Paint Degradation Research Articles

Combining Thermogravimetry‐Mass Spectrometry and Target Factor Analysis for Rapid Characterization of Volatiles from Degradation of Epoxy Paint

ABSTRACTThermogravimetry coupled with simultaneous evolved gas analysis by mass spectrometry was used for discerning organic compounds released during the thermal degradation of paint whose chemical compositions are not readily accessible. Thermogravimetric analyses up to 600°C revealed distinct degradation patterns under inert and oxidative conditions. Significant degradation of paint initiates at around 360°C and concludes at 500°C in a nitrogen atmosphere. However, under oxidative conditions, degradation began at 100°C, with notable mass loss extending from 300 to 600°C, with a distinct event at 500°C. Moreover, the overall mass loss in air has been observed to be 3% higher than that in nitrogen. The rapid characterization of the volatiles was made possible by model‐free target factor analyses of evolved gas mass spectra. The temperature‐correlated mass analyses revealed potential volatile sources, including structural breakdown and oxidative conversion. Comparative analyses revealed predominantly oxidative conversion of organics to CO2 during degradation in air. The evolution of several classes of organics during the thermal degradation of paint is a matter of great concern for postulated accident scenarios in nuclear power plants. The low molecular weight organic volatiles may be taken up by iodine aerosols released into the containment during an accident, potentially forming organic iodides, which are biological hazards. Thus, identifying these volatile organics is crucial for accurately estimating the source term of volatile organic iodine.

A Study on the Color Prediction of Ancient Chinese Architecture Paintings Based on a Digital Color Camera and the Color Design System

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.

Post-service analysis of the degradation and protective mechanisms of chromate-based structural aircraft coatings

The substitution of chromate-containing structural coating systems in aviation with alternatives complying with nowadays strict environmental, health and safety regulations remains a formidable challenge. This complexity is partly due to the absence of a standardized from-test-to-market methodology, including a performance comparison between chromate-containing and alternative coating systems. To address this gap, the present study delves into the identification of crucial degradation factors that merit inclusion in such a methodology. Concurrently, it investigates the protective mechanisms inherent in chromate-containing coating systems and proposes improvements that can be applied to alternative coating systems. This study entails a comprehensive post-service examination of the degradation of paint applied to an aircraft component with over 35 years of service, employing electrochemical, microscopic and spectroscopic techniques. The findings underscore the role of thermo-oxidation as a significant degradation factor in the aging process of such coatings. Furthermore, the investigation elucidates a notable phenomenon in which aluminium ions within the coating pores form an aluminium hydroxide gel onto which chromate adsorbs. This process contributes to an increase in pore resistance upon exposure to electrolyte, leading to a self-healing barrier effect within the coating. Remarkably, this self-healing mechanism continues to offer long-term protection even when the coating matrix is sub-optimally cured due to application errors. Furthermore, this study reveals that the significant changes in capacitance during immersion testing result primarily from inhibitor leaching, emphasizing the effectiveness of combining Electrochemical Impedance Spectroscopy (EIS) with Scanning Electron Microscopy (SEM) analysis for studying coating degradation.

A Deep Learning Approach for Digital Color Reconstruction of Van Gogh’s Paintings Using Unpaired Areas Under the Frame

Factors such as dirt accumulation, aging of paint materials and chemical reactions with the surrounding atmosphere lead to alteration and degradation of paintings. As a result, colors in the paintings can change. Van Gogh’s paintings are no exception to this process, and virtual reconstruction of the original colors is a very challenging problem. In this work we propose a novel approach for color reconstruction that does not require any pre-existing digital reconstructions, physical reproductions or artificial aging experiments, and relies purely on the data within the painting. We exploit the fact that areas of the painting located under the frame are typically well-preserved (mainly due to the protection from light exposure and dirt accumulation offered by the frame) and contain colors which are relatively close to their original look. Inspired by the recent advances in machine learning techniques for unpaired image-to-image translation, a practical weakly supervised approach for digital color reconstruction is formulated. Moreover, its performance is demonstrated for paintings by Vincent van Gogh. To our knowledge, this is the first time that a method for color reconstruction that relies purely on the data available within one painting is described in literature.

