Glass fibers silica

Tensile strength of gel-derived fibers have been measured. It has been found (8) that gel-derived fibers are a little weaker than silica glass fibers, especially when the diameter is large, as shown... 

The entire spectrum of inorganic fibers can be divided into two classes, based on differences in the crystallinity of the solids (Ray, 1978). Synthetic fibers have been known as man-made mineral fibers (MMMF) and manmade vitreous fibers (MMVF). But fibrous materials can be approached or divided in other ways. For example, in the Concise Encyclopedia of Chemical Technology (1985) the entry for chemical fibers includes both manmade and natural polymers, with the discussion centering on carbon-based compounds such as acetates, acrylics, and cellulose. Fibers of other inorganic compounds were not mentioned in the encyclopedia under this entry, but silica glass fibers were described under the heading Optical Fibers. ... 

Sol-gel preparations of tetraethoxysilane can be spun into fibers once the appropriate viscosity has been achieved. These fibers are only slightly weaker than silica-glass fibers. 

Fiber-optic biosensors are analytical devices in which a fiber optic device serves as a transduction element. The usual aim of fiber-optic biosensors is to produce a signal proportional to the concentration of target analyte to which the biological element reacts. Fiber-optic biosensors are based on the transmission of light along silica glass fiber, or POF to the site of analysis. They can be used in combination with different types of spectroscopic technique, e.g. absorption, fluorescence, phosphorescence, or surface plasmon resonance (SPR) (14). 

Andrade, A. L., Ferreira, J. M. F. and Domingues, R. Z. (2004). Surface modifications of alumina-silica glass fiber. J. Biomed Mater. Res. Part B Applied Biomaterials 70B 378-383. 

Hofstadler, K., Bauner, R., Novallc, S., andHeisler, K., 1994, New reactor design for photocatalytic wastewater treatment with Ti02 immobilized on fused silica glass fibers photo-mineralization of 4-chlorophenol. Environ. Sci. Tech., 28 670-674. 

The optical region of the spectrum where fiber-optic devices operate is from 300 to 2 pm wavelengths. The wavelengths used in fiber-optic systems are matched to the particular characteristics of the system. Plastic fibers operate best at visible wavelengths, non-silica glass fibers are designed to operate at infrared wavelengths, and... 

Excellent precipitated silica, filmed silica, glass fiber, cristobalite, quartz, sand, kaolin, aluminum trihydrate, wollastonite... 

Small diameter, structural silica glass fibers and large diameter, bicomponent optical silica fibers are downdrawn from the surface melt of a solid preform. The melt temperatures needed to contain the melt exceed the capability of practical ceramic and bushing materials. 

Only dry spinning facilitates the formation of amorphous silica glass fibers from viscous solutions. Two process variants are known. One uses a viscous water glass or sodium silicate solution, wherein water is the solvent, and produces a pure and relatively low cost fiber. The other uses a viscous tetraethylorthosilicate solution wherein alcohol is the solvent, and produces an ultrapure premium fiber. In either process, the viscous solution is spun from, or extruded through, multiple spinneret orifices into a hot column that removes the solvent. Before the as-spun fibers are wound onto a package, they are solidified in a final, high temperature curing step. 

In either process, the final curing step may be an integral part of the entire process sequence, or it may be a separate step. In the first process, the as-spun precursor fiber is already an amorphous silica glass fiber, except that it is not yet entirely free of solvent and not yet fully consolidated. In the second process, the as-spun precursor fiber still has a different chemical composition than the final silica fiber, but it has the same morphology, i.e., an amorphous structure. In these examples, a glass fiber is therefore directly derived from the liquid phase, i.e., from a viscous solution. 

The fourth process which yieids high siiica giass fibers relies on acid leaching of borosilicate or aluminosiiicate precursor fibers in fabric form (Chapters 4 and 6). This is the oldest and least expensive process. Acid ieaching removes most of the compositionai oxides other than silica from a precursor fabric, individual fibers can be leached also, but they are not satisfactorily converted into sliver, braids of woven fabrics. Process details and properties of melt spun and acid leached silica substrate processes have been discussed in Chapter 4. Commercial applications of all four silica glass fibers will be discussed in Chapter 6. 

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