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Investigation on the role of the molecular weight of polyvinyl pyrrolidone in the shape control of high-yield silver nanospheres and nanowires

Yuan-Jun Song123, Mingliang Wang1*, Xiao-Yang Zhang23, Jing-Yuan Wu23 and Tong Zhang23*

Author Affiliations

1 School of Chemistry and Chemical Engineering, Southeast University, Nanjing 211189, People’s Republic of China

2 School of Electronic Science and Engineering, Key Laboratory of Micro-Inertial Instrument and Advanced Navigation Technology, Ministry of Education, Southeast University, Nanjing 210096, People’s Republic of China

3 Suzhou Key Laboratory of Metal Nano-Optoelectronic Technology, Suzhou Research Institute of Southeast University, Suzhou 215123, People’s Republic of China

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Nanoscale Research Letters 2014, 9:17  doi:10.1186/1556-276X-9-17

Published: 13 January 2014


Serving as shape control agent, polyvinyl pyrrolidone (PVP) has been widely used in chemical synthesis of metal nanoparticles. However, the role of molecular weight (MW) of PVP has been rarely concerned. In this study, we show a facile method to control the shapes of silver nanocrystals using PVP with different MWs. PVPMW=8,000, PVPMW=29,000, PVPMW=40,000, and PVPMW=1,300,000 are compared in the present study. Surprisingly, high-yield silver rodlike nanostructures, nanospheres, and nanowires can be obtained under the same growth environment and reactant concentrations by simply changing the MW of PVP. The mechanism studies of the role of PVP with different MWs in the growth process were carried out systemically using the morphology and spectroscopic measurement, FT-IR spectrum analysis, and seed crystallization monitoring. The results indicate that the MW of PVP plays a determinant role in the morphology and optical property control of the silver nanocrystals. Meantime, the concentration of PVP was found to be an assistant factor to further improve the shape and the yield of the synthesized nanocrystals.

Polyvinyl pyrrolidone; Molecular weight; Nanowire; Nanosphere