Search Results (95)

The durability of interior coatings is an important factor in the environmental performance of buildings, as the service life of the coatings directly determines the frequency of maintenance, material costs, and the overall life cycle impact. This study proposes the use of wet scrub resistance as a functional indicator of durability, providing an open dataset of commercial paints, analyzing their performance trends, and developing an integrated assessment framework. Data were collected through long-term tests according to EN ISO 11998 and EN 13300 standards from 2004 to 2025, ensuring the reliability and comparability of the results. The analysis shows that 56.8% of the tested paints met resistance class 1 and 31.5% met resistance class 2, meaning that these two classes account for almost 90% of all samples. Only around 10% of the paints were classified as class 3, while the share of the worst paints (classes 4–5) was only 1.6%. Long-term data show that class 1 has remained dominant for many years, exceeding 80% in some periods, but an increase in class 2 paints has been observed in recent years. The results of the study provide a quantitative basis for assessing the durability of coatings, allow for the prediction of maintenance intervals and analysis of technological advances, and facilitate data-driven decision-making, including the selection of sustainable building materials. The structured and standardized nature of the dataset also allows for its application in data-driven materials science, including the future development of machine learning models for predicting the durability of coatings and optimizing paint formulations based on sustainability criteria. Full article

This study investigates the efficacy of wollastonite-enriched acrylic paint in protecting spruce wood (Picea abies) against the brown-rot fungus Coniophora puteana. Unheated and heat-treated wood samples (185 °C for 4 h) were coated with either plain acrylic paint or wollastonite-enriched acrylic paint and exposed to the fungus. Fungal resistance was evaluated by measuring mass loss (ML) and compression strength parallel to the grain. While conventional acrylic coatings provide a physical barrier against moisture and limited microbial attack, their effectiveness against C. puteana is often insufficient. Our results show that untreated controls lost 23.8% of their mass, whereas plain acrylic paint reduced mass loss only slightly. In contrast, wollastonite-enriched paint significantly decreased ML in both unheated and heat-treated specimens, demonstrating superior antifungal performance. These findings indicate that incorporating wollastonite into acrylic paint enhances fungal resistance, offering a simple, environmentally friendly, and effective surface treatment for spruce wood. This study fills a research gap in the use of mineral additives in acrylic coatings and highlights a practical approach for improving wood durability against fungal decay. Full article

This study investigates how asphalt mixture type influences the degradation of pavement-marking retroreflectivity and luminance contrast under real operational conditions on Israeli intercity roads. Field measurements were collected along 65.1 km of roadway constructed with three asphalt mixtures: basalt dense-graded concrete (Basalt DCG), basalt stone mastic asphalt (Basalt SMA), and basalt–dolomite dense-graded concrete (Zebra DCG). Linear degradation models provided the best representation of retroreflectivity decay (R² = 0.63). Results show that asphalt mixture type significantly affects initial retroreflectivity, contrast, and effective service life of left-side white paint markings. Markings applied on Basalt DCG exhibited initial retroreflectivity values up to 1.6–1.9 times higher and maintained acceptable visibility for approximately 7–8 months, compared with about 3 months on Zebra DCG under comparable conditions. Traffic volume was not a statistically significant predictor, indicating that degradation is dominated by time-dependent material and optical aging processes. Pavement background reflectivity and its evolution play a critical role in contrast degradation. The results demonstrate that asphalt mixture selection can reduce repainting frequency by approximately 10–15%, highlighting asphalt mixture choice as a practical and previously underrecognized lever for improving pavement-marking durability and long-term visibility. Full article

