Better Chemistry through Ceramics:  The Physical Bases of the Outstanding Chemistry of ORMOSIL

Abstract

Twenty years after their invention, sol-gel organically modified silicates (ORMOSIL) are finding a number of impressive applications that range from efficient deliver of genes into mouse brains to self-ordered helices of interest to fields as diverse as optics, catalysis, molecular recognition, and chromatography. The physical bases of this mulifaceted chemistry, therefore, are of immense importance to scientists working toward new applications such as photovoltaics and catalysis that are crucially important in making sustainable global development. The purpose of this article is to provide a general picture of ORMOSIL's physical chemistry that will be useful in the creative development of new materials capable to solve a number of relevant open problems.

Electron Exchange Columns through Entrapment of a Nickel Cyclam in a Sol–Gel Matrix

“…[19,[23][24][25]27] We tried to do the same; first cyclam was entrapped and then efforts to complex it with Ni 2 + were performed. Even under extreme conditions (two weeks reflux in methanol and tenfold excess of the nickel ion) the solid matrix did not change its color.…”

“…The addition of R' groups to the surface decreases the polarity of the pore walls, because the number of silanol groups on the surface decreases and shielding of the remaining silanol groups can also occur. [15,27] The hydrolysis of ORMOSILs is slower relative to that of Si(OR) 4 , and the R'Si(OH) 3 monomers formed slowly condense fast to form micellar like structures. Pagliaro et al have shown that matrices made only from TMOS have structures that contain mainly four-membered rings.…”

Fifty Years of Hydrosilylation in Polymer Science: A Review of Current Trends of Low-Cost Transition-Metal and Metal-Free Catalysts, Non-Thermally Triggered Hydrosilylation Reactions, and Industrial Applications

“…However, a possible route to lower process costs is to minimize the consumption of catalyst. Cririminna et al reported the use of platinum nanoparticles incorporated into a silicate porous matrix for the hydrosilylation of long-chained alkenes (Figure 42) [122]. The benefit of the system is the minimized leaching of catalyst during reaction, preventing loss of the catalyst and contamination of the product.…”

Electrocatalytic Oxidation of Amines by Ni­(1,4,8,11‐tetraazacyclotetradecane)2+ Entrapped in Sol–Gel Electrodes

“…[12] (2) The electrode can operate in a medium in which the electrocatalyst is insoluble and/or unstable. [2,12b] The applications of these matrices in electrocatalysis are limited, because the matrices are insulators [13] and therefore the plausible current densities are low. [14] Furthermore, the diffusion of the substrate to the electrocatalyst is slow.…”