The use of small-angle X-ray scattering (SAXS) and synchrotron-IR (SR-IR) was examined in conjunction with multivariate data analysis to study degradation of an extended set of historic parchment samples. In the data analysis, shrinkage temperature, lipid content, sample age, presence of ink and accelerated degradation were included. The analysis of loading factors in partial least-squares regression and principal component analyses based on SAXS, SR-IR and other analytical and descriptive data reveals the effect of lipid removal on diffraction patterns, and lipids are found to cause the degradation process in parchment to accelerate. The effect of iron gall ink is also evident, although the mechanism of ageing is different to that of natural ageing in the absence of ink.
COBISS.SI-ID: 35750405
Electrocatalytic films of mixed (substitutional) nickel–iron hexacyanoferrate with the Ni/Fe molar ratio up to 0.13 were prepared by incorporation of Ni2+ ions into the structure of electrochemically deposited thin Prussian blue films. The obtained films retained the high electrocatalytic activity inherent to Prussian blue and were stable towards degradation in alkaline media up to pH 9.3, enabling the sensing of H2O2 in the range between 5 × 10−8 to 2 × 10−4 mol/dm3 at pH 9.0. Based on the results of electrochemical, XPS, and SEM investigations, the stability of mixed nickel–iron hexacyanoferrate films at pH 9.0 was attributed to the hydrolysis-induced lattice transformation occurring at the film/solution interface and resulting in the formation of a thin and compact layer of an alkaline-stable nickel hexacyanoferrate.
COBISS.SI-ID: 26051111
Terahertz (THz) time-domain spectroscopy and 3D THz pulsed imaging have been explored with regard to polymer materials, both commodity and historic polymers. A systematic spectroscopic study of a wide range of different polymer materials showed significant differences in their spectra. It was also examined how the presence of plasticisers in poly(vinyl chloride), the presence of fillers in polypropylene, and the degree of branching in polyethylene and polystyrene affect the spectra; inorganic fillers in polypropylene affected the absorption most. Terahertz spectroscopy is thus shown to have significant potential for both chemical and structural characterisation of polymers, which will be of interest to heritage science, but also to the polymer industry and development of analytical technologies in general.
COBISS.SI-ID: 35930373