Materials最新文献

{"title":"Modification of Light-Cured Composition for Permanent Dental Fillings; Mass Stability of New Composites Containing Quinoline and Quinoxaline Derivatives in Solutions Simulating the Oral Cavity Environment.","authors":"Ilona Pyszka, Beata Jędrzejewska","doi":"10.3390/ma17236003","DOIUrl":"10.3390/ma17236003","url":null,"abstract":"<p><p>Billions of patients struggle with dental diseases every year. These mainly comprise caries and related diseases. This results in an extremely high demand for innovative, polymer composite filling materials that meet a number of dental requirements. The aim of the study was to modify the light-cured composition of permanent dental fillings by changing the composition of the liquid organic matrix. New photoinitiators (DQ1-DQ5) based on a quinoline or quinoxaline skeleton and a co-initiator-(phenylthio)acetic acid (PhTAA) were used. In addition, monomers that have been traditionally used in dental materials were replaced by trimethylolpropane triacrylate (TMPTA). The neutral dental glass IDG functioned as an inorganic filler. The influence of the storage conditions of the developed composites in solutions simulating the natural oral environment during the consumption of different meals on sorption, solubility, and mass changes was assessed. For the tests, fifty-four cylindrical composite samples were prepared according to ISO 4049 guidelines and stored in different solutions. Distilled water, artificial saliva, heptane, 10% ethanol, and 3% acetic acid, as well as solutions containing pigments such as coffee, tea, red wine, and Coca-Cola, were used for the studies. The samples were stored in these solutions for 7, 14, 28, 35, 42, 49, 56, and 63 days at 37 °C. The sorption, solubility, and mass changes in the tested samples were determined, and the trend of these changes as a function of storage time was presented. The results were analyzed considering the nature of the solution used, i.e., aqueous, hydrophobic, and acidic. The properties evaluated changed in a different way, characteristic for each of the abovementioned solution groups. It was found that the type of solution simulating the natural environment of the oral cavity has the greatest influence on the sorption, solubility, and changes in the mass of the tested material.</p>","PeriodicalId":18281,"journal":{"name":"Materials","volume":"17 23","pages":""},"PeriodicalIF":3.1,"publicationDate":"2024-12-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11643679/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142837271","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Synthetic Aggregates and Bituminous Materials Based on Industrial Waste.","authors":"Alexandrina Nan, Cristina Dima, Marinela Ghita, Iolanda-Veronica Ganea, Teodora Radu, Alexander Bunge","doi":"10.3390/ma17236002","DOIUrl":"10.3390/ma17236002","url":null,"abstract":"<p><p>The transition to a circular economy requires new materials and products with new production designs, technologies, and processes. In order to create new materials with physico-chemical qualities suitable for application in the building materials engineering sector, stone dust and polymer waste-two environmentally hazardous industrial wastes-were combined in this study. The materials obtained were evaluated based on an analysis performed using the Micro-Deval test. The results obtained showed a Micro-Deval coefficient value of 7.7%, indicating that these artificial aggregates can replace the natural aggregates used in road construction. Additionally, it was shown that the stone dust used could be applied as a sorbent for dyes without later leaching this dye from the final synthetic stones. Another category of materials that meets the principles of the circular economy and was developed in this study is bituminous mastic, which is currently used for the hot sealing of joints in road infrastructure. For this purpose, a composite material was developed using stone dust and cooking oil to replace the filler, a non-regenerable source used for obtaining bituminous mixtures. Specific standard methods were used to assess the degree to which the new materials approach the behavior of commercially available products.</p>","PeriodicalId":18281,"journal":{"name":"Materials","volume":"17 23","pages":""},"PeriodicalIF":3.1,"publicationDate":"2024-12-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11643777/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142837022","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"VN Quantum Dots Anchored onto Carbon Nanofibers as a Superior Anode for Sodium Ion Storage.","authors":"Xiaoyu Wu, Haimin Zhang, Jiachen Yanghe, Sainan Liu","doi":"10.3390/ma17236004","DOIUrl":"10.3390/ma17236004","url":null,"abstract":"<p><p>Vanadium-based compounds exhibit a high theoretical capacity to be used as anode materials in sodium-ion batteries, but the volume change in the active ions during the process of release leads to structural instability during the cycle. The structure of carbon nanofibers is stable, while it is difficult to deform. At the same time, the huge specific surface area energy of quantum dot materials can speed up the electrochemical reaction rate. Here, we coupled quantum-grade VN nanodots with carbon nanofibers. The strong coupling of VN quantum dots and carbon nanofibers makes the material have a network structure of interwoven nanofibers. Secondly, the carbon skeleton provides a three-dimensional channel for the rapid migration of sodium ions, and the material has low charge transfer resistance, which promotes the diffusion, intercalation and release of sodium ions, and significantly improves the electrochemical activity of sodium storage. When the material is used as the anode material in sodium ion batteries, the specific capacity is stable at 230.3 mAh g^-1 after 500 cycles at 0.5 A g^-1, and the specific capacity is still maintained at 154.7 mAh g^-1 after 1000 cycles at 2 A g^-1.