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In this paper, a comparative study was conducted on the extraction effects of six agents for collagen-based mural painting binders. These agents were used to extract the residual proteins in the non-aged and thermal aged samples. The protein extraction efficiencies of different extracting agents were quantitatively determined by bicinchoninic acid (BCA) method, and then processed by multivariate analysis of variance (MANOVA). The impact of the extraction process on the protein structure was characterized by sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE), ultraviolet absorption spectrum (UV) and circular dichroism (CD). The results showed that, for both non-aged and aged samples, the extraction efficiency of 2 M guanidine hydrochloride (GuHCl) was significantly higher than the other five agents, with less damage to the protein structure during the extraction process.

Three gilded samples collected from the ancient lacquered wooden coffins excavated in Yangqu County, Shanxi Province were analyzed by scientific techniques including digital microscopy, SEM-EDS, XRD, FTIR and ICP-MS. Two kinds of lacquering craft, “painting in gold” and “painting lacquer above the gold” were discovered while “Jin Jiao” (considered as mixtion) is identified for joining the metal layer to the preparation layer. The craft “pasting the fabric to the wood by lacquer” was found, improving the wooden body's stability and mechanical strength. The results show that apart from the broken porcelain, ground shell was also added into the stucco in ground layer. The metal layer above the lacquer film is composed of gold-silver-copper alloy with different proportions. The coffins are suffering from severe degradation and effective conservation measures should be taken as soon as possible. Our study revealed the Chinese traditional lacquering and gilding techniques employed in wooden coffins, and provided support for scientific protection and restoration schemes.

In order to accurately identify the ancient liquid contained in the plum vase excavated from Jurou Li’s Grave of the Jin Dynasty (1115–1234 CE) in Xi’an, mass spectrometry was applied to determine the amino acid sequences of the residual proteins extracted from the liquid sample. The sequences were searched against a standard protein sequence database. The proteins extracted was identified as glycosyltransferase from Sorghum bicolor, calcium-dependent protein kinase 2 from Wickerhamomyces ciferrii, and cytochrome b-c1 complex subunit Rieske from Nadsonia fulvescens. These findings indicate that the extremely degraded liquid in the plum vase was made from the cereal of sorghum by alcoholic fermentation of Wickerhamomyces ciferrii and Nadsonia fulvescens, providing direct evidence for liquor in the Jin Dynasty.

This article reviews cultural materials conservation in China from its foundations in the early 1950s when traditional craftsmanship and workshop techniques were practised, through its growth in the 1980s to the present day as a prestigious profession at the leading edge of multidisciplinary science. Its historical evolution is delineated into four phases: traditional, post-revolution, post-1980 and contemporary cultural materials conservation. The current situation of the conservation profession in China is discussed in terms of regulation, organisation, education, cooperation, current challenges and future opportunities.

It is widely accepted experience among archaeologists that the mechanical properties of waterlogged historic silk artifacts will be improved to some extent after the gradual evaporation of water. For the purpose of understanding the micro-mechanism of this interesting phenomenon, near-infrared spectroscopy was applied to study the microstructure of historic silk fibers before and after the transition from a water-saturated to dry state. It is demonstrated that the interaction of water with silk varies significantly depending on the condition of the material. The change of moisture content can induce rearrangement of hydrogen bonds and conformation transition in silk fibers, thus altering their mechanical properties. Our results vindicate the practical observation that by exploiting the dehydration effects, fragile water-saturated silk artifacts in archaeological sites can successfully be extracted and transported to conservation laboratories with reduced risk of damage.

Cellulose acetate (CA) was widely used by the film industry as well as by artists to create fine and decorative art. CA films plasticized with different content of diethyl phthalate (DEP) and triphenyl phosphate (TPP) were aged in different conditions for the study of the degradation markers and the plasticizer loss by means of optical microscope (OM), scanning electron microscope (SEM), X-ray diffusion (XRD), Gel Permeation Chromatography (GPC), Fourier-transform Infrared Spectroscopy (FTIR), Thermogravimetric Analysis (TG) and Thermogravimetric Analysis combined with Fourier-transform Infrared Spectroscopy (TG-FTIR). Degradation markers, such as changing of appearance, decreasing of molecular weight and changing of crystallinity were observed in ageing samples. At the same time, plasticizer loss of ageing samples appeared but differs among different ageing condition. In perspective, this systematic approach can be extended to the study of CA artefacts and other degradation conditions that would affect the deterioration pathways.

Unlike the traditional methods of silk restoration based on the application of synthetic polymers, transglutaminase-mediated polymerization was used as a compatible and innocuous method to reinforce the aged silk fabrics. Artificially aged (dry thermal ageing) silk samples were restored using this method. The optimal experimental conditions of the treatment were determined by orthogonal experiment. The effects of the reaction on silk fibers were investigated by tensile tests, TGA and SDS-PAGE. The results showed that tensile strength, elongation rate at breakage and thermal stability of the silk samples were remarkably improved by using this method. Biopolymers with a molecular weight of more than 260 kDa were formed in the reaction. From the results of this study, the potential of transglutaminase-mediated polymerization to restore historic silk was demonstrated.

In order to identify the fibre material of the pall imprint excavated from the Peng-state cemetery in Shanxi, biomass spectrometry was applied to determine the amino acid sequences of the residual protein extracted from the soil underneath the imprint. The sequences were searched against a standard protein sequence database. A well-preserved silk pall sample from the Warring States Period was used as a comparative template. The protein extracted is identified as silk fibroin (Bombyx mori). This finding indicates that the extremely degraded pall was made of silk and that the deceased in the Peng-state cemetery enjoyed high social status. In this way, a novel methodology, which is very promising in uncovering the origin of silk, could be initiated.

(1)H NMR cryoporometry and solid-state (13)C cross-polarization (CP) magic-angle spinning (MAS) NMR spectroscopy were used to characterize the microstructure of historic and fresh silk samples. Silk is a polymeric bicomponent material composed of fibroin and water located in micropores. According to the (1)H NMR cryoporometry method, the intensity of the water resonance as a function of the temperature was used to obtain the pore size distribution, which was strongly asymmetric with a well-defined maximum at 1.1 nm. Compared with the fresh silk samples, the volume of pores around 1.1 nm decreased distinctly in the historic silk, and more pores larger than 2 nm emerged accordingly. In addition, these results correlated well with solid-state (13)C CP/MAS NMR spectroscopy as the percentage of random coil in the historic silk sample was much less than that in the fresh silk samples. Therefore, it is suggested that the water-filled microvoids grow larger as the random coil conformation fades away in the degradation process.