Painted Surfaces Research Articles

Images in transformation: The color and its change in a group of Portuguese paintings from the second half of the 16th century

AbstractFour panel paintings depicting episodes related to the birth of Christ and attributed to the Portuguese mannerist painter Francisco João (doc. 1558–1585) were found to exhibit a muted palette that had no correspondence with the traditionally vivid colors used in the sixteenth century to represent joyful biblical events. Complementing previous research on the disruption and loss of the red glazes in these paintings, the investigation focused on the analysis of materials, painting technique and degradation issues that further affected the original paintings, changing the viewer's perception and understanding of these artworks. The investigation combined the visual examination of the painting surface with microscopic and spectroscopic analysis of the binder and pigments. A conventional palette made of lead white, lead‐tin yellow, ochres, vermilion, verdigris, smalt, azurite, carbon black and a red lake made of brazilwood and cochineal was identified. The pigments were bound in an oil‐based medium. Chemical and physical alterations detected in paints rich in smalt and verdigris were found to be responsible for color changes affecting significant areas of the compositions. The presence of moisture and the reaction between pigment and binder leading, among other products, to soap and oxalate formation, played a central role in the long‐term behavior of the paint film. Understanding the main degradation processes involved and their consequences is crucial when interpreting an artists' color palette and designing the best approach to preserve these paintings.

A Tool for Removing Metal Inclusions from the Surface of Paint and Varnish Car Coatings

In this article, we presents the synthesis and research of a tool for removing metal inclusions from the surface of car paint coatings. The optimal composition of the product was determined, which includes sodium laureth sulfate, citric acid, sulfosalicylic acid, hydrogen peroxide and water. As a result of the conducted studies, a connection was established between the composition and the physicochemical, surface-active properties of the developed agent. Approbation of this tool was carried out, which confirmed its effectiveness and showed that within 30–45 s after applying the developed tool, not only are metal inclusions on the surface of car paint coating removed but also mineral contaminants in the form of sand, earth, clay and other particles. The aim of the work was to develop and optimize a method for obtaining a low-toxicity, highly effective agent for removing metal inclusions from the surface of car paint coatings and to investigate its effectiveness, as well as its physicochemical, optical and surface-active properties.

Green Synthesis of Ligand, Volumetric Analysis Using Micellar Medium and Antibacterial Investigations on Cu (II)-thiosemicarbazone Systems

Surfactants containing potential donor ligands can coordinate with metal ions and such compounds can beused for the removal of toxic metals and organometallic compounds from aqueous systems. Micelles haveplayed role as soil and water decontamination agents. Micellar solutions and microemulsions are efficientenvironmentally-friendly agents for cleaning artworks, especially for the selective removal of aged polymericcoatings from the surface of wall paintings. Thus micelles have great importance in chemistry. Presentwork explains the synthesis of ligand (4-(Diethylamino) benzaldehyde thiosemicarbazone) by conventionalas well as green method, volumetric analysis and antimicrobial investigations on Cu (II)- Thiosemicarbazone complexes. Solution studies on the complexes have also been carried out in different micellar (SDS, HTAB,TX-100 ) systems at 25 °C. Stability constants have been determined in 60% ethanol by pH metric study. Protonligand stability constant and metal-ligand stability have been determined potentiometrically. Antibacterialinvestigations have been carried out against, S. aureus, B.substilis bacterial strain.

Bioinspired microgroove arrays with drag reduction and hydrophobic properties

Reducing energy consumption is one of the most effective ways to solve the problem of energy shortage. In this work, nature-inspired paint microgroove arrays with different periods were fabricated using a one-step laser ablation method. A wind tunnel experiment was performed at two wind speeds, 27.7 and 33.3 m/s, to collect drag force data on smooth and structured paint coatings. The results showed that microgroove arrays oriented perpendicular to the flow direction were beneficial to drag reduction, and a drag reduction rate of up to 7.2% was obtained. Meanwhile, the microgroove arrays induced by laser ablation changed the wettability of the paint surface to hydrophobicity. The contact angle shows a slightly decreasing trend with an increase in the periodic scale. Furthermore, the anticorrosion properties of these microgrooves make them advantageous in harsh environments. The fabricated drag-reducing paint microstructures, with the features of self-cleaning and durability, have the potential to be applied on vehicles to realize speed improvement and energy saving.

