title: Triconstituent co-assembly to ordered mesostructured polymer-silica and carbon-silica nanocomposites and large-pore mesoporous carbons with high surface areas.
abstract: Highly ordered mesoporous polymer-silica and carbon-silica nanocomposites with interpenetrating networks have been successfully synthesized by the evaporation-induced triconstituent co-assembly method, wherein soluble resol polymer is used as an organic precursor, prehydrolyzed TEOS is used as an inorganic precursor, and triblock copolymer F127 is used as a template. It is proposed for the first time that ordered mesoporous nanocomposites have "reinforced concrete"-structured frameworks. By adjusting the initial mass ratios of TEOS to resol, we determined the obtained nanocomposites possess continuous composition with the ratios ranging from zero to infinity for the two constituents that are "homogeneously" dispersed inside the pore walls. The presence of silicates in nanocomposites dramatically inhibits framework shrinkage during the calcination, resulting in highly ordered large-pore mesoporous carbon-silica nanocomposites. Combustion in air or etching in HF solution can remove carbon or silica from the carbon-silica nanocomposites and yield ordered mesoporous pure silica or carbon frameworks. The process generates plenty of small pores in carbon or/and silica pore walls. Ordered mesoporous carbons can then be obtained with large pore sizes of approximately 6.7 nm, pore volumes of approximately 2.0 cm(3)/g, and high surface areas of approximately 2470 m(2)/g. The pore structures and textures can be controlled by varying the sizes and polymerization degrees of two constituent precursors. Accordingly, by simply tuning the aging time of TEOS, ordered mesoporous carbons with evident bimodal pores at 2.6 and 5.8 nm can be synthesized.
authors.affiliation: Department of Chemistry, Shanghai Key Laboratory of Molecular Catalysis and Innovative Materials, Fudan University, Shanghai 200433, People's Republic of China.
authors.forename: Ruili
authors.initials: R
authors.lastname: Liu
authors.forename: Yifeng
authors.initials: Y
authors.lastname: Shi
authors.forename: Ying
authors.initials: Y
authors.lastname: Wan
authors.forename: Yan
authors.initials: Y
authors.lastname: Meng
authors.forename: Fuqiang
authors.initials: F
authors.lastname: Zhang
authors.forename: Dong
authors.initials: D
authors.lastname: Gu
authors.forename: Zhenxia
authors.initials: Z
authors.lastname: Chen
authors.forename: Bo
authors.initials: B
authors.lastname: Tu
authors.forename: Dongyuan
authors.initials: D
authors.lastname: Zhao