Prepared mesoporous organosilicas

Indeed, the compositional flexibility of mesoporous materials is such that it is possible to prepare mesoporous organosilicas with organic groups (e.g., ethene) inside the pore walls. An unusual property of mesoporous silicas is that they can themselves be used as templates for the formation of mesoporous carbon. The mesoscopi-cally ordered nanoporous (or mesoporous) carbon molecular sieves are prepared by carbonizing sucrose (or other carbon precursors) inside the pores of mesoporous silica molecular sieve. The mesoporous carbon is obtained after subsequent removal of the silica template by dissolution in HF (hydrofluoric acid) or NaOH (sodium hydroxide) solution. 

This all-in-one approach was employed by the same group to prepare highly amine-functionalized mesoporous organosilicas.340... 

Then, we attempted to prepare a 2D hexagonal mesoporous organosilica thin film containing 1 in the channel pores and an erbium complex 5Er (the synthesis of which was previously described [17]) in the framework (Scheme 3). 

Mixed micelles can be exploited as templates for preparation of nanoporous materials. Oligomeric alkyl-ethylene oxide surfactant (Polyoxyethylene (2) cetyl ether, B52), and ionic surfactant (cetyltrimethylammonium bromide, CTAB) form mixed micelles that self-assemble into well-ordered hexagonal and bimodal mesostructures. These systems can be used as templates to synthesize hydrothermally stable organized periodic mesoporous organosilicas (PMOs). The X-ray diffraction (XRD), TEM, BET, NMR and hydrothermal studies have been used to investigate the effects of B52 on the formation of various PMOs. The addition of B52 in the surfactant solution improves... 

One-pot synthesis [11-14], in addition to the surface modification, is widely used for the preparation of framework-modified materials known as periodic mesoporous organosilicas (PMOs) [15]. They are synthesized by hydrolysis and condensation of bis(trialkoxysilyl) organic precursors and related compounds in the presence of both ionic and nonionic templates. In contrast to the conventional OMOs that possess surface organic groups [2, 8-14], the PMO framework contains Si-R-Si linkages (where R is an organic bridging spacer) [15]. 

N., Tani, T., and Inagaki, S. (2011) Syntheses, properties and applications of periodic mesoporous organosilicas prepared fi om bridged organosilane precursors. Chem. Soc. Rev., 40 (2), 789-800 (g) G6mez-Romero, P. and Sanchez, C. (eds) (2003) Functional Hybrids Materials, Wiley-VCH Verlag GmbH, Weinheim. 

Wahab, M.A., Kim, I.I., and Ha, C.S. (2004) Hybrid periodic mesoporous organosilica materials prepared from l,2-bis(triethoxysilyl)ethane and (3-cyanopropyl)triethoxysilane. Microporous Mesoporous Mater., 69, 19-27. 

Li, C., and Di, B. (2011) Aminopropyl-functionalized ethane-bridged periodic mesoporous organosilica spheres preparation and application in liquid chromatography. /. Chromatogr. A,... 

Yang, Y. and Sayari, A. (2007) Molecularly ordered biphenyl-bridged mesoporous organosilica prepared under acidic conditions. Chem. Mata"., 19, 4117-4119. 

Scheme 10.3 Schematic illustration for the preparation of periodic mesoporous organosilicas.

This chapter deals with the selective preparation, TEM/EXAFS/XPS characterization and catalysis of mono- and bimetallic nanowires and nanoparticles highly ordered in silica FSM-16, organosilica HMM-1 and mesoporous silica thin films. The mechanism of nanowire formation is discussed with the specific surface-mediated reactions of metal precursors in the restraint of nanoscale void space of mesoporous silica templates. The unique catalytic performances of nanowires and particles occluded in mesoporous cavities are also reviewed in terms of their shape and size dependency in catalysis as well as their unique electronic and magnetic properties for the device application. 

The possible compositions for the walls of the ordered mesoporous materials go beyond the field of inorganic chemistry, and materials with hybrid organosilica walls have been prepared [81-84], Some mesoporous benzene-silica hybrids are stable at a temperature higher than 500 °C [84], Mesoporous materials prepared from polysilazanes and nonionic surfactants can be activated to form silicon carbonilride ceramics, which retain an ordered mesoporosity up to 1500 °C [85],... 

---