Search Results (17)

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

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

Epoxy resin coatings are widely employed for steel protection owing to their excellent adhesion, chemical stability, mechanical strength, and barrier properties. However, conventional bisphenol A-based resins and organic solvents may pose risks to reproductive, developmental, and immune systems, as well as contribute to atmospheric pollution. This mini-review critically evaluates recent advancements in fully waterborne bio-based epoxy nanocomposites as sustainable alternatives, with particular emphasis on their enhanced antibacterial and corrosion-resistant performance in tropical marine environments. A central focus is the role of chitosan-grafted graphene oxide (Chi-GO) as a multifunctional nanofiller that significantly enhances both antibacterial efficacy and barrier capabilities. For instance, coatings reinforced with Chi-GO exhibit up to two orders of magnitude lower corrosion current density than pristine epoxy coatings, and achieve over 95% bacterial inhibition against Escherichia coli and Staphylococcus aureus at a 1 wt.% loading. The review summarizes key synthesis methods, functional modification techniques, and commonly adopted evaluation approaches. Emerging research further underscores environmental performance metrics, including reduced volatile organic compound (VOC) emissions and improved life-cycle assessments. By integrating bio-based polymer matrices with Chi-GO, these composite systems present a promising pathway toward environmentally benign and durable protective coatings. Nevertheless, critical challenges concerning scalability and long-term stability under real-world operating conditions remain insufficiently addressed. Future research should emphasize scalable manufacturing strategies, such as roll-to-roll processing, and conduct extended tropical exposure testing (e.g., salt spray tests beyond 2000 h). Additionally, developing comprehensive life-cycle assessment (LCA) frameworks will be crucial for sustainable industrial implementation. Full article

Printed electronics (PEs) are rapidly attracting interest, especially in wearable sensors, smart textiles, and IoT devices. Conductive inks, essential for the fabrication of PE, must be highly conductive, cost-effective, biocompatible, easy to prepare, and less viscous. Conductive inks comprise a conducting material (metals like silver, gold, copper, or carbon-based alternatives like graphite, graphene, and carbon nanotubes), a binder, and a solvent. In this work, a water-based graphite conductive ink is developed using graphite as a conductive material, corn starch powder (non-toxic and biodegradable) as a binder, and distilled water as a solvent. Firstly, corn starch powder is added to distilled water, which is heated up to 100 °C and stirred continuously until a homogeneous gel-like mixture is formed. After cooling the mixture, graphite powder is added to it, and it is stirred for an hour at 450 rpm to obtain the ink. To check the conductivity, the ink is brush-painted on a paper substrate with a dimension of 20 mm × 10 mm and the result shows a low ohmic resistance of ~560 Ω, confirming the highly conductive nature of the ink. Additionally, thermogravimetric analysis (TGA) is performed on the prepared ink to evaluate its thermal stability, and a very strong X-ray diffraction (XRD) peak obtained at 2θ° = 26.5426° and a small peak at 2θ° = 54.6145°, along with a few other small peaks, confirms the presence of graphite with corn starch. Thus, this conductive ink can be used for PEs owing to its affordability, biocompatibility, and ease of preparation. Full article

The electro-Fenton process is based on the generation of hydroxyl radicals (OH•) from hydroxide peroxide (H₂O₂) generated in situ by an oxygen reduction reaction (ORR). Catalysts based on carbon gels have aroused the interest of researchers as ORR catalysts due to their textural, chemical and even electrical properties. In this work, we synthesized metal-free electrocatalysts based on carbon gels doped with graphene oxide, which were conformed to a working electrode. The catalysts were prepared from organic-gel-based inks using painted (brush) and screen-printed methods free of binders. These new methods of electrode preparation were compared with the conventional pasted method on graphite supports using a binder. All these materials were tested for the electro-Fenton degradation of amoxicillin using a homemade magnetite coated with carbon (Fe₃O₄/C) as a Fenton catalyst. All catalysts showed very good behavior, but the one prepared by ink painting (brush) was the best one. The degradation of amoxicillin was close to 90% under optimal conditions ([Fe₃O₄/C] = 100 mg L⁻¹, −0.55 V) with the catalyst prepared using the painted method with a brush, which had 14.59 mA cm⁻² as J_K and a H₂O₂ electrogeneration close to 100% at the optimal voltage. These results show that carbon-gel-based electrocatalysts are not only very good at this type of application but can be adhered to graphite free of binders, thus enhancing all their catalytic properties. Full article

