Kumar Brijesh, Kaur Gagandeep, Rai S B
Laser and Spectroscopy Laboratory, Department of Physics, Banaras Hindu University, Varanasi 221005, India.
Laser and Spectroscopy Laboratory, Department of Physics, Banaras Hindu University, Varanasi 221005, India.
Spectrochim Acta A Mol Biomol Spectrosc. 2017 Dec 5;187:75-81. doi: 10.1016/j.saa.2017.06.025. Epub 2017 Jun 20.
Tb doped polyvinyl alcohol: polyvinyl pyrrolidone blends with dibenzoylmethane (DBM) and 1, 10 Phenanthroline (Phen) have been prepared by solution cast technique. Bond formation amongst the ligands and Tb ions in the doped polymer has been confirmed employing Fourier Transform Infrared (FTIR) techniques. Optical properties of the Tb ions have been investigated using UV-Vis absorption, excitation and fluorescence studies excited by different radiations. Addition of dimethylbenzoate and 1, 10 Phenanthroline to the polymer blend increases the luminescence from Tb ions along with energy transfer from the polymer blend itself. Luminescence decay curve analysis affirms the non-radiative energy transfer from DBM and Phen to Tb ions, which is identified as the reason behind this enhancement. The fluorescence decay time of PVA-PVP host decreases from 6.02ns to 2.31ns showing an evidence of energy transfer from the host blend to the complexed Tb ions. Similarly the lifetime of DBM and Phen and both in the blend reduces in the complexed system showing the feasibility of energy transfer from these excited DBM and Phen to Tb and is proposed as the cause of the above observations. These entire phenomena have been explained by the energy level diagram.
通过溶液浇铸技术制备了掺铽聚乙烯醇与聚乙烯吡咯烷酮的共混物，其中含有二苯甲酰甲烷（DBM）和1,10 - 菲咯啉（Phen）。利用傅里叶变换红外（FTIR）技术证实了掺杂聚合物中配体与铽离子之间的键形成。通过紫外 - 可见吸收、激发和不同辐射激发的荧光研究，对铽离子的光学性质进行了研究。向聚合物共混物中添加苯甲酸二甲酯和1,10 - 菲咯啉，增加了铽离子的发光以及聚合物共混物本身的能量转移。发光衰减曲线分析证实了从DBM和Phen到铽离子的非辐射能量转移，这被认为是这种增强背后的原因。PVA - PVP主体的荧光衰减时间从6.02ns降至2.31ns，表明存在从主体共混物到络合铽离子的能量转移。同样，在络合体系中，共混物中DBM和Phen的寿命均降低，表明从这些激发的DBM和Phen到铽存在能量转移的可行性，并被认为是上述观察结果的原因。这些全部现象已通过能级图进行了解释。
