Search Results (807)

The hybrid inorganic–organic material concept plays a bold role in multifunctional materials, combining different features on one platform. Once varying properties coexist without cancelling each other on one matrix, a new type of supermaterial can be formed. This concept showed that silver nanoparticles can be embedded together with inorganic and organic surface coatings and silicon quantum dots for symbiotic antibacterial character and UV-excited visible light fluorescent features. Additionally, fluorosilane material can be coupled with this prepolymeric structure to add the hydrophobic feature, showing water contact angles around 120°, providing self-cleaning features. Optical properties of the components and the final material were investigated by UV-Vis spectroscopy and PL analysis. Atomic investigations and structural variations were detected by XPS, SEM, and EDX atomic mapping methods, correcting the atomic entities inside the coating. FT-IR tracked surface features, and statistical analysis of the quantum dots and nanoparticles was conducted. Multifunctional final materials showed antibacterial properties against E. coli and S. aureus, exhibiting self-cleaning features with high surface contact angles and visible light fluorescence due to the silicon quantum dot incorporation into the sol-gel-produced nanocomposite hybrid structure. Full article

Halogenated flame retardants have been amongst the most widely used and effective solutions for enhancing fire resistance. However, their use is currently strictly regulated due to serious health and environmental concerns. In this context, phosphorus-based and mineral flame retardants have emerged as promising alternatives. Despite this, their combined use is neither straightforward nor guaranteed to be effective. This study scrutinizes the interactions between these two classes of flame retardants (FR) through a systematic analysis aimed at elucidating the antagonistic pathways that arise from their coexistence. Specifically, this study focuses on two inorganic fillers, mineral huntite and chemically precipitated magnesium hydroxide, both of which produce basic oxides upon thermal decomposition. These fillers were incorporated into a poly(butylene terephthalate) (PBT) matrix to be utilized as advanced-mattress FR coating fabric and were subjected to a series of flammability tests. The pyrolysis products of the prepared polymeric composite compounds were isolated and thoroughly characterized using a combination of analytical techniques. Thermogravimetric analysis (TGA) and differential thermogravimetric analysis (dTGA) were employed to monitor decomposition behavior, while the char residues collected at different pyrolysis stages were examined spectroscopically, using FTIR-ATR and Raman spectroscopy, to identify their structure and the chemical reactions that led to their formation. X-ray diffraction (XRD) experiments were also conducted to complement the spectroscopic findings in the chemical composition of the resulting char residues and to pinpoint the different species that constitute them. The morphological changes of the char’s structure were monitored by scanning electron microscopy with energy dispersive X-ray spectroscopy (SEM-EDS). Finally, the Limited Oxygen Index (LOI) and UL94 (vertical sample mode) methods were used to assess the relative flammability of the samples, revealing a significant drop in flame retardancy when both types of flame retardants are present. This reduction is attributed to the neutralization of acidic phosphorus species by the basic oxides generated during the decomposition of the basic inorganic fillers, as confirmed by the characterization techniques employed. These findings underscore the challenge of combining organophosphorus with popular flame-retardant classes such as mineral or basic metal flame retardants, offering insight into a key difficulty in formulating next-generation halogen-free flame-retardant composite coatings. Full article

The development of sustainable and functional nanocomposites has attracted considerable attention in recent years due to their broad spectrum of potential applications, including wood preservation. Also, a global goal is to reuse the large volumes of waste for environmental issues. In this context, the aim of the study was to obtain soda lignin particles, to graft ZnO nanoparticles onto their surface and to apply these hybrids, embedded into a biodegradable polymer matrix, as protection/preservation coating for oak wood. The organic–inorganic hybrids were characterized in terms of compositional, structural, thermal, and morphological properties that confirm the efficacy of soda lignin extraction and ZnO grafting by physical adsorption onto the decorating support and by weak interactions and coordination bonding between the components. The developed solution based on poly(3-hydroxybutyrate-co-3-hydroxyvalerate) and lignin-ZnO was applied to oak wood specimens by brushing, and the improvement in hydrophobicity (evaluated by water absorption that decreased by 48.8% more than wood, humidity tests where the treated sample had a humidity of 4.734% in comparison with 34.911% for control, and contact angle of 97.8° vs. 80.5° for untreated wood) and UV and fungal attack protection, while maintaining the color and aspect of specimens, was sustained. L.ZnO are well dispersed into the polymer matrix, ensuring a smooth and less porous wood surface. According to the results, the obtained wood coating using both a biodegradable polymeric matrix and a waste-based preservative can be applied for protection against weathering degradation factors, with limited water uptake and swelling of the wood, UV shielding, reduced wood discoloration and photo-degradation, effective protection against fungi, and esthetic quality. Full article

