摘要
本文通过湿法化学还原法合成了平均粒径为4.42nm、标准差为0.98nm的球形银纳米颗粒,并研究了在不同反应时间后获得的银纳米颗粒对PVP和Alq3的荧光猝灭效应。通过深入研究发现,PVP的荧光猝灭效应主要由于其分子链上的酮基与Ag颗粒之间发生了静电吸附,进而导致处在激发态的PVP分子与银颗粒之间产生电子或者能量转移(即非辐射弛豫),猝灭了PVP的荧光发光;而Alq3的荧光猝灭效应则主要归因于银纳米颗粒的欧姆损耗。通过采用时域有限差分法进行模拟发现,溶液中随机分布的银纳米颗粒,不仅能够吸收激发电磁波,削弱激发场强度,而且能够吸收荧光分子辐射的电磁波,进而猝灭了Alq3分子的荧光效应。这些研究成果将有利于了解金属纳米颗粒与PVP及Alq3分子荧光发光之间的关系,为调控荧光发光提供指导。
In this paper, the silver nanoparticles with average size of 4.42 nm have been sythesized. Through mixing silver nanopartieles with emitters （PVP or Alq3） in solution, we observe obvious fluorescence quenching effect. The in-depth experimental and theoreti- cal researches indicate that the quenching effect for PVP mainly comes from electrostatic adsorption between the silver nanoparticles and the ketone groups of PVP, which will lead to the transfer of eletron or energy from the excited state PVP molecules to silver parti- cles, and reduce the emitted photonics. While the quenching effect for Alq3 is mainly at- tributed to Ohmic loss in the silver nanoparticles. The theoretical simulation indicates that this Ohmic loss can not only absorb the excitated electromagnetic wave and reduce the strength of electromagnetic field, but also absorb the emitted photonies. These research results are beneficial to understand the relationship between the metal nanoparticles and the fluorescence emission, and will provide guidance for modulating the fluorescence emis- sion.
出处
《光散射学报》
北大核心
2013年第4期433-439,共7页
The Journal of Light Scattering
