Ceramics rheological properties

MC is used as an adhesive in ceramics to provide water retention and lubricity in cosmetics to control rheological properties and in the stabilization of foams in foods as a binder, emulsifier, stabilizer, thickener, and suspending agent in paints, paper products, plywood as a rheology control for the adhesive in inks, and in textiles as a binder, and for coatings. 

As noted above, for the most part, the first synthetic step resulted in oligomers with low ceramic yields, poor rheological properties and/or limited latent reactivity. As such, numerous approaches were explored with the idea of introducing latent reactivity and better viscoelastic properties. In the following, we discuss several of these synthetic approaches, some of the materials that result and a few applications. 

A variation on this approach used multifilament coextrusion, so-called microfabrication by coextrusion (MFCX) . A limitation of the single-filament process is the size of the filament. The rheological properties of the polymer/ ceramic blends make spinning fibers smaller than 250 pm very difficult. Additionally, spooling fine-diameter fibers is quite challenging. The MFCX is shown schematically in Fig. 1.3. The setup is the same as that used to spin fibers except that the spinneret is replaced with an extrusion die with a diameter between 1 mm and 6 mm. Two separate extrusion steps are used. In the first step, coarse primary filaments are extruded from the feedrod (Fig. 

Ceramic suspensions can also be deposited by dispensing or extrusion from a nozzle. While printing is a parallel process, i.e., many nozzles per color or substance are involved — say 128 or more, dispensing and extrusion processes usually use a single nozzle. The rheological properties of the ceramic suspensions are different from those of inkjet inks they may be much more viscous, i.e., contain a... 

Yang C. Y., Shih W. Y. and Shih W. H., Gelation, consolidation, and rheological properties of boehmite-coated silicon carbide suspensions. J. Am. Ceram. Soc. 83 (2000)pp. 1879-1884. 

Millan, A., Nieto, M., Baudin, C. et al., Thermogelling polysaccharides for aqueous gelcasting—Part II influence of gelling additives on rheological properties and gelcasting of alumina, J. Eur. Ceram. Soc., 22, 2217, 2002. 

Rheological properties of ceramic dispersions and green structures are related to the interaction forces between the particles and with the microstructure of the material. Unfortunately, detailed quantitative interpretation in terms of microstructure is only possible for model systems of monodisperse particles of which the interaction energies are precisely known [14]. 

Huang, Q. et al.. Effect of pretreatment on rheological properties of silicon carbide aqueous suspension, Ceram. Int., 28, 747, 2002. 

Tsai, M.-S., Yung, F.-H., and Yang, F.-H., Boehmite modification of nano grade a-alumina and the rheological properties of the modified slurry, Ceram. Int., 33, 739, 2007. 

Goski. D.G. et al., Effect of kyanite on rheological properties of dense aqueous alumina suspensions, Br. Ceram. Trans., 98, 192, 1999. 

Wang, G. and Nicholson, P.S., Influence of acidity on the stability and rheological properties of ionically stabilized alumina suspensions in ethanol, 7. Am. Ceram. Soc.,i, 1977, 2001. 

Agrafiotis, C., Tsetsekou. A., and Leon. L. Effect of slurry rheological properties on the coating of ceramic honeycombs with yttria-stabilized-zirconia washcoats, J. Am. Ceram. Soc., 83. 1033. 2000. 

Shih, C.J. and Hon, M.H., Electrokinetic and rheological properties of aqueous TiN suspensions with ammonium salt of poly(methacryhc acid), 7. Eur. Ceram. Soc., 19, 2773, 1999. 

---