Search Results (12)

Acrylic resin is widely used in the fabrication of complete dentures, interacting significantly with the intraoral environment. However, complete dentures face challenges such as stability issues and biofilm accumulation. Glaze application is a common method to reduce surface porosity and microbial adhesion, but it also decreases surface wettability, potentially impairing salivary film formation essential for peripheral sealing. This study aimed to incorporate titanium dioxide and zinc oxide nanoparticles into the glaze applied to thermally activated acrylic resin (TAAR) via spray coating to enhance surface wettability and antifungal activity. Four groups were tested: G (TAAR + commercial glaze − control); AlG (TAAR + commercial glaze + aluminum oxide − roughness control); TiG (TAAR + commercial glaze + titanium dioxide); and ZnG (TAAR + commercial glaze + zinc oxide). Evaluations included flexural strength, color and translucency, surface analysis and antibiofilm activity against Candida albicans. Data were analyzed using one-way ANOVA. No statistically significant differences in mechanical strength (MPa) were observed (G: 108.54 ± 8.36; AlG: 113.60 ± 11.95; ZnG: 111.98 ± 9.27; TiG: 113.66 ± 10.41). Surface roughness significantly increased, and contact angle decreased, indicating improved wettability. Regardless of the antifungal activity no improvement was detected (G: 6.71 ± 0.10; AlG: 6.82 ± 0.08; ZnG: 6.72 ± 0.20; TiG: 6.66 ± 0.18). In conclusion, the incorporation of nanoparticles into the glaze improves the wettability of acrylic resin surfaces, potentially enhancing peripheral sealing and denture retention, which is beneficial for patients with reduced alveolar ridge height. Full article

Marine biofouling presents a persistent challenge for maritime industries, necessitating the development of eco-friendly and intelligent antifouling strategies. In this work, an ATP-responsive nanocontainer was developed by encapsulating a natural organic compound (CS106-10), isolated from Talaromyces trachyspermus in cold seep sediments, together with D-phenylalanine (D-Phe) into ZIF-90 nanoparticles (D-Phe/CS106-10@ZIF-90). These nanoparticles were incorporated into zinc acrylate resin to fabricate a novel self-polishing antifouling coating. CS106-10, as a natural antifoulant, provided efficient and environmentally sustainable bactericidal activity, while D-Phe acted as a synergistic adjuvant to inhibit and disrupt biofilm formation. More importantly, the ATP-responsive ZIF-90 framework enabled controlled, on-demand release of antifouling agents in response to local metabolic signals associated with biofilm growth. Laboratory and real-sea evaluations confirmed that the composite coating effectively suppressed biofilm formation and significantly reduced the required dosage of conventional toxic antifoulants. This study integrates a natural antifoulant with an ATP-responsive metal–organic framework, providing new insight for developing antifouling coatings. Full article

In addition to zinc oxide-based cements, resin-based materials are also available for temporary cementation. The aim of this in vitro study was to determine the influence of the different material compositions on temporary bonds. In nine test series (n = 30), temporary bis-acrylate single-tooth crowns were bonded onto prefabricated titanium abutments with nine different temporary luting materials. After simulating an initial (24 h, distilled water, 37 °C), a short-term (7 days, distilled water, 37 °C) and a long-term provisional restoration period (12h, distilled water, 37 °C; thermocycling: 5000 cycles) in subgroups (n = 10), the bond strength was examined using a combined tensile–shear test. Statistical analysis was performed by univariate analysis of variance or a non-parametric Kruskal–Wallis test, followed by post hoc tests. Of the three resin-based materials, two showed significantly higher bond strength values compared to all other materials (p < 0.001), regardless of the storage procedure. The resin-based materials were followed by eugenol-free and eugenol-containing zinc oxide materials. Significant intragroup differences were observed between the composite-based materials after all storage periods. This was only observed for some of the zinc oxide-based materials. The results show that under in vitro conditions, not only the composition of the temporary luting materials but also the different storage conditions have a significant influence on temporary bonds. Full article

Coating materials are used on surfaces such as steel and ceramic to offer protection, corrosion resistance, wear and erosion resistance, a thermal barrier, or aesthetics. Although organic coating materials such as epoxy resins, silane, and acrylic are widely used, there are restrictions and drawbacks associated with their use, including the ease with which cracking, hazardous and harmful human health and environment, peeling, and deterioration occur. Organic matrices also have the capacity to release vapor pressure, which can lead to the delamination of coatings. Geopolymer coating materials offer an environmentally friendly solution to this concern to encourage sustainable growth. The simplicity with which geopolymers can be synthesized and their low emission of greenhouse gases such as CO₂, SO₂, and NO_x are advantages of geopolymers. The advent of geopolymer coatings with photocatalytic properties is advantageous for the decomposition of pollution and self-cleaning properties. The aim of this paper is to study the optimum solid-to-liquid ratio of metakaolin geopolymer paste added TiO₂ and ZnO by adhesion strength. Through iterative mixture optimization, we investigated the effects of different design parameters on the performance of a metakaolin-based geopolymer as a coating material. The assessed material was a metakaolin which was activated by an alkali activator (a mixture of sodium hydroxide and sodium silicate), with the addition of titanium dioxide and zinc oxide as photocatalyst substances. Varying proportions of solid-to-liquid ratio were tested to optimize the best mix proportion related to the coating application. Adhesion analyses of geopolymer coating paste were evaluated after 7 days. According to the findings, the optimal parameters for metakaolin geopolymer coating material are 0.6 solid-to-liquid ratios with the highest adhesion strength (19 MPa) that is suitable as coating material and enhanced the properties of geopolymer. Full article

