The rheology of suspensions of titanate fibers in polymer solution

The, Theological properties of suspensions of relatively small amounts of titanate fibers in polystyrene solution have been measured by means of a Weissenberg rheogoniometer. The titanate fibers employed have diameters smaller than 0.5 micron and aspect ratios higher than 40. It has been found that the rheological properties of the suspensions are markedly time dependent; the steady‐flow shearing stress increases with increasing time when the rate of shear is changed abruptly from an initial high value to a considerably lower final value. This behavior can be attributed to the re‐formation of a structure formed by the dispersed fibers and broken at higher shear rates. The dynamic storage modulus G′ also depends strongly upon the re‐formation of the structure. Although the structure reformation process under shear appears too complicated to be analyzed satisfactorily, an attempt has been made to generalize the experimental data with a simple equation.