Organosilica mesoporous materials

Organosilica Mesoporous Materials with Double Functionality Amino Groups and p-Cyclodextrin Synthesis and Properties... 

Organosilica Mesoporous Materials with Double Functionality... 

Sulfonic Acid Functionalization of Ordered Mesoporous Materials and Periodic Organosilicas... 

Figure 15.1 Ordered nanoscale structures of mesoporous materials such as FSM-16 and HMM-1 (Et-HMM-1) as the silica and organosilica templates for surface-mediated synthesis of metal/alloy nanowires and nanoparticles.

Inagaki S., Guan S., Ohsuna T. and Terasaki O., An ordered mesoporous organosilica hybrid material with a crystal-like wall structure. Nature 416 (2002), pp. 304-307. 

Si CP/MAS-NMR was used to characterise mesoporous materials derived from sodium silicate and organotrialkoxysilanes.493 Multinuclear NMR studies have been reported on periodic mesoporous organosilicas.494,495 13C and 29Si MAS-NMR spectra were used to characterise ordered macroporous organo-silica materials.496 A similar study has been made of mesoporous organosilica/ clay heterostructures.497... 

S. Inagaki, S. Guan, T. Ohsuna, and O. Terasaki, An Ordered Mesoporous Organosilica Hybrid Material with a Crystal-like Wall Structure. Nature (London), 2002, 416, 304-307. 

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],... 

Mesoporous materials present exceptionally high surface area, and thermal and mechanical stability thus, mesoporous hybrid organosilica represents a suitable solid support for the design of organocatalysts (Nandi et al., 2011 Jain et al., 2011). 

We do not consider so-called periodic mesoporous materials , for example certain organosilicas, which do have a very narrow mesopore spectrum and presently are subject to intensive investigations. 

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. 

As shown in Scheme 4.4, an organosilica that showed pore structure with 2D hexagonal symmetry was obtained upon hydrolysis-condensation of the disUy-lated organic precursor in the presence of a surfactant as a structure-directing agent. Cationic or neutral surfectants were used to generate mesoporous material. 

A new solid acid catalyst is developed by the direct sulphonation of the ethene bond of a pure trans ethene bridged Periodic Mesoporous Organosilica. The catalytic activity of this mesoporous material is evaluated in an esterification reaction and compared with p-toluenesulphonic acid. The sulphonated ethene PMO can compete with a homogeneous catalyst and maintains its porosity. 

Another approach for the functionalization of mesoporous material is the PMO. It is a special type of mesoporous organosilica with integrating organic groups (R) such as (R 0)3-Si-R-Si-(0R)j (R = methane, ethane, ethylene, acetylene, tris[3-(trimethoxysilyljpropyljisocyanurate, porphyrin, and so on) inside the siliceous walls. 

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