Painting antifouling coatings is one of the most important methods to prevent marine biofouling. Acrylic resin is widely used in marine antifouling because of its excellent stickiness, water resistance, and film-forming capabilities. At present, the widely used acrylate antifouling coatings require a high concentration of cuprous oxide as antifoulant. The release and accumulation of copper ions are the main factors affecting the marine environment. In this study, BIT–allyl methacrylate (BM) and zinc acrylate (ZM) were selected as functional monomers copolymerized with methyl methacrylate (MMA) and butyl acrylate (BA) to prepare a series of BIT acrylate antifouling resins. The inhibitory effects of all resins against marine bacteria (S. aureus, V. coralliilyticus, and V. parahaemolyticus), marine algae (Chlorella, I. galbana, and C. curvisetus), and barnacle larvae were studied. Moreover, marine field tests on the BIT modified resin in coastal waters were conducted. The results demonstrate that the grafted BIT–zinc acrylate resin not only exhibits excellent antifouling properties but also a significant self-polishing performance, providing a novel strategy to design a long-term antifouling resin with stable antifoulant release. Full article

In this study, the investigation of the oil painting on canvas I Tesori del Mare made by Plinio Nomellini in 1901 is presented. The aim of the research was threefold: the examination of the state of conservation in view of the restoration treatment, together with the identification of the causes of degradation and the study of the artistic technique. During the years, the artwork underwent several cleaning and fixing interventions, resulting in a patchy appearance of the surface. Nevertheless, the presence of consistent liftings persists, while the protective coating shows uneven chromatic alteration, both requiring further analysis. Multispectral imaging allowed for better visualization of the figuration’s structure and the restored areas. The combined use of Raman spectroscopy, Fourier Transform Infrared spectroscopy in the Attenuated Total Reflection mode (FT-IR ATR), and Scanning Electron Microscopy coupled with an Energy Dispersive Spectroscopy (SEM/EDS) enabled better understanding of the stratigraphy through the identification of some pigments, the binder, and the aged varnish layer on the top. SEM/EDS highlighted the presence of zinc in both the ground layer and the paint layers. Furthermore, FT-IR ATR spectroscopy showed peaks related to metal soaps such as zinc stearate, which are known to cause severe delamination of the paint layers, explaining the recurring lifting issues. Eventually, the varnish layer was found to be acrylic resin, presumably mixed with varnishes applied in past restoration treatments. Full article

The accumulation of marine biological growth has irreversible negative effects on shipping and coastal fisheries. In this paper, a new antibacterial nanofiller—triazole fluoroaromatic hydrocarbon−modified nano−zinc oxide (ZnO−APTES−TRF)—was prepared by a Cu(I)−catalyzed azide–alkyne click chemical reaction. The modification of nano−ZnO with triazole ring fluoroaromatic hydrocarbons were testified by FT−IR, XPS, and EDS. The grafting rate of ZnO−APTES−TRF can reach 32.38%, which was verified by the TGA test. The ZnO−APTES−TRF was mixed with zinc acrylate resin to produce a low surface energy antifouling coating with a surface water contact angle of 106°. The bactericidal rate of ZnO−APTES−TRF against Escherichia coli, Staphylococcus aureus, and Pseudoalteromonas sp. can reach more than 98% due to the synergistic effect of triazole and fluorine. The 120−day marine experiment shows that the low surface energy antifouling coating of ZnO−APTES−TRF/ZA is expected to be widely used in the field of marine antifouling. Full article

For the design of stretchable and flexible high-performing materials, the reinforcement of elastomeric grades plays a crucial role. State-of-the-art fillers such as carbon black benefit from a high reinforcement but often negatively affect the processing and mixing properties of rubber compounds. To overcome this drawback, the synergistic properties of hybrid in situ filler systems are studied for EPDM compounds comprising a phenol novolac resin and ionic coagents such as zinc (meth)acrylates (ZD(M)A. With the help of a combined novolac/ZD(M)A system, the compounds could be tailored in a unique way towards higher toughness and enhanced cross-link density. Further, the fracture surface of the EPDM–novolac compounds was analyzed by scanning electron microscopy, revealing a significant change of the morphology from rough and disordered to smooth and homogenous for samples with coagents. In addition, the results clearly showed that the introduction of ionic coagents is able to compensate shares of carbon black filler in the EPDM compound. The toughening of samples with zinc (meth)acrylates is attributed to the synergistic formation of an interpenetrating polymer-filler network by simultaneous covalent and ionic cross-linking. Full article