Hydrogel films receive significant attention among researchers because they combine increased stimuli responsiveness and faster responses to the already excellent properties of their component materials. However, their preparation is complex and requires that many difficulties are overcome. The present work presents a new study regarding the preparation of pure and nanoparticle-loaded alginate-based films by spin-coating. Two-microliter solutions of sodium alginate and calcium chloride with different concentrations were deposited on a glass substrate and subjected to rapid rotations of between 100 and 1000 RPM. Film formation can be achieved by optimizing the ratio between the viscosity of the solutions, depending on their concentrations and the rotation speed. When these conditions are in the right range, a homogeneous film is obtained, showing good adherence to the substrate and uniform thickness. Films containing silver nanoparticles were prepared, exploiting the reaction between sodium borohydride and silver nitrate. The two reagents were added to the sodium alginate and calcium nitrate solution, respectively. Their concentration is the driving force for the formation of a uniform film: particles of about 50 nm that are well-dispersed throughout the film are obtained using AgNO₃ at 4 mM and NaBH₄ at 2 or 0.2 mM; meanwhile, at higher concentrations, one can also obtain the precipitation of inorganic crystals. Full article

Background/Objectives: The increasing demand for aesthetics in dentistry has driven significant advancements in both materials and techniques. The primary cause of ceramic detachment in dental restorations is extensive mechanical stress, which often results in detachment and clinical complications. This study aims to improve the bond strength between NiCr-based metal frameworks and ceramic coatings by introducing biocompatible inorganic MeSiON thin films (Me = Cr or Zr) as interlayers. Methods: MeSiON coatings with a thickness of ~2 μm were deposited on NiCr alloy using cathodic arc evaporation. To tailor the stoichiometry, morphology, and mechanical properties of the coatings, the substrate bias voltage was varied: −50 V, −100 V, −150 V, −200 V. Structural and surface characterization was performed using SEM/EDS, XRD, profilometry, and contact angle analysis. The coating adhesion was evaluated by using standardized scratch testing, while the bond strength was evaluated using a three-point bending test. Results: The NiCr alloy exhibited a dendritic microstructure, and the ceramic layer consisted mainly of quartz, feldspar, kaolin, and ZrO₂. ZrSiON coatings showed superior roughness, elemental incorporation, and adhesion compared to Cr-based coatings, these properties being further improved by increasing the substrate bias. The highest bond strength was achieved with a ZrSiON coating deposited at −200 V, a result we attributed to increased surface roughness and mechanical interlocking at the ceramic-metal interface. Conclusions: CrSiON and ZrSiON interlayers enhanced ceramic-to-metal adhesion in NiCr-based dental restorations. The enhancement in bond strength is primarily ascribed to substrate bias-induced modifications in the coating’s stoichiometry, roughness, and adhesion. Full article

Lime plaster has historically been a key material in the preservation of architectural heritage in Peru; however, its availability has been restricted by state regulations that limit its production and commercialization. This study evaluates the performance of paints formulated with inorganic pigments extracted from soils in the Cusco valley, combined with natural and synthetic binders, as a sustainable alternative for the protection of heritage buildings in this Andean region characterized by high altitude, wide thermal variations, and high solar radiation. Adhesion, hardness, drying time, and weather resistance tests were conducted according to applicable ASTM standards for architectural coatings. The results show that these formulations exhibit good adhesion to historic surfaces and greater durability against extreme environmental conditions compared to traditional lime plaster. Their potential compatibility with historic substrates and lower environmental impact suggest that these paints represent a viable alternative in sustainable conservation strategies; however, further studies are needed to more accurately characterize the mineralogical composition of the pigments used. Full article