A study of cadmium yellow paints from Joan Miró’s paintings and studio materials preserved at the Fundació Miró Mallorca

The deterioration of cadmium yellow paints in artworks by Joan Miró (1893–1983) and in painting materials from his studios in Mallorca (Spain) was investigated. Analysis of samples from Miró’s paintings and from paint tubes and palettes showed that degraded paints are composed of poorly crystalline cadmium sulfide/zinc cadmium sulfide (CdS/Cd1−xZnxS) with a low percentage of zinc, in an oil binding medium. Cadmium sulfates were identified as the main deterioration products, forming superficial white crusts detected using SR µXANES and µXRD techniques. Time-resolved photoluminescence measurements demonstrated that highly degraded samples display a pink/orange emission from the paint surface with a microsecond lifetime, a phenomenon observed in other degraded cadmium yellow paints. In agreement with recent studies on altered cadmium paints, these results suggest that the stability of the paint is related to its manufacturing method, which affects the degree of crystallinity of the resulting pigment. This, together with the environmental conditions in which artworks have been exposed, have induced the degradation of yellow paints in Miró’s artworks. It was finally noted that the paints exhibiting alteration in the analysed Miró artworks have a chemical composition that is very similar to the tube paint ‘Cadmium Yellow Lemon No. 1’ produced by Lucien Lefebvre-Foinet. Indeed, paint tubes from this brand were found in the studio, linking the use of this product with Miro’s degraded artworks.

Quantification of the degradation of paintings due to the deposition of atmospheric aerosols

Soiling of cultural heritage due to air pollution is a major challenge for the conservation community and it has motivated scientists to understand the mechanisms that govern the processes of degradation and the effectiveness of potential preventative measures. The relationship between perceptible optical degradation of paintings and cumulative exposure to particulate matter has so far not been well established. This study develops a method for the quantification of optical changes resulting from particulate mass deposition on the surface of realistic paintings simulating prolonged exposure in ambient conditions. For that purpose, a painting was exposed to diesel exhaust emissions simulating exposure equivalent to approximately 5 months in polluted atmospheric conditions. The color changes, assessed by a colorimetric technique, indicated detectable color changes under close observation by the end of the exposure. Similar results were obtained following the exposure of a blank canvas acting as a reference to omit potential color sensitivity to the measured optical changes. The experiments showed that exposing the canvases to levels of moderate ambient pollution results in perceptible color difference in less than a year, through a darkening and yellowing effect indicating the vulnerability of unprotected artwork.

Formaldehyde degradation of waterborne paints over S- and C-doped titanium dioxide under visible light

Fabrication technique of S- and C-doped TiO2 nano-particle via solvo-thermal treatments was introduced, and its appearance and crystal property were studied using transmission electron microscopy, energy-dispersive X-ray and powder X-ray diffraction. All of these characterisations gave a reasonable explanation to satisfactory doping of S and C in the anatase. The photo-catalytic oxidation was conducted in environmental chambers, together with UV-VIS spectra. The catalytically active S- and C-doped anatase was assessed via surveying the formaldehyde degradation of waterborne paints, and a removal efficiency of 93.9% in 85 min illustrated an enhanced visible-light activity.

Spectral Study of the Mural Painting Degradation in Wooden Churches

Abstract The aim of the paper is a spectral study of a mural fresco from Serbesti wooden church, Dambovita county, partially painted, a historical monument from 1828 (or 1804 after some other documents). Spectral techniques as X-ray Fluorescence wavelengths dispersive (WDXRF), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR) or Raman spectroscopy, have been used in order to highlight the presence of the degradation processes. Also, the chromatic parameters have been used as additional data in order to observe the discoloring aspect of these mural fresco.

Service life prediction of paint coating of Algiers building envelopes by applying a multiple linear regression analysis

The durability of a building is strongly related to the service life of its various components, including the coatings of its envelope. The paint on the building envelope is the first protective layer exposed to the harmful effects of the climate and environmental conditions. These effects are manifested over time by degradations such as color change, cracking, peeling, etc. In this contribution, a predictive model of the service life of paints coating, applied on cementitious materials of building envelopes located in Algiers, is proposed. The model is based on a multiple linear regression analysis of descriptive results of visual investigations combined with in situ tests on the degradation of the facade paints of 45 buildings sample, selected according to their age, their distance to the coast as well as their orientation with respect to the climatic factor exposures. The proposed predictive model satisfactorily reproduces the field results.

