Morphology templating of nanofibrous silica through pH-sensitive gels: “in situ” and “post-diffusion” strategies

Abstract

A pH-sensitive pyridine-based gelator has been found as a flexible and efficient template for the transcription of nanofibrous silica. The morphology and aggregation degree of silica nanofibers and nanotubes (30–60 nm thick, with 3–10 nm inner channels) could be tuned by simply adjusting the pH conditions through the use of “in situ” formed organogels. Interestingly, silica nanotubes with larger inner mesoporous channels (5–35 nm) were obtained by using a “post-diffusion” route instead of the conventional “one pot” or in situ strategy. Preliminary results about the templating of nanofibrous Fe-based hybrid xerogels are also shown, suggesting that this family of gelators could be used to design nanofibers and nanotubes of more complex inorganic phases.