Release Mechanism of Octadecyl Rhodamine B Chloride from Au Nanorods by Ultrafast Laser Pulses
Release Mechanism of Octadecyl Rhodamine B Chloride from Au Nanorods by Ultrafast Laser Pulses
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DOI：
10.1021/jp809646e
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发表时间：
2009-04-16
影响因子：
3.7
通讯作者：
Hamad-Schifferli, Kimberly
中科院分区：
文献类型：
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作者：
Alper, Joshua;Crespo, Monica;Hamad-Schifferli, Kimberly
研究了十六烷基三甲基溴化铵(CTAB)包覆的金纳米棒(NR)上负载的十八烷基罗丹明B氯化物(R-18)在脉冲超快激光激发下的释放。R-18嵌入到天然橡胶表面疏水的CTAB双层膜中，并能与溶液中的游离CTAB胶束在天然橡胶表面进行交换。我们发现，随着激光剂量的增加，R-18从天然橡胶中释放以及R-18与天然橡胶结合的速率都加快了。然而，在激光能量密度为220mJ/cm(2)时，R-18的热降解占主导地位。我们还发现，CTAB的浓度，特别是在临界胶束浓度附近，对释放和结合速率有很大的影响。
We investigated the release of octadecyl rhodamine B chloride (R-18) loaded onto cetyltrimethylammonium bromide (CTAB) coated gold nanorods (NR) by pulsed ultrafast laser excitation. R-18 intercalates into the hydrophobic CTAB bilayer on the NR surface and can exchange on and off the NR with free CTAB micelles in solution. We find that laser excitation accelerates the rate of both R-18 release from the NR and R-18 binding to the NR with increasing fluence. However, at laser fluences >220 mu J/cm(2) thermal degradation of the R-18 dominates. We also find that the concentration of CTAB, particularly around the critical micelle concentration, strongly influences the release and binding rates.