Fibers: natural, silica content

The use of silane treated carbon fibers and silane treated silica fume led to increases in tensile strength of cement paste by 56% and modulus and ductility by 39% [30], as compared to the values obtained for cement paste with either as-received carbon fibers or as-received silica fume. Silane treatment of fibers and silica fume contributed about equally to the strengthening. Silane treatment of fibers and silica fume also decreased the air void content. The strengthening and reduction in air void content were less when the fiber treatment involved the use of K2Cr20v instead of silane, and even less when the treatment involved the use of O3. The effectiveness of silane is due to its hydrophilic nature. 

Practically any natural plant can be utilized as a source of papermaking fibers, but there is considerable variation in the quality of paper realized from alternate plant sources. Factors such as fiber length, content of non-fibrous components such as parenchyma tissue, contaminants such as silica, etc. greatly influence the quality of the final sheet. Procurement of sufficient quantities of the raw material and seasonal fluctuations in supply can also pose problems. It is also necessary to use alternate pulping equipment to handle the plant materials since the material tends to mat down in the digester making it difficult to get uniform circulation of the cooking chemicals. 

Fumed silica, grades, 146 In rice hulls, 145 Moisture content, 146 Natural, 146 Oil absorption, 146 Particle sizes, 146 Precipitated, 146 Specific gravity, 146 Specific surface area, 146 Synthetic, 146 Silicates, 87, 98, 123 Silicosis, 133 Mica, 133 Silylating agent, 85 Simple beam bending, 225 Single-screw compounder, 568 Sink/float procedure, 212, 216-218 Sisal fiber, 82, 86, 90, 110 Slip at the wall, 667 Slip coefficient, 211, 369-382 Slip enhancer, 381 Slip index, 376 Slip modifier, 381... 

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