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Here, we propose a sensing scheme based on an all-dielectric metamaterial with the smooth reflection and transmission spectral lines in 10-60THz, and verify the applications of the measuring the resonance characteristics of Xuan paper samples. The reflection and thermal conductivity of Xuan paper samples enhance with the concentration of alum water increasing and weaken due to the thickness increasing. These results provide a solid foundation for this metamaterials in measuring the reflective and thermal resonance properties of Xuan paper samples. [ABSTRACT FROM AUTHOR]

Abstract In the process of conservation mounting, starch paste made from wheat flour is the glue of choice to paste reinforcing strips and backing papers, often Xuan paper, for mending and decorating aged and damaged paper-based Chinese artworks. To keep objects intact and select appropriate conservation materials, this research explored the applicability of near-infrared (NIR) spectroscopy coupled with multivariate analysis for the characterization of contemporary unsized Xuan paper with and without starch. In particular, partial least squares (PLS) regression was used to predict the degree of polymerization (DP) of the paper, i.e., one of the most important properties of paper materials, and principal component analysis (PCA) was used to detect starch and to distinguish between papers with different amounts of starch. Using 12 contemporary unsized Xuan papers, the NIR-PLS method for DP prediction was validated, and the best-performed model was generated using the logarithmic transformation of DP−1 as a response variable, with root mean square error of prediction (RMSEP) of DP 128. The NIR-PCA method was also found to be applicable to separate starch-free papers and papers treated with starch, and the results indicate that the higher the content of starch, the better PCA classification performs. This research provides supporting data for the non-destructive characterization of Xuan paper-based objects and differentiates between Xuan paper before and after treatment with starch.

In the process of conservation mounting, starch paste made from wheat flour is the glue of choice to paste reinforcing strips and backing papers, often Xuan paper, for mending and decorating aged and damaged paper-based Chinese artworks. To keep objects intact and select appropriate conservation materials, this research explored the applicability of near-infrared (NIR) spectroscopy coupled with multivariate analysis for the characterization of contemporary unsized Xuan paper with and without starch. In particular, partial least squares (PLS) regression was used to predict the degree of polymerization (DP) of the paper, i.e., one of the most important properties of paper materials, and principal component analysis (PCA) was used to detect starch and to distinguish between papers with different amounts of starch. Using 12 contemporary unsized Xuan papers, the NIR-PLS method for DP prediction was validated, and the best-performed model was generated using the logarithmic transformation of DP−1 as a response variable, with root mean square error of prediction (RMSEP) of DP 128. The NIR-PCA method was also found to be applicable to separate starch-free papers and papers treated with starch, and the results indicate that the higher the content of starch, the better PCA classification performs. This research provides supporting data for the non-destructive characterization of Xuan paper-based objects and differentiates between Xuan paper before and after treatment with starch. [ABSTRACT FROM AUTHOR]

Copyright of China Pulp & Paper is the property of China Pulp & Paper Magazines Publisher and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Xuan paper is one of the most famous handmade papers in China and is an important paper for conservation. However, the evenness of Xuan paper has not yet received much attention. In this study, the distribution of the in-plane grammage and mechanical properties of Xuan paper are measured. It is found that the distribution of the in-plane grammage and mechanical properties of Xuan paper is uneven. In the handmade direction, the grammage and mechanical properties of Xuan paper are overall largest in the lower area, followed by the upper and middle areas. The sheet forming process of Xuan paper has an important effect on the distribution of in-plane grammage, mechanical properties, and fiber orientation of Xuan paper. The folded state has a negative effect on the mechanical properties of the folded area of Xuan paper. This study will help raise awareness of the unevenness in physical properties of Xuan paper, which is important in both conservation and research applications. [ABSTRACT FROM AUTHOR]

