944 research outputs found

    From the bottom of the sea to the display case: A study into the long-term preservation of archaeological maritime silk textiles in controlled atmosphere

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    An exceptional group of silk fragments was unearthed in 2014 from a shipwreck, which sank in the mid-17th century, in the Wadden Sea, The Netherlands. A unique example of 17th-century fashion, it comprises about 300 textile fragments from garments, parts of garments and furnishing fabrics, almost entirely made of silk and embroidered or woven with metal thread. These are in remarkably good condition, which may be related to the archaeological environment, the quality of the silk yarns in the fragments, and the presence of metal threads and other metallic objects from the shipwreck. Surviving archaeological maritime silk textiles are extremely rare, which makes this a distinctive find posing challenges for selecting the most suitable conditions for exhibition and storage. Scientific research was carried out with the aim to evaluate the response of modern and archaeological silks to temperature, relative humidity, light and oxygen, in order to define the most suitable parameters for the long-term storage and exhibition of the collection. Artificially aged samples taken from one of the archaeological fragments were analysed at the visual, structural and molecular level by means of colour measurements, Fourier transform infrared spectroscopy (FTIR) and ultra-high performance liquid chromatography coupled to a fluorescence detector (UHPLC-FLD). The results showed that light exposure, in combination with high temperatures, oxygen and moisture strongly affected the silk's structure and molecular composition. Limiting exposure to light and removing oxygen reduced this effect and increased life expectancy significantly. Therefore, the analytical results obtained were essential to defining a preliminary preservation strategy for the collection: while on display, anoxic conditions slow down degradation of the silk by a factor of 4–5, whereas in a in dark storage, a low RH is the most important factor, with anoxic conditions providing additional reduction of decay

    Protecting Substrates from Enzymatic Cleavage:Hydrogels of Low Molecular Weight Gelators Do The Trick

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    An enzymatically cleavable low molecular weight gelator (LMWG)-drug conjugate is described that is capable of gelating water at concentrations as low as 0.45 mM (=0.03 wt.%). By comparing the enzymatic cleavage kinetics of the LMWG-drug conjugate with those of a nongelating substrate, it was shown that although the enzyme (α-chymotrypsin) is still functional in the gel, molecules present within the gel fibers are protected from enzymatic cleavage

    Comparing different light-degradation approaches for the degradation of crystal violet and eosin Y

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    Organic colourants have important applications in many fields. Their photostability is an important characteristic. Several methods to study photodegradation were compared in this work. Eosin Y (C.I. Generic name: Acid Red 87, EY) and crystal violet (C.I. Generic Name: Basic Violet 3, CV) were used as test compounds, both in solution and dyed on silk. Commonly applied methods were included, viz. Xenotest, Microfading-Tester, and light-box (Spectrolinker) experiments. A novel method was based on a liquid-core-waveguide (LCW) cell. After photodegradation on textile, extraction was performed using dimethyl sulfoxide (DMSO). The degraded solutions and extracts were analysed with liquid chromatography combined with diode-array detection and mass spectrometry. The degradation products were compared between techniques. Degradation in the LCW cell progressed much faster than in standard tests (Xenotest and Spectrolinker) and could be performed online, without a need for extraction or sample transfer. The degradation of CV in the LCW was comparable to its degradation in standard tests. For EY, there was a clear difference in degradation mechanisms between in-solution and on-textile samples. This could be due to the matrix or to incomplete extraction. Because the light sources used in the different experiments differed in energy and spectral emission, the results could not be quantitatively compared. However, the degradation products formed were shown to be independent of the light source. Therefore, the LCW is an attractive method for rapid and efficient studies into the chemistry of photodegradation
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