Materialia最新文献

{"title":"Characterization of pentenoate-functionalized hyaluronic acid and pentenoate-functionalized gelatin hydrogels for printing and future surgical placement in regenerative medicine applications","authors":"","doi":"10.1016/j.mtla.2024.102242","DOIUrl":"10.1016/j.mtla.2024.102242","url":null,"abstract":"<div><div>Injectable hydrogels with <em>in situ</em> crosslinking may be more suitable than pre-fabricated scaffolds for surgical delivery to clinical injuries. However, low viscosity hydrogel precursors may be challenging to surgically place into an injury if the precursor leaks or is washed out. The biomaterials field for extrusion bioprinting is a fertile ground for discovering biomaterials with injectable and paste-like precursor rheology with <em>in situ</em> gelation capabilities, which may promote better material retention in clinical injuries. We previously developed and evaluated one formulation of a pentenoate-functionalized hyaluronic acid (PHA) / pentenoate-functionalized gelatin (PGel) hydrogel with a paste-like, printable precursor and rapid photocrosslinking in a spinal cord injury application. Further characterization of the material and cell response to PHA/PGel hydrogel formulations is needed to expand the bioprinting and other regenerative medicine opportunities for PHA/PGel hydrogels. In the current study, we utilized 2D NMR methods (i.e., ¹H–¹H TOCSY) to confirm and quantify a high degree of pentenoate functionalization of PGel and PHA. We characterized the stiffness, swelling, and cell viability using varying formulations of PGel or PHA/PGel hydrogels. For compression testing, a straightforward application of the Ogden model enabled evaluation of the full stress-strain range for improved moduli comparisons. We identified two formulations that best supported cell viability (i.e., 3%/10% and 4%/5% PHA/PGel). Furthermore, one of the identified formulations (4%/5% PHA/PGel) had superior printability compared to the other. With better printability and potentially better clinical surgical placement, the new PHA/PGel hydrogel formulations may be more widely applied in the bioprinting and regenerative medicine fields.</div></div>","PeriodicalId":47623,"journal":{"name":"Materialia","volume":null,"pages":null},"PeriodicalIF":3.0,"publicationDate":"2024-09-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142417789","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Bone regeneration in rabbit cranial defects: 3D printed polylactic acid scaffolds gradually enriched with marine bioderived calcium phosphate","authors":"","doi":"10.1016/j.mtla.2024.102240","DOIUrl":"10.1016/j.mtla.2024.102240","url":null,"abstract":"<div><h3>Objective</h3><div>This study aimed to evaluate the in vivo biocompatibility, mechanical performance and osteoconductive potential of 3D-printed polylactic acid (PLA) scaffolds enriched with marine bioderived calcium phosphate (bioCaP) for bone tissue engineering.</div></div><div><h3>Materials and methods</h3><div>PLA-bioCaP composite scaffolds were specifically designed for the rabbit cranial defect model by 3D printing, with a uniform distribution of open square-shaped pores and contributions in bioCaP. Physicochemical and mechanical characterization and the evaluation of biological response are presented.</div></div><div><h3>Results</h3><div>The scaffolds demonstrated mechanical properties comparable to human bones, integration with the host bone, and osteoconductive behavior promoting cell ingrowth from the defect edge. Strong mineralized tissue ingrowth through the scaffolds’ pores was observed, providing notable support to the host bone. In quantitative terms, micro-CT and histomorphometry analysis post-implantation revealed no significant differences in bone regeneration across all groups.</div></div><div><h3>Conclusion</h3><div>The 3D-printed scaffolds with perpendicular patterning, open porosity, and proposed composition displayed satisfactory mechanical properties, biocompatibility, and osteoconductive response. The scaffolds promoted bone regeneration at similar levels as the PLA. The highest contribution of bioCaP promoted a positive influence in certain histomorphometric parameters; however, it did not significantly improve their osteogenic capability. Further research is required to optimize scaffold composition and enhance their osteogenic potential.