Effects of GNP addition on optical properties and band gap energies of PMMA films
Küçük Resim Yok
Tarih
2019
Dergi Başlığı
Dergi ISSN
Cilt Başlığı
Yayıncı
Wiley
Erişim Hakkı
info:eu-repo/semantics/closedAccess
Özet
In this study, the effects of graphene nanoplatelet (GNP) doping on the optical parameters (absorption coefficient, alpha and extinction coefficient, k) and the optical transition energies (optical band gap and Urbach energies) of poly(methyl methacrylate)/graphene nanoplatelet (PMMA/GNP) composite films were studied. PMMA/GNP composite films with various GNP mass fractions were prepared by spin coating technique. The absorbance (A) changes of the prepared composites were measured by using UV-Vis technique. The alpha and k values of the composites were obtained from UV-Vis data. The observed rapid increase in A values in UV-region were associated with the optical transitions of GNP electrons from valence to conduction band. The direct (E-d) and indirect (E-i) optical band gap energies of the composites were determined by using Tauc method. Both of the band gap energies were decreased when the GNP content in the PMMA matrix is increased. The decrease in the band gap energies was interpreted as evidence of increased conductivity of the composites. Additionally, energies of the band tails (Urbach energy) were calculated. It was seen that the Urbach energy levels were increased with GNP content. POLYM. COMPOS., 40:1862-1869, 2019. (c) 2018 Society of Plastics Engineers
Açıklama
Anahtar Kelimeler
[No Keywords]
Kaynak
Polymer Composites
WoS Q Değeri
Q2
Scopus Q Değeri
Q1
Cilt
40
Sayı
5
