Effects of ionizing radiation on the color and morphology properties of leather

Leather has been present material for various applications throughout human history, valued for its versatility with unique properties. Leather is the result of processing skin through stages of cleaning, stabilization-tanning, and finishing, generating a stable and non-decomposable material [1] utilized in both industrial uses and the creation of cultural heritage artifacts. Preservation of cultural collections is essential [2] and requires a multifaceted approach, including risk assessment, conservation, and restoration, all guided by systematic strategies and common concepts, but with a priority on regional aspects [3]. The preservation of leather artifacts remains a significant challenge due to the susceptibility to biological degradation agents and risks of traditional methods. Each type of leather is made up of a group of related products with common characteristics, but varying in their properties and reaction to conservation treatments [4]. Brazil's predominantly tropical climate enhances infestation and biological infection. Consequently, cultural heritage artifacts containing leather in their composition are primarily threatened by humidity and biological factors. In this context, ionizing radiation has emerged as a technique utilized since the 1970s as an efficient alternative for treating biological degradation. Its increasing application in scientific and museum collections underscores its viability as a non-toxic and advantageous option compared to traditional conservation methods. [5][6]. This study investigates the application of ionizing radiation as a preservation technique for bovine and snake leather samples with preliminary results of the effects on color and morphology properties of leather samples, two of the main characteristics of leather. Gamma radiation was applied to the samples at doses of 1 kGy and 3 kGy, which are minimum doses to establish the beginning of primary and secondary effects evaluation. Colorimetry using the CIELAB color space was utilized to objectively measure color differences and quantify color characteristics. Additionally, scanning electron microscopy (SEM) was used to investigate potential morphological alterations, especially on the surface and internal fiber structures. (author)