Published online by Cambridge University Press: 15 February 2011
We have previously shown that suspension dry spinning of green ceramic fibers can produce continuous fibers of alumina in an ethyl methacrylate binder. The spinning behavior of the dope and the particle packing in the dried fiber are highly dependent on the interparticle interactions in the dope prior to spinning. In particular, the interactions between the ceramic powder and both the dispersant and the binder are critical in determining the processability and spinnability of the dope. We have used rheological techniques to probe these interactions in alumina dispersions in methyl ethyl ketone employing ethyl methacrylate as the binder and a phosphate ester as the dispersant. Measurements of the viscosity of the dispersion as a function of dispersant concentration demonstrate that there is an optimum dispersant concentration to achieve a minimum viscosity at a given binder concentration. In addition, the relative viscosity (viscosity of the dispersion relative to that of the dispersing medium) is found to decrease significantly with increasing binder concentration. These results highlight the importance of characterizing the power-binder-dispersant interactions to fully understand the stability and ultimate spinnability of a ceramic dope. In addition, this work illustrates the general applicability of rheological characterization in ceramic fiber spinning.