• KAl(SO 4) 2 ·12H 2 O and gelatin in the alum-glue solution play devastating and relatively beneficial roles in paper durability respectively. • A 23 full factorial experiment was performed to explore the effects of KAl(SO 4) 2 ·12H 2 O (denoted as alum), gelatin (denoted as glue), and water contents on rates of paper degradation and color changes, by measuring rates of changes in DP [ k Δ(1/DP)], lightness and b* (k ΔL and k Δb) respectively. • Alum is mainly responsible for lightness decrease of the treated papers,. • Glue content (gelatin) plays a primary role in paper yellowing. In the traditional Chinese conservation mounting process, it is well acknowledged that the alum-glue solution, composed of potassium aluminum sulfate [KAl(SO 4) 2 ·12H 2 O], gelatin, and water, is commonly used for paper sizing. In this study, its adverse effects when prepared in different ratios on the contemporary Xuan paper are explored, demonstrating certain negative influences on material properties and paper durability. We primarily characterized an extra-pure Xuan paper as a reference sample. Then, a 23 full factorial experiment was designed and performed to explore the effects of the three factors, i.e., KAl(SO 4) 2 ·12H 2 O (denoted as alum), animal glue or gelatin (denoted as glue), and water contents on rates of paper degradation [ k Δ(1/DP)] and color changes (k ΔL and k Δb). The results show that the unsized extra-pure Xuan paper sample has good stability due to appreciable alkaline reserve, weakly alkalinity, and no presence of transition metals. Fourier transform infrared (FTIR) spectra and scanning electron microscope (SEM) images demonstrate the presence of sizing. Given that the alum-glue solution has been widely used in paper conservation, the results in this study demonstrate the devastating role of KAl(SO 4) 2 ·12H 2 O and the protective effects of gelatin on durability of treated papers, verified by the DP-related data. Additionally, it was found that the presence of alum is mainly responsible for the lightness decrease of the treated papers, and animal glue plays a primary role in paper yellowing. The findings in this research can deepen our understanding of the rate of paper degradation and color changes for the Xuan paper treated with the alum-glue solution. [ABSTRACT FROM AUTHOR]

Invaluable paper relics that embody a rich traditional culture have suffered damage, requiring urgent restoration. In this context, the utilization of soymilk as a sizing agent holds great significance and reverence. This study investigates the use of soymilk as a sizing agent for Xuan paper and evaluates its effects on various properties and the long-term behavior of the paper. The findings reveal that the application of soymilk as a sizing agent for Xuan paper imparts distinct properties, including hydrophobicity, improved mechanical properties, and unique chromaticity. These characteristics—arising from the papillae on the surface of the Xuan paper, the protein folding of the soy protein, and hydrogen-bonding interactions between the soy protein and paper fibers—play a crucial role in shaping the paper's unique attributes. From a physicochemical perspective, the aging process leads to multiple changes in paper properties. These changes include acidification, which refers to a decrease in pH, as well as a decline in mechanical strength, an increase in chromaticity, and a decrease in the degree of polymerization (DP) of the paper. The Ekenstam equation is employed to predict the lifespan of the paper, showing longer lifespans for Sheng Xuan paper and a negative correlation between soymilk concentration and lifespan in soymilk-sized paper. Our work provides valuable insights for the preservation and maintenance of paper, highlighting the potential benefits and challenges of using soymilk for surface sizing. [ABSTRACT FROM AUTHOR]

Up to now, it is always a delicate and challenging task to clean and protect Xuan paper ink painting. Xuan paper is composed of cellulose with a rough surface and easy to absorb dust, which leads to poor cleaning effect and irreversible damage in traditional cleaning process. Hydrogel is one of the most effective tools to clean the artworks. However, in the practice of cleaning Xuan paper, most hydrogels cannot achieve fine cleaning result due to the interfacial adhesion issues. Herein, to protectively and effectively clean Xuan paper, using physical yet strong poly(vinyl alcohol)/poly(N-(2-hydroxyethyl) acrylamide) (PVA/PHEAA) hydrogel with suitable stiffness as the model, the interfacial adhesion between hydrogel and Xuan paper was systematically investigated, and various technologies were used to evaluate the cleaning effect. A critical interfacial adhesive energy (< 4 J/m2) is found to achieve the protective and effective cleaning purpose. To the best of our knowledge, this is the first report to estimate the adhesion of hydrogel on the cleaning of paper artwork, which will provide a new viewport in the conservation practice. [ABSTRACT FROM AUTHOR]