</p>","PeriodicalId":18281,"journal":{"name":"Materials","volume":"17 23","pages":""},"PeriodicalIF":3.1,"publicationDate":"2024-12-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11643878/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142837730","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Hydrated Calcium Silicate Erosion in Sulfate Environments a Molecular Dynamics Simulation Study.","authors":"Mengjie You, Xiaosan Yin, Yuzhou Sun, Hairong Wu, Jimin Li, Xiangming Zhou","doi":"10.3390/ma17236005","DOIUrl":"10.3390/ma17236005","url":null,"abstract":"<p><p>To investigate the micro-mechanism of the erosion of hydrated calcium silicate (C-S-H gel) in a sulfate environment, a solid-liquid molecular dynamics model of C-S-H gel/sodium sulfate was developed. This model employs molecular dynamics methods to simulate the transport processes between C-S-H gel and corrosive ions at concentrations of 5%, 8%, and 10% sodium sulfate (Na₂SO₄), aiming to elucidate the interaction mechanism between sulfate and C-S-H gel. The micro-morphology of the eroded samples was also investigated using scanning electron microscopy (SEM). The findings indicate that the adsorption capacity of C-S-H for ions significantly increases with higher concentrations of Na₂SO₄ solution. Notably, the presence of sulfate ions facilitates the decalcification reaction of C-S-H, leading to the formation of swollen gypsum and AFt (ettringite). This process results not only in the hydrolysis of the C-S-H gel but also in an increase in the diffusion coefficients of Na⁺ and Ca²⁺, thereby exacerbating the erosion. Additionally, the pore surfaces of the C-S-H structure exhibited strong adsorption of Na⁺, and as the concentration of Na₂SO₄ solution increased, Na+ was more stably adsorbed onto the C-S-H pore surfaces via Na-O_s bonds. The root-mean-square displacement curves of water molecules were significantly higher than those of SO42-, Na⁺ and Ca²⁺, which indicated that SO42- could co-penetrate and migrate with water molecules faster compared with other ions in the solution containing SO42-, resulting in stronger corrosion and hydrolysis effects on the C-S-H structure.</p>","PeriodicalId":18281,"journal":{"name":"Materials","volume":"17 23","pages":""},"PeriodicalIF":3.1,"publicationDate":"2024-12-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11643564/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142836887","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Improving Visible Light Photocatalysis Using Optical Defects in CoO_x-TiO₂ Photonic Crystals.","authors":"Alexia Toumazatou, Elias Sakellis, Vlassis Likodimos","doi":"10.3390/ma17235996","DOIUrl":"10.3390/ma17235996","url":null,"abstract":"<p><p>The rational design of photonic crystal photocatalysts has attracted significant interest in order to improve their light harvesting and photocatalytic performances. In this work, an advanced approach to enhance slow light propagation and visible light photocatalysis is demonstrated for the first time by integrating a planar defect into CoO_x-TiO₂ inverse opals. Trilayer photonic crystal films were fabricated through the successive deposition of an inverse opal TiO₂ underlayer, a thin titania interlayer, and a photonic top layer, whose visible light activation was implemented through surface modification with CoO_x nanoscale complexes. Optical measurements showed the formation of \"donor\"-like localized states within the photonic band gap, which reduced the Bragg reflection and expanded the slow photon spectral range. The optimization of CoO_x loading and photonic band gap tuning resulted in a markedly improved photocatalytic performance for salicylic acid degradation and photocurrent generation compared to the additive effects of the constituent monolayers, indicative of light localization in the defect layer. The electrochemical impedance results showed reduced recombination kinetics, corroborating that the introduction of an optical defect into inverse opal photocatalysts provides a versatile and effective strategy for boosting the photonic amplification effects in visible light photocatalysis by evading the constraints imposed by narrow slow photon spectral regions.