Search Results (36)

Soot particle deposition is a common form of surface contamination in enclosed architectural environments and can significantly alter the optical appearance of painted surfaces. In the Zhaomiao temple halls of Inner Mongolia, long-term exposure to soot generated by butter lamps and incense burning has led to pronounced color darkening of mural pigments. To clarify the mechanisms by which soot deposition affects pigment optical behavior, this study investigates the surface deposition-induced color degradation of mineral pigment coatings, using Zhaomiao temple murals as a representative application context. Thirty-six typical mineral pigments were prepared as standardized coating specimens, and controlled soot deposition experiments were conducted to simulate progressive particulate accumulation on pigment surfaces. Variations in Commission Internationale de l’Éclairage (CIE) XYZ tristimulus values, luminance, and color difference (ΔE) were quantitatively analyzed under different soot-loading conditions. The results show systematic luminance attenuation and chromatic compression with increasing soot deposition, indicating that optical degradation is primarily governed by surface absorption and scattering effects introduced by carbonaceous particles. These results establish a quantitative framework based on measurable optical parameters—rather than a single absolute value—for evaluating particulate-induced optical degradation of pigment coatings. This study provides a quantitative basis for evaluating particulate-induced optical degradation of pigment coatings and supports surface condition assessment and digital reconstruction of soot-contaminated painted surfaces in architectural contexts such as the Zhaomiao temples. Full article

Throughout the lifetime, road markings (RMs) accumulate dirt, oils, and greases, which reduce visibility, shorten service life, and compromise road safety. If RMs could degrade these pollutants, their service life would increase. When exposed to UV light and humidity, semiconductors, such as titanium dioxide (TiO₂), can interact with contaminants and promote their chemical degradation. Semiconductors are commonly used on different types of substrates to achieve self-cleaning ability. In this study, 0.25–3 wt% TiO₂ was incorporated into a commercial RM paint for this purpose. After functionalization, the RM paint samples were contaminated with Methylene Blue and Rhodamine B. After pollution, the specimens were irradiated with a light source that simulates sunlight. To assess the self-cleaning capacity of the paints, visual analysis, color variation and discoloration by using CIELAB color coordinates, diffuse reflectance, and digital image processing techniques were applied. In both techniques, the samples with 2% and 3% of TiO₂ showed a greater capacity to degrade pollutants. Further, the chemical and morphological characteristics of the reference paint and the samples that showed the best self-cleaning results were analyzed by using Fourier Transform Infrared Spectroscopy (FTIR), Scanning Electron Microscopy (SEM), Energy-Dispersive X-ray Spectroscopy (EDS), and X-ray Diffraction (XRD). They identified the polymer, filler, and pigment in the commercial paint and confirmed the TiO₂ increase after functionalization. This study demonstrated the innovative potential of incorporating semiconductors to achieve a new capability (self-cleaning) for RM paints. This breakthrough not only has the potential to extend the RM service life, but also to improve road safety through greater visibility. Full article

Accelerated artificial aging of zinc oxide (ZnO)-based acrylic artists’ paint, filled with calcium carbonate (CaCO₃) as an extender, was carried out for a total of 1963 h (~8 × 10⁷ lux·h), with assessments at specific intervals. The total color difference ΔE* was <2 (CIELab-76 system) over 1725 h of aging, while the human eye notices color change at ΔE* > 2. Oxidative degradation of organic components in the paint to form volatile products was revealed by attenuated total reflectance–Fourier transform infrared (ATR-FTIR) spectroscopy, micro-Raman spectroscopy, and scanning electron microscopy with energy-dispersive X-ray spectroscopy (SEM-EDS). It appears that deep oxidation of organic intermediates and volatilization of organic matter may be responsible for the relatively small value of ΔE* color difference during aging of the samples. To elucidate the degradation pathways, principal component analysis (PCA) was applied to the spectral data, revealing: (1) the catalytic role of ZnO in accelerating photodegradation, (2) the Kolbe photoreaction, (3) the decomposition of the binder to form volatile degradation products, and (4) the relative photoinactivity of CaCO₃ compared with ZnO, showing slower degradation in areas with a higher CaCO₃ content compared with those dominated by ZnO. These results provide fundamental insights into formulation-specific degradation processes, offering practical guidance for the development of more durable artist paints and conservation strategies for acrylic artworks. Full article