Based on the actual processing of Xuan paper surface sizing, we used bone glue solution with mass fractions of 0.5–2.5% to apply manual drag-dye surface sizing. Organic elemental analysis, scanning electron microscopy, surface pH determination, water contact angle measurement, dynamic vapour sorption, and thermogravimetric analysis were used to characterize the bone glue content, surface properties and thermal stability of the sized Xuan paper. Different bone glue concentrations were retained uniformly and effectively on Xuan paper. The surface morphology of Xuan paper changed significantly after sizing due to the bone glue coating on the fibres and the fibre network. With an increase in sizing concentration from 1.0 to 1.5%, the hydrophobicity of the sizing Xuan paper's surface increased considerably. The weak acidity of bone glue solution lowered Xuan paper's surface pH. Increasing bone glue concentration can boost Xuan paper's saturation moisture absorption. When bone glue concentration was over 1.0%, sized Xuan paper's moisture absorption rate increased, while sized Xuan paper with a concentration below 1.0% showed a slight inhibition of moisture absorption within a certain humidity range. The sized Xuan paper with a concentration of 1.0% had a more stable and slower hygroscopic reaction in the absorption–desorption cycle. As bone glue concentration increased, Xuan paper's initial moisture content decreased and then increased, with the lowest value for sized Xuan paper at 1.0% concentration. The sized Xuan paper with a concentration of 1.0% bone glue showed the best thermal stability. Surface sizing should have little effect on Xuan paper's calcium carbonate content, but bone glue complicated its thermal behaviour. [ABSTRACT FROM AUTHOR]

Copyright of Chemistry & Industry of Forest Products is the property of Chemistry & Industry of Forest Products Editorial Department and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The development of bio-based flame retardants has received increasing attention. In this study, fully bio-based chitosan/sodium alginate (CS/SA) coating was applied by layer-by-layer (LbL) assembly on Xuan paper to improve its flame retardancy. The LOI value of Xuan paper reached 33.3% after 20 BLs CS/SA coating. Its char length was reduced to 8.8 cm with no after-flame and after-glow. These results showed that the flame retardancy of Xuan paper was greatly improved by LbL assembly CS/SA coating. Thermogravimetry results revealed that CS/SA coating on Xuan paper slowed down the thermal degradation process and promoted the char formation both under nitrogen and air atmosphere. The stable char layer formation by CS/SA coating covered on the Xuan paper inhibited the heat transfer and diffusion of combustible gases, showing obvious condensed phase flame retardant action. Scanning electron microscopy confirmed that CS/SA coating on paper fiber promoted the char formation to form the stable covering layer. Furthermore, the CS/SA coating formed non-flammable gases to enhance the flame retardancy of Xuan paper, showing a certain gas phase flame retardant action. This research provides a new approach for fire-resistant Xuan paper by using fully bio-based compounds.

Spatially resolved fluid-flow modulation and its corresponding integration becomes a crucial aspect to consider when designing high-performing paper-based analytical devices. As such, high demand exists for cost-effective techniques able to selectively control flow in patternable regions of the device. In this regard, a solution composed of potassium alum and animal glue; sizing materials used in the fabrication of calligraphy Xuan paper, is successfully adapted for the first time in a revolutionary approach to efficiently modulate the capillary flow in paper microfluidic channels. Flow delays are achieved by coating the substrate systematically through the variation of parameters such as the ratio of alum to glue, the concentration of alum-glue in the solution, and the number of subsequent coating layers of alum-glue. Moreover, digitized patterning with alum-glue is developed to achieve programmable wicking profiles of accelerating, decelerating, and quasi-linear flow displacement by alternating coated and uncoated zones in the channel. Additionally, the influence of alum-glue when performing biometric assays is investigated by performing a horseradish peroxidase activity colorimetric assay and found to have negligible effects on reading, where a negligible difference of 5.2% was observed in an assay performed in a coated paper substrate, compared to an uncoated one.

