Search results
Results From The WOW.Com Content Network
The sol–gel approach is a cheap and low-temperature technique that allows the fine control of the product's chemical composition. Even small quantities of dopants, such as organic dyes and rare-earth elements , can be introduced in the sol and end up uniformly dispersed in the final product.
The first step of the sol-gel process is the creation of a colloidal suspension of solid particles known as a "sol". The precursors are a liquid alcohol such as ethanol which is mixed with a silicon alkoxide , such as tetramethoxysilane (TMOS), tetraethoxysilane (TEOS), and polyethoxydisiloxane (PEDS) (earlier work used sodium silicates). [ 23 ]
Bioactive glasses have been synthesized through methods such as conventional melting, quenching, the sol–gel process, flame synthesis, and microwave irradiation.The synthesis of bioglass has been reviewed by various groups, with sol-gel synthesis being one of the most frequently used methods for producing bioglass composites, particularly for tissue engineering applications.
Mechanics of gelation describes processes relevant to sol-gel process. In a static sense, the fundamental difference between a liquid and a solid is that the solid has elastic resistance against a shearing stress while a liquid does not. Thus, a simple liquid will not typically support a transverse acoustic phonon, or shear wave. Gels have been ...
Typically, gels are synthesized via sol-gel processing, a wet-chemical technique involving a colloidal solution (sol) that acts as the precursor for an integrated network (gel). There are two possible mechanisms whereby organogels form depending on the physical intermolecular inter-actions, namely the fluid-filled fiber and the solid fiber ...
This method has been used for synthesizing over 100 mixed metal oxides including lanthanum manganite for solid oxide fuel cells and BaTiO3 (Lessing 1989). [5] Unlike the sol–gel process in which the metal alkoxide participates in the gel-forming reactions this process is based on a gelation reaction between the alcohol and acid used as solvents.
The inherent porosity of the sol-gel-derived material was cited as a possible explanation for why bioactivity was retained, and often enhanced with respect to the melt-derived glass. Subsequent advances in DNA microarray technology enabled an entirely new perspective on the mechanisms of bioactivity in bioactive glasses. Previously, it was ...
The Stöber process is a sol-gel approach to preparing monodisperse (uniform) spherical silica (SiO 2 ) materials that was developed by a team led by Werner Stöber and reported in 1968. [ 1 ] The process, an evolution and extension of research described in Gerhard Kolbe's 1956 PhD dissertation, [ 24 ] was an innovative discovery that still has ...