Tuning the physico-chemical and structural properties of cellulose acetate films by gamma radiation

The effects of gamma irradiation on the optical, photoluminescence, and compositional structural properties of cellulose acetate (CA) films are investigated. Here, gamma dosages of 0, 60, 120, 180, 240, and 300 kGy were used to irradiate CA films. The structure, chemical functional groups, surface roughness parameters, and photophysical properties were all examined using FTIR spectroscopy, X-ray diffraction, a surface roughness tester, ultraviolet–visible spectroscopy, and fluorescence spectroscopy. After irradiation, FTIR showed no new absorbance band was observed, suggesting that the irradiation had not created any new chemical bonds or functional groups. The FTIR band intensities show that both crosslinking and degradation occur, with chain scission being the most common mechanism associated with radiation dosage. A decreasing in the band intensity of C-H bond was observed due to the scissioning of the carbonate linkage and withdrawal of the hydrogen atom from the backbone chain of irradiation films that is leading to the production of a hydroxide group. XRD patterns display that notable rise in peak intensities was noted as the irradiation dose increased due to degradation in the irradiated samples, referring to an increase in crystallinity. According to surface parameters measurements, the surface amendment is attributable to the formation of an oxidized layer on the irradiated surface. The absorption edge shifts to a higher wavelength region as gamma dose increases, according to the UV/Vis data. The direct energy gap of pure sample decreased from 4.22 eV to 4.11 eV and the indirect energy gap decreases from 4.07 eV for the pure sample to 3.80 eV when the CA was exposed to 300 kGy doses. The refractive index increases from 1.7977 of pristine sample to 2.0980 at the highest dose. The nonlinear optical parameters were influenced by gamma rays, which indicate that the cellulose acetate films may be used nonlinear optical systems. As gamma dosages have risen, increasing the photoluminescence intensity due flaws have been created in irradiated CA samples. These results show that irradiated cellulose acetate films have improved optical and structural characteristics that make them fit for use as a film foundation in photography, as retardation films in displays, and even in the production of luminous materials for sensors.