Aerosol-assisted synthesis of titania-based spherical and fibrous materials with a rational design of mesopores using PS-b-PEO†
Surfactant-assisted synthesis is a promising technique for the tailor-made design of highly porous metal oxide based nanomaterials. There has been a demand for the comprehensive design of their morphology, porous structure and crystallinity to extend potential applications using metal oxide based materials such as titania (TiO2). However, the porous structure is often deformed and/or destroyed during the process of crystallizing metal oxide frameworks. Herein, the aerosol-assisted synthesis of mesoporous TiO2 powders was conducted in the presence of high-molecular-weight poly(styrene)-block-poly(ethylene oxide) (PS-b-PEO), which improved the stability of the derivative mesoporous structure with an increase in the thickness of the TiO2 frameworks. To propose a rational synthetic route for stable and porous metal oxides, the resultant mesoporous structure and the textural morphology of the mesoporous TiO2 powders were surveyed using PS-b-PEO with different lengths of PS and PEO chains. By a judicious choice of the molecular structure of PS-b-PEO, the morphological design of the fully crystallized anatase phase of TiO2 from spherical to fibrous ones was achieved with control over the mesopore diameter.