烷基硫酸钠在二氧化钛上的吸附研究

The Adsorption of Sodium Alkylsulfate on Titanium Dioxide

表面活性剂在氧化物表面上的吸附,因其在浮选中的重要作用而被广泛研究。但迄今为上的工作多是关于表面活性离子在电性相反的氧化物表面上,例如阳离子表面活性剂在带负电的氧化物表面上的吸附,而对电性相同的表面活性离子的吸附则很少涉及,虽然许多实际问题中遇到的是后一种情形。本工作研究了烷基硫酸钠在带负电的TiO_(2)表面上的吸附,根据吸附与电泳的实验结果计算了吸附自由能,并提出了可能的吸附机理。

The adsorption of sodium decyl-,dodecyl-and tetradecyl sulfate on negatively charged TiO_(2) surface has been investigated.The adsorption isotherms display a sigmoid pattern,indicating the lateral interaction between the adsorbed surface active ions The adsorption free energy and lateral interaction parameter were calculated based on the FFG equation from the adsorption and electrokinetic data.From the experimental results it was deduced that,the adsorbed surface active ions were laying flat and formed hemimicelles at the TiO_(2)/solution interface.