Shrinkage and mechanical properties of drying oil paints

Understanding how the evolving molecular composition of an oil paint layer on its transition to an aged solid film affects its dimensional change and mechanical properties is fundamental to the assessment of material durability and more broadly risk of degradation of oil paintings. Tensile properties—modulus of elasticity and strain at break—as well as cumulative shrinkage were determined for a selection of oil paints from Mecklenburg’s Paint Reference Collection now after approximately 30 years of drying. The oil paints were found to get stiffer and more brittle with diminishing plastic deformation and increasingly elastic behaviour. For some paints, the increases in stiffness and decreases in the strain at break were dramatic during the late stage of drying. The observations modify the current physical model of paintings in which the mismatch in the response of glue-based ground layer and unrestrained wood or canvas support to variations in relative humidity (RH) has been identified as the worst-case condition for the fracturing of the entire pictorial layer. This study demonstrated that some paints were more brittle than the glue-based ground layer and as a consequence more vulnerable to cracking. The shrinkage of paints due to molecular relocation and/or evaporation of organic medium as they dry and age was measured. This shrinkage can exceed their strain at break and lead to fracturing of the oil paint layer if it is restrained by a dimensionally stable substrate. Consequently, after long-term drying, the cumulative shrinkage can cause oil paints to crack even in absence of fluctuations in RH or temperature. An example of cracking developed in an oil paint layer on the top of an undamaged ground layer in a historic panel painting was made evident by the X-ray microtomography.

Chemo-mechanical model for degradation of oil paintings by amorphous and crystalline metal soaps

Metal soap formation is recognised as a critical degradation mechanism in historical oil paintings, which threatens the preservation of museum collections worldwide. Metal soaps form via a complex sequence of chemical reactions between metal ions released by the pigments and saturated fatty acids originating from the drying oil. The latest advances in chemistry research suggest that metal ions and saturated fatty acids may initially react by means of a reversible reaction, which leads to the formation of metal soaps in an amorphous state. Metal soaps may subsequently crystallise via an irreversible reaction into large aggregates that deform the paint layers, potentially triggering delamination, cracking, and ultimately flaking of the paint. This paper proposes a chemo-mechanical model to predict metal soap formation and the consequent mechanical damage in historical oil paintings. The chemical process is described in terms of a set of diffusion–reaction equations, which account for both the reversible reaction between free saturated fatty acids and metal ions forming amorphous metal soap, and the subsequent irreversible reaction to crystalline metal soap. The chemical model is two-way coupled with a mechanical model that effectively describes the cracking processes caused by metal soap formation and growth. The coupling is generated from the mechanical model by accounting for the development of a chemically-induced growth strain in the crystalline metal soap. In addition, the presence of cracks locally hampers the diffusion of chemical species, which is taken into account in the chemical model through a dependency of the diffusion parameter at the crack faces on the amount of mechanical damage generated. The spatial development of the crystalline metal soap phase is simulated by using a tailor-made scanning algorithm that identifies the reaction zone in which metal soap formation takes place. The proposed model is calibrated on experimental data presented in the literature. The model is subsequently applied to analyse two numerical examples that are representative of typical metal soap-related degradation processes observed in historical oil paintings, revealing that the growth process of crystalline metal soap, the deformation of the paint surface, and the consequent cracking and delamination patterns are predicted in a realistic fashion.

