Date of Graduation
Statler College of Engineering and Mineral Resources
Chemical and Biomedical Engineering
Rakesh K. Gupta.
Paints and caulks typically contain (spherical) fumed silica particulates as viscosity enhancers. A similar viscosity enhancement can be achieved by using aramid fibrids. Aramid fibrids are believed to form microstructures in suspensions because of the "space-filling" nature of their shapes and thus provide a convenient means of introducing desired rheological behavior for various commercial applications.;The flow responses of aramid fibrids dispersed in mixtures of corn syrup and water were determined in dynamic shear, steady shear, low shear capillary, and extensional stretching flows. Yield stress, strong shear thinning, thixotropy, and strong dispersion effects were observed, and these are consistent with observed equilibrium structures. Intrinsic viscosity measurements revealed Einstein coefficients about 200 times larger than the corresponding value for spheres, and this demonstrates their remarkable viscosity enhancement as well as the strong effect of dispersion. Large Trouton ratios observed during extensional viscosity measurement also prove that fibrids have a tremendous enhancement effect on suspension viscosity.
Han, Long, "Study of the rheological properties of nomex fibrids" (2001). Graduate Theses, Dissertations, and Problem Reports. 1193.