动态光散射和电泳对栲胶溶液的电化学行为研究

从栲胶的胶体化学性质的角度,使用ZetasizerNano-ZS系列仪器研究了,橡栲胶(水解类)和荆树皮栲胶(缩合类)溶液的Zeta电位和电导率,随中性盐浓度和pH的变化;溶液中鞣质被铬皮粉吸附以后的Zeta电位和电导率随pH的变化。结果显示:栲胶溶液的Zeta电位的绝对值随中性盐浓度的增大而迅速降低,而与溶液的pH呈正相关关系;溶液的电导率随中性盐浓度的增大而增大,而在广泛的pH范围内无大的变化,当pH值小于2时电导率升高并出现突变,且各种栲胶溶液具有一致性。溶液中鞣质存在与否对溶液的Zeta电位和电导率随pH的变化无明显影响,而鞣质被吸附以后的橡栲胶溶液的Zeta电位在碱性条件下的变化明显减小。

Study on the Electrochemical Behavior of Tannin Solutions by Dynamic Light Scattering(DLS) and Electrophoresis

The electrochemical properties, including the Zeta potentials and the conductivity, of valonia (hydrolysable tannin) and wattle (condensable tannin) solutions were investigated from the view of the property of colloid of the extract solutions. The variety of the Zeta potentials,and of the conductivity with the pH and the neutral salt concentration were evaluated. Meanwhile, the Zeta potentials and the conductivity of the extract solutions, in which the tannins were adsorbed by previously added chrome hide powder, were measured. The results show that the absolute values of the Zeta potentials of the two investigated extracts rose with the increase of the pH, and fell dramatically with the increase of the neutral salt concentration. There is little change on the conductivity in an extensive pH range, but rose sharply when the pH is less than 2. Moreover, the Zeta potentials and the conductivity are little related to the tannin percentages in the solution, they both present a similar way by the changing of the solution pH even if the tannins were removed by the chrome hide powder.