The long-term durability of hydraulic concrete infrastructure is severely compromised by water penetration, carbonation, and chloride ion erosion, necessitating the development of high-performance protective coatings. This study designed two polyaspartic ester polyurea coatings, PAE-PTMEG and PAE-PPG, derived from isocyanate prepolymers with polytetramethylene ether glycol (PTMEG) and polypropylene glycol (PPG) soft segments, respectively. The results demonstrated that the PTMEG-based prepolymer exhibited higher reactivity, leading to shorter curing times. The resulting PAE-PTMEG coating showed outstanding mechanical properties (tensile strength: 43.8 Mpa; elongation: 646.1%) and excellent water resistance (<1% absorption), attributable to its well-defined microphase-separated structure. When formulated into a practical paint (PAE-C), it surpassed mechanical standards for waterproofing and demonstrated exceptional resistance to chloride ion penetration (1.3 × 10⁻⁴ mg·cm⁻²·d⁻¹), complete carbonation resistance, and high frost resistance (200 cycles). This work confirms that tailoring the soft segment structure is a crucial strategy for developing durable polyurea coatings, with PAE-PTMEG showing significant potential for protecting critical water conservancy infrastructure. Full article

A firewood stove’s combustion chamber can withstand temperatures of 1500 °C. To prevent the deterioration of a firewood stove due to excessive heat, it is necessary to use thermal insulation materials that stop heat transfer to the walls. These materials must be economical and durable. This work examines the materials used in the construction of combustion chambers of firewood stoves in southern Mexico and Central America. This field study collects information and samples of materials used in the manufacture of firewood stoves. Heat transfer experiments are conducted, and the thermal properties of each material are analyzed. As a result, methodology and information is provided for the manufacture of future plancha-type firewood stoves used in the study area, such as pine wood (pinus chiapensis) which is mainly used as casing for firewood stoves in coniferous forest areas; in addition, the use of wood ash as thermal insulation material is proposed since it does not present direct costs and has a thermal conductivity between 0.10 and 0.20 W/m°C and a melting point greater than 1500 °C. The next layer proposed is hollow brick, a high-temperature-resistant material that can be used as support due to its mechanical strength and low thermal conductivity of 0.6 W/m°C. Finally, the use of calcium hydroxide as a coating material is proposed, applied in the form of a paste or paint to detail the imperfections of the combustion chamber construction as it resists temperatures above 1000 °C. Full article

Radiative cooling (RC) offers a passive pathway to reduce surface and system temperatures by emitting thermal radiation through the atmospheric window, yet its daytime effectiveness is often constrained by geometry, angular solar exposure, and practical integration limits. This work experimentally investigates the use of passive non-imaging optics, specifically compound parabolic concentrators (CPCs), as enhancers of RC performance under realistic conditions. A three-tier experimental methodology is followed. First, controlled indoor screening using an infrared lamp quantifies the intrinsic heat gain suppression of a commercial RC film, showing a temperature reduction of nearly 88 °C relative to a black-painted reference. Second, outdoor rooftop experiments on aluminum plates assess partial RC coverage, with and without CPCs, under varying orientations and tilt angles, revealing peak daytime temperature reductions close to 8 °C when CPCs are integrated. Third, system-level validation is conducted using a modified GUNT ET-202 solar thermal unit to evaluate the transfer of RC effects to a water circuit absorber. While RC strips alone produce modest reductions in water temperature, the addition of CPC optics amplifies the effect by factors of approximately three for ambient water and nine for water at 70 °C. Across all configurations, statistical analysis confirms stable, repeatable measurements. These results demonstrate that coupling commercially available RC materials with non-imaging optics provides consistent and measurable performance gains, supporting CPC-assisted RC as a scalable and retrofit-friendly strategy for urban and building energy applications while calling for longer-term experiments, durability assessments, and techno-economic analysis before deriving definitive deployment guidelines. Full article

