Fabrication and Properties of Biopolymer-Ceramics Nanocomposites as UV-Shielding for Bionanoscience Application

Structural, Electronic, Optical Properties and Antibacterial Application of Novel (PMMA-Al2O3-Ag) Nanocomposites for Dental Industries Applications

“…The absorption coefficient contributions in order to know the nature involving electron transition . When the values in the absorption coefficient of material α >10 4 cm -1 , the electron transmission is probable to be direct transition of electron but the electron transmission will be probable to be indirect transition if the values of the absorption coefficient of material are usually minimal α<10 As is shown in the figures, the energies gaps for allowed and forbidden indirect transitions of nanocomposites are decreased with the increasing of the Ag nanoparticles, this performance is due to the making of levels in the energy gap; the transition of electron in this instance is conducted in two stages that include the transition from the valence band to the local levels in energy gap and to the conduction band as a result of increasing the Ag nanoparticles, the electronic conduction depends on addition of nanoparticles [41][42][43][44]. Figures (21-23) show the variation of extinction coefficient (k) with wavelength for the (PMMA-Al 2 O 3 -Ag) nanocomposites , in general, it will be clear that the extinction coefficient (k) decreases with increasing of wavelength (λ) for all samples of (PMMA-Al 2 O 3 -Ag) nanocomposites which is related to increase the absorbance [45][46][47].…”

Synthesis of (Polymer–SnO) Nanocomposites: Structural and Optical Properties for Flexible Optoelectronics Applications

“…From this figure, it is noticed that the optical conductivity of PVA increases with increasing SnO 2 nanoparticles. This increase due to creation of new levels in the band gap leads to facilitate the crossing of electrons from the valence band to these local levels to the conduction band; consequently, the band gap decreases and the conductivity increase [48][49][50][51][52].…”

Novel (PMMA-ZrO2-Ag) Nanocomposites: Structural, Electronic, Optical Properties as Antibacterial for Dental Industries

“…The absorption coefficient of (PMMA-ZrO 2 -Ag) nanocomposites is increased with the increase of the adding of Ag nanoparticle, this is property to the increase of number of charge carriers, hence,increase the absorbance of (PMMA-ZrO 2 -Ag) and absorption coefficient[28][29][30][31][32][33].Figures(12)(13)(14)indicate the energy gap for allowed indirect transition of nanocomposites. From the figures observed the energy gap of (PMMA-ZrO 2 -Ag) nanocomposites is decreased with the increase of the addingAg nanoparticle, due tothe creation sub levels between valance and conduction bands; as a result of addition of the Ag nanoparticle[34][35][36][37][38][39]. Figures(15)(16)(17)showthe variation of real dielectric constant (ε 1 ) as a function of wavelength for (PMMA-ZrO 2 -Ag) nanocomposites.…”