In this study, graphene flakes were obtained using an electrolytic method and characterized using X-ray diffraction (XRD), Raman and FTIR spectroscopy, scanning and transmission electron microscopy (SEM/TEM). Graphene-based composites with varying concentrations of 0.5%, 1% and 3% by weight were prepared with acrylic paint, enamel and varnish matrices. The mechanical properties were evaluated using micro-hardness testing, while wettability and antimicrobial activity against three pathogens (Staphylococcus aureus 33591, Pseudomonas aeruginosa 15442, Candida albicans 10231) were also examined. The results indicate that the addition of graphene flakes significantly enhances both the mechanical and antimicrobial properties of the coatings. Full article

Graphene-based polymer composites are innovative materials which have recently found wide application in many industrial sectors thanks to the combination of their enhanced properties. The production of such materials at the nanoscale and their handling in combination with other materials introduce growing concerns regarding workers’ exposure to nano-sized materials. The present study aims to evaluate the nanomaterials emissions during the work phases required to produce an innovative graphene-based polymer coating made of a water-based polyurethane paint filled with graphene nanoplatelets (GNPs) and deposited via the spray casting technique. For this purpose, a multi-metric exposure measurement strategy was adopted in accordance with the harmonized tiered approach published by the Organization for Economic Co-operation and Development (OECD). As a result, potential GNPs release has been indicated near the operator in a restricted area not involving other workers. The ventilated hood inside the production laboratory guarantees a rapid reduction of particle number concentration levels, limiting the exposure time. Such findings allowed us to identify the work phases of the production process with a high risk of exposure by inhalation to GNPs and to define proper risk mitigation strategies. Full article

Water-based polyurethane paint is widely used for wood furniture by virtue of the eco-friendliness, rich gloss, and flexible tailorability of its mechanical properties. However, its low solution (water or alcohol) resistance and poor hardness and wear resistance limit its application. The emerging graphene oxide has a high specific surface area and abundant functional groups with excellent mechanical properties, endowing it with great potential to modify waterborne polyurethane as a nanofiller. In this study, graphene oxide prepared by Hummers’ method is introduced in the chemosynthetic waterborne polyurethane through physical blending. The testing results demonstrate that the appropriate usage of graphene oxide at 0.1 wt% could obviously improve water absorption resistance and alcohol resistance, significantly enhancing the mechanical properties of waterborne polyurethane paint. The corresponding tensile strength, abrasion resistance, and pendulum hardness of the graphene oxide-modified paint film increase by 62.23%, 14.76%, and 12.7%, respectively, compared with the pristine paint film. Meanwhile, the composite paint film containing graphene oxide possesses superiority, including gloss, abrasion resistance, pendulum hardness, and tensile strength in contrast with the commercial paint. The use of graphene oxide to enhance the waterborne polyurethane possesses strong operability and practical value, and could provide useful reference for the modification of waterborne wood paint. Full article

Within the paradigm of smart mobility, the development of innovative materials aimed at improving resilience against structural failure in lightweight vehicles and electromagnetic interferences (EMI) due to wireless communications in guidance systems is of crucial relevance to improve safety, sustainability, and reliability in both aeronautical and automotive applications. In particular, the integration of intelligent structural health monitoring and electromagnetic (EM) shielding systems with radio frequency absorbing properties into a polymer composite laminate is still a challenge. In this paper, we present an innovative system consisting of a multi-layered thin panel which integrates nanostructured coatings to combine EM disturbance suppression and low-energy impact monitoring ability. Specifically, it is composed of a stack of dielectric and conductive layers constituting the sensing and EM-absorbing laminate (SEAL). The conductive layers are made of a polyurethane paint filled with graphene nanoplatelets (GNPs) at different concentrations to tailor the effective electrical conductivity and the functionality of the material. Basically, the panel includes a piezoresistive grid, obtained by selectively spraying onto mylar a low-conductive paint with 4.5 wt.% of GNPs and an EM-absorbing lossy sheet made of the same polyurethane paint but properly modified with a higher weight fraction (8 wt.%) of graphene. The responses of the grid’s strain sensors were analyzed through quasi-static mechanical bending tests, whereas the absorbing properties were evaluated through free-space and waveguide-based measurement techniques in the X, Ku, K, and Ka bands. The experimental results were also validated by numerical simulations. Full article