</div></div><div><h3>Clinical relevance</h3><div>This study presents a significant advancement in bone tissue engineering through the development of personalized composite scaffolds for bone-related applications. The clinical implications of this research are profound, especially considering the increasing demand for functional bone regeneration technologies capable of producing cost-effective producing cost-effective customized scaffolds.</div></div>","PeriodicalId":47623,"journal":{"name":"Materialia","volume":null,"pages":null},"PeriodicalIF":3.0,"publicationDate":"2024-09-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S2589152924002370/pdfft?md5=54f3a24d6be11d6ea6ee5071dde3f14e&pid=1-s2.0-S2589152924002370-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142310513","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Grain boundary diffusion in additively manufactured CoCrFeMnNi high-entropy alloys: Impact of non-equilibrium state, temperature and relaxation","authors":"","doi":"10.1016/j.mtla.2024.102228","DOIUrl":"10.1016/j.mtla.2024.102228","url":null,"abstract":"<div><p>Grain boundary diffusion of Ni in the equiatomic CoCrFeMnNi high-entropy alloy, produced by additive manufacturing, is measured using a radiotracer technique in an extended temperature interval of 350 to 703 K. A strongly non-monotonic temperature dependence of the Ni grain boundary diffusion coefficients (with a spectacular intermittent retardation of the diffusion rates with increasing temperature) is seen and explained by relaxation of a non-equilibrium state induced by rapid solidification during fabrication. The grain boundary excess energy of the non-equilibrium state of these grain boundaries, as estimated from the diffusion data, is found to be larger than 0.3 J/m<span><math><msup><mrow></mrow><mrow><mn>2</mn></mrow></msup></math></span>. This corresponds to an increase of about 30% of the interface energy compared to relaxed general high-angle grain boundaries. The temperature-induced evolution of the grain boundary state is analyzed in terms of the concomitant structure evolution, segregation, phase stability and precipitation in the multi-component alloy.</p></div>","PeriodicalId":47623,"journal":{"name":"Materialia","volume":null,"pages":null},"PeriodicalIF":3.0,"publicationDate":"2024-09-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S2589152924002254/pdfft?md5=3ff1246eb05b14c71387b1f571a17c17&pid=1-s2.0-S2589152924002254-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142274280","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Approximating nucleation rates of glass ceramics using in-situ X-ray diffraction","authors":"","doi":"10.1016/j.mtla.2024.102239","DOIUrl":"10.1016/j.mtla.2024.102239","url":null,"abstract":"<div><div>Glass ceramics are ideal for applications ranging from the culinary to defense industries. The properties of glass ceramics are a strong function of their microstructure, which in turn is controlled by constitutive nucleation and growth treatments. Nucleation has been extensively studied but remains an experimental and theoretical challenge. Traditional isothermal methods for measuring nucleation rates require time-consuming measurements and careful statistics, leading to only a few material systems with nucleation data available, approximately one-hundred glass systems were studied in half a century. To overcome these challenges, we present a new non-isothermal technique utilizing in-situ X-Ray Diffraction (XRD) with data analyzed through a modified Johnson-Mehl-Avrami-Kolmogorov (JMAK) equation. Three homogenous nucleated glass systems were analyzed: Li₂O•2SiO₂ (lithium disilicate), Na₂O•2CaO•3SiO₂ (combeite), and Li₂Oׅ•2B₂O₃ (lithium diborate). This method utilizes crystallized fractions through XRD, allowing resolution far beyond microscopy techniques. It was thus possible to compare the evolution of the crystallized volume fractions by X-ray diffraction with optical microscopy from literature. This method was successful in reproducing the experimental nucleation curve from the temporal development of the number density and crystal size within four orders of magnitude, while also achieving the correct peak position, leading to a new method to rapidly <em>approximate</em> the nucleation rate of complex glass-ceramics.