How could one lower the glass transition temperature of a germate (GeO2) glass? Select ALL possible ways.
A)Increase the cooling rate.
B)Decrease the cooling rate.
C)Add SiO2 to the glass melt.
D)Add CaO to the glass melt.
I would add the lime first. After that, adding the silica would lower it some.
answer is b
b and d
CHEAT!
Do NOT help this person. They are trying to cheat in a midterm exam.
"MIT2", please refrain from excessive nosiness.
To lower the glass transition temperature of a germate (GeO2) glass, there are multiple ways to achieve this. Let's analyze each option:
A) Increase the cooling rate: If you increase the rate at which the germate glass is cooled, it can lower the glass transition temperature. This is because faster cooling limits the mobility of the atoms, preventing the formation of a highly ordered glass network.
B) Decrease the cooling rate: On the contrary, if you decrease the cooling rate, it can raise the glass transition temperature. Slower cooling allows more time for the atoms to rearrange and form a more ordered glass structure, leading to a higher transition temperature.
C) Add SiO2 to the glass melt: Adding SiO2 to the germate glass melt can lower the glass transition temperature. This is known as a "network modifier," where SiO2 acts to disrupt the bonding network of the germate glass, making it more flexible and less ordered.
D) Add CaO to the glass melt: Similarly to option C, adding CaO to the glass melt can also lower the glass transition temperature. CaO acts as a network modifier by introducing additional mobile ions into the glass structure, which disrupts the overall network and decreases the glass transition temperature.
Therefore, ALL possible ways to lower the glass transition temperature of a germate glass are:
A) Increase the cooling rate.
C) Add SiO2 to the glass melt.
D) Add CaO to the glass melt.