Silicon alkoxides physical properties

The size of silica nanoparticles affects their physical, chemical, electronic, and optical properties. Proper size of silica nanoparticles is crucial for design of silica-based nanomaterials. In Stober methods, the size of silica nanoparticles is adjusted by changing the type of organic solvent, the amount of silicon alkoxide, and the... 

The present paper provides an overview of the physical properties of silica mesostructures with representative wormhole and lamellar framework structures assembled through S°P pathways. The wormhole framework silica, denoted HMS silica, was assembled using an alkylamine surfactant as the structure director and a silicon alkoxide as the inorganic precursor. The lamellar framework silica with a vesicular hierarchical structure, denoted MSU-G silica, was obtained from tetraethylorthosilicate (TEOS) as the silica precursor and a bi-functional gemini amine surfactant of the type RNH(CH2)2NH2. We then provide examples of the catalytic activity of these disordered mesostructures in comparison to more ordered framework mesostructures such as hexagonal MCM-41. 

The precursors used in the sol-gel technique are mainly silicon alkoxides that possess high degree of purity. Many of these silicon derivatives are used in various types of solvents and catalysts to produce silica aerogels. Each of these produces varying degrees of physical, thermal, mechanical and optical properties in the aerogels. Some of these precursors used are Tetramethoxysilane (TMOS), tetraethoxysilane (TEOS), polyethoxydisilane (PEDS), methyltriethoxysilane (MTES), and many others (Rao et al. 2003, 2005 Soleimani Dorcheh and Abbasi 2008 Wei et al. 2011). However, they are very expensive and hazardous materials that are known to cause blindness. 

Table 5.3 Physical Properties of the Commonly Used Silicon Alkoxides...

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