Corrosion Acceleration Test on Weathering Steel and Paint-coated Steel for Bridge Structural Members

A new accelerated corrosion test authorized as ISO16539 Method B in 2013 has shown a good correlation with corrosion behavior in an actual corrosive atmospheric environment. This study aims to extend the application of this method to steel bridge members. The corrosion acceleration tests by the ISO 16539 Method B to weathering steel without anti-corrosive coating and paint-coated steel were conducted through 6 months of the test periods. A series of fundamental studies were conducted to clarify the characteristics of this test in the durability evaluation of the steel used for bridge structural members by comparing the results of the atmospheric exposure test. The accelerated test of 168 days produced the thickness reduction by 10 to 14 times larger than the exposure test of 365 days to the weathering steel. The blister area of the paint-coating as a measure of the paint degradation by the accelerated test was 11 to 14 times larger than the exposure test of 365 days to paint-coated steel. These results showed the effectiveness of the accelerated test by ISO16539 Method B to evaluate the degradation characteristics of the weathering steel and the paint-coated steel.

Vibrational spectroscopy and non-parametric analysis for biodegradation evaluation: The acrylic-emulsion paint scenario

The utility of Raman spectroscopy, characterized by excellent lateral resolution, in capturing the degradation of paints was investigated. Six fresh and six spoilt acrylic emulsion paint samples obtained from a paint company in Lagos, Nigeria and were used for this study. They were analyzed for microbial population and types using total viable count method and analytical profile index (API20E &20NE). Physicochemical quality markers [transmittance (TR), pH, OD600, and specific gravity (SG)] of the paints were evaluated by standard methods. Raman spectroscopy was deployed to analyze components of both fresh and spoilt paint samples. Lead (Pb) concentrations were assessed using atomic absorption spectrophotometry. The fresh samples had 9.50–7.00 × 108 CFU/mL; 0.07–0.12 × 106 CFU/mL; 1.54–2.70; 7.41–7.74; 1.69–1.92; 0.87–1.01 and 0.48–1.86 mg/kg for total bacterial count(TBC), total coliform count(TCC), TR, pH, OD, SG and Pb concentration respectively. Microbes observed in the fresh samples belonged to the genera Aeromonas, Bacillus, Paenibacillus, Enterobacter, Corynebacterium, Micrococcus, Pseudomonas, Burkholderia, Serratia, Klebsiella and Alcaligens. Spoilt samples had 1.80 × 109-3.20 × 1011CFU/mL; 1.02 × 105-3.30 × 106 CFU/mL; 2.69 × 109- 6.95 × 109CFU/mL; 1.21–1.71; 6.71–8.21; 1.76–1.93; 0.86–1.01 and 0.61–2.88 mg/kg for TBC, TCC, total fungal count, transmission, pH, OD600, SG and Pb respectively. The spoilt samples had the genera Pseudomonas, Staphylococcus, Streptococcus, Citrobacter, Bacillus, Enterobacter, Corynebacterium, Escherichia, Burkholderia, Alcaligens, Penicillium and Aspergillus. Raman spectroscopy indicated a shift in prominent peaks corresponding to component degradation in spoilt samples. Differences revealed by Wilcoxon Signed Rank non-parametric statistical test results further corroborate extent of microbial degradation of the paint matrix.

Numerical modelling of mechanical degradation of canvas paintings under desiccation

Mechanical damage in oil paintings on canvas show up as cracks and loss of original paint. Several parameters can contribute to this type of degradation. These paintings have a complex layered structure, typically composed of minimum four or more hygroscopic materials, each of which has different (non-linear) material properties and geometrical complexities. The mechanical degradation of canvas paintings occurs because each of these materials have diverse responses under fluctuating environmental conditions, especially temperature and relative humidity (RH). By examining the geometrical complexities and the non-linear material properties, this paper presents an investigation of three degradation phenomena under desiccation: (1) bulging formation around the corners, (2) crack formation in glue and ground layers, and (3) plastic deformation in the ground and oil paint layers.This on-going investigation provides further insights into the global and local stress distribution in typically constructed oil canvas paintings. This includes finite element method (FEM) and extended-FEM (XFEM) computer models at various scales, under desiccation from the initial RH of 90%, and 50–10%. The models consist of four to five different materials, namely lead white oil paint, red iron oxide oil paint, rabbit skin glue, linen canvas, and a spruce stretcher. The models were constructed using several combinations of materials to conduct parametric studies on the effects of glue shrinkage in paintings due to desiccation, and changing the mechanical properties of the ground layers. The relevant geometrical and mechanical properties with respect to the stress relaxation conditions are discussed in detail.The simulation results of the full-scale models show that the shrinkage of glue lowers the level of induced tension stresses in the paint layers in the central area of the painting due to the inward bowing of the stretcher. The inward deformation of the stretcher can be 4.5 times as large in a painting with a glue layer as in one without. This indicates the difficulty in forming cracks near the center of paintings purely by desiccation; however, in close-up cross-section model, cracks of 20 μm in length could still be observed in the ground exposed to an extreme RH change of 90% to 10%.The analysis of cross-section models with the full geometrical complexity for the corners showed that multiple cracks are likely to form in ground and paint layers in the corners when desiccated by 40%; RH 50–10%. Furthermore, in extreme cases with stiffer ground/paint such as zinc white, cracks can form from smaller drop in RH; RH 50% to 35%. Such cracks are form in the ground layers, and therefore, are not initially visible as they are positioned below the uncracked paint layer. This result can be the possible explanation for cracks in the ground, which are initially invisible with the naked eye, but can be revealed with X-radiographs.The results support the hypothesis that fluctuations in relative humidity can cause hidden cracks in the lower layers, which can eventually propagate further into the upper-lying paint layers of paintings. The cracks typically form when the desiccation reaches a 40% drop, but in cases of brittle materials the drop causing cracks can be lower. The actual RH drop causing cracks depends on the specific material composition.

