Formation of silica nanotubes through a TPPS J aggregates template

Abstract

It is found that 5,10,15,20-tetrakis (4-sulfonatophenyl) porphyrin (TPPS), which is known to form J aggregates in water under low pH value, acts as a template for the hydrolyzing of organosilane. The nanotube structures of silica with 4-8 nm inner diameters are obtained, which is consistent with the height of TPPS J aggregates, indicating that TPPS J aggregates are indeed acting as the template for the sol-gel transcription. The TPPS J aggregation disappear when the medium pH value is shifted from acidic to basic, consequently formed silica nanostructures are amorphous nanosphere rather than nanofiber structures. In contrast, the copper phthalocyanine (TSCuPc), which does not exist as linear J aggregates, cannot induce the silica to form one dimensional nanofiber structures, implying that the templating effect of TPPS J aggregates for inorganic nanostructures. © 2012 The Author(s).