This paper presents a review on the functionalization methods of leather materials using gamma radiation. There are few studies regarding the effects of gamma irradiation on leather materials while the majority of studies are on the irradiation of collagen for medical purposes, decontamination and preservation of heritage leather objects and parchment documents. Recent studies on leather and parchment treated with bigger doses then the sterilization or decontamination doses and on gamma irradiated collagen, new information about the solubility of collagen, crystalline structure, shrinkage temperature and mechanical properties were obtained. The relation between the shrinkage temperature and the gamma radiation dose absorbed by the material were investigated with the MHT (Micro Hot Table) method. Evidences of cross-linking of the collagen were found at doses up to 25 kGy while for doses of 50 kGy and more the principal process was the scission of the peptide chains. The mechanical properties of tanned leather and parchment such as tensile strength and elongation at break were studied. The parchment tensile strength decreases with the increase of absorbed dose, for doses bigger than 10 kGy. The behaviour of tanned leather is different, an increase in the tensile strength at doses up to 25 kGy which can be a threshold for collagen cross-linking. More evidence of cross-linking of the collagen fibrils in leather materials were shown with the SEM-EDX and TG investigations. There were no substantial modifications in the structure of collagen for doses of 5, 10 and 15 kGy as shown by the SEM and TG analysis, but a slightly smaller loss of mass in the case of the dose of 25 kGy which can prove the cross-linking of collagen in the tanned leather material. Based on literature review a conceptual application model for gamma irradiation on leather materials was elaborated.

This work focuses on the synthesis of multiple studies made on the investigation of gamma irradiation effects on textiles. Gamma radiation is used in the research for improved dyeing or to change the mechanical properties of textile and in some cases to reduce the ecological impact of the processing methods. One study researches the effects of gamma irradiation on specific composites such as silk with polypropylene and E-Glass with polypropylene and the changes of their mechanical properties, showing that the mechanical properties of the silk composite increase more compared to the E-Glass composite. The application of gamma irradiation in the process of dying polyester textiles can be used to reduce the dyeing temperature. Studies were made even on the effect of gamma irradiation only on dyes and the possibility that it can reduce wastewater production, resulting in the fact that gamma irradiation can result in the degradation and discoloration of dyes in water depending on the dose and dye used. In one study it was researched if gamma preirradiation can affect the growth of microorganism on the textiles for three different fibers. One study was made on reinforcement of synthetic fibers and compared the effect of ebeam radiation and gamma radiation. It resulted that the effects are similar while gamma radiation affects the mechanical properties more than e-beam.The synthesis of the literature review has lead to the development of a conceptual application model for gamma irradiation in the field of textiles.