Prasad Saradh, Alhandel Raya H, Asemi Nassar N, AlSalhi Mohamad S
Research Chair on Laser Diagnosis of Cancers, Department of Physics and Astronomy, College of Science, P.O. Box 2455, King Saud University, Riyadh 11451, Saudi Arabia.
Polymers (Basel). 2023 Nov 29;15(23):4572. doi: 10.3390/polym15234572.
The properties of a conjugated copolymer (CP), poly[(9,9-Dioctyl-2,7-divinylenefluorenylene)-alt-co-(2-methoxy-5-(2-ethylhexyloxy)-1,4-phenylene) (PDVF-co-MEH-PV), were investigated in the presence of graphene oxide (GO) and reduced graphene oxide (rGO) using absorption, fluorescence, laser, and time-resolved spectroscopy. CPs are usually dissolved in low-polar solvents. Although GO does not dissolve well, rGO and PDVF-co-MEH-PV dissolve in chloroform due to their oxygen acceptor sites. Hence, we studied rGO/PDVF-co-MEH-PV (CP/rGO), performing all experiments and simulations in chloroform. We performed simulations on PDVF-co-MEH-PV, approximate GO, and rGO using time-dependent density-functional theory calculations to comprehend the molecular dynamics and interactions at the molecular level. The simulation polymer used a tail-truncated oligomer model with up to three monomer units. The simulation and experimental results were in agreement. Further, the PDVF-co-MEH-PV exhibited fluorescence, laser quenching, rGO-mediated laser blinking, and spectral broadening effects when GO and rGO concentrations increased. The experimental and simulation results were compared to provide a plausible mechanism of interaction between PDVF-co-MEH-PV and rGO. We observed that for lower concentrations of rGO, the interaction did not considerably decrease the amplified spontaneous emissions of PDVF-co-MEH-PV. However, the fluorescence of PDVF-co-MEH-PV was considerably quenched at higher concentrations of rGO. These results could be helpful for future applications, such as in sensors, solar cells, and optoelectronic device design. To demonstrate the sensor capability of these composites, a paper-based sensor was designed to detect ethanol and nitrotoluene. An instrumentation setup was proposed that is cheap, reusable, and multifunctional.
在氧化石墨烯（GO）和还原氧化石墨烯（rGO）存在的情况下，使用吸收光谱、荧光光谱、激光光谱和时间分辨光谱对共轭共聚物（CP）聚[(9,9 - 二辛基 - 2,7 - 二亚乙烯基芴撑)-alt-共-(2 - 甲氧基 - 5 - (2 - 乙基己氧基)-1,4 - 亚苯基)]（PDVF - co - MEH - PV）的性质进行了研究。共轭共聚物通常溶解于低极性溶剂中。尽管GO溶解性不佳，但rGO和PDVF - co - MEH - PV由于其氧受体位点而可溶于氯仿。因此，我们研究了rGO/PDVF - co - MEH - PV（CP/rGO），并在氯仿中进行了所有实验和模拟。我们使用含时密度泛函理论计算对PDVF - co - MEH - PV、近似的GO和rGO进行了模拟，以理解分子水平上的分子动力学和相互作用。模拟聚合物使用了最多含三个单体单元的尾部截断低聚物模型。模拟结果与实验结果一致。此外，当GO和rGO浓度增加时，PDVF - co - MEH - PV表现出荧光、激光猝灭、rGO介导的激光闪烁和光谱展宽效应。通过比较实验和模拟结果，提供了PDVF - co - MEH - PV与rGO之间相互作用的合理机制。我们观察到，对于较低浓度的rGO，这种相互作用并未显著降低PDVF - co - MEH - PV的放大自发发射。然而，在较高浓度的rGO下，PDVF - co - MEH - PV的荧光被显著猝灭。这些结果可能有助于未来在传感器、太阳能电池和光电器件设计等方面的应用。为了展示这些复合材料的传感能力，设计了一种纸质传感器来检测乙醇和硝基甲苯。还提出了一种廉价、可重复使用且多功能的仪器装置。