Separators are generally considered inert components in lithium-ion batteries. In the past, some electroactive polymers have been successfully applied in separator modifications for overcharge protection or as acid scavengers. This study highlights the first use of two “electroactive” carbazole polymers (copolymer 9-phenyl-9H-carbazole-phenyl [PCP] and poly(9-vinylcarbazole) [PVC]), which were each applied separately as coatings on the cathode-facing side of commercial Celgard 2325 separators, respectively, to enhance the cycling performance of 0.3Li₂MnO₃·0.7LiMn_0.5Ni_0.5O₂//graphite (LMR-NM//Gr) full cells through interphase engineering. The team observed an irreversible polymer oxidation process of the carbazole-functionalized polymers—occurring only during the first charge—for the modified separator cells, and the results were confirmed by dQ/dV analysis, cyclic voltammetry measurements, and nuclear magnetic resonance characterizations. During this oxidation, carbazole polymers participate in the process of interphase formation, contributing to the improved cycling performance of LMR-NM//Gr batteries. Particularly, oxidation takes place at voltages of ~4.0 and ~3.5 V when PCP and PVC are used as separator coatings, which is highly irreversible. Further postmortem examinations suggest that the improvements using these modified separators arise from the formation of higher-quality and more inorganic SEI, as well as the beneficial CEI enriched in LixPOyFz. These interphases effectively inhibit the crosstalk effect by reducing TM dissolution. Full article

Magnesium alloys are lightweight metals but suffer from high corrosion susceptibility due to their chemical reactivity, limiting their large-scale applications. To enhance corrosion resistance, this work combines Li–Al layered double hydroxides (LDHs) with triethylenetetramine (TETA) inhibitors to form an efficient corrosion protection system. Electrochemical tests, SEM, FT-IR, XPS, and 3D depth-of-field microscopy were employed to evaluate TETA-modified Li–Al LDH coatings at varying concentrations. Among them, the Li–Al LDHs without the addition of a TETA corrosion inhibitor decreased significantly at |Z|_{0.01 Hz} after immersion for 4 h. However, the Li–Al LDHs coating of 23.5 mM TETA experienced a sudden drop at |Z|_{0.01 Hz} after holding for about 60 h, and the Li–Al LDHs coating of 70.5 mM TETA also experienced a sudden drop at |Z|_{0.01 Hz} after holding for about 132 h. By contrast, at the optimal concentration (47 mM), after 24 h of immersion, the maximum |Z|_{0.01 Hz} reached 7.56 × 10⁵ Ω∙cm²—three orders of magnitude higher than pure Li–Al LDH coated AZ31 (2.55 × 10² Ω∙cm²). After 300 h of immersion, the low-frequency impedance remained above 10⁵ Ω∙cm², demonstrating superior long-term protection. TETA modification significantly improved the durability of Li–Al LDHs coatings, addressing the short-term protection limitation of standalone Li–Al LDHs. Li–Al LDHs themselves have a layered structure and effectively capture corrosive Cl⁻ ions in the environment through ion exchange capacity, reducing the corrosion of the interface. Furthermore, TETA exhibits strong adsorption on Li–Al LDHs layers, particularly at coating defects, enabling rapid barrier formation. This inorganic–organic hybrid design achieves defect compensation and enhanced protective barriers. Full article

Anti-icing glass is particularly important for applications where ice formation can pose safety risks or impair functionality. The challenge of anti-icing modification for glass lies in maintaining water repellency while addressing the issue of transparency and durability. In this work, leveraging the robustness and wear resistance of inorganic/organic composite materials, a highly transparent coating, with strong adhesive properties to glass substrates and repellency to liquids has been developed. Briefly, 3-glycidoxypropyl polyhedral oligomeric silsesquioxane (GPOSS) is employed as a precursor to fabricate a high-strength, high-transparency coating through modification with acrylic acid and perfluorooctyl acrylate. The inorganic component imparts strength and wear resistance to the coating, while the organic component provides hydrophobic and near oleophobic features. Furthermore, a custom-built mechanical test instrument evaluated the absolute value of the de-icing shear force. The results reveal that at −20 °C, the fluorinated modified coating only exhibit a minimum de-icing pressure of 40.3 kPa, which is 75% lower than the unmodified glass substrate. As-prepared coating exhibits a transmittance of up to 99% and can endure a high-pressure water impact of 30 kPa for 1 min without cracking. Compared to existing anti-icing coating methods, the core innovation of the fluorinated GPOSS-based coating developed in this study lies in its inorganic/organic composite structure, which simultaneously achieves high transparency, mechanical durability, and enhanced anti-icing performance. Full article