Painted spaces: an exploration through embodied and expansive practice

ABSTRACT This article investigates the nature of perceptual and actual spaces created and occupied by painting. The focus is on two artistic projects taken up by the author that incorporate sculptural elements and site-specific explorations to create a series of work. The body of work retains characteristics unique to painting. These projects are situated against the background of a similar trend in contemporary painting that sees many painters taking their painterly gesture outside of the bounds and flat surface of the canvas. This investigation is also a search for establishing theory-practice relation as the author's own practice is analysed with the support of Maurice Merleau-Ponty's phenomenological theory of embodied perception. This theory proposes the radical notion that sensation is an active reflective process and vision works in unity with different tactile and kinaesthetic senses. Reflective analysis of author's evolving practice – from the two-dimensional flat canvas to expansive installations on the terrain of a Himalayan village – opens up a productive opportunity for exploring how contemporary paintings incorporate and respond to space. Application of pigments through gestural brushstrokes on appropriate surfaces and strategically positioning these painted surfaces following compositional rules are ways of creating paintings in an expanded space.

Electrostatic Interactions to Attach Latex to Pigment Surface to Reduce Binder Migration

For many paints, paper coatings, and other pigmented coatings, latex and soluble binders are used to impart mechanical properties. However, non-uniform latex binder distributions are often observed in the thickness direction during application and drying, leading to quality issues. While several publications have documented this issue, few solutions are offered in the literature. Here we report a simple process to use electrostatic interactions to attach latex binder to pigments. Coating suspensions are generated using cationic precipitated calcium carbonate (PCC) pigments that are mixed with anionic styrene-butadiene (SB) latex binders resulting in latex-covered pigments. The migration of latex binder in coatings generated on various substrates under various drying conditions was measured using Raman spectroscopy and compared with reference coatings. The new system shows reduced latex binder migration for most situations than those obtained with the reference coating. The coated papers were also measured for strength, opacity, gloss, water drainage rate, and porosity. Little difference is seen in the picking strength of the coating and gloss compared to coatings prepared with standard formulations. Water drainage rate, opacity, and porosity were higher for latex-covered pigment (LCP) coatings than the reference standard coating; this increased porosity is likely due to the strong electrostatic attraction that exists between the cationic pigment and anionic latex binder that reduces the densification of the coating during drying.

Study on coated titanium dioxide pigment and its performance test

In this study, TiO2/Al2(SO4)3 and ZrO2 composite pigments were prepared with Al2(SO4)3 and ZrO2 as coating agents. Firstly, Al2(SO4)3 was added into titanium dioxide pigment, and then ball-milled and dispersed to make the surface of pigment positively charged, and then combined with ZrO2 in solution. Titanium dioxide pigment coated with Al2(SO4)3 and zirconium oxide was prepared by double titration. The reaction pH was adjusted by controlling the ammonia flow, and finally TiO2/Al2(SO4)3 and ZrO2 composite pigment was obtained. The structure of modified pigment was analyzed by SEM and particle size distribution analysis. Furthermore, the effects of Al2(SO4)3 and ZrO2 coating on the tinting strength, dispersibility and hiding power of titanium dioxide pigment in water were studied. The results show that scanning electron microscope and particle size analysis show that good Al2(SO4)3 and ZrO2 coatings can be obtained by this experimental method. In the pigment performance test, the tinting power, hiding power and dispersibility of TiO2/Al2(SO4)3 and ZrO2 composite pigment are better than those of uncoated titanium dioxide pigment.