Microscale mechanochemical characterization of drying oil films by in situ correlative Brillouin and Raman spectroscopy.

Correlative Brillouin and Raman microspectroscopy (BRaMS) is applied for the in situ monitoring of the chemical and physical changes of linseed oil during polymerization. The viscoelastic properties of the drying oil throughout the phase transition were determined by Brillouin light scattering (BLS) and joined to the Raman spectroscopic information about the chemical process responsible for the oil hardening. A comparative study was then performed on an oil mock-up containing ZnO, one of the most common white pigments used in cultural heritage. The intriguing outcomes open new research perspectives for a deeper comprehension of the processes leading to the conversion of a fluid binder into a dry adhering film. The description of both chemical and structural properties of the polymeric network and their evolution are the basis for a better understanding of oil painting degradation. Last, as a feasibility test, BRaMS was applied to study a precious microfragment from J. Pollock’s masterpiece Alchemy.

Modelling the Interaction between Carboxylic Acids and Zinc Oxide: Insight into Degradation of ZnO Pigments.

Computational modelling applied to cultural heritage can assist the characterization of painting materials and help to understand their intrinsic and external degradation processes. The degradation of the widely employed zinc oxide (ZnO)—a white pigment mostly used in oil paints—leads to the formation of metal soaps, complexes of Zn ions and long-chain fatty acids coming from the degradation of the oil binder. Being a serious problem affecting the appearance and the structural integrity of many oil paintings, it is relevant to characterize the structure of these complexes and to understand the reaction pathways associated with this degradation process. Density functional theory (DFT) calculations were performed to investigate the adsorption of the acetate and acetic acid on relatively large ZnO clusters and the formation of Zn–acetate complexes. Carboxylic acids with longer alkyl chains were then investigated as more realistic models of the fatty acids present in the oil medium. In addition, DFT calculations using a periodic ZnO slab were performed in order to compare the obtained results at different levels of theory. Optimization calculations as well as the formation energies of the ZnO@carboxylate coupled systems and the thermodynamics leading to possible degradation products were computed. Our results highlight the potential for DFT calculations to provide a better understanding of oil paint degradation, with the aim of contributing to the development of strengthening and conservation strategies of paintings.

Degradation of paint and textile industrial effluents by indigenous bacterial isolates

