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Ormosils (organically modified silicate) are obtained when silane is added to gel-derived silica during sol–gel process. The product is a molecular-scale composite with improved mechanical properties. Sono-Ormosils are characterized by a higher density than classic gels as well as an improved thermal stability. An explanation therefore might ...
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 ...
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 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 ...
The filled mold is then frozen. On freezing, silica precipitates from the sol, forming a gel. This gel holds the filler powder together in something approximating a sintering greenform. The component is then dried in a furnace, leaving the component. The advantages of freeze-geleation over sintering are essentially cost-based.
This is a method analogous to the way fluorescent lamps work. Some newer white LEDs use a yellow and blue emitter in series, to approximate white; this technology is used in some Motorola phones such as the Blackberry as well as LED lighting and the original-version stacked emitters by using GaN on SiC on InGaP but was later found to fracture ...
In polymer chemistry, the gel point is an abrupt change in the viscosity of a solution containing polymerizable components. At the gel point, a solution undergoes gelation, as reflected in a loss in fluidity. After the monomer/polymer solution has passed the gel point, internal stress builds up in the gel phase, which can lead to volume shrinkage.