Surface properties of polymer adsorbed zirconia nanoparticles

Polyethylenimine (PEI) dispersed zirconia (3mol% yttria doped) aqueous suspensions were prepared and surface characteristics of PEI/ZrO2 system were studied. Adsorption isotherm of PEI on ZrO2 nanoparticles was a high affinity type and the optimum concentration of dispersant was about 1 dwb% (dry-weight-basis) of ZrO2. pH range with positive surface potential of ZrO2 was enbroaded and isoelectric point (IEP) of as synthesized powder was shifted to pH 10.5. Hydrogen bonding was proposed as the dominant mechanism of the adsorption process within the pH range studied and surface bond structure of nanoparticles was influenced by the polymer adsorbate between 300 and 400 cm(-1) in FTIR spectra. Auger electron spectroscopy (AES) investigation also confirmed that Zr peaks were affected by the polymer adsorbate and dramatic alternation of peak intensity was observed at 94 and 120 eV, respectively. (C)1999 Acta Metallurgica Inc.