This article provides a comprehensive review of the literature on the use of graphene-based nanomaterials (graphene oxide, reduced graphene oxide, and graphene nanoplatelets) and nanosilica (SiO₂) in architectural paint and coatings. The aim was to quantitatively assess their effect on dirt pickup resistance, hydrophobicity, and mechanical properties. In a systematic search across ScienceDirect, Scopus, and Web of Science (2010–2025), 20 studies that met the set inclusion criteria were identified. We extracted and generalized data with random-effects models (REML) based on standardized mean differences, conducting subgroup and meta-regression analyses to assess filler type, loading, and binder system impact. The results reveal that graphene-based fillers and SiO₂ improve coating performance at the same time, and hybrid graphene-SiO₂ systems may provide a synergistic improvement depending on the binder matrix. Our results present the first quantitative evidence of graphene-SiO₂ interaction in the coating formulations, identify remaining research gaps, and indicate methods for designing next-generation facade paints with better dirt repellence, durability, and sustainability. Full article

The escalating global heatwave crisis demands urgent advancements in high-efficiency, energy-saving cooling technologies. Radiative cooling (RC) paints, capable of passively dissipating heat through the atmospheric transparent window (ATW, 8–13 μm) without external energy input, have emerged as a groundbreaking solution for sustainable thermal management. This perspective advocates for a paradigm shift in the field from solely focusing on optical performance optimization to comprehensive system design that simultaneously achieves high cooling power, industrial-scale manufacturability, long-term environmental durability, and customizable aesthetics. We systematically analyzed the fundamental design principles of RC paints, reviewed the construction strategy of the state-of-the-art RC paints, advanced multi-band spectral engineering, synergistic integration with complementary cooling technologies, and robust structural configurations for large-scale deployment. Addressing critical challenges for commercialization, we also proposed targeted solutions, including enhanced application-specific durability, cost-effective production scaling, and multifunctional system integration. This work provides a strategic roadmap to accelerate the transition of RC paints from laboratory prototypes to ubiquitous real-world applications, ultimately contributing to a sustainable future with improved thermal comfort. Full article

The recycling and reuse of wood have gained importance as strategies for reducing construction waste, lowering costs, and promoting circular practices in the built environment. This study evaluates the performance of recycled wood particle/epoxy composites (WPECs) for façade applications by prototyping panels produced from granulated degraded wood bonded with epoxy resin and coated with intumescent fire-retardant paint. The panels were design to meet standards for ventilated façade applications in accordance with EN 310-93 and ASTM D1037-06a and relevant building codes for facade cladding. Three replicates of each panel type were tested under controlled laboratory conditions to assess water absorption, equilibrium moisture content, capillarity, fire resistance, and mechanical performance. Moisture measurements were performed at immersion and drying intervals of 12, 24, 36, 72, and 120 h for four WPEC types manufactured with pine, beech, oak, and olive fibers. Statistical evaluation using SPSS (one-way and two-way ANOVA) confirmed significant species effects across most parameters. Results indicated that olive and oak WPECs provided the highest dimensional stability under moisture exposure, with olive additionally demonstrating superior compressive strength (35.45 MPa) and hardness (˂10,000 N). Pine and beech WPECs exhibited intermediate bending strength (≈10 MPa) and elasticity, while oak contributed stable swelling values despite lower strength. Fire resistance tests suggested relative improvements, although further standardized evaluation is needed. Collectively, olive and oak WPECs emerged as the most promising façade materials, combining durability, mechanical strength, and sustainability. Full article

The consolidation of mural paintings presents a significant challenge for conservators, as the treatments applied must not only be effective but also preserve the aesthetic qualities of the artwork. Ongoing research focuses on developing new products that are more efficient, durable, and compatible with the physicochemical and aesthetic characteristics of the original materials, thereby addressing the limitations of existing consolidants. This study examines two consolidants for mural painting restoration: Estel 1200^® (C.T.S., Madrid, Spain), a commercially available and widely used ethyl silicate-based product, and Nanorepair UV^® (Patent: ES-2766074-B2, Pablo de Olavide University, Seville, Spain), a nanocomposite composed of calcium hydroxide nanoparticles doped with zinc quantum dots. On mortar specimens, prepared according to the Roman fresco technique, the application method for the proposed treatments was optimized. The applicability of the treatments for mural painting conservation was studied by colorimetric measurements and SEM imaging to detect and characterize the formation of surface layers. The effectiveness of the treatments was quantitatively evaluated with tape-peeling cycles. The results show that, although both treatments enhance the consolidation state of mural paintings, Nanorepair UV^® proved to be a more effective consolidant, without altering the aesthetic or physicochemical properties of the artwork. Additionally, this treatment allows for straightforward evaluation of its penetration and enables distinction between treated and untreated areas through the fluorescence of the zinc oxide quantum dots. Full article

