微孔玻璃的Zeta电势测定研究

EXPERIMENTAL INVESTIGATION OF ZETA POTENTIAL OF MICROPOROUS GLASS

以微电泳仪测定了微孔玻璃的Zeta电势,并研究不同的研磨方法、介质的pH值及离子强度和不同的温度对Zeta电势测定的影响,获得了不同条件下的微孔玻璃的等电点,对微孔玻璃的电动性质做了定量的描述。

The electrokinetic properties of microporous glass are measured using microelectrophoresis technique. With wet-milling MPG, the zeta potential varies with pH in 2×H_2O10^(-3)mol·kg^(-1) and 10^(-2) mol·kg^(-1) NaCl solution are investigated respectively at 16℃. The results show that the isoelectric point (i.e.p.) is pH=1.4; when pH>1.4, particles are negatively charged, and both Na^+ and Cl^- have no characteristic adsorption on surface of glass. The zeta potential will decrease if ionic strength increases under the same pH. Measurement of zeta potential of MPG at 30℃, shows that temperature has no effect on zeta potential. With dry-milling MPG, the zeta potential varies with pH similar to that of wet-milling MPG but with lower values; so the i.e.p, is pH=1.7. It is probably due to the diffusion of boron atoms to the surface.