</div></div>","PeriodicalId":47623,"journal":{"name":"Materialia","volume":null,"pages":null},"PeriodicalIF":3.0,"publicationDate":"2024-09-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142358018","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Cold sintering with functionalized polymers for ductile ceramic matrix composites with controllable mechanical performance","authors":"","doi":"10.1016/j.mtla.2024.102238","DOIUrl":"10.1016/j.mtla.2024.102238","url":null,"abstract":"<div><div>Structuring ceramics with polymers in hierarchical morphologies provide mechanisms for substantial toughening. Bi-continuous composites are generated in a single processing step through cold sintering of ceramic and polymer particles, which consolidates the inorganic phase at temperatures compatible with polymer processing. Here, we demonstrate that limited maleation (∼1 %) of polypropylene (PP) provides a chemical handle to alter the interaction between the polymer and inorganic phases that leads to a more homogeneous composite morphology at multiple length scales, as evidenced by X-ray microcomputed tomography (µ-CT) and elemental mapping during electron microscopy for a wide range of composite compositions from from 14.5 vol% to 68.2 vol% polymer. The extensibility of the composite and the ultimate tensile stress (UTS) of the hybrid composites are increased substantially in comparison to unfunctionalized PP at the same composition. Quantitative analysis of µ-CT data identifies an interphase in polymer-ceramic composites where there is significant mixing of inorganic and polymer phases that is associated with the generation of a hierarchical morphology. We find that the impact of the interphase is primarily in the reduction of the thickness of the pure ceramic domain. This domain size is inversely correlated with the UTS with universal behavior irrespective of the functionality of the PP. This observation underscores the pivotal role of functional groups on polymers to enhance composite homogeneity, reduce ceramic domain size, and consequently augment the mechanical response of cold sintered ceramic matrix composites that provides a route to sustainable composite materials.</div></div>","PeriodicalId":47623,"journal":{"name":"Materialia","volume":null,"pages":null},"PeriodicalIF":3.0,"publicationDate":"2024-09-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142310511","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Shape tailored nano-ceria as high performance supercapacitor electrode material","authors":"","doi":"10.1016/j.mtla.2024.102237","DOIUrl":"10.1016/j.mtla.2024.102237","url":null,"abstract":"<div><div>Electrochemical energy storage devices herald a brighter future, offering efficient and sustainable solutions to meet the escalating global energy demands. The current work investigates the development and characterization of different ceria nanostructures (nanorod, nanocube, and nanopolyhedra) as effective electrode materials for supercapacitor applications. The electrode materials are systematically characterized using various spectroscopic and non-spectroscopic techniques. Galvanostatic charge-discharge, electrochemical impedance spectroscopy, and cyclic voltammetry techniques are used to evaluate the electrochemical performance of the electrode materials. The optimum material for the said application is cerium nanorod which has the maximum specific capacitance of 437.27 F/g in acid electrolytes. The current-voltage (I-V) characteristics of the ceria nanostructures exhibit hysteresis behavior; ceria nanorod showing coexistence of memristive and memcapacitive nature. The loop area of the hysteresis curve, derived from the ratio of OFF resistance to ON resistance (R_OFF/R_ON) at 4 V, yields approximate values of 1.08, 1.33, and 1.57 for ceria nanocubes, ceria nanopolyhedra, and ceria nanorods, respectively. Impedance vs. frequency analysis of the samples was also carried out to study their electrical and transport properties. The results obtained from electrochemical analyses are complimented by electrical studies.