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以HAuCl_4·4H_2O为前驱体,抗坏血酸(VC)为还原剂,线性聚乙烯亚胺(L-PEI)为表面活性剂在水相中制备了单分散的近球形和片状金粉。采用SEM、XRD和激光粒度分析仪对金粉的形貌、粒径、结晶和分散性进行了测试和表征。研究了还原剂和金前驱体的摩尔比、L-PEI浓度、温度及反应溶液的pH对近球形和片状金粉的形貌和粒径大小的影响。给出了制备微米级近球形和片状金粉的反应条件,同时也提出了近球形和片状金粉的成核和晶核生长的可能解释。
Monodisperse near-spherical and flaky gold powders were prepared in the aqueous phase using HAuCl 4 · 4H 2 O as the precursor, ascorbic acid (VC) as the reducing agent and linear polyethyleneimine (L-PEI) as the surfactant. The morphology, particle size, crystallinity and dispersivity of the powders were tested and characterized by SEM, XRD and laser particle size analyzer. The effects of molar ratio of reductant to gold precursor, L-PEI concentration, temperature and reaction solution pH on morphology and particle size of near-spherical and flaky powders were investigated. The reaction conditions for the preparation of micron-scale near-spherical and flaky powders are given, and the possible explanations of nucleation and nucleation of nearly spherical and flaky powders are also proposed.