Search Results (169)

The restoration of gold leaf on sandstone sculptures requires structural stability, aesthetic considerations, and compliance with the principles of cultural heritage preservation. A primary issue is achieving visual and material compatibility between newly restored and original areas. Based on the “Diagnosis–Analysis–Selection–Restoration” methodology, the research team developed a targeted restoration approach for gilded stone sculptures, using the Shakyamuni sculpture at Erfo Temple in Chongqing as a case study. Assessment of the current situation revealed that over 70% of the sculpture’s surface exhibited gold leaf delamination. The composition and structure of the gold-sizing lacquer, lacquer plaster filler, ground layers, and pigments were investigated using SEM-EDS, XRD, Raman spectroscopy, and THM-Py-GC/MS techniques. The results confirmed that the sculpture featured a typical multilayer gilding structure with clear evidence of historical restorations. Considering both material performance and interfacial compatibility, an NHL2/SiO₂/SF016 composite emulsion and traditional lacquer plaster were selected as the optimal materials for reattachment and infill, respectively. A scientific restoration protocol was developed, encompassing gentle cleaning, targeted reattachment and reinforcement, and region-specific repair methods. Principal Component Analysis (PCA) was used to evaluate the influence of temperature and humidity on the curing behavior of lacquer layers. Additionally, a non-invasive gold leaf color-matching technique was developed by controlling the surface roughness of the gold-sizing lacquer, effectively avoiding the damage caused by traditional color-matching methods. Full article

This study analyzes a lacquered ear cup excavated from the Luobowan tomb complex in Guigang, Guangxi, attributed to the Nanyue Kingdom of the early Han dynasty. A range of analytical techniques, including optical microscopy (OM), scanning electron microscopy with energy-dispersive X-ray spectroscopy (SEM-EDS), pyrolysis–gas chromatography–mass spectrometry (Py-GC-MS), Fourier transform infrared spectroscopy (FT-IR), and X-ray diffraction (XRD), were employed to investigate the structural layers, material composition, and preservation state of the artifact. The lacquerware consists of four traditional layers: a wooden core, fabric reinforcement, lacquer ground, and lacquer film, reflecting Central Plains lacquerware techniques. The wooden core was identified as Phoebe sp., and the fabric layer is likely hemp, though fiber degradation limited exact identification. The lacquer ground layer contains natural lacquer mixed with SiO₂ from brick or tile powder. The lacquer film is a blend of Chinese and Vietnamese lacquer, with no synthetic additives or plant oils detected. The red lacquer layer contains cinnabar (HgS) as a pigment, while the black lacquer uses carbon black. Differences in moisture content between the red and black lacquer films are attributed to variations in surface porosity and pigment characteristics. This research provides valuable insights into Nanyue lacquer technology and preservation challenges. Full article

As a natural polymerized material, Chinese lacquer has numerous applications, although its processing is associated with volatile organic compounds (VOCs), which will cause a health risk. This paper was mainly focused on the detection of volatiles in the Chinese lacquer and its possible allergy mechanisms based on the properties of the lacquer, such as the main components, chemical properties, and allergy mechanisms of the unit phenols, aldehydes, and ketones and terpenes in the volatiles. Based on the detection technology (such as GC/MS) and allergy mechanism, a variety of prevention and control strategies are proposed, including the use of cyclodextrin–chitosan embedding technology to reduce the antigenicity of lacquer phenols and the directional modification of the active site of laccase to inhibit the generation of quinone toxicity products, as well as the research and development of antioxidant protective equipment for different volatiles, the installation of ventilation and purification devices, and the addition of antioxidants. They are all aimed at providing scientific evidence and practical guidance for the safe use of lacquer, the health protection of the practitioners, and the sustainable development of the related industries. Full article

As a core structure within the Qing Changling Mausoleum, a UNESCO World Cultural Heritage site, Long’en Hall preserves a relatively complete set of Qing dynasty imperial lacquered furniture. These furnishings provide critical physical evidence for studying Qing dynasty sacrificial rituals and the craftsmanship of court lacquerware. However, limited research has been conducted on the surface finishing techniques of such furnishings, posing challenges to their conservation and accurate restoration. This study focuses on representative furnishings from Long’en Hall—including an offering table, an incense pavilion, a throne, and a poke lamp—and employed a multi-method analytical approach comprising fluorescence microscopy (FM), scanning electron microscopy with energy-dispersive X-ray spectroscopy (SEM-EDS), X-ray photoelectron spectroscopy (XPS), and Fourier-transform infrared (FTIR) spectroscopy. The analysis was conducted on the following two levels: the lacquer layer structure and material composition. The results show that the furnishings in the Long’en Hall adopt the typical structure of “lacquer ash layer–color lacquer layer”, and the color lacquer layer is composed of raw lacquer, tung oil, animal glue, and other natural organic ingredients as film-forming materials, supplemented with inorganic mineral pigments such as red lead (Pb₃O₄) and Au metal, which constitutes a stable organic–inorganic composite structure with the lacquer ash layer. The multi-analysis results show a good complementary and cross-corroboration relationship, providing the necessary technical support and a theoretical reference for Qing dynasty palace lacquer wood furniture as cultural relics worthy of scientific protection and imitation. Full article