</div></div>","PeriodicalId":47623,"journal":{"name":"Materialia","volume":null,"pages":null},"PeriodicalIF":3.0,"publicationDate":"2024-09-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142319686","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"β-Grain refinement in WAAM Ti-6Al-4 V processed with inter-pass ultrasonic impact peening","authors":"","doi":"10.1016/j.mtla.2024.102236","DOIUrl":"10.1016/j.mtla.2024.102236","url":null,"abstract":"<div><p>As-deposited Wire-Arc Additive Manufactured (WAAM) Ti-6Al-4V parts typically contain large columnar β-grains on a centimetre scale, with a strong 〈001〉 fibre texture, leading to anisotropic mechanical properties and unacceptable scatter in damage tolerance. Inter-pass deformation, introduced by the application of Ultrasonic Impact Peening (UIP) across each added layer, has been shown to be effective in refining the β-grain structure and achieving a weaker texture. The depth of deformation and the grain refinement mechanism induced by UIP have been investigated by combining advanced electron backscatter diffraction (EBSD) characterization with a ‘stop action’ observation technique. UIP facilitates a similar refinement mechanism and nearly the same depth of deformation as conventional machine hammer peening, with the advantages of a much higher strain rate, lower peak force, and two orders of magnitude lower impact energy, making it a faster and more economical process. β recrystallization is seen within the deformation zone during re-heating through the α → β transition. Although new recrystallized β-grains formed in the UIP surface-deformed layer to a shallower depth than that of remelting, recrystallization initiated ahead of the melt pool and the recrystallized grains grew downwards to a greater depth before remelting. These refined grains were thus able to survive and act as nucleation sites at the fusion boundary for epitaxial regrowth during solidification, greatly refining the grain structure.</p></div>","PeriodicalId":47623,"journal":{"name":"Materialia","volume":null,"pages":null},"PeriodicalIF":3.0,"publicationDate":"2024-09-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142243922","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Nanotwinning grain refinement induced by micro-needle peening in arc-welded ultra-high strength steel sheet","authors":"","doi":"10.1016/j.mtla.2024.102231","DOIUrl":"10.1016/j.mtla.2024.102231","url":null,"abstract":"<div><p>Generally, the fatigue strength of ultra-high strength steel (UHSS) and high strength steel (HSS) arc-welded joints are comparable regardless of base metal's strength. Still, the micro-needle peening (MNP) method can improve the fatigue strength to the level of those of base metals. To understand the mechanism of this improvement, this paper investigates the microstructure of UHSS (tensile stress grade of 980 MPa) arc-welded joints treated with MNP and compares it to HSS (tensile stress grade of 440 MPa) joints. We focus on the presence of nanotwins, which exhibited a minimum thickness of 4.7 nm, observed in the UHSS joints following the MNP treatment. Importantly, these nanotwins demonstrated remarkable stability even under cyclic loading conditions (nominal stress <em>σ</em>_n = 600 MPa, <em>N</em> = 3 × 10⁶ cycles). This indicates that the nanotwins contribute to the significant improvement in fatigue strength demonstrated by MNP. However, the nanotwins were not observed in the HSS joints, suggesting sufficient driving stress is necessary for their occurrence. The dislocation pileup stress at the grain boundary during twinning was estimated by the thickness of the twin, which was 8.1 GPa. This value is of the same order of magnitude as the 3.7 GPa estimated by the Hall-Petch coefficient for ferritic steel. The lower levels of C, Si, and Mn can contribute to the lower pileup stress, resulting in absence of the nanotwins in the 440 MPa joint. Overall, this study provides insights into the microstructural changes induced by MNP treatment and their impact on the fatigue strength.</p></div>","PeriodicalId":47623,"journal":{"name":"Materialia","volume":null,"pages":null},"PeriodicalIF":3.0,"publicationDate":"2024-09-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S258915292400228X/pdfft?md5=de7365c499c8961fa05c7a9bc5c10fc8&pid=1-s2.0-S258915292400228X-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142274279","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Confinement effects on microstructure length scale selection in chill-cast stainless steel","authors":"","doi":"10.1016/j.mtla.2024.102229","DOIUrl":"10.1016/j.mtla.2024.102229","url":null,"abstract":"<div><p>This study reports experimental measurements of spacing selection of confined dendrite growth in chill-cast stainless steel under transient cooling conditions. This phenomenon is