Untreated paint and textile effluents discharged from industries cause serious environmental threats to fauna and flora. This study thus, investigated the potential of different indigenous bacterial cells for the degradation of paint and textile effluents. Paint and textile effluents samples were aseptically collected from paint and textile industries. Physical, chemical, heavy metals properties and microbial load of the effluent were investigated using standard methods. Enrichment, Isolation and identification of bacterial isolates were determined using the standard microbiological methods. Screening of paint and textile effluents degraders was carried out using solid phase screening method. Degradation of paint and textile effluents were determined by Fourier-transform infrared (FTIR) analysis and spectrophotometrically. Results revealed that among the heavy metals analyzed, lead from paint effluent had highest value of 5.49 ± 1.2 mg/L. All the samples collected were turbid with highest and lowest values of 865 ± 1.3 and 514 ± 2.5 (NTU) from paint effluent samples. Paint effluent also recorded highest bacterial count of 6.85 ± 1.13 CFU/ml while paint sludge had the lowest count of 1.16 ± 0. 15 CFU/g. Forty-seven bacterial isolates were obtained from the paint and textile effluents samples. Screening of the 47 isolates showed that 21 isolates possessed the ability to grow on agar plates amended with paints and textile dyes. Out of the 21 positive isolates, 12 isolates were obtained from paint samples while nine isolates were recovered from the textile samples. Highest degradation activity was recorded by Bacillus subtilis (94.37% ±5.35) obtained from textile effluent sample while Micrococcus sp (46.55% ±8.30) from paint polluted soil sample had the lowest degradation activity. FTIR analysis showed the transformation and disappearance of peaks in the treated paint and textile effluents by Bacillus subtilis. This study revealed the ability and effectiveness of Bacillus subtilis in the removal of toxic materials in paint and textile effluents, thus could be applied for industrial use.

Characterization and Improvement of Heat Resistance of a Polymer-Ceramic Pressure-Sensitive Paint at High Temperatures.

Degradation of fast response pressure-sensitive paints (PSP) above room temperature is a serious problem for PSP measurements in high-temperature environments. A standard polymer-ceramic PSP (PC-PSP) composed of platinum(II)-5,10,15,20-tetrakis-(2,3,4,5,6-pentafluorphenyl)-porphyrin (PtTFPP), titania particles and poly(isobutyl methacrylate) (polyIBM) was characterized to elucidate the degradation mechanism. Applying a two-gate lifetime-based method, the PC-PSP has sufficient pressure and temperature sensitivities even at 100 °C, while the luminescence intensity significantly decreases during the test. Subsequent measurements on thermal and photostability as well as luminescence spectra reveal that the main cause of the degradation is the photodegradation of PtTFPP due to direct exposure of the dye molecules to the atmosphere. In order to suppress such degradation, a small amount of urethane resin is added to the dye solution as a simple additional step in the preparation of PC-PSP. The addition of the urethane resin significantly reduces the degradation of the PSP, although its time response is slightly slower than that of the standard PC-PSP.

Characterization of metal carboxylates relevant for degradation of oil paintings by complementary XRPD and ssNMR

Characterization of metal carboxylates relevant for degradation of oil paintings by complementary XRPD and ssNMR

Release Analysis of Nano-Titanium Dioxide (TiO2) from Paint: An Accelerated Weathering Experiment

Engineered nanomaterials (ENM’s), particularly TiO2 nanoparticles are being incorporated on paints due to their capabilities to enhance optical properties and to scatter UV radiation, which eventually protects the paint from discoloration. In this study, the release of these nano-TiO2 from paint was investigated. Two (2) types of paint were used, one containing pigment- and nano-TiO2 (P1), while the other only contains pigment-TiO2 (P2). The paints were subjected to accelerated weathering wherein the paints were exposed to cycles of UV irradiation and water condensation. The SEM-EDX results showed the distribution of the pigment- and nano-TiO2 on the surface of P1 and P2, and the changes in the morphologies before and after weathering. The photomicrograph revealed the formation of cracks on the surface of P1 brought about by the photocatalytic degradation due to the presence of nano-TiO2. Leachate samples were also collected weekly in the duration of the weathering test and were analysed using ICP-OES. The presence of Ti, which can be correlated to the release TiO2, on the samples was detected. The release of Ti from P1 and P2 showed a decreasing trend throughout the weathering experiment, having the following initial amounts of release: 1.38 mg/L and 2.10 mg/L for P1 and P2, respectively. Moreover, a graphical release mechanism for the nano-TiO2 release was conceptualized based on the results of the study. In general, potential release of nano-TiO2 from paints could happen since these TiO2 nanoparticles serve as a photocatalyst in the paint degradation when exposed to prolonged weathering conditions.