Chinese lacquer, a historically significant bio-based coating, has garnered increasing attention in sustainable materials research due to its outstanding corrosion resistance, thermal stability, and environmental friendliness. Its curing process relies on the laccase-catalyzed oxidation and polymerization of urushiol to form a dense lacquer film. However, the stringent temperature and humidity requirements (20–30 °C, 70–80% humidity) and a curing period that can extend over several weeks severely constrain its industrial application. Recent studies have significantly enhanced the curing efficiency through strategies such as pre-polymerization control, metal ion catalysis (e.g., Cu²⁺ reducing drying time to just one day), and nanomaterial modification (e.g., nano-Al₂O₃ increasing film hardness to 6H). Nevertheless, challenges remain, including the sensitivity of laccase activity to environmental fluctuations, the trade-off between accelerated curing and film performance, and issues related to toxic pigments and VOC emissions. Future developments should integrate enzyme engineering (e.g., directed evolution to broaden laccase tolerance), intelligent catalytic systems (e.g., photo-enzyme synergy), and green technologies (e.g., UV curing), complemented by multiscale modeling and circular design strategies, to drive the innovative applications of Chinese lacquer in high-end fields such as aerospace sealing and cultural heritage preservation. Full article

Urushiol, the principal bioactive component of natural lacquer, has emerged as a promising candidate for developing eco-friendly antimicrobial coatings due to its unique catechol structure and long alkyl chains. This review systematically elucidates the molecular mechanisms underpinning urushiol’s broad-spectrum antimicrobial activity, including membrane disruption via hydrophobic interactions, oxidative stress induction through redox-active phenolic groups, and enzyme inhibition via hydrogen bonding. Recent advances in urushiol-based composite systems—such as metal coordination networks, organic–inorganic hybrids, and stimuli-responsive platforms—are critically analyzed, highlighting their enhanced antibacterial performance, environmental durability, and self-healing capabilities. Case studies demonstrate that urushiol derivatives achieve >99% inhibition against both Gram-positive and Gram-negative pathogens, outperforming conventional agents like silver ions and quaternary ammonium salts. Despite progress, challenges persist in balancing antimicrobial efficacy, mechanical stability, and biosafety for real-world applications. Future research directions emphasize precision molecular engineering, synergistic multi-target strategies, and lifecycle toxicity assessments to advance urushiol coatings in medical devices, marine antifouling, and antiviral surfaces. This work provides a comprehensive framework for harnessing natural phenolic compounds in next-generation sustainable antimicrobial materials. Full article

This study systematically investigates the effects of repeated Kurome treatment—a physical modification method combining mechanical stirring and oxidative regulation—on the processing characteristics and film properties of Chinese lacquer (urushi). By subjecting raw lacquer to 1–4 cycles of hydration–dehydration (KL1–KL4), the researchers observed a significant increase in viscosity (from 12,688 to 16,468 mPa·s) and a dramatic reduction in curing time (from 74 h to just 3.6 h), driven by deep oxidation of urushiol and quinone-mediated crosslinking, as confirmed by FTIR spectroscopy. The Kurome treatment enabled controlled darkening (L* value decreased from 29.31 to 26.89) while maintaining stable hue and gloss (88.96–90.96 GU), with no adverse effects on abrasion resistance (mass loss of 0.126–0.150 g/100 r) or adhesion (9.58–9.75 MPa). The reduced transparency of the KL3/KL4 films is associated with a densified polymer network, a feature that may benefit protective coatings. Scanning electron microscopy (SEM) analysis confirmed the formation of uniform, defect-free surfaces across all treatment groups. Among them, the KL2 group (viscosity of 14,630 mPa·s, curing time of 9.2 h) exhibited the most favorable balance for industrial applications. This study establishes Kurome technology as a low-carbon, additive-free strategy that enhances the processability of Chinese lacquer while preserving its traditional craftsmanship standards, offering scientific support for its sustainable use in modern coatings and cultural heritage conservation. Full article