Alumina nanoparticles have broad applications in catalysis, electronics, and the construction sector, and are widely incorporated as additives in coating formulations to enhance mechanical durability and functional performance. This work focuses on the green synthesis of aluminum oxide (Al₂O₃) nanoparticles using lemongrass (Cymbopogon citratus) extract. Aluminum nitrate [Al(NO₃)₃] and aluminum chloride (AlCl₃) were used with extract. The reaction was carried out at 70 °C for 1 h at 250 rpm and then thermal treatments at 700 °C and 900 °C were applied. The results showed that nanoparticles synthesized from the AlCl₃ and calcined at 700 °C exhibited a smaller particle size (36 ± 14 nm) as compared with those synthesized from the [Al(NO₃)₃] and calcined at 700 °C (49 ± 25 nm). Despite both precursors yielding nanoparticles, the peaks related to the γ-Al₂O₃ crystal phase were observed in the AlCl₃ at 700 °C calcination. Conversely, the nanoparticles synthesized from the [Al(NO₃)₃] required a high temperature treatment at 900 °C to display this stable crystal phase. This study reports an easy and cost-effective green chemistry route to obtain γ-Al₂O₃ nanoparticles, highlighting the importance of the selection of precursors as a critical step to achieve a sustainable and low-energy process, suggesting the potential applications in paints with multifunctional properties. Full article

In recent years, the automotive industry has experienced increasing demand for advanced paint protection solutions aimed at improving vehicle durability, preserving aesthetic appeal, and promoting environmental sustainability. This paper critically examines the main categories of paint protection coatings on wax, ceramic, graphene, and hybrid formulations by focusing on their chemical composition, application methods, protective performance, and limitations. Wax coatings remain widely adopted due to their affordability and ease of use, though they offer limited longevity. Ceramic coatings, in contrast, provide superior hardness, hydrophobicity, and resistance to scratches, corrosion, and ultraviolet (UV) degradation, albeit with higher costs and complex application procedures. Emerging graphene-based coatings demonstrate exceptional hydrophobicity, thermal stability, and durability, positioning them as potential next-generation solutions, though their environmental and economic feasibility remains under exploration. Hybrid and self-healing coatings further highlight the trend toward multifunctional, intelligent protection systems. This work also emphasizes the critical role of surface preparation in determining coating performance. Future research directions are outlined, including the development of biodegradable, zero-VOC, and intelligent self-aligning coatings, which could significantly advance sustainable automotive surface protection. Overall, this work provides a comprehensive synthesis of current technologies and identifies pathways for innovation in automotive paint protection materials. Full article

