Organosilane-assisted synthesis of ordered mesoporous poly(furfuryl alcohol) composites

Abstract

In the present work, we report an organosilane-assisted synthesis of ordered mesoporous poly(furfuryl alcohol) (PFA)-silica composites by employing TEOS, 3-(triethoxysilyl)furan and furfuryl alcohol as precursors, and triblock copolymer F127 as a structure-directing agent via an EISA process. After thermal curing of the PFA, the triblock copolymer can be removed by calcination at 350 °C in N₂ atmosphere. The PFA/silica nanocomposites have been characterized by SAXS, TEM, N₂ sorption, FT-IR, elemental analysis, ¹³C-NMR, ²⁹Si-NMR and TGA techniques. The results show that the organic–inorganic nanocomposites have ordered 2-D centered-rectangular (c2mm) mesostructure even when the organic content in the samples is as high as 60 wt%, but their surface areas (200–510 m²/g), pore volumes (0.15–0.54 cm³/g) and pore sizes (4.8–5.7 nm) gradually reduce with increasing organic component. Air (600 °C, 5 h) or HF (10 wt%) secondary treatments of the nanocomposite with 60 wt% PFA lead to a collapse of the mesostructure as shown by SAXS and N₂ sorption techniques, implying the existence of an interpenetrating PFA/silica framework, in which both silica and organic polymers synergistically support the structure. The adsorption performances of the hybrid materials for toluene were also conducted. Because of the hydrophobic property, i.e. affinity with toluene molecules, the PFA/silica nanocomposite having a similar surface area as ordered mesoporous silica shows an adsorption quantity twice as large as that of ordered mesoporous silica.