The preservation and innovation of traditional craftsmanship under industrialization pressures constitute critical challenges for cultural sustainability. Focusing on Chengdu lacquerware—a Chinese intangible cultural heritage facing multifaceted preservation dilemmas—this study develops a digital methodology for its systematic documentation and contemporary adaptation. Through computational analysis of 307 historical artifacts spanning four craftsmanship categories (carved silver mercer, carved lacquer hidden flower, carved filling, and broach needle carving), we established a three-phase digital preservation framework: (1) image preprocessing of 280 qualified samples using adaptive binarization and Canny edge detection for ornament extraction, (2) chromatic analysis via two-stage K-means clustering to decode traditional color schemes, and (3) creation of a digital repository encompassing color profiles and ornamental elements. The resource library facilitated three practical applications: modular recombination of high-frequency motifs, cross-media design adaptations, and interactive visualization of craftsmanship processes. Technical analysis confirmed that adaptive binarization effectively mitigated image noise compared to conventional methods, while secondary clustering enhanced color scheme representativeness. These advancements demonstrate that structured digital archiving coupled with computational analysis can reconcile traditional aesthetics with modern design requirements without compromising cultural authenticity. The workflow provides a transferable model for intangible heritage preservation, emphasizing rigorous documentation alongside adaptive reuse mechanisms. Full article

Marine antifouling coatings that rely on the release of antifouling agents are the most prevalent and effective strategy for combating fouling. However, the environmental concerns arising from the widespread discharge of these agents into marine ecosystems cannot be overlooked. An innovative and promising alternative involves incorporating antimicrobial groups into polymers to create coatings endowed with intrinsic antimicrobial properties. In this study, we reported an urushiol-based benzoxazine (URB) monomer, synthesized from natural urushiol and antibacterial rosin amine. The URB monomer was subsequently polymerized through thermal curing ring-opening polymerization, resulting in the formation of a urushiol-based benzoxazine polymer (URHP) coating with inherent antimicrobial properties. The surface of the URHP coating is smooth, flat, and non-permeable. Contact angle and surface energy measurements confirm that the URHP coating is hydrophobic with low surface energy. In the absence of antimicrobial agent release, the intrinsic properties of the URHP coating can effectively kill or repel fouling organisms. Furthermore, with bare glass slides serving as the control sample, the coating demonstrates outstanding anti-adhesion capabilities against four types of bacteria (E. coli, S. aureus, V. alginolyticus, and Bacillus sp.), and three marine microalgae (N. closterium, P. tricornutum, and D. zhan-jiangensis), proving its efficacy in preventing fouling organisms from settling and adhering to the surface. Thus, the combined antibacterial and anti-adhesion properties endow the URHP coating with superior antifouling performance. This non-release antifouling coating represents a green and environmentally sustainable strategy for antifouling. Full article

This study explores the application of Eastern philosophy in craft innovation education, identifying opportunities for interdisciplinary learning. Drawing on the I Ching and Laozi’s thought, it examines human needs in craft across three dimensions: Qi-form (material), Xin-form (psychological), and Dao-form (philosophical). Taiji theory’s Yin–Yang balance highlights the importance of interdisciplinary thinking in craft innovation. This study introduces the “Spiral Innovation Theory” as a framework for craft education, implemented in the 2024 Taiwan Craft Academy Summer Program with 43 participants. The curriculum covered lacquer, wood, metal, and ceramics, employing a multi-mentor system. Using the Learning Motivation Strategies Scale, Imaginative Thinking Scale, and interviews, the findings reveal that different crafts foster distinct creative abilities. The ANOVA results show woodworking enhances ideation, metalwork and ceramics improve fluency, ceramics and woodworking strengthen flexibility, while woodworking and lacquer work boost creativity. A significant correlation between learning motivation and imagination was found. These findings offer insights into future craft education, advocating the dual mentorship model as a strategy for interdisciplinary innovation. Full article

Lacquer trees are an important economic tree species in China, and raw lacquer is its main secondary metabolite. Polyphenolic compounds are the primary components of raw lacquer, among which diene urushiol exhibits high inhibitory activity against the reverse transcriptase of acquired immunodeficiency syndrome (AIDS). Therefore, this study established and optimized the ultrasound-assisted extraction process of diene urushiol from lacquer tree leaves. Based on single-factor experiments on the number of extractions, extraction time, extraction temperature, and solvent to solid ratio, the Box–Behnken Design response surface methodology was employed to obtain the optimal extraction process, which included three extractions, an extraction time of 55 min, an extraction temperature of 50 °C, and a solvent to solid ratio of 10:1 mL/g. Under these conditions, the content of diene urushiol was 4.56 mg/g (FW), which bore no significant difference from the theoretical value of 4.69 mg/g (FW), indicating a good model fit. Therefore, response surface methodology (RSM) can be used to optimize the extraction process of diene urushiol from lacquer leaves. This method lays a solid foundation for the comprehensive development and utilization of lacquer tree resources. Full article

