Rheological control of reactive and nonreactive particles

Official URL: https://risc01.sabanciuniv.edu/record=b2553596_ (Table of contents)

Controlling the shear response of colloidal systems is critical in the ceramics industry as it affects the final properties of the product. In this thesis, reactive cementitious particles and nonreactive ceramic particles were studied and characterized by a colloidal science point of view. In the first part, the formulation of an extrudable, lightweight, high-strength cement-based material that utilizes industrial waste products was achieved. A random grafted copolymer that capitalizes electrostatic repulsion and steric hindrance was the key to control the flow of the particles. In the optimized mixture, high performance was maintained in terms of the compressive strength at 80 MPa and the dry hardened density at 1900 kg/cm3. According to the American Concrete Institute, this formulation is classified as highstrength (>55 MPa) and lightweight (320–1920 kg/m3). In the second part, the green machinability of yttria-stabilized zirconia was attained by employing a linear random copolymer. The copolymer was designed to coagulate the system by polymerpolymer bridging and facilitated an innovative ceramic gelcasting approach. The optimized system resulted in a shrinkage of 22.8%, a flexural strength of 149 MPa, and a density of 5.93 g/cm3. Compared to the values given in the literature; the shrinkage is 20–30%, the flexural strength is 150 MPa, and the theoretical density is 6.07 g/cm3