In this work, we report on the fabrication and photonic activation of a novel kind of photomobile polymer (PMP) film based mainly on a double layered asymmetric configuration. The PMP is cheap and extremely easy to make. It is made of PVC/isoprene tape with a layer of graphene-oxide (GO) attached. Under illumination at different intensities, and with coherent and incoherent light sources, the bending of the PMP film changes considerably. In particular, we noticed a more efficient bending effect when the film is directly exposed to high light intensities or to NIR radiation in the case of incoherent light sources. For the exposure times used in our experiments, the process is completely reversible when the light source is switched off. Additionally, if we paint the side of the PVC tape exposed to light black, the film is not able to return to its starting position and the bending results are permanent. This suggests that the presence of the GO-layer is responsible for the restoration of the position of the PMP film. Full article

The development of a piezoresistive coating produced from dispersing graphene nanoplatelets (GNPs) inside a commercial water-based polyurethane paint is presented. The feasibility of its exploitation for realizing highly sensitive discrete strain sensors and to measure spatial strain distribution using linear and two-dimensional depositions was investigated. Firstly, the production process was optimized to achieve the best electromechanical response. The obtained materials were then subjected to different characterizations for structural and functional investigations. Morphological analyses showed a homogenous dispersion of GNPs within the host matrix and an average thickness of about 75 µm of the obtained nanostructured films. By several adhesion tests, it was demonstrated that the presence of the nanostructures inside the paint film lowered the adhesion strength by only 20% in respect to neat paint. Through electrical tests, the percolation curve of the nanomaterial was acquired, showing an effective electrical conductivity ranging from about 10⁻⁴ S/m to 3.5 S/m in relation to the different amounts of filler dispersed in the neat paint: in particular, samples with weight fractions of 2, 2.5, 3, 3.5, 4, 5 and 6 wt% of GNPs were produced and characterized. Next, the sensitivity to flexural strain of small piezoresistive sensors deposited by a spray-coating technique on a fiberglass-reinforced epoxy laminate beam was measured: a high gauge factor of 33 was obtained at a maximum strain of 1%. Thus, the sensitivity curve of the piezoresistive material was successively adopted to predict the strain along a multicontact painted strip on the same beam. Finally, for a painted laminate plate subjected to a mechanical flexural load, we demonstrated, through an electrical resistance tomography technique, the feasibility to map the electrical conductivity variations, which are strictly related to the induced strain/stress field. As a further example, we also showed the possibility of using the coating to detect the presence of conducting objects and damage. Full article

The present manuscript reports on optimized formulations of alcohol-based conductive paints for electromagnetic interference shielding (EMI), which can ensure compatibility and reduce the visibility of electronic equipment, as a continuation of our previous work in this field, which examined water-based formulations for other applications. Graphite, carbon black, graphene, Fe₃O₄, Fe ore, and PEDOT:PSS in various ratios and combinations were employed in an alcohol base for developing homogeneous paint-like fluid mixtures that could be easily applied to surfaces with a paintbrush, leading to homogeneous, uniform, opaque layers, drying fast in the air at room temperature; these layers had a reasonably good electrical conductivity and, subsequently, an efficient EMI-shielding performance. Uniform, homogeneous and conductive layers with a thickness of over 1 mm without exfoliations and cracking were prepared with the developed paints, offering an attenuation of up to 50 dB of incoming GHz electromagnetic radiation. The structural and morphological characteristics of the paints, which were studied in detail, indicated that these are not simple physical mixtures of the ingredients but new composite materials. Finally, mechano-climatic and environmental tests on the coatings demonstrated their quality, since temperature, humidity and vibration stressors did not affect them; this result proves that these coatings are suitable for commercial products. Full article

