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Specialty Chemistry Forums => Materials and Nanochemistry forum => Topic started by: stulti on June 18, 2008, 06:39:57 PM

Title: silicon melting point
Post by: stulti on June 18, 2008, 06:39:57 PM

Can anyone tell me why gold lowers the melting point of glass? Is there a way I can find out what else might do the same? Can solvents do this?

I'm uneducated, lay mans terms are appreciated but not required.
Stulti

Title: Re: silicon melting point
Post by: PolymerKnowHow on June 18, 2008, 11:14:48 PM

I can't speak for glass specifically, but polymer scientists are well aware of an effect called plasticization. In layman's terms, small molecules are commonly added to polymeric materials (large, very long molecules) to make them more flexible. This happens because the small molecules act locally as a solvent and increase the mobility of the polymer chains.

For glass, they add certain chemicals to accomplish more or less the same effect. The one that I am most aware of is Boron. Boron is added to glass in the form of boron oxide to produce a glass that doesn't change dimensions with changes in temperature. AKA Pyrex.