Physical Chemical Investigation of Gamma-Irradiated Parchment for Preservation of Cultural Heritage.

The historical artefacts of parchment are prone to degradation if the storage conditions are improper due to the collagen structure having a limited stability under physical, chemical, and biological agent attacks. The parchment structure is difficult to characterize due to the variety of manufacturing traditions (eastern/western), intrinsic variability of skins (i.e., species, breeding variation, living conditions, effects of pathologies, etc.), biodeterioration, and aging, and the main concern in its analysis is its uniformity. The deterioration of parchment collagen produces a rather stiff or in some circumstances, a relaxed structure. Any intervention or treatment of unique, very precious cultural heritage artefacts must not negatively influence the properties of the component materials. Gamma irradiation is a relatively new technique of bioremediation. Data on the leather properties pre- and post-ionizing radiation bioremediation treatments are few in the literature. Fewer data are available on the historical leather and parchment physical chemical characteristics after ionizing gamma irradiation. This research had two main objectives: (i) the characterization of the parchment structure's uniformity across the analyzed areas and its mechanical properties, i.e., tensile stress by mechanical tests and ATR-FTIR spectroscopy; and (ii) to establish parchment tolerance when exposed to ionizing gamma radiation as a pre-requisite for cultural heritage preservation irradiation treatment. It was found that the mechanical tests and ATR-FTIR spectroscopy may identify changes in the parchment's irradiated structure and that the preservation of cultural heritage parchment artefacts may be performed at maximum 15 kGy gamma irradiation dose.

Gamma Irradiation and Ag and ZnO Nanoparticles Combined Treatment of Cotton Textile Materials.

In this work, cotton textile materials were impregnated by immersion with three different nanocomposites: Ag/chitosan, Ag/polyvinylpyrrolidone, and ZnO/polyvinylpyrrolidone and irradiated with a 60Co gamma source. After the nanoparticles impregnation, the cotton materials were irradiated in a dry and wet state at 5 and 20 kGy radiation doses. The following methods were used for the characterization of the obtained cotton materials to reveal the modification of the textile materials: Fourier transform infrared-attenuated total reflection spectroscopy (FTIR-ATR) and thermogravimetry (TG). The obtained materials have good antibacterial properties. The microbiological tests have shown the best material results for the gamma irradition and Ag nanoparticles combined treatment. The objective was to create a more environmentally friendly approach for textile functionalization by eliminating toxic chemicals-based technology and replacing it with the eco-friendlier gamma technology.

Thermal desorption/gas chromatography/mass spectrometry approach for characterization of the volatile fraction from amber specimens: a possibility of tracking geological origins.

Research on the chemical composition of fossil resins has evolved during the last decades as a multidisciplinary field and is strongly oriented toward the correlation with their geological and botanical origin. Various extraction procedures and chromatographic techniques have been used together for identifying the volatile compounds contained in the fossil resin matrix. Hyphenation between thermal desorption (TD), gas chromatography (GC) and mass spectrometry detection (MS) has been chosen to investigate the volatile compounds fraction from ambers with a focus on Romanite (Romanian amber) and Baltic amber species. A data analysis procedure was developed for the main purpose of fingerprinting ambers based on the MS identity of the peaks generated by the volatile fraction, together with their relative percentual area within the chromatogram. Chromatographic data analysis was based entirely on Automated Mass Spectral Deconvolution &Identification System (AMDIS) software to produce deconvoluted mass spectra which were used to build-up a mixed mass spectra and relative retention scale library. Multivariate data analysis was further applied on AMDIS results with successful discrimination between Romanite and Baltic ambers. A special trial was conducted to generate pyrolysis "like" macromolecular structure breakdown to volatile compounds by gamma irradiation with a high absorbed dose of 500 kGy. Contrary to our expectations the volatile fraction fingerprints were not modified after irradiation experiments. A complementary non-destructive new approach by ESR spectroscopy was also proposed for discriminating between Romanite and Baltic ambers.