Modification of optical properties of PC-PBT/Cr

Nanocomposite (NCP) films of polycarbonate-polybutylene terephthalate (PC-PBT) blend as a host material to Cr2O3 and CdS nanoparticles (NPs) were fabricated by both thermolysis and casting techniques. Samples from the PC-PBT/Cr2O3 and PC-PBT/CdS NCPs were irradiated using different doses (20–110 kGy) of γ radiation. The induced modifications in the optical properties of the γ irradiated NCPs have been studied as a function of γ dose using UV Vis spectroscopy and CIE color difference method. Optical dielectric loss and Tauc's model were used to estimate the optical band gaps of the NCP films and to identify the types of electronic transition. The value of optical band gap energy of PC-PBT/Cr2O3 NCP was reduced from 3.23 to 3.06 upon γ irradiation up to 110 kGy, while it decreased from 4.26 to 4.14 eV for PC-PBT/CdS NCP, indicating the growth of disordered phase in both NCPs. This was accompanied by a rise in the refractive index for both the PC-PBT/Cr2O3 and PC-PBT/CdS NCP films, leading to an enhancement in their isotropic nature. The Cr2O3 NPs were found to be more effective in changing the band gap energy and refractive index due to the presence of excess oxygen atoms that help with the oxygen atoms of the carbonyl group in increasing the chance of covalent bonds formation between the NPs and the PC-PBT blend. Moreover, the color intensity, ΔE has been computed; results show that both the two synthesized NCPs have a response to color alteration by γ irradiation, but the PC-PBT/Cr2O3 has a more response since the values of ΔE achieved a significant color difference >5 which is an acceptable match in commercial reproduction on printing presses. According to the resulting enhancement in the optical characteristics of the developed NCPs, they can be a suitable candidate as activate materials in optoelectronic devices, or shielding sheets for solar cells

Modification of structural, thermal and optical properties of PC-PET/CdSe NCP using gamma radiation

In the current study we synthesized a nanocomposite (NCP) from polycarbonate/polybutylene terephthalate (PC-PET) blend and CdSe nanoparticles (NPs) through ex-situ casting methodology. CdSe NPs were synthesized using thermolysis technique with N2 gas flow. X-ray diffraction data for CdSe NPs are reported. The Rietveld refinement indicated that the synthesized CdSe acclimatizes cubic zinc blends constitution of a lattice parameter 6.057 Å and an average grain size of 2 nm. The PC-PET/CdSe NCP samples were irradiated by gamma doses between 20 and 230 kGy. The induced variations in the structure, thermal and optical properties of the gamma irradiated PC-PET/CdSe NCP have been illustrated by means of TEM, XRD, TGA, FTIR and UV–vis spectroscopes. The irradiation with doses in the range 50–230 kGy leads to the domination of crosslinking that improves the amorphous content. This increases the degradation temperature from 417 to 432 °C indicative of an enhancement in the thermostability of the NCP samples. Also, the optical band gap is reduced from 4.28 to 3.76 eV which is ascribed to the enhancement in the amorphous content of the irradiated PC-PET/CdSe NCP. This specifies that the gamma irradiation causes a more compactness of the NCP and leads to appropriate spreading of CdSe NPs within the PC-PET matrix. Additionally, the CIE approach was used to describe the colored samples. It is found that the PC-PET/CdSe NCP acquires color due to gamma doses, as the color intensity reached a remarkable color difference larger than 5 (14.9) which is a reasonable challenge in saleable reproduction on printing press

Color changes in X-ray irradiated PM-355 and Makrofol DE 7-2 nuclear track detectors

Effects of X-ray irradiation on the color changes of PM-355 and Makrofol DE 7-2 nuclear track detectors have been investigated. Samples from PM-355 and Makrofol DE 7-2 polycarbonates were irradiated with X-ray doses at levels between 10 and 250 kGy. The transmission of these samples in the wavelength range 370–780 nm, as well as any color changes, was studied. The Commission International de E’Claire (CIE units x, y and z) methodology was used in this work for the description of colored samples. The color differences between the non-irradiated sample and those irradiated with different X-ray doses were calculated. The results indicate that both PM-355 and Makrofol DE 7-2 detectors acquire color changes under X-ray irradiation, but the PM-355 detector has more response to color change than that of Makrofol DE 7-2

Modification of optical properties of PC-PBT/Cr 2

Nanocomposite (NCP) films of polycarbonate-polybutylene terephthalate (PC-PBT) blend as a host material to Cr2O3 and CdS nanoparticles (NPs) were fabricated by both thermolysis and casting techniques. Samples from the PC-PBT/Cr2O3 and PC-PBT/CdS NCPs were irradiated using different doses (20–110 kGy) of γ radiation. The induced modifications in the optical properties of the γ irradiated NCPs have been studied as a function of γ dose using UV Vis spectroscopy and CIE color difference method. Optical dielectric loss and Tauc's model were used to estimate the optical band gaps of the NCP films and to identify the types of electronic transition. The value of optical band gap energy of PC-PBT/Cr2O3 NCP was reduced from 3.23 to 3.06 upon γ irradiation up to 110 kGy, while it decreased from 4.26 to 4.14 eV for PC-PBT/CdS NCP, indicating the growth of disordered phase in both NCPs. This was accompanied by a rise in the refractive index for both the PC-PBT/Cr2O3 and PC-PBT/CdS NCP films, leading to an enhancement in their isotropic nature. The Cr2O3 NPs were found to be more effective in changing the band gap energy and refractive index due to the presence of excess oxygen atoms that help with the oxygen atoms of the carbonyl group in increasing the chance of covalent bonds formation between the NPs and the PC-PBT blend. Moreover, the color intensity, ΔE has been computed; results show that both the two synthesized NCPs have a response to color alteration by γ irradiation, but the PC-PBT/Cr2O3 has a more response since the values of ΔE achieved a significant color difference >5 which is an acceptable match in commercial reproduction on printing presses. According to the resulting enhancement in the optical characteristics of the developed NCPs, they can be a suitable candidate as activate materials in optoelectronic devices, or shielding sheets for solar cells