Wang Meng, Zhang Qi, Hao Wei, Sun Zhong-Xi
School of Chemistry and Chemical Engineering, University of Jinan, Jinan 250022, China.
Chem Cent J. 2011 Nov 24;5(1):73. doi: 10.1186/1752-153X-5-73.
In this paper, the surface stoichiometry, acid-base properties as well as the adsorption of xanthate at ZnS surfaces were studied by means of potentiometric titration, adsorption and solution speciation modeling. The surface proton binding site was determined by using Gran plot to evaluate the potentiometric titration data. Testing results implied that for stoichiometric surfaces of zinc sulfide, the proton and hydroxide determine the surface charge. For the nonstoichiometric surfaces, the surface charge is controlled by proton, hydroxide, zinc and sulfide ions depending on specific conditions. The xanthate adsorption decreases with increasing solution pH, which indicates an ion exchange reaction at the surfaces. Based on experimental results, the surface protonation, deprotonation, stoichiometry and xanthate adsorption mechanism were discussed.
本文通过电位滴定、吸附和溶液形态建模等方法，研究了硫化锌表面的化学计量、酸碱性质以及黄药在硫化锌表面的吸附情况。利用格兰作图法评估电位滴定数据，确定了表面质子结合位点。测试结果表明，对于化学计量比的硫化锌表面，质子和氢氧根决定表面电荷。对于非化学计量比的表面，表面电荷根据具体条件由质子、氢氧根、锌离子和硫离子控制。黄药吸附量随溶液pH值升高而降低，这表明在表面发生了离子交换反应。基于实验结果，讨论了表面质子化、去质子化、化学计量和黄药吸附机理。
