Etching, of glass

The names fluorine and fluorospar are derived from the Latin fluere meaning flow or flux. In 1529 the use of fluorspar as a flux was described. In 1670 the etching of glass by acid-treated fluorspar was reported. Elemental fluorine was isolated by Moissan ia 1886 (7). 

Analytical Methods. Fluorite is readily identified by its crystal shape, usually simple cubes or interpenetrating twins, by its prominent octahedral cleavage, its relative softness, and the production of hydrogen fluoride when treated with sulfuric acid, evidenced by etching of glass. The presence of fluorite in ore specimens, or when associated with other fluorine-containing minerals, may be deterrnined by x-ray diffraction. 

Lab Video Figure 15.22 Etching of glass by hydrogen fluoride... 

Microfabrication is achieved by photolithography and isotropic etching of glass using HF [4—13]. Thermal bonding serves for interconnection. Holes are drilled in the top plate for connection to the fluidic peripherals. 

The etching of glass, Si02, by hydrofluoric acid, HF, is not an oxidation-reduction reaction, since no element in the reaction is undergoing a change in oxidation number. 

CaFa, mw 78.08, wh pdr, sp gr 3.18 at 20°, mp 1330° nearly in sol in w si sol in ale reacts with hot coned sulfuric acid to liberate HF. Can be prepd by, powdering pure fluorite or by the interaction of soluble Ca salt and NaF. Used in manuf of HF, ceramics, smelting, cements, etching of glass, etc. Clear cryst is used in optical equipment. Was used by E. Turpin in expls named Fluorine , described in Vol 6, under "Explosifs de Turpin Refs 1) Gmelin-Kraut Syst Number 28(1956),... 

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. 

Etching of Glass with Gaseous Hydrogen Fluoride. (The experiment is performed by one student and demonstrated to the class.)... 

The mixer was made by wet-chemical etching of glass substrates, following a photolithographic step, yielding channels for the fluid flow and for the electrodes. The electrodes (100 Q resistors) were made by an electron-beam evaporation process generating thin metallic films in the etched channels [92], Holes were drilled into the cover plate for inlet and outlet connection. Fusion bonding was used to seal the plates. 

The importance of fluorine lies largely in the use of several compounds of that element. Calcium fluoride, or fluorspar (CaF2), is used as a flux and, like sodium fluoride (NaF), as an insecticide. Ammonium fluoride (NH4F) is used as a disinfectant hydrofluoric acid is used in the etching of glass and organic compounds are used as commercial refrigerants. 

Microfluidic Lab-on-a-chip for Chemical/Biological Analysis and Discovery 2.2.1 Etching of Glass Microchannels... 

Etching of glass is commonly achieved by isotropic wet etch. Various etching conditions based on HF are tabulated in Table 2.3. A typical glass channel created by wet etch is shown in Figure 2.4. 

Toma, Y., Hatakeyama, M., Ichiki, K., Huang, H.L., Yamauchi, K., Watanabe, K., Kato, T., Fast atom beam etching of glass materials with contact and non-contact masks. Jpn. J. Appl. Phys. 1997, 36, 7655-5322. 

Isotropic wet chemical etching of glass (buffered 10% hydrofluoric add). 

Enamelling, 403 English crystal glass, 198 Enstatite, 46-48,315-317 Environmental pollution, 154—155 Etching of glass, 202 Eucryptite, 175, 232—234 Eutal, see E-glass Exchange capacity of ions, 37 Extrusion, 260—262... 

The etching of glass by hydrofluoric acid may be represented by the simplified reaction of silica with HE... 

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