The durability of piezoresistive sensor materials is a core prerequisite for their implementation in structural health monitoring systems. In this work, three piezoresistive materials were subjected to extensive cyclic tensile loadings, and their behaviour was analysed before, after, and during testing. To this end, aluminium specimens were coated with three different industry-grade lacquers, and then piezoresistive materials were applied onto each specimen. Sensors made from carbon black displayed excellent linearity even after tensile loading cycles ($R^2>0.88$). A decline in linearity of all sensors based on carbon allotropes was discovered, whereas the polymer-based sensors improved. Furthermore, their adhesion to the substrate is of great importance. Good adhesion ensures the strains in the underlying structure are correctly transmitted into the sensor materials. Based on contact angle measurements of liquids on sensor materials and on lacquers, their work of adhesion was determined. The findings were verified by tape adhesion tests. Full article

This Special Issue brings the Indigenous American lacquer community together, building bridges and overcoming the existing geographical and language obstacles. With dual-language (English and Spanish) articles focusing on barniz de Pasto and mopa mopa, Mexican lacquer (or maque) and cumatê, this collection includes contributions covering a number of disciplines. This volume is a ‘go-to’ research resource encompassing scientific and historical reviews, case studies, articles focusing on sociological and anthropological perspectives, and on cross-cultural contact and exchanges between Asia, Europe and the ‘New World’. The approach used to compile this Special Issue goes beyond European and North American perspectives, and includes voices that represent the genesis and context of Indigenous American lacquer objects more faithfully and objectively. Full article

The shift from fossil-based packaging materials to more sustainable alternatives is driven by evolving environmental regulations aiming for enhanced recyclability and biodegradability. Dispersion coatings, as opposed to extrusion-based approaches, offer significant advantages by reducing the coat weights, but generally, multiple coating layers are needed to meet functional performance requirements. This study explores the application of upscaled multilayer dispersion coatings comprising polylactic acid-based coating (PLAX) and hybrid nanomaterial lacquer (bioORMOCER^®) on commercial base papers for barrier packaging using semi-pilot reverse gravure and industrial-scale rod coaters. One multilayer structure demonstrated a low water vapour transmission rate (WVTR), achieving a WVTR of 12 g/(m²·day) under standard conditions and a 78% reduction of WVTR compared to the substrate under elevated humidity. The other multilayer structure exhibited an excellent oxygen transmission rate (OTR) of 2.3 cc/(m²·day·bar) at dry conditions, which is comparable to conventional high-performance alternatives. Both multilayer coatings enhanced the grease and mineral oil barriers significantly, as heptane vapour transmission rate (HVTR) reductions exceeded 97%. The multilayer coatings demonstrated strong potential for scalable production of sustainable, high-barrier packaging materials. These findings highlight the capability of dispersion coatings to replace traditional fossil-based barriers, advancing the development of environmentally friendly packaging solutions. Full article

This study investigated the bonding strength and chemical composition (as an influencing factor of adhesion) of red eucalyptus (Eucalyptus camaldulensis) (EUW) and grey poplar (Populus canescens) (GPOW) wood surfaces, comparing their suitability for indoor and outdoor wood-building applications. The research focused on adhesion strength using different coatings and adhesives, including lasure and 2K lacquer. The results showed that whilst both wood species had a conveniently high cellulose content, GPOW had a higher cellulose content (48.21%) than EUW (45.18%). However, EUW demonstrated superiority in tensile shear strength tests when using structural adhesives. Additionally, EUW exhibited stronger pull-off adhesion with 2K lacquer (5.25 MPa) compared with GPOW (3.42 MPa), suggesting that whilst both reached the expectations, EUW was more appropriate for high-stress indoor applications like flooring or wall cladding. EUW and GPOW performed well with lasure, achieving comparable adhesion strengths. EUW had a density of 1020 kg/m³ vs. 575 kg/m³ for GPOW and stronger bonding capabilities than GPOW, which suggests that it is equally suitable for wood applications inside and outside buildings. The study concluded that whilst both wood species met expectations and proved to be suitable for doors, windows, and other wood-building product applications, GPOW was suitable for the production of cellulose-based products, while EUW was worth relying on for its excellent adhesion to coatings and adhesives. Full article