This paper presents field experiments of mineral deposition on steel, induced by cathodic polarization in natural seawater, as a sustainable strategy for the life extension of marine steel structures. Although this approach is quite well known, the ability of the mineral deposit to both protect steel from corrosion in the absence of a cathodic current, thus operating as an inorganic coating, and provide an effective substrate for colonization by microorganisms still needs to be fully explained. To this end, two identical steel structure prototypes were installed at a depth of 20 m: one was submitted to cathodic polarization, while the other was left under free corrosion for comparison. After 6 months, the current supplied to the electrified structure was interrupted. A multidisciplinary approach was used to analyze the deposits on steel round bars installed in the prototypes over time, in the presence and in the absence of a cathodic current. Different investigation techniques were employed to provide the following information on the deposit: the composition in terms of elements, compounds and macro-biofouling; the morphology; the thickness and the degree of protection estimated by electrochemical impedance spectroscopy (EIS). The results showed that under cathodic polarization, the thickness of the deposit increased to 2.5 mm and then remained almost constant after the current was interrupted. Conversely, the surface impedance decreased from 3 kΩ cm² to about 1.5 kΩ cm² at the same time, and the aragonite–brucite ratio also decreased. This indicates a deterioration in the protection performance and soundness of the deposit, respectively. Considering the trends in thickness and impedance together, it can be concluded that the preformed mineral deposit does not undergo generalized deterioration after current interruption, which would result in a reduction in thickness, but rather localized degradation. This phenomenon was attributed to the burrowing action of marine organisms, which created porosities and/or capillary pathways through the deposit. Therefore, the corrosion protection offered by the mineral deposit without a cathodic current is insufficient because it loses its protective properties. However, the necessary current can be quite limited in the presence of the deposit, which in any case provides a suitable substrate for sustaining the colonization and growth of sessile marine organisms, thus promoting biodiversity. Full article

Titanium nitride (TiN) is a typical inorganic compound capable of achieving resistance modulation by adjusting the element ratio. In this work, to deeply investigate the resistance-tunable characteristics and electron emission properties of TiN, we prepared 10 sets of TiN films by adjusting the magnetron sputtering parameters. The microscopic analyses show that the film thicknesses ranged from about 355 to 459 nm. Moreover, with the process parameters used in this work, TiN nanostructures are formed more easily when the nitrogen flow rate is ≤5 sccm, and compact TiN films are formed more easily when the nitrogen flow rate is ≥10 sccm. Elemental analyses showed that the N:Ti atomic ratios of the TiN films ranged from about 0.587 to 1.40. The results of surface analysis showed the presence of a certain amount of oxygen on the surface of the TiN film, indicating that the surface TiN may exist in the form of TiN:O. The electrical resistance test showed that the resistivity of the TiN coating ranges from 1.59 × 10⁻⁴ to 1.83 × 10⁻¹ Ω·m. And the closer the N:Ti atomic ratio is to one, the lower the TiN film resistivity is. The electron emission coefficient (EEC) results show that among the film samples from #3 to #10, sample #8 has the lowest EEC, with a peak EEC of only 1.61. By comparing the resistivity and EEC data, a novel phenomenon was discovered: a decrease in the resistivity of TiN films leads to a decrease in their EEC values. The results show that the resistivity and EEC of TiN films can be adjusted according to the film-forming components, which is important for the application of TiN in the electronics industry. Full article

Maize (Zea mays L.) relies heavily on nitrogen and phosphorus inputs, typically supplied through organic and inorganic fertilizers. However, excessive agrochemical use threatens soil fertility and environmental health. Sustainable alternatives, such as poultry manure (PM) and plant growth-promoting rhizobacteria (PGPR), offer promising solutions. This study examines the effects of a phytobiotic bacterial formulation (PHY), composed of Bacillus subtilis and Microbacterium sp., applied alone and in combination with PM, on maize’s rhizosphere bacteriobiome across key growth stages. Field trials included four treatments: a control, PHY-coated seeds, PM, and combined PHY_PM. The results show that early in development, the PM-treated rhizospheres increased the abundance of beneficial genera such as Sphingomonas, Microvirga, and Streptomyces, though levels declined in later stages. The PHY_PM-treated roots in the seedling phase showed a reduced abundance of taxa like Chryseobacterium, Pedobacter, Phyllobacterium, Sphingobacterium, and Stenotrophomonas, but this effect did not persist. In the PM-treated roots, Flavisolibacter was significantly enriched at harvesting. Overall, beneficial bacteria improved microbial evenness, and the PHY_PM treatment promoted bacterial diversity and maize growth. A genome analysis of the PHY strains revealed plant-beneficial traits, including nutrient mobilization, stress resilience, and biocontrol potential. This study highlights the complementarity of PM and PGPR, showing how their integration reshapes bacteriobiome and correlates with plant parameters in sustainable agriculture. Full article