With the increasing demands to better the marine environment, environmentally friendly anti-fouling coatings have attracted attention from society. Adding hydrolyzable microcapsules without toxin to paints is a very useful and safe method to get bionic anti-fouling coatings with a micro-nano surface structure. Based on this trend, a form of environment-friendly microcapsules were prepared through mini-emulsion polymerization. The target microcapsules had a poly(urea-formaldehyde) (PUF) shell and a mixed core of silicone oil and capsaicin. Additionally, the microcapsules were introduced into zinc acrylate resin to obtain bionic anti-fouling coatings with micro-nano morphology. The effects of polyvinyl alcohol (PVA) molecular weight, stirring rate, and temperature on the morphology of the microcapsules were studied by optical microscopy (OM), scanning electron microscopy (SEM) and transmission electron microscopy (TEM). It was found that spherical nanoparticles with smooth surfaces were obtained, and the mean diameter was approximately 1.38 μm when the molecular weight of PVA was 77 K, the stirring rate was 600 rpm and the temperature was 55 °C. Fourier-transform infrared spectra (FTIR) results showed that the silicone oil and capsaicin were successfully encapsulated, the core materials of the microcapsules reached 72.37% and the yield of microcapsules was 68.91% by the Soxhlet method. Furthermore, the hydrophobicity, corrosion resistance and anti-fouling performance of the coatings were evaluated by the water contact angle, electrochemical and real-sea tests. The results indicated that the anti-fouling coatings had excellent hydrophobicity and anti-fouling performance due to the micro-nano convex structure and the release of core materials. Encouragingly, the anti-fouling coatings show excellent and long-term anti-fouling performance, which is expected to be widely applied in marine anti-fouling coatings. Full article

A new root canal sealer was developed based on urethane acrylates using polycarbonate polyol (PCPO), a macrodiol prepared in the consumption of carbon dioxide as feedstock. The superior mechanical properties and biostability nature of PCPO-based urethane acrylates were then co-crosslinked with a difunctional monomer of tripropylene glycol diarylate (TPGDA) as sealers for resin matrix. Moreover, nanoscale silicate platelets (NSPs) immobilized with silver nanoparticles (AgNPs) and/or zinc oxide nanoparticles (ZnONPs) were introduced to enhance the antibacterial effect for the sealers. The biocompatibility and the antibacterial effect were investigated by Alamar blue assay and LDH assay. In addition, the antibacterial efficiency was performed by using Enterococcus faecalis (E. faecalis) as microbial response evaluation. These results demonstrate that the PCPO-based urethane acrylates with 50 ppm of both AgNP and ZnONP immobilized on silicate platelets, i.e., Ag/ZnO@NSP, exhibited great potential as an antibacterial composite for the sealer of root canal obturation. Full article

Aim: The aim of this study was to investigate the selected properties of zinc oxide- polymethyl methacrylate (ZnO-PMMA) nanocomposites that can influence the microorganism deposition on their surface. Materials and Methods: Non-commercial ZnO-NPs were prepared, characterized and used for the preparation of PMMA nanocomposite. Roughness, absorbability, contact angle and hardness of this new nanomaterial were evaluated. PMMA without ZnO-NPs served as control. Outcomes: Compared to unenriched PMMA, incorporation of ZnO-NPs to 7.5% for PMMA nanocomposite increases the hardness (by 5.92%) and the hydrophilicity. After modification of the material with zinc oxide nanoparticles the roughness parameter did not change. All tested materials showed absorption within the range of 1.82 to 2.03%, which meets the requirements of International Organization for Standardization (ISO) standards for denture base polymers. Conclusions: The results showed no significant deterioration in the properties of acrylic resin that could disqualify the nanocomposite for clinical use. Increased hydrophilicity and hardness with absorbability within the normal range can explain the reduced microorganism growth on the denture base, as has been proven in a previous study. Full article

Waterborne coating has recently been paid much attention. However, it cannot be used widely due to its performance limitations. Under the specified conditions of the selected resin, selecting the function pigment is key to improving the anticorrosive properties of the coating. Zinc phosphate is an environmentally protective and efficient anticorrosion pigment. In this work, zinc phosphate was used in modifying waterborne acrylic coatings. Moreover, the disbonding resistance of the coating was studied. Results showed that adding zinc phosphate can effectively inhibit the anode process of metal corrosion and enhance the wet adhesion of the coating, and consequently prevent the horizontal diffusion of the corrosive medium into the coating/metal interface and slow down the disbonding of the coating. Full article