The use of nanostructured fluids for the removal of polymer coatings from a Nuxalk monumental carving – exploring the cleaning mechanism

• Nuxalk painted carving conserved at AMNH was darkened by aged organic coatings • The stubborn coating was identified via FTIR and NMR as aged poly(vinyl acetal) • Poly(vinyl acetal) could not be removed using conventional methodologies • Nanofluids-loaded PVA-based hydrogels were used to successfully clean the carving • Lab experiments were performed to unveil the physico-chemical cleaning mechanism While undertaking treatment of a monumental Northwest Coast wooden carving at the American Museum of Natural History, conservators encountered a difficult cleaning challenge. The 19 th century painted red cedar carving served as a house entry pole in the Nuxalk village of Bella Coola in the province of British Columbia, Canada. The painted surface was weathered by years out of doors in front of the house of Chief Pootlass and obscured by darkened museum-applied coatings and grime acquired during more than 100 years of open display at the museum. The methods used to reduce the grime and cellulose nitrate coating found on the surface overall were not successful when applied to the green painted areas on the bottom of the pole, as it was covered with an additional coating of poly(vinyl acetal) resin. The present work reports on the testing and use of aqueous nanostructured fluids (NSFs) and hydrogels for succesfully cleaning these areas, where other methods could not be used safely. There have only been a few published examples of these recently developed cleaning fluids and gels being used on art objects and this is the first known use on this type of material. Further analyses were performed following the cleaning. Micro-reflectance FTIR, optical microscopy, SEM-EDX, and NMR were used to characterize paint and coating samples taken from the carving. In addition, laboratory tests were performed to evaluate the response of poly(vinyl acetal) to a selection of NSFs, providing an understanding of the mechanisms underlying the successful cleaning performed on the pole by the conservators.

Reflectance of Oil Paintings: Influence of Paint Layer Thickness and Binder Amount

Roughness, pigment impurities, and neoformed minerals are important factors affecting the reflectance of painted surfaces. However, other factors that have not yet been studied in detail, such as the total thickness of the paint layer and the amount of binder, should also be considered. In this research, oil painting mock-ups, each made with a different number of layers of paint containing a single pigment (lead white, orpiment, cinnabar, azurite or malachite) mixed with different proportions of oil binder, were examined using a hyperspectral imaging system. The results indicate that these characteristics do not directly influence the reflectance of the painted surface. Interestingly, we found that the distribution of the pigments and the oil binder in the paint system (and pigment-binder interaction) are also key to understanding the reflectance values. Thus, accumulation of oil on top of the uppermost paint layer in the multilayer painting mock-ups caused a reduction in reflectance. The increased translucency of the oil paint containing lead white pigment also modified the reflectance, possibly due to the formation of metal soap. Other factors found to affect the reflectance of the painting mock-ups are discussed.

Multifunctional superhydrophobic and cool coating surfaces of the blue ceramic nanopigments based on the heulandite zeolite

The heulandite zeolite was successfully used as the host structure for a new Co-based blue colorant ceramic pigment. The method was the ion exchange of Co and Zn cations with the host structure, which induced a heat-collapsed structure followed by a recrystallization process at 1200 °C/h. The synthesized blue pigment was coated by spraying on the surface of pre-sintered ceramic tile followed by firing at 980 °C/10min. For modification of its surface, ZnO nanoparticles (NPs) and commercial antifouling were used. The blue powder pigment and ceramic coated surface were characterized with XRD, Rietveld refinement, TGA-DTA, FE-SEM-EDS, BET-BJH, UV-VIS-NIR spectroscopy, CIEL*a*b* color measurement, water contact angle (WCA), and roughness analysis. The single-crystal Co-willemite has been achieved (b* = −45 and a* = −0.5). The blue pigment coated on the surface after being modified with ZnO NPs and antifouling revealed a superhydrophobic surface with WCA = 153.7°. Due to this, a low water sliding angle of less than 5° have achieved. The surface showed high thermal stability and adherence. The superhydrophobicity was mainly due to the micro-nanopatterned lotus leaf-like crystal structure and roughness of 3.15 μm on the surface. The surface showed 64% total reflectance from 700 to 2500 nm (UV and NIR), which resulted in a perfect candidate for a cool coating.