Contemporary murals are highly susceptible to rapid color fading due to outdoor urban exposure. This study investigates the photodegradation mechanisms affecting synthetic organic pigments (SOPs) and commercial acrylic–vinyl paints under simulated visible light exposure. Artificial aging experiments were conducted on two types of systems: (a) pigment pellets, composed of pre-fixed pigments on mineral bases, as supplied by the manufacturer, and (b) commercial paints applied on glass substrates. Both systems were aged under controlled and uncontrolled relative humidity (RH) conditions. Colorimetric analyses revealed significant color fading, particularly in pigments PR112, PO5, and PV23. Vibrational spectroscopies highlighted the reduction in pigment-related bands after aging, indicating SOPs’ vulnerability to photodegradation. In paint mock-ups, FTIR-ATR measurements indicated binder degradation and an increase in signals from inorganic fillers. A superficial layer enriched in inorganic components was investigated non-invasively by Micro Spatially Offset Raman spectroscopy (Micro-SORS) in the beamsteer modality. It highlighted a gradient of calcite to pigment with depth. These findings indicate that color fading in mural paints results from the combined degradation of both pigments and binders. Full article

This paper presents the redesign of a door handle as a case study in applying long-life manufacturing (LLM) principles to the furniture sector, utilizing additive manufacturing with polylactic acid (PLA), a biodegradable and sustainable polymer. The primary objective of this study is to explore the potential of PLA-based components to enhance sustainability, repairability, and durability in everyday furniture items. A door handle was chosen as a representative product to demonstrate the feasibility of this approach. The redesign emphasizes the potential for consumers to 3D print and replace parts as needed, thereby reducing waste and extending product life-cycles. To assess the material’s performance, PLA door handles were subjected to degradation tests under UV light exposure and thermal cycles, simulating real-world conditions. The redesigned handles demonstrated a mass reduction of over 50% compared to the original target, while retaining more than 95% of their initial tensile strength after 14 days of UV-B exposure and thermal cycling between 5 °C and 50 °C. The color change remained minimal, particularly for the white-painted samples, indicating satisfactory aesthetic stability. This research contributes to the growing field of sustainable design, highlighting how additive manufacturing can transform the furniture industry by promoting a circular economy through repairable, durable, and eco-friendly solutions. Full article

Archaeology is a well-established discipline that sheds light on human history and uncovers the mysteries of materials, their origins, production methods, and areas of use. It provides significant insights into various topics such as the production history of glass and other materials, trade routes, manufacturing processes, degradation mechanisms, regional usages, and coloring com-positions. Glass, an ancient yet contemporary material, can transmit, absorb, and reflect light. Appreciating glass art requires recognizing its rich history, offering artists technical and aesthetic possibilities in modern life and architecture. This study examines the influence of archaeological research and the artistic character of ancient glass on contemporary glass art. Archaeological findings from Turkey and around the world have been reviewed, with a particular focus on the Phrygian Valley, located in and around Eskişehir, an important region for the Phrygian civilization. Artifacts unearthed through excavations and sur-face surveys conducted in the Phrygian Valley, and preserved in the Eskişehir Eti Archaeology Museum, have been analyzed. The museum houses approximately 22.500 artifacts, including sculptures, steles, ceramics, glass vessels, metal objects, jewelry, and coins. Inspired by these artifacts and Phrygian culture, original glass designs have been created using techniques such as stained glass, lampworking, and glass painting. The aim of the study is to interpret Phrygian art and culture through innovative designs. Full article

Louise Nevelson’s Erol Beker Chapel of the Good Shepherd (1977) is a sculptural environment consisting of wooden sculptures painted a monochromatic white color. The paints show signs of degradation including cracking, chipping, peeling, and the formation of blisters and powdery efflorescence. A significant amount of pentaerythritol (PER) detected during a former analysis was concluded to originate from an alkyd paint. We show that the PER originates from the PVAc paint on the sculptures, which we have determined to be an intumescent, fire-retardant (IFR) coating. IFR paints and coatings are functional materials designed specifically to delay the combustion of their substrate. At least one other sculpture by Louise Nevelson is known to have been painted with an IFR coating. Our analyses by Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy with energy dispersive X-ray spectroscopy (SEM-EDX), pyrolysis–gas chromatography/mass spectrometry (Py-GCMS), and cross-section microscopy show the presence and distribution of common IFR additives including PER, dicyandiamide, melamine, inositol, ethylenediamine, and phosphates. These are present throughout the PVAc paint and are enriched in the powdery efflorescence. In addition, the degradation behavior of the paint is typical for IFR coating systems that have been exposed to uncontrolled environmental conditions and especially high humidity events. Full article

