Dyes and biological sources in nineteenth to twentieth century ethnographic textiles from Transylvania, Romania

Abstract Liquid chromatography with UV–Vis and mass spectrometric detection (LC–DAD–MS) was applied to the identification of dyes and biological sources in samples from nineteenth to twentieth century ethnographic textiles from ASTRA National Museum Complex, Sibiu, Transylvania. The objects are part of the Romanian traditional costume and are among the first to be acquired for the museum collections, around 1905. Oral and written information mention such objects as homemade, with nearby materials, while literature mentions a significant number of local vegetal sources as being used for textile dyeing. The analytical protocol developed, based on the combined use of the UV–Vis and mass spectrometric detectors to associate the information and distinguish between major and minor dyes, facilitates a clear attribution of the dyes and biological source/sources used. Other techniques, such as X-ray spectroscopy and FTIR-ATR were successfully used to identify inorganic dyes, which may not be detected by LC–DAD–MS, as was the case of Prussian blue. A large number of biological sources was identified in the studied objects, both local and imported. The local sources identified include dyer’s broom (Genista tinctoria L.), sawwort (Serratula tinctoria L.), young fustic (Cotinus coggygria Scop.), Rhamnus berries, emodin based dyes (Rhamnus, Rheum, Rumex sp.) and woad (Isatis tinctoria L.), in perfect correlation with literature which states that local dyes were still in use in the period under discussion. Carminic acid containing insects (Dactylopius coccus Costa and Porphyrophora sp.) and redwood type Caesalpinia species should be considered a result of trade. Almost all the natural and synthetic dyes detected are frequently mentioned in a collection of recipes published by the Romanian Academy, in 1914. The richness in colours in belts, the use of insect dyes in shirts decoration and the large amount of cotton in shirts are illustrative for the owners’ status. The study provides a better valorisation of the Romanian traditional costume as witness of the rural society at the end of the nineteenth to beginning of the twentieth century and emphasizes the usefulness of chemistry in cultural heritage dedicated applications

Luminescence, Paramagnetic, and Electrochemical Properties of Copper Oxides-Decorated TiO₂/Graphene Oxide Nanocomposites

The properties of newly synthesized Cu2O/CuO-decorated TiO2/graphene oxide (GO) nanocomposites (NC) were analyzed aiming to obtain insight into their photocatalytic behavior and their various applications, including water remediation, self-cleaning surfaces, antibacterial materials, and electrochemical sensors. The physico-chemical methods of research were photoluminescence (PL), electron paramagnetic resonance (EPR) spectroscopy, cyclic voltammetry (CV), and differential pulse voltammetry (DPV). The solid samples evidenced an EPR signal that can be attributed to the oxygen-vacancy defects and copper ions in correlation with PL results. Free radicals generated before and after UV-Vis irradiation of powders and aqueous dispersions of Cu2O/CuO-decorated TiO2/GO nanocomposites were studied by EPR spectroscopy using two spin traps, DMPO (5,5-dimethyl-1-pyrroline-N-oxide) and CPH (1-hydroxy-3-carboxy-2,2,5,5-tetramethylpyrrolidine), to highlight the formation of hydroxyl and superoxide reactive oxygen species, respectively. The electrochemical characterization of the NC modified carbon-paste electrodes (CPE) was carried out by CV and DPV. As such, modified carbon-paste electrodes were prepared by mixing carbon paste with copper oxides-decorated TiO2/GO nanocomposites. We have shown that GO reduces the recombination process in TiO2 by immediate electron transfer from excited TiO2 to GO sheets. The results suggest that differences in the PL, respectively, EPR data and electrochemical behavior, are due to the different copper oxides and GO content, presenting new perspectives of materials functionalization

Preliminary results on the measurement of plutonium isotopic ratios at the 1MV AMS facility in IFIN-HH

The range of radioisotopes measured at the Accelerator Mass Spectrometry (AMS) facility based on the 1MV TandetronTM of IFIN-HH has been extended to actinides. The paper presents the preliminary results obtained for measuring the isotopic ratios of 239Pu / 242Pu and 240Pu / 242Pu using a secondary standard prepared at CNA Seville.Peer reviewe