Sodium Silicate random network Flashcards
1
Q
What are bridging oxygens?
A
~ oxygens bonded to two Si4+ ions (between two SiO4(4-) tetrahedra)
2
Q
What are non bridging oxygens?
A
~ oxygen anions ionically bond to Na+, don’t form a bridge between two Si4+ ions
3
Q
What are network formers?
A
~ Si4+
4
Q
What are network modifiers?
A
~ Na+
~ these ions cluster together
~ easily rearrange, transforms bridging oxygens into NBO
~ makes manufacturing easier
~ the glass will be fluid at a lower temp
5
Q
What is a flux?
A
~ Na2O
~ substantially lowers melting temp of silica
6
Q
Why is Na2O-SiO2 not used as a commercial glass?
A
~ the glass is water soluble
~ Na+ ion exchanges with water, everything falls apart