Nanostructured fluids confined into Highly Viscous Polymeric Dispersions as cleaning tools for artifacts: A rheological, SAXS, DSC and TOF-SIMS study

The development, and the structural and mechanical characterization of an new complex system composed by an oil-in-water microemulsion (μE) embedded in a aqueous 3D Highly Viscous Polymeric Dispersion (HVPD) of poly(vinyl alcohol) (PVA) cross-linked by borax, is here presented together with its possible implications in paintings conservation. The HVPD/μE was characterized by Small Angle X-Rays Scattering (SAXS), Differential Scanning Calorimetric (DSC) and rheology to obtain information about the mutual effect of the μE and of the PVA network on both the nanostructure of the μE, and on the mechanical behavior of the system. Experimental data indicate that the nanostructure of the μE is retained even in the presence of the PVA/borax network whose mechanical properties are enhanced by the presence of the nanofluid. The effect of HVPD/μE on organic molecules thin films of varnish coatings usually used on easel paintings, was studied by Attenuated Total Reflection Fourier Transform InfraRed spectroscopy (ATR-FTIR) and Time-of-Flight Secondary Ion Mass Spectrometry (TOF-SIMS). The results showed that an interaction occurred leading to the extraction of the organic molecules within the HVPD/μE. The applicative consequence was that the HVPD/μE complex fluid revealed itself to be a potential, very powerful and “green” tool for selective cleaning of easel paintings affected by artificial aged coatings, with very low environmental impact and leaving no residues onto the painting surface.

Empirical analysis of amylolytic and proteolytic activities of microbial isolates recovered from deteriorating painted wall surfaces in Lagos Nigeria

The biodeterioration of painted walls have been associated with several biological mechanisms such as organic acid production and enzymatic activity of microorganisms amongst other factors. Therefore, this study aims to reveal the involvement of amylases and proteases from indigenous microbes on biodeteriorating painted walls. Microbial strains isolated from biodeteriorating painted walls of selected buildings in Lagos, Nigeria and previously characterized as belonging to the genera Pseudomonas, Candida, Fusarium, Aspergillus, Cerrena and Meyerozyma were used in this study. Amylolytic and proteolytic activities at varying conditions of temperature, pH, incubation time and substrate concentrations were tested. To bridge the knowledge gaps regarding statistical quantification of enzymatic mechanisms in biodeterioration, the Wilcoxon signed rank sum test was used to test the hypothesis that amylolytic/proteolytic activities are equal at all conditions tested. The conditions for optimal activity were observed to be 24h, 37oC, pH 2 and 0.01% substrate concentration and 48h, 25oC, pH 2, and 1% substrate concentration for amylase and protease respectively. Wilcoxon signed rank test revealed that amylolytic and proteolytic activities do not impact aesthetics on painted walls equally at all environmental conditions considered.

Assessment of cleaning techniques and its effectiveness for controlling biodeterioration fungi on wall paintings of Maijishan Grottoes

Biodeterioration is one of the main challenges in conservation of cultural heritage. This study tested and evaluated non-destructive methods to clean and control the microbial mycelia grown on the surface of wall paintings at the World Cultural Heritage Site of Maijishan Grottoes in China. Culture-dependent methods were used for isolation of fungi prior to identification by ITS rRNA gene sequences. The mycelia grown on the surface of wall paintings were removed with soft brushes under a negative pressure provided by a modified vacuum pump, and the pre-screened biocides were then selected and applied. Using a portable microscope, a microbial ATP bioluminescence detector, and a colorimeter, the effectiveness of cleaning and controlling against fungal mycelia on the wall paintings was evaluated. The results showed that the fungal isolates were dominated by Arachnomyces spp. with 92.28% sequence identity. Other major culturable fungal isolates were Parengyodontium album, Beauveria bassiana, and Scopulariopsis brumptii. The microscopic examination indicated the surface of the wall paintings was nearly free of visible fungal mycelia after the manual removal. There was a significant reduction of ATP bioluminescence before (43,303 ± 10, 280 RLU/cm2) and after (2,833 ± 388, RLU/cm2) the mechanical removal. The color difference (ΔE∗ab value) were less than 2.0 before and after biocide treatment, such difference could almost be ignored. Additionally, octylisothiazolinone was found to be the most efficient biocide for controlling fungal growth and could be an emergency protection measure. Furthermore, the key environmental factors that triggered periodic breakouts of the microorganisms on wall paintings were long-term higher relative humidity at the interface of earthen plaster layer and supporting sandstone during raining seasons and poor ventilation of the cave. This study provides a reference for the scientific conservation of biodeteriorated ancient wall paintings.