The development of materials offering electromagnetic interference (EMI) shielding is of significant consideration, since this can help in expanding the lifetime of devices, electromagnetic compatibility, as well as the protection of biological systems. Conductive paints used widely today in electromagnetic interference (EMI) shielding applications are often based on organic solvents that can create safety issues due to the subsequent environment problems. This paper concerned the development of eco-friendly conductive water-based paints for use in EMI-shielding applications. Graphene nanoplatelets, polyaniline emeraldine (PANI) doped with poly(styrene sulfonic acid) (PSS) or HCl or HBr and poly(3,4-ethylenedioxythiophene) poly(styrene sulfonic acid) (PEDOT:PSS) in various ratios were employed in a water base for developing the paints. The target was to develop homogeneous water-based paint-like fluid mixtures easily applied onto surfaces using a paint brush, leading in homogeneous, uniform, opaque layers, draying fast in air at room temperature, and having quite good electrical conductivity that can offer efficient EMI-shielding performance. The results of this parametric trial indicated the optimum compositions leading in paints with optimized properties that can result in uniform, homogeneous, and conductive layers up to a thickness of over 500 μm without deformation and cracking, offering attenuation of up to 60 dBs of incoming GHz electromagnetic radiation. In addition, the structural and morphological characteristics of these paints were studied in detail. Full article

Owed to current environmental concerns and crude oil price fluctuations, the design of feasible substitutes to petroleum-based polymeric materials is a major challenge. A lot of effort has been focused on transforming natural vegetable oils (VOs), which are inexpensive, abundant, and sustainable, into polymeric materials. Different nanofillers have been combined with these bio-based polymer matrices to improve their thermal, mechanical, and antibacterial properties. The development of multifunctional nanocomposites materials facilitates their application in novel areas such as sensors, medical devices, coatings, paints, adhesives, food packaging, and other industrial appliances. In this work, a brief description of current literature on polymeric nanocomposites from vegetable oils reinforced with carbon nanomaterials is provided, in terms of preparation, and properties. Different strategies to improve the nanomaterial state of dispersion within the biopolymer matrix are discussed, and a correlation between structure and properties is given. In particular, the mechanical, thermal, and electrical properties of these natural polymers can be considerably enhanced through the addition of small quantities of single-walled carbon nanotubes (SWCNTs), multi-walled carbon nanotubes (MWCNTs), graphene (G), or its derivatives such as graphene oxide (GO) or fullerenes (C60). Finally, some current and potential future applications of these materials in diverse fields are briefly discussed. Full article

In contrast to traditional pigment colors, structural colors have developed a great potential in practical applications, thanks to their unique nonfading and color tunable properties; especially amorphous photonic structures with noniridescent structural colors have attracted considerable attention and their applications have expanded to more fields. Herein, graphene oxide (GO) and reduced graphene oxide (RGO) enhanced noniridescent structural colors with excellent mechanical robustness were established by a time-saving approach named spray coating, which allows for rapid fabrication of angular independent structural colors by spraying different photonic spray paints (PSPs) to ensure color multiplicity that was adjusted by the silica nanoparticles (SiO₂ NPs) sizes onto the substrates. The incorporation of poly(methyl methacrylate-butyl acrylate) (PMB) improved the adhesion existing among SiO₂ inter-nanoparticles and between SiO₂ NPs and the substrates, taking advantages of the low glass transition temperature ($T_g$) of butyl acrylate derivative polymer and made PMB embedded PSPs coated patterns being imparted with good mechanical robustness and abrasive resistance. The peculiar light adsorption of GO and RGO across visible light spectrum facilitate higher color saturation. The improvement in color saturation of GO and RGO doped PSPs is expected to boost the promising applications in structurally colored paintings, inks and other color-related optical fields. Full article