From Insulating PMMA Polymer to Conjugated Double Bond Behavior: Green Chemistry as a Novel Approach to Fabricate Small Band Gap Polymers

Polymers

Hameed M. Ahmed¹  Ahang M. Hussein¹  Shujahadeen B. Aziz¹  Omed Gh. Abdullah¹ 

[1] Advanced Polymeric Materials Research Laboratory, Department of Physics, College of Science, University of Sulaimani, Qlyasan Street, Sulaymaniyah 46001, Kurdistan Regional Government, Iraq;

关键词: dye doped polymer;    extract GT solution;    FTIR study;    band gap analysis;    Urbach energy;    XRD study;   

DOI  :  10.3390/polym9110626

来源: DOAJ

【 摘 要 】

Dye-doped polymer films of Poly(methyl methacrylate) PMMA have been prepared with the use of the conventional solution cast technique. Natural dye has been extracted from environmentally friendly material of green tea (GT) leaves. Obvious Fourier transform infrared (FTIR) spectra for the GT extract were observed, showing absorption bands at 3401 cm−1, 1628 cm−1, and 1029 cm−1, corresponding to O–H/N–H, C=O, and C–O groups, respectively. The shift and decrease in the intensity of the FTIR bands in the doped PMMA sample have been investigated to confirm the complex formation between the GT dye and PMMA polymer. Different types of electronic transition could be seen in the absorption spectra of the dye-doped samples. For the PMMA sample incorporated with 28 mL of GT dye, distinguishable intense peak around 670 nm appeared, which opens new frontiers in the green chemistry field that are particularly suitable for laser technology and optoelectronic applications. The main result of this study showed that the doping of the PMMA polymer with green tea dye exhibited a strong absorption peak around 670 nm in the visible range. The absorption edge was found to be shifted towards the lower photon energy for the doped samples. Optical dielectric loss and Tauc’s model were used to estimate the optical band gaps of the samples and to specify the transition types between the valence band (VB) and conduction band (CB), respectively. A small band gap of around 2.6 eV for the dye-doped PMMA films was observed. From the scientific and engineering viewpoints, this topic has been found to be very important and relevant. The amorphous nature of the doped samples was found and ascribed to the increase of Urbach energy. The Urbach energy has been correlated to the analysis of X-ray diffraction (XRD) to display the structure-properties relationships.

【 授权许可】

Unknown