Historical tempera paints exposed to pollutant gases suffer chemical and mineralogical deterioration which manifests through physical changes. Knowledge about these changes is fundamental to develop strategies for preventive conservation of wall paintings. In this research, binary tempera mock-ups composed of calcite, gypsum or lead white mixed with a proteinaceous binder (i.e., egg yolk or rabbit glue) were exposed to an aging test by using SO₂-rich atmosphere exposure to learn about the degradation mechanisms and forms related to the pigment–binder interaction. Reference (unaltered) and aged mock-ups were studied from a physical point of view, characterizing the morphological changes by using stereomicroscopy and profilometry, color variations by using spectrophotometry, gloss changes, and reflectance changes by using a hyperspectral camera. Also, mineralogical and chemical changes were studied by means of X-ray diffraction, Fourier transform infrared spectroscopy and scanning electron microscopy with energy-dispersive X-ray spectroscopy. Egg-yolk-based paints showed higher chromatic changes than their counterparts made of rabbit glue binder. Also, sulfate and sulfite salts precipitated on the surface of the aged paints regardless of their binder, influencing the painting reflectance which subsequently increased. Egg-yolk-based mock-ups exhibited roughness increases while the rabbit-glue-based paints showed roughness reduction, with the exception of lead-white-based paints. Therefore, the important influence of the type of binder and the interaction between the binder and the pigment on the durability of tempera paints in atmospheres rich in SO₂ was confirmed. Full article

Based on a multi-analytical approach involving mobile techniques and lab-based devices (XPS, portable and micro-Raman spectroscopies, and ATR-FTIR spectroscopy, combined with SEM/EDS and optical microscopy), this study presents the first in-depth investigation of two cultural heritage artworks painted by the famous Romanian artist Ștefan Luchian. The research highlights the artist’s use of a wide range of colors, with his palette including classic pigments such as ochers, lead white, barium white, zinc white, and viridian, as well as contemporary colors such as cobalt purple, alizarin crimson, and the little-known indium yellow. Additionally, attempts are made to characterize the binders used in the paintings, which include linseed oil and animal glue. Beyond identifying the types of pigments and materials used by the artist and assessing the degradation stage of the paintings, this study is the first to provide information regarding the use of In₂O₃ as a yellow pigment in artwork. Full article

This study examined the degradation of oil paint coatings on wood under UV light and heat, focusing on three drying oils: tung oil (TO), linseed oil (LO), and walnut oil (WO). Model coatings were prepared with malachite pigment on rubber wood, then exposed to 240 h of UV light at temperatures of 40 °C, 50 °C, and 60 °C. The results showed that tung oil (TO) was the most prone to degradation. After exposure to 60 °C, the lightness (L value) of TO decreased from 51.44 to 50.98, while LO and WO maintained higher lightness. The color differences (ΔE) for TO, LO, and WO were 3.08, 3.26, and 2.87, respectively. Gloss measurements revealed that TO had the lowest initial gloss (3.87 GU), while WO had the highest gloss value. After UV exposure, all three coatings showed a decrease in gloss to varying degrees. Fourier transform infrared spectroscopy (FTIR) analysis confirmed oxidative degradation in TO, characterized by increased hydroxyl and carbonyl bands, while LO and WO exhibited better chemical stability. Scanning electron microscopy (SEM) images revealed that the surface of TO was the roughest, while the WO surface was the smoothest. After UV exposure, the surface of TO became significantly rougher, while the WO coating showed almost no changes, maintaining better structural integrity. The results suggest that LO and WO are more resilient to UV light and thermal stress, making them more suitable for protecting wooden products. Full article

Caisson paintings are an integral part of the unique interior decoration ceiling of traditional Chinese architecture. There are a large number of Yuan Dynasty caisson paintings in the Puzhao Temple, in Hancheng, Shaanxi Province, China. These caisson paintings have exquisite patterns and rich colors, which are rare artistic treasures of the Yuan Dynasty. In the history of nearly 700 years, due to various environmental and human factors, the caisson paintings have experienced various degradation; for example, the paper of the caisson paintings is acidified, the surface is polluted, the color is faded, mottled, and it is difficult to identify. Therefore, their protection is vital. In order to ensure the scientific and targeted development of the protection scheme, this study conducted a comprehensive and in-depth analysis of the paper fibers, pigments, adhesives, wood supports, and pollutants of the caisson paintings and carried out a series of protection experiments in the field and laboratory, providing a step-by-step review of the protection treatment application for the caisson paintings. Mechanical and wet cleaning were used to remove the pollutants. The caisson painting was deacidified with a barium hydroxide ethanol solution, and the paper and pigments of the caisson painting were strengthened with water-based fluorine. Several conservation problems, such as the removal of pollutants, the deacidification of acidified paper, and the reinforcement of flaking paper and pigments, were solved. Meanwhile, good conservation and restoration results for caisson paintings were obtained. This research method of combining theory and practice has greatly improved the scientificity and success rate of conservation work. These research results provide valuable experience and reference for other caisson paintings in similar environments. Full article