This paper presents an overview of a research line developed at the Istituto Centrale per il Restauro within the CHANGES (Cultural Heritage Active Innovation for Next-Gen Sustainable Society) project, funded under the Italian National Recovery and Resilience Plan. The research was developed in different phases: a first one dedicated to the study of the deep background and the state of the art in the ICR background: history, methodologies and research in the field; a second phase was dedicated to the selection of a specific urban art mural, as a key study with conservation problems connected to some of the principal preservation treatments related to the outdoor context; the mural was also identified as a beloved icon in the public space with a profound socio-cultural meaning for the community. Nido di Vespe, created in 2014 by the artist Lucamaleonte is part of a broader artistic project called M.U.Ro-Museum of Urban Art of Rome, an open-air public art museum located in the Quadraro district in Rome, designed by the artist Diavù. A third phase focused on the research in ICR laboratories, specifically addressing: cleaning, reintegration, and protection strategies adapted to dynamic outdoor environments. A multi-step cleaning system based on polyvinyl alcohol-borax semi-interpenetrated hydrogels loaded with nanostructured fluids was developed to selectively remove spray-paint vandalism while preserving the chemically similar original pictorial layers. The reintegration phase investigated acrylic and urea-aldehyde resins as binders to produce compatible, reversible, and UV-traceable retouching and infilling materials. For surface protection, multilayer coating systems incorporating nanoparticles with antimicrobial, photocatalytic, and UV-stabilizing properties were formulated to enhance durability and chromatic stability. Laboratory tests on mock-ups simulating typical street and urban art materials and morphologies showed satisfactory results, while diagnostic investigations on Nido di Vespe provided the reference data to calibrate the experiments with real mural conditions. Cleaning tests demonstrated promising removal efficiency, influenced by the chemical composition, thickness of the overpainted layers, and surface roughness. The reintegration system met the expected performance requirements, as the tested binders provided good results and allowed the development of compatible, reversible, and distinguishable solutions. Protective coatings showed good results in terms of chromatic stability and surface integrity; however, the long-term behavior of both reintegration, cleaning, and protection systems requires further evaluation. The results achieved so far support the development of sustainable and flexible conservation strategies for the conservation of contemporary street and urban murals and will guide the future application of the selected materials and methodologies in pilot conservation interventions on the mural chosen as a meaningful case study within the broader research. Full article

Preventive conservation and restoration of mural paintings in hypogean environments is a significant challenge. These types of settings are particularly difficult to manage due to their peculiar morphological and microclimatic features. Since its foundation in 1939, the Central Institute for Restoration (Istituto Centrale per il Restauro—ICR) within the Italian Ministry of Culture has been engaged in the prevention and safety of these unique cultural heritage assets. Starting from a holistic analysis of vulnerability and hazards specific to hypogean environments, this study examines the main risks and corresponding conservation strategies. Particular attention is given to the impact of residual risk on restoration decision-making, with the aim of defining logistical and operational requirements to carry out sustainable and enduring interventions in these complex settings. The compatibility and durability of restoration materials under hypogean conditions are also examined. Furthermore, thanks to funding provided by the PNRR CHANGES project, a few research directions are proposed to address unresolved issues through the investigation and assessment of innovative products and methodologies. This review aims to lay the foundation for the development of guidelines incorporating protocols for the conservation and restoration of mural paintings in hypogean contexts, with particular attention to the needs and constraints imposed by these specific environments. Full article

Polychrome paintings on wooden artifacts are vital elements of cultural heritage, where plant-derived binders play a crucial role in color formation and durability. This study aims to systematically compare the chemical, optical, and surface characteristics of two traditional natural adhesives—acacia gum (AG) and tragacanth gum (TG)—to better understand their influence on the preservation and reproduction of wood-supported polychrome coatings. Fourier-transform infrared spectroscopy (FTIR) confirmed their polysaccharide-rich structures, with distinct ester and glycosidic linkages, while rheological tests demonstrated that TG exhibited higher viscosity at 1–3% concentrations, whereas AG showed a sharper increase at 5%, reflecting different molecular architectures. Colorimetric analysis combined with two-way ANOVA revealed that gum type significantly influenced color development in blue and red coatings (p < 0.001), while yellow and green coatings remained largely unaffected. Gum concentration (1–5%) generally showed no significant effect on color. All coatings exhibited a matte appearance (<3 GU), with statistical analysis indicating that gloss was mainly determined by pigment particle distribution rather than adhesive type. Surface roughness increased notably with gum concentration (p < 0.001), demonstrating that binder content strongly affects coating microtexture. Overall, pigment type was the dominant factor for color, whereas gum concentration critically influenced surface morphology. These findings provide practical guidance for optimizing natural adhesives in the conservation of traditional polychrome artifacts. Full article