Creases and folds in Chinese paintings and calligraphies scrolls are hard to avoid during the handling in storage and exhibitions. The creases are usually reinforced with paper strips in the conservation treatment. However, adhering the paper strips will create unwanted secondary creases along the joining edge on the painting scrolls after repeated openings and rolling. This study proposes a new consolidant, bacteria cellulose (BC), for the conservation of creased Chinese painting scrolls. Different tests were carried out and the results showed that BC was a better approach than the traditional paper strip reinforcement method. The method not only had an excellent effect on conserving the creased artwork on Xuan-paper aesthetically, but also improved its physical properties. [ABSTRACT FROM AUTHOR]

Copyright of China Pulp & Paper is the property of China Pulp & Paper Magazines Publisher and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Invaluable paper relics that embody a rich traditional culture have suffered damage, requiring urgent restoration. In this context, the utilization of soymilk as a sizing agent holds great significance and reverence. This study investigates the use of soymilk as a sizing agent for Xuan paper and evaluates its effects on various properties and the long-term behavior of the paper. The findings reveal that the application of soymilk as a sizing agent for Xuan paper imparts distinct properties, including hydrophobicity, improved mechanical properties, and unique chromaticity. These characteristics—arising from the papillae on the surface of the Xuan paper, the protein folding of the soy protein, and hydrogen-bonding interactions between the soy protein and paper fibers—play a crucial role in shaping the paper’s unique attributes. From a physicochemical perspective, the aging process leads to multiple changes in paper properties. These changes include acidification, which refers to a decrease in pH, as well as a decline in mechanical strength, an increase in chromaticity, and a decrease in the degree of polymerization (DP) of the paper. The Ekenstam equation is employed to predict the lifespan of the paper, showing longer lifespans for Sheng Xuan paper and a negative correlation between soymilk concentration and lifespan in soymilk-sized paper. Our work provides valuable insights for the preservation and maintenance of paper, highlighting the potential benefits and challenges of using soymilk for surface sizing.

Spatially resolved fluid-flow modulation and its corresponding integration becomes a crucial aspect to consider when designing high-performing paper-based analytical devices. As such, high demand exists for cost-effective techniques able to selectively control flow in patternable regions of the device. In this regard, a solution composed of potassium alum and animal glue; sizing materials used in the fabrication of calligraphy Xuan paper, is successfully adapted for the first time in a revolutionary approach to efficiently modulate the capillary flow in paper microfluidic channels. Flow delays are achieved by coating the substrate systematically through the variation of parameters such as the ratio of alum to glue, the concentration of alum-glue in the solution, and the number of subsequent coating layers of alum-glue. Moreover, digitized patterning with alum-glue is developed to achieve programmable wicking profiles of accelerating, decelerating, and quasi-linear flow displacement by alternating coated and uncoated zones in the channel. Additionally, the influence of alum-glue when performing biometric assays is investigated by performing a horseradish peroxidase activity colorimetric assay and found to have negligible effects on reading, where a negligible difference of 5.2% was observed in an assay performed in a coated paper substrate, compared to an uncoated one. [ABSTRACT FROM AUTHOR]

