Glass-making Reactions

It would be impossible to study all of the reactions simultaneously by thermal analysis. Instead, the technique of investigating two, or perhaps more, pure substances reacting together has been used. The results are then taken as representative of one of the many processes occurring and used to forecast what happens in the overall batch reaction. 

2 mols 425 pm Silica heated with 1 mol Sodium Carbonate 

Further experiments were also carried out using various silica particle sizes with only one rate of heating. Details may be found in reference 12. The reactions are thus seen to be complex, and ancillary information, such as the analysis of the residue material or the volatile material given off and condensed out, helps in formulating a reaction scheme. 

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Figure 11 Glass-making reactions - reaction of silica with sodium carbonate at various heating rates...

Wilburn Fred W. (1925-) Brit, thermoanal., heat transfer models, glass-making reactions... 

Etching of Glass with Hydrofluoric Acid. Cover a glass plate with a layer of paraffin. To do this, lower it into paraffin melted in a porcelain bowl and immediately extract it. Make an inscription with a penknife on the paraffin-coated surface so as to uncover the surface of the glass. Make a small paraffin barrier at the edges of the inscription. Pour a 10% hydrofluoric acid solution onto the paraffin-coated plate and let it stand in a fume cupboard. After one or two hours, wash the solution off the plate and remove the paraffin. What happened to the glass Write the equations of the reactions. 

To avoid reaction between the Si substrate and A1 metallizations during the manufacture of integrated circuits at high temperatures, diffusion barriers are necessary. It has been demonstrated that high crystallization-temperature glasses such as Ta Ir glasses make excellent diffusion barriers in many microelectronics applications. 

Problem 32.14 When pbly(vinyl acetate) is treated with methanol (b.p. 65°) in the presence of a little sulfuric acid, a substance of b.p. 57° distills from the mixture, and a new polymer is left behind, (a) What reaction has taken place What is the structure of the new polymer Why must it be prepared in this indirect manner (b) When this new polymer is treated with i-butyraldehyde in the presence of a little phosphoric acid, a third polymer is formed, Butvar, which is used in making safety glass. What reaction has taken place here, and what is the structure of Butvar ... 

The surfaces of glasses contain silanol groups. The presence of silanol groups on the surface of a glass microchip makes reaction with silanol the first choice for modification of glass surfaces. In one approach, after the channels have been fiushed with NaOH, the channels are first filled with y-methacryloxypropyltrimethoxysilane in diluted acetic acid and/or acetonitrile for an hour. In a sec-... 

Corrosion Resistant Fiber-Reinforced Plastic (FRP). Fiber glass reinforcement bonded with furfuryl alcohol thermosetting resias provides plastics with unique properties. Excellent resistance to corrosion and heat distortion coupled with low flame spread and low smoke emission are characteristics that make them valuable as laminating resins with fiber glass (75,76). Another valuable property of furan FRP is its strength at elevated temperature. Hand-layup, spray-up, and filament-win ding techniques are employed to produce an array of corrosion-resistant equipment, pipes, tanks, vats, ducts, scmbbers, stacks, and reaction vessels for industrial appHcations throughout the world. 

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