Fabrication of silica monolithic columns with ordered meso/macropore structure

Recently, much effort has been focused on the materials with ordered meso/macropores, because of their potential applications in catalysis, separations, coatings, microelectronics and electro-optics. In this paper, silica monoliths with well-defined columnar shape more than 1 cm in length are successfully fabricated by using the micelles of triblock copolymer F127 and colloidal crystals composed of polystyrene (PS) latex microspheres as mesopore and macropore template, respectively. The column templated by PS microspheres 870 nm in diameter and 0.5 g F127 (MCL-0.5-870) shows uniform ordered macropores, contact pores connecting macropores together, and assembled and inter-particle pores increasing the BET specific surface area and adsorption capability of the monolithic column. The backpressure curve and hydraulic permeability experiment exhibit its good penetrability and mechanical stability. These excellent characteristics, together with high BET specific surface area (387.4 m2 g−1) and porosity (80%), may endow its potential application for chromatography separation. In addition, the size of macropores and mesopores can be easily regulated by changing the diameter of PS spheres and F127 weight, respectively. This indicates that this method is a facile and universal protocol to fabricate the applied monolithic column with ordered meso/macropores.

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► SiO2 monolithic columns are fabricated by using a dual templating method.
► The macropore size is regulated by the polystyrene colloidal crystals.
► The mesopore size is regulated by the triblock copolymer F127.
► The as-prepared monoliths have the potential application for chromatography media.