Positively charged chitosan (CS) and negatively charged montmorillonite (MMT) were layer-by-layer (LBL) assembled on Xuan paper pulp fiber to fabricate an organic/inorganic flame-retardant coating. The Xuan paper achieved a limiting oxygen index (LOI) value of 24.6% when the pulp fiber was treated by 20 bilayers (BLs) of CS/MMT coating, and its vertical flame properties also improved with less after-flame and after-glow times compared to the untreated one. These results demonstrated that the flame retardancy of Xuan paper could be enhanced by this organic/inorganic composite coating. Thermogravimetric (TG) analysis results revealed that LBL assembly of CS/MMT coating on pulp fiber improved the thermal stability at higher temperature and promoted char formation, showing the obvious condensed phase flame retardant action. Scanning electron microscopy results further confirmed that the treated Xuan paper by CS/MMT coating on pulp fiber promoted the char formation and formed the stable covering layer. The ink wetting property of Xuan paper was not influenced through the LBL assembly flame-retardant treatment of the pulp fibers by CS and MMT. This research provides a new approach for flameretardant Xuan paper without influencing its ink wetting property using the eco-friendly organic/inorganic composite flame-retardant system. [ABSTRACT FROM AUTHOR]

Aqueous cleaning of works of art on paper is one of the most important and delicate steps in a conservation process. It allows the removal of inorganic (metals) and organic substances, such as degradation products and other contaminants. These substances are responsible for yellowing, weakening, and loss of mechanical properties of paper. In this article, the cleaning effect of gellan gum was assessed on xuan paper, a traditional Chinese paper different in composition and papermaking technology compared to many Western papers. To assess the effect of gellan gum on xuan paper, its characteristics were studied before and after cleaning utilizing non-invasive and micro-invasive techniques. Results were compared to those obtained when treating Western papers and indicated that gellan gum can be applied effectively for aqueous cleaning of xuan paper. Zusammenfassung: Die wässrige Reinigung von Kunstwerken auf Papier ist einer der wichtigsten und heikelsten Schritte in einem Restaurierungssprozess. Sie ermöglicht die Entfernung anorganischer (Metalle) und organischer Substanzen wie Abbauprodukte und anderer Verunreinigungen aus dem Papier. Diese Substanzen können Vergilbung und den Verlust mechanischer Festigkeit von Papier verursachen. In diesem Beitrag wurde die Reinigungswirkung von Gellan Gum auf Xuan-Papier untersucht. Xuan-Papier ist ein traditionelles chinesisches Papier, das sich von historischen westlichen Papieren sowohl in der Faserzusammensetzung als auch in der Herstellung unterscheidet. Um die Wirkung von Gellan Gum auf Xuan-Papier zu bewerten, wurden die Eigenschaften des Papiers vor und nach der Reinigung unter Verwendung nicht-invasiver und mikro-invasiver Techniken untersucht. Die Ergebnisse wurden mit jenen einer Gellan Gum Behandlung von westlichen Papieren verglichen, und es konnte gezeigt werden, dass Gellan Gum effektiv zur wässrigen Reinigung von Xuan-Papier angewendet werden kann. [ABSTRACT FROM AUTHOR]

In China, Xuan paper has been the paper of choice as artwork support and for conservation, for several centuries. However, little is known about its material properties, especially given the many grades of sized and unsized Xuan paper. In addition, there is a lack of information on its degradation. In this research, a selection of contemporary unsized Xuan papers was investigated, representing diverse raw materials. Seven out of twelve contemporary unsized Xuan papers were determined to be approximately neutral and contain > 2% alkaline reserve, indicating good durability. Viscometry was used to determine the degree of polymerisation (DP) as none of the samples gave significant reactions to the phloroglucinol spot test. The average DP of ten contemporary unsized Xuan papers is ~ 1700, excluding two papers that have presumably been sun-bleached, and that exhibit significantly lower DP. Using X-ray fluorescence, it can be demonstrated that Ca and Si are the dominant elements and interestingly, Ca content is directly correlated with ash content and with alkaline reserve. Accelerated degradation was performed at two sets of environmental conditions, i.e. 90 °C, 30% RH and 60 °C, 70% RH, and the established degradation rates agreed with the Collections Demography model of paper degradation meaning that degradation of Xuan papers proceeds in the same way as other types of paper. This research gives fundamental insights into contemporary unsized Xuan papers, which exhibit good stability during accelerated degradation despite the low starting DP in the context of the samples used in this study. Our findings may inform methods of Xuan paper production, selection of Xuan paper for conservation purposes, as well as preventive conservation of Xuan paper-based artefacts. [ABSTRACT FROM AUTHOR]

