期刊
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
卷 126, 期 16, 页码 5292-5299出版社
AMER CHEMICAL SOC
DOI: 10.1021/ja038953v
关键词
-
An unusual aggregation phenomenon that involves positively charged poly(L-lysine) (PLL) and negatively charged gold nanoparticles (Au NPs) is reported. Discrete, submicrometer-sized spherical aggregates are found to form immediately upon combining a PILL solution with gold Sol (diameter; approximate to 14 nm). These PLL-Au NP assemblies grow in size with time, according to light scattering experiments, which indicates a dynamic flocculation process. Water-filled, silica hollow microspheres (outer diameter approximate to microns) are obtained upon the addition of negatively charged SiO2 NPs (diameter approximate to 13 nm) to a suspension of the PLL-Au NP assemblies, around which the SiO2 NPS form a shell. Structural analysis through confocal microscopy indicates the PLL (tagged with a fluorescent dye) is located in the interior of the hollow sphere, and mostly within the silica shell wall. The hollow spheres are theorized to form through flocculation, in which the charge-driven aggregation of Au NPs by PLL provides the critical first step in the two-step synthesis process (flocculation assembly). The SiO2 shell can be removed and re-formed by decreasing and increasing the suspension pH about the point-of-zero charge of SiO2, respectively.
作者
我是这篇论文的作者
点击您的名字以认领此论文并将其添加到您的个人资料中。
推荐
暂无数据