Effect of Gallol-PEG Surfactant on Rheological Behavior of Aqueous Nickel-Yttrium Stabilized Zirconia (Ni-YSZ) Composite Suspensions

• Main Authors: Chir-Jang Tsai, 蔡奇璋
• Other Authors: Wen-Jea Tseng
• Format: Others
• Language: zh-TW
• Published: 2014
• Online Access: http://ndltd.ncl.edu.tw/handle/89400869429312605126

博士 === 國立中興大學 === 材料科學與工程學系所 === 102 === Nickel-Yttrium stabilized zirconia (Ni-YSZ) nanoparticles have been dispersed in de-ionized water with pyrogallol-poly(ethylene glycol) polymer (i.e., Gallol-PEG) as surfactant. Measurement of zeta potential and adsorption isotherm confirms the preferential anchoring from polar end of the surfactant molecules on the particle surface. Fluid Ni-YSZ suspensions with an apparent viscosity < 0.55 at a shear rate about 102 s−1 have been prepared with a solids concentration of 40 vol.% with the Ni/YSZ volume ratio of 25/75, indicating that the Gallol-PEG adsorption is effective in facilitating the suspension flow under shear stress. Theoretical calculation of interparticle potentials indicates that the adsorbed Gallol-PEG polymer with an average thickness of 4 nm observed in the HR-TEM renders steric hindrance critical to the suspension stabilization. The concentrated Ni-YSZ suspensions (40 vol.%, Ni:YSZ=25:75) exhibit shear-thinning flow over a broad shear-rate range, resulted from the weak attractive minimum (∼3.47 kBT) found between the neighbouring particles in close proximity.