also explored using phase-field simulations under non-steady state cooling conditions. Two phase-field models are employed, a ternary phase-field (PF) model where Ni and Cr are explicitly simulated, and a pseudobinary model which acts as a special case. Simulations reveal a strong finite-size dependence in the primary arm spacing (PAS) of cells and dendrites. This behavior is also observed experimentally within individual grains, where dendritic fronts evolve within parent grains that impose constraints on the solidification front. Quantifying PAS by a characteristic length <span><math><msub><mrow><mi>λ</mi></mrow><mrow><mn>1</mn></mrow></msub></math></span>, this metric is observed to exhibit a stick–slip behavior as the front advances, which corresponds to times in the solidification of slow (or no) change in <span><math><msub><mrow><mi>λ</mi></mrow><mrow><mn>1</mn></mrow></msub></math></span> followed by a rapid increase in <span><math><msub><mrow><mi>λ</mi></mrow><mrow><mn>1</mn></mrow></msub></math></span> caused by a succession of cell elimination events. The statistics of cell extinction are also analyzed, finding a correlation in the statistical time between extinction events and system size. Specifically, simulations reveal that the length of time of such PAS plateaus is stochastic, exhibiting a mean time that decays approximately exponentially with system size. As system size increases, this effect diminishes and a more monotonic relation between <span><math><msub><mrow><mi>λ</mi></mrow><mrow><mn>1</mn></mrow></msub></math></span> vs. front speed is observed, consistent with classic geometric theories.</p></div>","PeriodicalId":47623,"journal":{"name":"Materialia","volume":null,"pages":null},"PeriodicalIF":3.0,"publicationDate":"2024-09-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S2589152924002266/pdfft?md5=1e0411477b227b2ab7f63ec49dbd0f3d&pid=1-s2.0-S2589152924002266-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142229079","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"AC electric field-induced changes in viscosity of aqueous ceramic suspensions and tuning of freeze-cast microstructure and compressive strength","authors":"","doi":"10.1016/j.mtla.2024.102232","DOIUrl":"10.1016/j.mtla.2024.102232","url":null,"abstract":"<div><p>A systematic parametric study was conducted on alternating current (AC) electric field-assisted freeze-casting to enable a comprehensive understanding of tuning freeze-cast microstructure and compressive strength and provide insights into the role of AC field. A novel finding was that the AC field increased the viscosity of aqueous ceramic suspensions, where the viscosity increase was dependent on the ceramic loading of suspensions, dispersant concentration, and field duration. Viscosity increased with field duration for a fixed solid loading and dispersant concentration. It was suggested that AC field-induced dielectrophoretic (DEP) forces decreased interparticle distances and increased interparticle interactions in ceramic suspensions, hence viscosity. It was revealed that the increase in viscosity of ceramic suspensions due to the AC field could be reversed. It was demonstrated that simple magnetic stirring of the suspensions previously subjected to an AC field (which increased viscosity) reduced viscosity to the level of the as-prepared suspensions. For materials fabrication, an AC electric field was applied to aqueous ceramic suspensions for the desired duration, then turned OFF, followed by freeze-casting, which remarkably influenced freeze-cast sintered microstructure. The impact of the field on microstructure increased with solid loading, dispersant concentration, and field duration, and microstructure changes were associated with viscosity of suspensions prior to freeze-casting. With increasing viscosity, freeze-cast microstructure became increasingly dendritic, i.e., bridge density increased. A positive correlation was observed between bridge density and compressive strength for all the materials. Depending on the solid loading, dispersant concentration, and field duration, about 5- to 8-fold increase in strength was achieved.</p></div>","PeriodicalId":47623,"journal":{"name":"Materialia","volume":null,"pages":null},"PeriodicalIF":3.0,"publicationDate":"2024-09-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142243921","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}