Abstract: The quantitative adsorption of ammonium salt of polyacrylic acid on nano-size Y-TZP powder was investigated by using UV adsorption spectrum. The adsorption of
PAA-NH₄ decreases as pH increases, because the PAA-NH_4 is more negatively dissociated. When the pH is 1.02, the adsorption type belongs to high affinity. The highest
adsorption percent can reach as high as 98%. If initial pH falls in the range of 2.7 to 13.6, the pH of the supernate is near to 8.3 and their Zeta potential
is in the range of --35 to --40mV. In a wide pH range the adsorption ability is less effected by the initial pH, due to the high buffer ability of PAA-NH₄.

Key words: ammonium salt of polyacrylic acid, quantitative adsorption, UV spectrum, nano Y-TZP powder