Search results
Results From The WOW.Com Content Network
The structural theories of glass formation only consider the relative ease of glass formation. Materials which form glasses under a moderate cooling rate are called good glass formers, those that require a rapid cooling rate are called poor glass formers and those that require extreme cooling rates are referred to a non-glass formers.
The glass transition of a liquid to a solid-like state may occur with either cooling or compression. [10] The transition comprises a smooth increase in the viscosity of a material by as much as 17 orders of magnitude within a temperature range of 500 K without any pronounced change in material structure. [11]
Glass disease, also referred to as sick glass or glass illness, is a degradation process of glass that can result in weeping, crizzling, spalling, cracking and fragmentation. [ 1 ] [ 2 ] Glass disease is caused by an inherent instability in the chemical composition of the original glass formula. [ 3 ]
[62] [63] Glass is typically inert, resistant to chemical attack, and can mostly withstand the action of water, making it an ideal material for the manufacture of containers for foodstuffs and most chemicals. [21] [64] [65] Nevertheless, although usually highly resistant to chemical attack, glass will corrode or dissolve under some conditions.
The calculation of glass properties allows "fine-tuning" of desired material characteristics, e.g., the refractive index. [1]The calculation of glass properties (glass modeling) is used to predict glass properties of interest or glass behavior under certain conditions (e.g., during production) without experimental investigation, based on past data and experience, with the intention to save ...
Porous glass is glass that includes pores, usually in the nanometre- or micrometre-range, commonly prepared by one of the following processes: through metastable phase separation in borosilicate glasses (such as in their system SiO 2-B 2 O 3-Na 2 O), followed by liquid extraction of one of the formed phases; [1] [2] through the sol-gel process; or simply by sintering glass powder.
The chemical reaction is as follows: CaCO 3 → CaO + CO 2 The reaction is used to make quick lime, which is an industrially important product. Another example of thermal decomposition is 2Pb(NO 3) 2 → 2PbO + O 2 + 4NO 2. Some oxides, especially of weakly electropositive metals decompose when heated to high enough temperature.
Structure of glass bead matrix and interactions with metal ions. The synthesis of these beads begins when calcium carbonate is heated to anywhere from 800 to 1300 C. This heating causes a decomposition reaction which forms solid calcium oxide and releases carbon dioxide gas.