Color paintings such as painted facades and interiors are important decoration elements of ancient Chinese architectures. The color of the paintings usually fades over time due to exposure to strong light, high humidity, high temperatures, and other environmental factors. In order to restore or reproduce the color appearance of ancient architecture paintings correctly, it was necessary to study the color degradation process of such paintings. To meet the needs of on-site colorimetric measurement of the paintings on ancient Chinese architectures, we propose using a digital color camera and the CDS (Color Design System) to measure and evaluate the colors of such paintings. The CDS is a color order system recommended by the Chinese national technical committee for color standardization (SAC/TC 120) in 2017 (GB/Z 35473-2017). The current version of the CDS atlas contains about 2740 samples which were uniformly distributed on the whole color space, and can be used to set up the colorimetric characterization model for the digital camera. Particularly, the digital CDS lookup table contains over 400 thousand samples, and it can be used to express the color of paintings on ancient Chinese architectures. In the experiment, a digital color camera was used to capture the colors of the paintings on the ancient Chinese architectures of different years based on the CDS and polynomial transform method. Moreover, a linear interpolation method was proposed for calculating and predicting the color degradation of such paintings. The experimental results show that with the increase in years, the color hue of the paintings changes slowly, while the lightness and the chroma of them fade obviously. In the future, more ancient architectures of different years and from different places should be selected as experimental samples to improve the method and the results of the paper. Full article

The degradation of cadmium yellow in paintings is influenced by various factors, primarily environmental conditions and light exposure. Applying a thin protective layer of linseed oil on the surface could help mitigate these processes. Linseed oil, being a natural material, acts as a barrier against harmful atmospheric agents like moisture and oxygen, which contribute to the degradation of pigments including cadmium yellow. Additionally, linseed oil reduces direct light exposure, thereby lowering the risk of fading and color alteration. In this study, we explored the degradation of cadmium pigments mixed with oil and applied on canvas. We elucidated how the use of a binder prevents the direct oxidation of the pigment, inducing artificial degradation by irradiating samples with UVA (365 nm) and UVC (250 nm) sources. By employing various spectroscopic techniques such as three-dimensional fluorescence mapping (PLE) and Raman, along with colorimetric analysis, we gained a comprehensive understanding of the degradation process, particularly when linseed oil serves as a protective layer. Full article

In order to detect abnormal heat generation in time, a reversible color-changing coating temperature measurement method is proposed for self-detection of temperature by power equipment, and its adhesion characteristics and aging performance were analyzed. The results showed that the reversible color-changing coating prepared with crystalline violet lactone as the colorant, bisphenol A as the color developer, octadecanol as the solvent, and RTV-II as the base paint can meet the requirements of self-detection of temperature by power equipment with its adhesion performance. The accelerated aging tests using high temperature, light and humidity were carried out in the laboratory, and we concluded that the deterioration degree of the color-changing coating was positively correlated with the temperature. Light can accelerate the aging rate of reversible color-changing coatings, and the degradation process of the coating was significantly accelerated under UV light. The effect of humidity on the coating was not significant. The degradation of the coating after aging for 288 h under indoor conditions was small, while it was accelerated under outdoor natural conditions. This research can provide a reference for the on-site application of reversible color-changing coatings for self-detection of temperature by power equipment. Full article

The scroll paintings for ancestor trees have been used to inherit the spirit of ancestor worship as a historical record of family development since the late Ming Dynasty in China. A severely degraded scroll painting of an ancestor tree (made of cotton textiles) needs intervention and conservation treatment to mitigate further deterioration. On the basis of the previously reported characterization results for the painting, in this paper, a suspension that is composed of 0.6% cellulose nanofibril (CNF) and nanosized 0.15% MgO in aqueous solvent (denoted as the CNF-MgO susairpension) was prepared. Conventional characterization methods were used to assess the properties of model samples before and after treatment with the CNF-MgO suspension, as well as before and after degradation under two sets of conditions. The results show that the treated model samples are slightly alkaline, given the deposit of alkaline particles, and demonstrate good mechanical properties before and after degradation due to the increase in fiber-to-fiber bond and mitigation of acid-catalyzed hydrolysis. In spite of the non-transparency of CNF and MgO nanoparticles, they have little impact on the optical properties of textiles, as verified by transmittance data and the determination of color changes. This suspension was then used to reinforce and restore the scroll painting in a practical conservation process. The application of CNF and MgO nanoparticles on textile objects investigated in this study would expand our understanding of the conservation of such objects, especially for those that have already become acidic and degraded. Full article