摘要
此工作中,我们通过使用动态光散射和Zeta电位仪仔细评估了金纳米颗粒的尺寸和表面电荷的时间演变,成功地发展了一个新的且一致的描述柠檬酸钠还原氯金酸制备金纳米颗粒生长的模型。这个新模型证明了金纳米颗粒的成核和生长全部发生在Au~+离子和丙酮二羧酸钠(来自柠檬酸钠还原氯金酸的产物)的复合物(Au~+/SAD)形成的颗粒中,并且遵守Lamer模型。伴随着金纳米颗粒在Au~+/SAD复合物颗粒中生长的同时,这些Au~+/SAD复合物颗粒也经历着可逆的聚集。这个行为导致了反应介质异常的颜色变化,但是对于金纳米颗粒的影响很小。基于这个新模型,我们通过简单的柠檬酸钠法,一步成功地制备了尺寸可在2到330纳米范围内精细调控的单分散、类球形的金纳米颗粒。
In this work,we have successfully developed a new and consistent model to describe the growth of gold nanoparticles(Au NPs) via citrate reduction of HAuCl_4 by carefully assessing the temporal evolution of the NP sizes and surface charges by means of dynamic light scattering and zeta potential measurement.The new model demonstrates that the nucleation and growth of the Au NPs occur exclusively in the particles of the complexes of Au~+ ions and sodium acetone dicarboxylate(SAD) derived from citrate/HAuCl_4 redox reaction,which proceed in a way described by classic LaMer Model.Concomitant with the Au NP growing therein,the Au~+/SAD complex particles undergo reversible agglomeration with the reaction time,which may result in the abnormal color change of the reaction media,but have little impact on the Au NP growth.Built on the new model,we have successfully produced monodisperse,quasi-spherical Au NPs with sizes precisely regulated from 2 to 330 nm via simple citrate reduction in a one-pot manner.
引文