</p>","PeriodicalId":18281,"journal":{"name":"Materials","volume":"17 23","pages":""},"PeriodicalIF":3.1,"publicationDate":"2024-12-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11643774/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142837435","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Photo-Excited Carrier Dynamics in Ammonothermal Mn-Compensated GaN Semiconductor.","authors":"Patrik Ščajev, Paweł Prystawko, Robert Kucharski, Irmantas Kašalynas","doi":"10.3390/ma17235995","DOIUrl":"10.3390/ma17235995","url":null,"abstract":"<p><p>We investigated the carrier dynamics of ammonothermal Mn-compensated gallium nitride (GaN:Mn) semiconductors by using sub-bandgap and above-bandgap photo-excitation in a photoluminescence analysis and pump-probe measurements. The contactless probing methods elucidated their versatility for the complex analysis of defects in GaN:Mn crystals. The impurities of Mn were found to show photoconductivity and absorption bands starting at the 700 nm wavelength threshold and a broad peak located at 800 nm. Here, we determined the impact of Mn-induced states and Mg acceptors on the relaxation rates of charge carriers in GaN:Mn based on a photoluminescence analysis and pump-probe measurements. The electrons in the conduction band tails were found to be responsible for both the photoconductivity and yellow luminescence decays. The slower red luminescence and pump-probe decays were dominated by Mg acceptors. After photo-excitation, the electrons and holes were quickly thermalized to the conduction band tails and Mg acceptors, respectively. The yellow photoluminescence decays exhibited a 1 ns decay time at low laser excitations, whereas, at the highest ones, it increased up to 7 ns due to the saturation of the nonradiative defects, resembling the photoconductivity lifetime dependence. The fast photo-carrier decay time observed in ammonothermal GaN:Mn is of critical importance in high-frequency and high-voltage device applications.</p>","PeriodicalId":18281,"journal":{"name":"Materials","volume":"17 23","pages":""},"PeriodicalIF":3.1,"publicationDate":"2024-12-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11643307/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142837535","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Influence of Laser Micro-Texturing and Plasma Treatment on Adhesive Bonding Properties of WC-Co Carbides with Steel.","authors":"Tomasz Karol Wojdat, Tomasz Piwowarczyk","doi":"10.3390/ma17235999","DOIUrl":"10.3390/ma17235999","url":null,"abstract":"<p><p>This article presents research on advanced surface preparation methods for sintered carbides (WC-Co, grade B2) commonly used in the tool industry, particularly in the context of bonding these materials with C45 steel using adhesives. Sintered carbides are widely used due to their high hardness, wear resistance, and good ductility, making them ideal for manufacturing tools operating in harsh conditions. Traditional bonding methods, such as brazing and welding, often result in stresses and cracks. Adhesive bonding has therefore emerged as an effective alternative to mitigate these challenges. The research focuses on comparing the results obtained through modern surface treatment techniques, such as laser micro-texturing and plasma treatment, with traditional methods like grinding, abrasive blasting, and electrolytic etching. The influence of these methods on adhesion properties and the strength of adhesive bonds was evaluated through mechanical tests, including static shear and pull-off tests. An approximately 50% increase in the mechanical strength of adhesive joints was observed for surfaces treated with low-temperature plasma (operating voltage: 18 kV, flow of gasses: 20 l/min., treatment time: 60 s) and laser micro-texturing (infrared fiber laser, wavelength: 1064 nm (±5 nm), power: 20 W), as compared to mechanical grinding. The shear strength of the adhesive joints was equal to 32 MPa and 30 MPa on average in the case of treatment with low-temperature plasma made of helium and argon, respectively. The highest strength of an adhesive joint was equal to 34.5 MPa on average in the case of laser micro-texturing.</p>","PeriodicalId":18281,"journal":{"name":"Materials","volume":"17 23","pages":""},"PeriodicalIF":3.1,"publicationDate":"2024-12-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11643448/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142837463","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Preliminary Aspects Regarding the Anticorrosive Effect of Multi-Layered Silane-Hydroxyapatite Coatings Deposited on Titanium Grade 2 for Medical Applications.","authors":"Agata Dudek, Oliwia Kierat","doi":"10.3390/ma17236001","DOIUrl":"10.3390/ma17236001","url":null,"abstract":"<p><p>This paper presents a method for producing VTMS/HAp/VTMS/VTMS multilayer coatings on a Grade 2 titanium substrate and characterizes their structure and functional properties. Two solutions were used to produce the coatings: one based on vinyltrimethoxysilane (VTMS) and the other on hydroxyapatite (HAp) powder. The coatings were applied using immersion using the sol-gel method. Microstructural tests of the multilayer coatings were performed, their chemical composition was determined, and the structure was characterized using Fourier Transform Infrared Spectroscopy (FTIR). A detailed analysis of the geometric structure of the coatings was carried out both before and after corrosion tests. The geometric structure of the multilayer coatings was analyzed using a light microscope and an atomic force microscope (AFM). The thickness of the coatings was determined using a Testan DT-10 AN 120 157 m, and the adhesion of the coatings to the substrate was analyzed using Scotch™ tape. The corrosion resistance of the coatings in simulated body fluid was tested to evaluate their suitability for implantology. As demonstrated by the research presented in this paper, the sol-gel process can successfully produce silane coatings by adding hydroxyapatite powder. The new materials proposed in this study can effectively protect metal materials used in medicine against corrosion.