appropriate metal precursors. The removal of the template yielded isolated single nanowires. (Abstract shortened by UMI.)