聚乙烯醇在Al_2O_3、SiO_2颗粒上的吸附及对Zeta电位的影响

Adsorption of Polyvinyl Alcohol on Al_2O_3, SiO_2 and Its Effect on the Zeta Potential of Particles

摘要: 测定了超细 Al2 O3、Si O2 颗粒对聚乙烯醇 (PVA)的吸附 ,考察了 Na Cl对吸附量的影响 ,发现当 Na Cl浓度大于 0 .1 mol· L-1时 ,随着 PVA浓度的升高 ,吸附量会出现一个突跃性的升高。用微电泳仪测定了吸附 PVA前后 Al2 O3、Si O2 颗粒 Zeta电位的变化 ,发现 Si O2 的等电点不受PVA的影响 ,而 Al2 O3吸附了 PVA后 ,等电点降低。

Abstract: The adsorption isothermals of polyvinyl alcohol (PVA) on Al 2O 3 and SiO 2 particles have been measured. The effect of NaCl on the adsorption of PVA has been inspected. It is found that the adsorption amount increases rapidly with increase of PVA concentration when NaCl concentration is higher than 0.1mol/L. Zeta potentials of Al 2O 3 and SiO 2 particles with and without PVA adsorption have been obtained from the electrophoresis measurement. It is shown that the isoelectric point of SiO 2 is not affected by the adsorption of PVA, while the isoelectric point of Al 2O 3 decreases with the adsorption of PVA.