Changes in Structural and Optical Properties of Polycarbonate Induced by Ag⁺Ion Implantation

Abstract

Transparent polycarbonate samples were implanted with 1 MeV Ag + ions to various doses ranging from 5 × 10 14 to 3 × 10 16 ions cm −2 with a beam current density of 900 nA cm −2 . Modification in the structure of polycarbonate as a function of the implantation fluence was investigated using micro-Raman spectroscopy, glancing angle X-ray diffraction, and UV-Vis spectroscopy. Raman spectroscopy pointed toward the formation of graphite structures/clusters due to the ion implantation. UV-Vis absorption analysis suggests the formation of a carbonaceous layer and a drastic decrease in optical band gap from 4.12 eV to 0.50 eV at an implanted dose of 3 × 10 16 ions cm −2 . The correlation between the decrease in band gap and the structural changes is discussed.

Evaluation of Fracture Toughness of Ultraviolet-Irradiated Polycarbonate Using the Essential Work of Fracture Method

“…In Table 1, as well in subsequent tables, the values of non-irradiated PC display in parenthesis 100% or 1 for comparison with changes produced in the other values of UV irradiated conditions. This behavior, characterized by a decrease in molar weight and an increase in polydispersity, can be related to a backbone scission of the polymeric chains 23,30 . In terms of amount of scissions, the results in Table 1 indicate a damage of 1% after 300 h and 4% after 600 h of irradiation.…”

“…In fact, cracks propagate in the central region of the fractured surface where "necking" process is taking place. This is followed by plastic tearing, as highlighted of the oxidation index suggests that the macromolecular chains were broken at the carbonyl group 23,24,30 due to UV irradiation but independent of the dose.…”

Emergent Insulator–Metal Transition with Tunable Optical and Electrical Gap in Thin Films of a Molecular Conducting Composite

“…From the conducting point of view, the two main ingredients of α-ET 2 I 3 BL-films are (i) polycarbonate, which is electrically insulating with a relatively large optical bandgap ( E g = 4.12 ± 0.01 eV) 30 and a very low electrical conductivity (σ PC = 10 –12 –10 –10 S/cm) 31 due to a broken π-conjugation between the phenyl rings in its chemical structure, and (ii) α-ET 2 I 3 crystallites, which behave as an organic 2D metal at room temperature. 22 Figure 3 a shows the electrical sheet resistance of BL films measured at different iodine vapor treatment times.…”

<i>γ</i>-Ray Modifications of Optical/Chemical Properties of Polycarbonate Polymer

“…This energy deposition may lead to the excitation and ionization lading to the breaking of original bonds, main chain scission, radical formation, cross linking [4] etc. This in turn results in the formation of double/triple bonds, conjugation of bonds [7], formation of carbon clusters [10] etc. The absorption bands in the investigated range are associated to the π -π * electronic transition [13]- [15].…”

“…While the Ar ion implantation produced a material that showed optical properties like evaporated amorphous carbon. The Raman spectroscopy of 1 MeV Ag + ions irradiated PC was studied by Bahniwal et al [10] and pointed out the formation of carbonaceous graphite-like layer containing a network of graphite clusters. Navarro et al [11] showed that PC irradiation was accompanied with the preferential release of carbon monoxide followed by minor production of hydrogen, carbon dioxide and methane.…”