Abstract

The spectral and luminescent properties of benzene and toluene solutions of poly[2-methoxy-5-(2'-ethylhexyloxy)-1,4-phenylenevinylene] (MEH-PPV) with single-walled and double-walled carbon nanotube (CNT) additives are studied with the purpose of detecting the plasmonic properties of CNTs in the luminescence of MEH-PPV solutions. It is established that the dependence of the luminescence intensity of a solution of the polymer on the concentration of CNTs is nonmonotonic in nature; in particular, the luminescence intensity initially increases with an increase in the number of dissolved nanotubes and then decreases. In this case, the luminescence spectrum itself is barely deformed. This effect is observed with both single-walled CNTs (SWCNTs) and double-walled CNTs (DWCNTs). The depth of light intensity modulation in the case of DWCNTs was higher than in the case of SWCNTs. To explain the observed dependences, various versions of the electrodynamic model of exciting/quenching the luminescence of MEH-PPV by carbon nanotubes are proposed. Direct simulation of the characteristics of near and far fields is performed on the basis of Maxwell equations, for the numerical solution of which the finite difference time domain (FDTD) method is used. Computational experiments have shown that CNTs with a MEH-PPV layer have directional antenna properties and act as unusual waveguides. Thus, the energy of radiation that reached the far-field region in the nanotube axis direction is an order of magnitude higher than that in the case of a solution without CNTs. Fountain electromagnetic waves that emanate from both ends of the nanotube and the stage of plasmon wave beats, which characterizes the nanotube as a waveguide, are detected. Molecular dynamic simulation of the configurations of the adsorbed MEH-PPV chain in various solvents is performed both on an isolated CNT and on two parallel CNTs with different distances between them. It is found that the conformational structure of MEH-PPV becomes more and more loose as the distance between CNTs increases; in particular, an increase in the number of large loops of the macrochain in the bulk of the solution is observed.

中文翻译：

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单壁和双壁碳纳米管对聚苯撑乙烯（MEH-PPV）溶液的等离子体活化和发光猝灭

摘要

具有单壁和双壁碳纳米管的聚[2-甲氧基-5-（2'-乙基己氧基）-1,4-亚苯基亚乙烯基]（MEH-PPV）的苯和甲苯溶液的光谱和发光特性为了检测MEH-PPV溶液的发光过程中CNT的等离子体特性，对添加剂进行了研究。已经确定，聚合物溶液的发光强度对CNT的浓度的依赖性本质上是非单调的。特别地，发光强度首先随着溶解的纳米管数量的增加而增加，然后降低。在这种情况下，发光光谱本身几乎不变形。在单壁CNT（SWCNT）和双壁CNT（DWCNT）中都可以观察到这种效果。在DWCNT的情况下，光强度调制的深度比在SWCNT的情况下高。为了解释观察到的依赖性，提出了各种版本的碳纳米管激发/猝灭MEH-PPV发光的电动力学模型。基于麦克斯韦方程组，对近场和远场的特性进行了直接仿真，为此采用了时差有限差分法（FDTD）进行数值求解。计算实验表明，具有MEH-PPV层的CNT具有定向天线特性，并充当特殊的波导。因此，与没有CNT的溶液的情况相比，在纳米管轴方向上到达远场区域的放射线的能量高一个数量级。检测到从纳米管的两端发出的喷泉电磁波，以及表征纳米管为波导的等离激元波拍的阶段。分子动力学模拟了在各种溶剂中吸附的MEH-PPV链的构型，这些分子动力学分别在孤立的CNT和两个平行的CNT之间进行，它们之间的距离不同。结果发现，随着碳纳米管之间的距离增加，MEH-PPV的构象结构变得越来越疏松。特别地，在溶液的大部分中观察到大链的大环的数量增加。分子动力学模拟了在各种溶剂中吸附的MEH-PPV链的构型，这些分子动力学分别在孤立的CNT和两个平行的CNT之间进行，它们之间的距离不同。结果发现，随着碳纳米管之间的距离增加，MEH-PPV的构象结构变得越来越疏松。特别地，在溶液的大部分中观察到大链的大环的数量增加。分子动力学模拟了在各种溶剂中吸附的MEH-PPV链的构型，这些分子动力学分别在孤立的CNT和两个平行的CNT之间进行，它们之间的距离不同。结果发现，随着碳纳米管之间的距离增加，MEH-PPV的构象结构变得越来越疏松。特别地，在溶液的大部分中观察到大链的大环的数量增加。