Xuan paper, also named rice paper, was invented in the Tang Dynasty around 700 AD. Due to its softness, flexibility, fine texture and excellent durability, Xuan paper has been one of the most carriers for a large number of extraordinary artworks since its invention. The mechanical properties of Xuan paper will be varied over time, which has a significant impact on its application and preservation. In this study, for the first time, we employed atomic force microscopy nanoindentation measurement, a simple and nondestructive technique to quantitatively analyze the nanomechanical properties of Xuan paper. Combined with other characterizations, the property of Xuan paper under different aging times was investigated. It is expected that our results should lead to a better understanding of Xuan Paper as ancient materials with superior properties. The current results should provide useful information on the identification and protection of paper-based artifacts. [ABSTRACT FROM AUTHOR]

This paper proposed phytoliths as promising for identifying and distinguishing sources of fibre in Chinese handmade papers. For an initial methodological exploration, two types of Raw Xuan (unprocessed Xuan paper) and the two plant materials used in making them—namely rice straw and bark from blue sandalwood (Pteroceltis tatarinowii Maxim.)—were collected. The dry ashing method was used to extract phytoliths from Raw Xuan and its plant materials. The results can be summarized as follows. First, phytoliths characteristic of rice (Oryza sativa) were abundant in both rice straw and Raw Xuan. By looking for rice phytoliths, it is possible to tell whether or not rice straw fibre is used in a particular paper. Second, hair cell phytoliths were observed in considerable quantities in blue sandalwood bark, but absent in the examined papers. Heat experiments showed that phytoliths in blue sandalwood were resistant to long-term heat and they would unlikely be eliminated when exposed to the heat in papermaking (with heat source barely above 200°C). It is hypothesised that they dissolved while cooked in an alkaline pH (limewater). Further studies are necessary to understand whether phytoliths in blue sandalwood—while cooked in limewater—undergo morphological changes and, if yes, how.

Copyright of China Pulp & Paper is the property of China Pulp & Paper Magazines Publisher and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The cellulose microfibril-precipitated calcium carbonate (CMF–PCC) composite filler has been studied in improving the printing and optical properties of ordinary paper. However, the effect of CMF–PCC composite filler on the properties of Xuan paper, especially the ink diffusion properties, has rarely been investigated. In this study, the CMF–PCC composite filler was prepared by double-exchange reaction. The effects of CMF–PCC composite filler on the physical properties and ink diffusion properties of Xuan paper were detailedly studied. The results showed that the PCC particles in the CMF–PCC composite filler were rhombohedral calcite, with a uniform particle size and high adhesion rate, under the optimum reaction conditions. The Xuan paper filled with the CMF–PCC composite filler had higher tensile strengths and opacity than the conventional PCC or GCC loading. Notably, the CMF–PCC composite filler can effectively improve and regulate the Chinese ink diffusion properties of Xuan paper. [ABSTRACT FROM AUTHOR]

Copyright of Transactions of China Pulp & Paper is the property of China Pulp & Paper Magazines Publisher and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

[Display omitted] • Acidification defines the preservation state of Xuan paper in museums. • Photochemical damage to Xuan paper is owing to oxidation and hydrolysis reactions. • FTIR combined with PCA is able to evaluate photochemical damage law of Xuan paper. • pH values, λ, and their interaction promotes photochemical damage to Xuan paper. • Photochemical damage is fitted as a mathematical function of pH values and λ. In museums, there is a huge storage of Xuan paper cultural relics with profound historical and artistic significances. Exploring the photochemical damage behavior of Xuan paper that is generally in acidification, namely its damage mechanisms and laws, is crucial for the preventive lighting protection for paper cultural relics. In this study, the accelerated aging experiments in the range of visible light were conducted on Xuan paper samples with different degrees of acidification. The photochemical damage mechanisms of samples were traced, which is related with the synergistic effects of oxidation and hydrolysis reactions. It can be found that there is an effect of acidification, a long-standing material property of Xuan paper, on its damage, which further defines its preservation state in museums. On this basis, a spectral quantification method of infrared spectra combined with the principal component analysis was proposed to comprehensively analyze the photochemical damage law of Xuan paper in different preservation states. The analysis shows that the effect of acidification degree (pH values), spectra wavelength (λ), and their interaction on the damage to Xuan paper are statistically significant. Furthermore, the fitted mathematical function of pH values and λ is of great importance for evaluating photochemical damage, in order to further develop preventive lighting protection applications. [ABSTRACT FROM AUTHOR]