The influence of structural water in alumina (Al₂O₃) and silica (SiO₂) coated titanium dioxide (TiO₂) pigments on the photodegradation behavior of polypropylene (PP) composites was investigated. Four commercial rutile TiO₂ pigments with varying surface inorganic coatings were incorporated into PP plaques and subjected to accelerated UV weathering to simulate outdoor exposure. Photodegradation was assessed through gloss retention measurements, the carbonyl index (CI), and stress at break retention, while pigment morphology and composition were analyzed using transmission electron microscopy (TEM) and energy-dispersive X-ray spectroscopy (EDS). Surface charge and water content were determined through the zeta potential (ζ), Karl Fischer titration, thermogravimetric analysis (TGA), and Diffuse Reflectance Infrared Fourier Transform Spectroscopy (DRIFTS). The results showed that low-alumina coating alone led to the lowest photodegradation resistance, the highest CI, and the lowest stress at break retention. In contrast, increasing alumina content enhanced photostability, reaching its maximum for combined alumina–silica coatings, which mitigated electron–hole pair migration. PP composites with high alumina–silica-coated TiO₂ exhibited higher gloss retention (36%) compared to low-alumina samples (21%). Furthermore, statistical analysis using ANOVA revealed significant differences in coating content and ζ potential among the pigment grades. These findings provide novel insights into oxide-water interactions and the impact of structural water on the photodegradation of polymer composites. Full article

The widespread phase-out of long-chain per- and poly-fluoroalkyl substances (PFASs) has created an urgent need for durable, fluorine-free water-repellent finishes that match the performance of legacy chemistries while minimising environmental impact. Here, the performance of an eco-friendly hybrid organic–inorganic treatment obtained by the in situ hydrolysis–condensation of triethoxy(octyl)silane (OS) in an amino-terminated polydimethylsiloxane (APT-PDMS) aqueous dispersion was investigated. The sol was applied to plain-weave cotton and polyester by a pad-dry-cure process and benchmarked against a commercial fluorinated finish. Morphology and chemistry were characterised by SEM–EDS, ATR-FTIR, and Raman spectroscopy; wettability was assessed by static contact angle, ISO 4920 spray ratings, and AATCC 193 water/alcohol repellence; and durability, handle, and breathability were evaluated through repeated laundering, bending stiffness, and water-vapour transmission rate measurements. The silica/PDMS coating formed a uniform, strongly adherent nanostructured layer conferring static contact angles of 130° on cotton and 145° on polyester. After five ISO 105-C10 wash cycles, the treated fabrics still displayed a spray rating of 5/5 and AATCC 193 grade 7, outperforming or equalling the fluorinated control, while causing ≤5% loss of water-vapour permeability and only a marginal increase in bending stiffness. These results demonstrate that the proposed one-step, water-borne sol–gel process affords a sustainable, industrially scalable route to high-performance, durable, water-repellent finishes for both natural and synthetic textiles, offering a viable alternative to PFAS-based chemistry for outdoor apparel and technical applications. Full article

This review article focuses on providing an accumulated knowledge on state-of-the-art composite polymer coating technologies that are studied for corrosion protection. A specific focus has been given to epoxy resin-based composite systems, considering their wide use due to remarkable chemical resistance, excellent adhesion to substrate, thermal stability, and mechanical strength. The addition of various functional polymers to the epoxy matrix has spurred significant advancements in the prevention of corrosion. Light has been shed on the epoxy resin composite systems that are produced by blending with functional polymers like conductive polymers, hydrophobic polymers, etc., and nanofillers. In many cases, the formation of a passive layer at the metal/polymer interface was aided by the addition of such a functional polymer and nanofiller to the epoxy matrix. As a result, corrosive ions are prevented from penetrating by the physical barrier that composite coatings provide. Comparable blends of epoxy and polyamide, epoxy and polyester, and epoxy/poly(vinyl alcohol) and epoxy/polyurethane have superior adhesion, wear, barrier, and anticorrosion properties due to the fine dispersion of nanocarbon and inorganic nanoparticles. The several strategies used to prevent metals from corroding are covered in this review article. Full article