</p>","PeriodicalId":18281,"journal":{"name":"Materials","volume":"17 23","pages":""},"PeriodicalIF":3.1,"publicationDate":"2024-12-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11643174/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142837599","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Styrene-Butadiene Rubber Latex Modified Mortars Prepared with High Early Strength Portland Cement.","authors":"Modestas Kligys, Giedrius Girskas","doi":"10.3390/ma17236000","DOIUrl":"10.3390/ma17236000","url":null,"abstract":"<p><p>The increased early hydration rate of high early strength cement has economic advantages in many civil engineering fields (faster formwork removal or earlier demoulding of precast elements). Styrene-butadiene rubber (SBR) latex is the most common polymer in aqueous dispersions suitable for admixing in cement-based materials. It allows the designing of structures with specific properties for a variety of applications. The analysis of literature sources has shown that different properties of SBR latex-modified cement-based material samples reported were usually measured at 3, 7, 14, and 28 days of hardening. In this research, the authors decided to investigate a combined effect of high early strength Portland cement, characterized by an increased hydration rate, and SBR latex able to retard this process for a prolonged hardening period-up to 90 days in modified mortar samples. This study covers the results of the effect of different amounts of SBR latex (5%, 10%, 15%, and 20%) on the properties of modified mortar samples with a constant water-to-cement ratio prepared with high early strength Portland cement 42.5 R. The mortar samples were prepared from local raw materials produced by the Lithuanian companies. The properties, such as dry bulk density, ultrasonic pulse velocity, capillary water absorption, compressive and flexural strengths, and toughness, after three different hardening periods (7, 28, and 90 days) of the mortar samples were investigated. The applied mathematical-statistical methods allowed a detailed prognosis of the dependence between the dry bulk density and the strength properties of modified mortar samples. The combination of 42.5 R strength class Portland cement with the SBR latex in amounts ranging from 5% to 20% seems to be suitable for designing durable structures with specific properties.</p>","PeriodicalId":18281,"journal":{"name":"Materials","volume":"17 23","pages":""},"PeriodicalIF":3.1,"publicationDate":"2024-12-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11643066/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142837639","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"On the Use of Cyclic Cryogenic Treatment to Improve the Properties of High-Speed Steel.","authors":"Paweł Pieśko, Jarosław Korpysa, Magdalena Zawada-Michałowska","doi":"10.3390/ma17235998","DOIUrl":"10.3390/ma17235998","url":null,"abstract":"<p><p>Cryogenic treatment is a process of controlled gradual cooling of the workpiece to a temperature ranging from -60 °C to even below -190 °C, holding the workpiece at this temperature and then slowly reheating it to ambient temperature. According to the current state of knowledge, the purpose of cryogenic treatment is to reduce the concentration of retained austenite by transforming it into hard martensite under low-temperature treatment. The retained austenite reduction in steels results in improved hardness, impact strength, and wear resistance. This study involved conducting comparative tests of the hardness, tensile strength, and impact strength of high-speed steel samples with and without cryogenic treatment, which made it possible to determine the effect of cyclic cryogenic treatment on the properties of this steel. In addition to that, machining tests were conducted to assess the life of a cutting tool edge made from both cryogenic-treated and non-cryogenic-treated high-speed steel. Also, the austenite concentration in the samples was measured by X-ray diffraction. Obtained results confirmed that the cyclic cryogenic treatment enhanced all tested properties of the high-speed steel.</p>","PeriodicalId":18281,"journal":{"name":"Materials","volume":"17 23","pages":""},"PeriodicalIF":3.1,"publicationDate":"2024-12-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11643623/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142837445","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}