Copyright of China Pulp & Paper is the property of China Pulp & Paper Magazines Publisher and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of China Pulp & Paper is the property of China Pulp & Paper Magazines Publisher and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

This paper proposed phytoliths as promising for identifying and distinguishing sources of fibre in Chinese handmade papers. For an initial methodological exploration, two types of Raw Xuan (unprocessed Xuan paper) and the two plant materials used in making them—namely rice straw and bark from blue sandalwood (Pteroceltis tatarinowii Maxim.)—were collected. The dry ashing method was used to extract phytoliths from Raw Xuan and its plant materials. The results can be summarized as follows. First, phytoliths characteristic of rice (Oryza sativa) were abundant in both rice straw and Raw Xuan. By looking for rice phytoliths, it is possible to tell whether or not rice straw fibre is used in a particular paper. Second, hair cell phytoliths were observed in considerable quantities in blue sandalwood bark, but absent in the examined papers. Heat experiments showed that phytoliths in blue sandalwood were resistant to long-term heat and they would unlikely be eliminated when exposed to the heat in papermaking (with heat source barely above 200°C). It is hypothesised that they dissolved while cooked in an alkaline pH (limewater). Further studies are necessary to understand whether phytoliths in blue sandalwood—while cooked in limewater—undergo morphological changes and, if yes, how. [ABSTRACT FROM AUTHOR]

Copyright of China Pulp & Paper is the property of China Pulp & Paper Magazines Publisher and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of China Pulp & Paper is the property of China Pulp & Paper Magazines Publisher and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of China Pulp & Paper is the property of China Pulp & Paper Magazines Publisher and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Pteroceltis tatarinowii is a monotypic plant endemic to eastern China. It is an endangered tertiary relic and famous for Xuan paper manufacturing. In this study, we reported the Pteroceltis tatarinowii chloroplast genome with a length of 158,506 bp. In total, 132 genes were identified, including 83 protein-coding genes, 8 rRNA genes, and 33 tRNA genes. The overall GC content of this genome was 36.3%. Twenty-two species from Urticales were selected for phylogenomic analysis to determine the placement of P. tatarinowii. The complete plastome of P. tatarinowii will provide a valuable resource for further genetic conservation, phylogenomic, and evolution studies of the genus and the Ulmaceae.

Copyright of China Pulp & Paper is the property of China Pulp & Paper Magazines Publisher and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Xuan paper is outstanding representative of the precious Chinese handmade papers which is popular with traditional calligraphy and painting. However, the highly flammability of Xuan paper results in the latent fire risk. In this research, fire-resistant and antibacterial Chinese Xuan papers were prepared by fully bio-based chitosan (CS)/phytic acid (PA) intumescent flame retardant system. Xuan paper achieved the excellent flame retardancy with limit oxygen index value of 36.4% when it was coated with 20 BL CS/PA on pulp fibers. The vertical flame properties and cone calorimetry test of Xuan papers also revealed their flame retardancy were greatly improved. The tensile strength of Xuna paper was slightly influenced by CS/PA coating. The CS/PA coating on Xuan papers could greatly enhance their antibacterial properties. The flame retardant mechanism of coated Xuan papers was investigated. The results showed the CS/PA coating on pulp fibers could act through intumescent flame retardant action. The ink wetting property of Xuan paper won't be influenced by CS/PA coating on the pulp fibers. This research provides research basis for fire-resistant and antibacterial Xuan papers by using the fully bio-based chitosan/phytic acid coating on pulp fibers. • Fire-resistant and antibacterial Xuan paper was prepared by fully bio-based coating. • Xuan paper achieved a LOI value of 36.4% when it was coated by 20 BLs CS/PA. • CS/PA coating on pulp fibers greatly enhance the antibacterial property of Xuan paper. [ABSTRACT FROM AUTHOR]

