title: Ethane-bridged periodic mesoporous organosilicas functionalized with high loadings of carboxylic acid groups: synthesis, bifunctionalization, and fabrication of metal nanoparticles.
abstract: Well-ordered periodic mesoporous organosilicas (PMOs) functionalized with high contents of carboxylic acid (COOH) groups, up to 85 mol % based on silica, were synthesized by co-condensation of 1,2-bis(triethoxysilyl)ethane (BTEE) and carboxyethylsilanetriol sodium salt (CES) under acidic conditions by using alkyl poly(oxyethylene) surfactant Brij 76 as a structure-directing agent. A variety of techniques including powder X-ray diffraction (XRD), nitrogen adsorption/desorption, Fourier-transformed infrared (FTIR), transmission electron microscopy (TEM), (13) C- and (29) Si solid-state nuclear magnetic resonance (NMR) were used to characterize the products. The materials thus obtained were used as an effective support to synthesize metal nanoparticles (Ag and Pt) within the channel of 2D hexagonal mesostructure of PMOs. The size and distribution of the nanoparticles were observed to be highly dependent on the interaction between the carboxylic acid functionalized group and the metal precursors. The size of Pt nanoparticles reduced from 3.6 to 2.5 nm and that of Ag nanoparticles reduced from 5.3 to 3.4 nm with the increase in the COOH loading from 10 to 50 %.
authors: Department of Chemistry, National Central University, Chung-Li, 32054, Taiwan (R.O.C.), Fax: (+886) 3-4227664.
authors: Juti Rani
authors: JR
authors: Deka
authors: Hsien-Ming
authors: HM
authors: Kao
authors: Shu-Ying
authors: SY
authors: Huang
authors: Wei-Chieh
authors: WC
authors: Chang
authors: Chun-Chiang
authors: CC
authors: Ting
authors: Purna Chandra
authors: PC
authors: Rath
authors: Ching-Shiun
authors: CS
authors: Chen
keywords: carboxylic acids; mesoporous materials; nanoparticles; platinum; silver