An Object Detection Model for Paint Surface Detection Based on Improved YOLOv3

To solve the problem of poor performance of the target detection algorithm and false detection in the detection of paint surface defects of office chairs five-star feet, we propose a defect detection method based on the improved YOLOv3 algorithm. Firstly, a new feature fusion structure is designed to reduce the missed detection rate of small targets. Then we used the CIOU loss function to improve the positioning accuracy. At the same time, a parallel version of the k-means++ initialization algorithm (K-means||) is used to optimize and determine the parameters of the a priori anchor so as to improve the matching degree between the a priori anchor and the feature layer. We constructed a dataset of paint surface defects on the five-star feet of office chairs and performed optimization training, and used multiple algorithms and different datasets to conduct comparative experiments to validate the algorithm. The experimental results show that the improved YOLOv3 algorithm is effective in that the average precision on the self-made dataset reaches 88.3%, which is 5.8% higher than the original algorithm. At the same time, it has also been verified based on the Aliyun Tianchi competition aluminum dataset, and the average precision has reached 89.2%. This method realizes the real-time detection of the paint surface defects of the five-star feet of the office chair very well.

Assessing the effectiveness of several passive design strategies using the CIBSE overheating criteria: case study of an Earth Brick Shell House in Johannesburg, South Africa

This study seeks to evaluate the efficacy of several passive design strategies to reduce the risk of overheating in a Compressed Stabilized Earth Brick (CSEB) house situated in Johannesburg. The roof features CSEB masonry vaults and the walls were built from dry-stack (mortarless) masonry. The vaults were initially coated with maroon paint, which resulted in uncomfortably high temperatures during summer months. Several passive design strategies were considered to improve the thermal performance, and the effectiveness of each were assessed against the CIBSE TM52: 2013 overheating criteria. Surface shading and painting external surfaces white were especially effective at reducing the potential of overheating in the first-floor vaults. Ventilating the space in the late afternoon and evening reduced the period during which indoor operative temperatures exceeded Tmax. An insulated ceiling proved effective at reducing the indoor temperature in early- and late-summer but had little impact on the severity of overheating during mid-summer.

The Performance of Antifouling Paint for Prolonged Exposure in Madura Strait, East Java Province, Indonesia

Antifouling paints are commonly utilized to minimize attached biofouling on the submerged marine structure. The evaluation of commercial both antifouling (AF) paints (Paint A and Paint B) for prolonged exposure has been investigated through field test in Suramadu Bridge, Madura strait, East Java Province, Indonesia. In addition, commercial anti-corrosion (AC) paints were also studied as a controlled coated specimen. The test panels containing all specimens of paint were exposure up to 3-months. Seawater quality parameters consisting of temperature, pH, salinity, conductivity, and dissolved oxygen (DO) were also measured during the test field. The coating properties, which consist of thickness, gloss, hardness, and adhesion strength, were carried out. It was found that both antifouling paints are remarkable to protect attached fouling organisms, but not anti-corrosion paints. Both antifouling paints' properties gradually decrease, such as adhesion strength and gloss, but not in their hardness. There were attached various fouling organisms such as barnacles, tubeworms, and brown algae, where barnacles mainly in the surface of both AC paints after exposure. Based on the result, there was no or less primary biocide of Cu2O in both AF paints where that biocide can inhibit those fouling after three months of exposure. The rapid reduction of thickness for both AF paints is maybe predominantly induced by seawater current rather than pH, salinity, and temperature.

