Effective mesopore tuning using aromatic compounds in the aerosol-assisted system of aluminium organophosphonate spherical particles

Abstract

Spherical particles of ordered mesoporous aluminium organophosphonates (AOPs) were fabricated by spray-drying of precursor solutions containing Pluronic F127 (EO₁₀₆PO₇₀EO₁₀₆) at low temperature. Expansion of the mesopores (10.5 nm) were investigated using the triblock copolymer by the addition of typical aromatic compounds such as 1,3,5-trimethylbenzene (TMB) and 1,3,5-triisopropylbenzene (TIPBz). 1,3,5-TIPBz was more useful than 1,3,5-TMB for obtaining spherical AOP particles with large mesopores (>20 nm) because 1,3,5-TIPBz with the boiling point (235 °C) much higher than the spray-drying temperature (∼110 °C) was accommodated in the surfactant assemblies effectively. The boiling point of 1,3,5-TMB (165 °C) was not so high that it cannot stay completely in the surfactant assemblies during the spray-drying process, and thus smoothness of the surfaces was also deteriorated by evaporation of 1,3,5-TMB. Accordingly, the use of 1,3,5-TIPBz is effective for tuning uniform mesopores in the aerosol-assisted system of mesoporous AOP spherical particles with smooth surfaces.