木质素磺酸钠在氧化铁表面的吸附驱动力

Adsorption Driving Force of Sodium Lignosulphonate on Fe_2O_3 Surface

研究吸附介质的pH值、尿素及盐类对木质素磺酸钠(SL)在氧化铁表面吸附性能的影响规律,结果表明,络合能力较强的柠檬酸钠使SL的吸附量几乎减少至零,较弱络合能力的亚硫酸钠使SL的吸附量具有一定程度的降低,而无络合能力的硫酸钠增大了SL的吸附量.说明SL的羧基与氧化铁之间的络合吸附驱动力对吸附起主导作用,磺酸基对其在氧化铁上吸附的影响很弱.采用氯化锂屏蔽部分羧基后SL在氧化铁上的吸附量也有所降低,进一步证明了羧基与氧化铁表面的络合作用是其吸附的主要驱动力.

The effect of the pH of adsorption medium, the urea and the salts on the adsorption property of sodium lignosulphonate（ SL） on the surface of the ferric oxide particles was studied. The results showed that the sodium citrate with strongest complexing power maked the adsorption amount of SL on ferric oxide reduce to almost zero. The sodium sulfite with weak complexing power causes the adsorption amount of SL a certain re-duction. The sodium sulfate with no complexing power causes the adsorption amount of SL a certain increase instead. It is concluded that the complex adsorption driving force between the carboxyl groups of SL and the ferric oxide plays a leading role in the adsorption process and the sulfonic groups of SL have very weak influence on the adsorption on the ferric oxide. The lithium chloride was used to mask most carboxyl groups of SL, and the adsorption amount of the masked SL on ferric oxide was reduced evidently. The results further proved that the complex force between the carboxyl groups of SL and the ferric oxide played the leading role in the adsorption process. In addition, the results showed that the electrostatic and hydrogen bond interaction between SL and ferric oxide had little influence on the adsorption.