Methodology Of Imaging Photometric Device Using In Museum

A method of using a digital imaging luminance meters (ILMD) for noncontact measurement of the illumination distribution over the surface of paintings is proposed. These measurements require a digital imaging luminance meters, an auxiliary diffuse reflection screen, and a ILMD software. The estimation of uncertainty of proposed method is fulfilled.

Design and Development of Site Specific Grape Vineyard Fertilizer Applicator Prototype

The current fertiliser application methods for grape vines are labour intensive and lead to overuse of fertiliser. Frequent rain and vineyard orchard wash over often pollute water sources. Therefore, the right amount and placement of fertiliser can not only improve crop growth but also reduce the risk of chemicals to human health and the environment. To overcome the above problems a site specific fertiliser applicator for grape vineyard with mechanical sensing system was developed. The sensing system was designed to apply fertiliser to the root zone of the plant canopy. An experimental unit was developed to optimise design and operation parameters for fertiliser production per plant. The urea's physical and engineering qualities were determined for metering mechanism design. The average value of bulk density, angle of repose, urea grain diameter, grain weight in single flute measured were 0.759 ± 0.011 gcm −3 , 26.22 ± 1.18°, 3.38 ± 0.23 mm, 1.46 ± 0.04 g, respectively. The coefficient of static friction with plywood, galvanised iron and mild steel with painted surface were observed 0.3177 ± 0.0092, 0.2868 ± 0.0077, and 0.3177 ± 0.0092, respectively. For fertiliser given per plant, the effect of exposure length was p < 0.001. The sensor device opens the delivery tube for fertiliser in 0.9–0.95s.

Analysis of the distribution of titanium oxide nanoparticles on paintings

Abstract This work is addressed to analyse the distribution of titanium dioxide nanoparticles on painting crossing data coming from two methodologies. Scanning Electron Microscope and Proton Induced X-Ray emission techniques have been employed in the study of the interaction between a colloidal dispersion constituted by titanium dioxide nanoparticles and the painting surface. The former e was used to understand and morphology of the painting and to investigate the distribution of the nanoparticles on the entire cross section of the pictorial layers. Proton induced X-ray emission is aimed at examining the surface titanium distribution by mapping. This study is important because the exploitation of the photocatalytic activity of the titanium dioxide is possible only in the case of absorption of proper energy that can promote the oxide reduction reactions and thus the dirt and dust degradation.

Hyperspectral Imaging Analyses of Cleaning Tests on Edvard Munch's Monumental Aula Paintings

ABSTRACT The development of innovative applications of imaging technologies for monitoring change in cultural heritage objects is central to the CHANGE-ITN project. Within this framework, the authors’ ongoing work targets the harnessing of hyperspectral imaging (HSI) for the documentation of cleaning treatments on the monumental University of Oslo Aula unvarnished oil paintings on canvas (1909–1916) by Edvard Munch (1863–1944). This is applicable to unvarnished paint surfaces in general. Particularly, this paper evaluates HSI techniques for the investigation of cleaning tests carried out in 2008, which targeted the removal of visible, ingrained particulate matter from Munch's unvarnished oil paints and exposed grounds on Kjemi (1914–1916). An exploratory in situ HSI campaign using visible to near-infrared (VNIR) and short-wave infrared (SWIR) cameras was undertaken to capture the soiled or previously cleaned areas on the painting's surface, with comparisons to analogous mock-ups. Principal component analysis (PCA) was used to extract information about possible trends with respect to the soiling. Results indicate that in both VNIR and SWIR ranges, the intensity of reflectance can be used to discriminate statistically between soiled and unsoiled/cleaned areas, whereas in SWIR, combination and first overtone bands of oil peaks can also serve as markers.