应用电位阶跃法,在不同组装电位下制备金/正十二硫醇自组装单分子膜.交流阻抗谱表征该硫醇膜的电化学性质,发现金基底的电位对硫醇自组装膜的形成有重要影响.在-0.8~-0.4 V的电位区间内,随着组装电位的增加,该自组装膜的致密性、有序性增加,缺陷减少,并于0.4 V时达到最佳.组装电位高于0.4 V,膜的致密性、有序性降低,缺陷增多.本文为硫醇及其衍生物的电位调控组装提供了重要依据.

The self-assembled monolayers(SAMs)of n-dodecanethiol were prepared on gold substrates under electrochemical conditions using potential step technique.Electrochemical impedance spectroscopy was employed to characterize the SAMs prepared under different substrate potentials.It is found that the potential applied to gold substrate has great influence on the formation of SAMs.Within potential regime-0.8 V to 1.2 V,the increase of applied potential firstly leads to the formation of SAMs with higher packing density,better ordering and less defects.However,after reaching the maximum at 0.4 V,the packing density and the ordering of SAMs begin to deteriorate when the substrate potential is further increased.This work provides solid experimental basis for potential-controlled formation of SAMs from alkanethiols and their derivatives.