Abstract: Xuan paper is a type of Chinese handmade paper produced for traditional calligraphy and painting in China since the Tang Dynasty (618–907AD), and is therefore an important cultural heritage material. In this study, the fluorescence and photochemical properties of Xuan paper were investigated. Xuan paper exhibits auto-fluorescence in the blue spectral range (450–500nm) and UVA photolysis of the paper resulted in a substantial reduction in the blue fluorescence together with the formation of chromophores absorbing in the visible spectrum, resulting in photoyellowing of the paper. A more significant yellowing of paper was observed when irradiated in the dry state than under wet conditions. The associated photogeneration of hydrogen peroxide and superoxide from three types of Xuan paper samples during irradiation showed a correlation between the yields of reactive oxygen species and their relative yellowing rates. The results are interpreted in terms of sensitised photooxidation via a mechanism of electron transfer involving the fluorophores in their excited singlet states being responsible for the photodegradation of Xuan paper. SEM/EDS analyses were performed on the Xuan paper samples to investigate their morphological and elemental characteristics. Silica-containing fibres characteristic of a special rice straw that grows in siliceous soil were observed in all types of Xuan paper. Micron-sized calcium precipitates possibly formed from the “lime-steaming” manufacture process were shown to protect against the acidification of paper during accelerated thermal ageing. [Copyright &y& Elsevier]

Pteroceltis tatarinowii is a monotypic plant endemic to eastern China. It is an endangered tertiary relic and famous for Xuan paper manufacturing. In this study, we reported the Pteroceltis tatarinowii chloroplast genome with a length of 158,506 bp. In total, 132 genes were identified, including 83 protein-coding genes, 8 rRNA genes, and 33 tRNA genes. The overall GC content of this genome was 36.3%. Twenty-two species from Urticales were selected for phylogenomic analysis to determine the placement of P. tatarinowii. The complete plastome of P. tatarinowii will provide a valuable resource for further genetic conservation, phylogenomic, and evolution studies of the genus and the Ulmaceae. [ABSTRACT FROM AUTHOR]

• Nacre-mimetic flame retardant Xuan paper was fabricated via LBL assembly CH/MMT. • Nacre-mimetic CH/MMT nanocoating endow Xuan paper with excellent flame retardancy. • Nacre-mimetic CH/MMT nanocoating promote Xuan paper to form compact and dense char. • Xuan paper achieves acceptable ink wetting performance with less than 10 BL CH/MMT. Nacre-mimetic materials possess excellent thermostability and barrier performance which provide novel idea for high efficient flame retardant strategy. In this study, we propose an eco-friendly approach to fabricate fire-resistant cellulosic Chinese Xuan paper by layer-by-layer (LBL) assembly chitosan (CH) and montmorillonite (MMT). The flame retardancy of Xuan paper was greatly improved after the LBL assembly coated CH/MMT, it achieved excellent flame retardancy when the CH/MMT bilayer was over 10 BL with the LOI value higher than of 35 %. The results of thermal stability of treated Xuan paper revealed the nacre-mimetic CH/MMT nanocoating on Xuan paper would promote the formation of compact and dense char which will be beneficial to inhibit the heat transmission and combustible gas diffusion. The ink wetting performance was also investigated in this study. This research would provide experimental basis for the development of fire-resisting paper using bio-mimetic method to construct nacre-mimetic organic/inorganic hybrid flame retardant system. [ABSTRACT FROM AUTHOR]