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Materials, Volume 10, Issue 1 (January 2017)

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Cover Story (view full-size image) Breaking the habits is healthy when talking about fundamental researches on materials. Here, the [...] Read more.
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Open AccessArticle Marginal Accuracy and Internal Fit of 3-D Printing Laser-Sintered Co-Cr Alloy Copings
Materials 2017, 10(1), 93; https://doi.org/10.3390/ma10010093
Received: 8 December 2016 / Revised: 17 January 2017 / Accepted: 18 January 2017 / Published: 23 January 2017
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Abstract
Laser sintered technology has been introduced for clinical use and can be utilized more widely, accompanied by the digitalization of dentistry and the development of direct oral scanning devices. This study was performed with the aim of comparing the marginal accuracy and internal
[...] Read more.
Laser sintered technology has been introduced for clinical use and can be utilized more widely, accompanied by the digitalization of dentistry and the development of direct oral scanning devices. This study was performed with the aim of comparing the marginal accuracy and internal fit of Co-Cr alloy copings fabricated by casting, CAD/CAM (Computer-aided design/Computer-assisted manufacture) milled, and 3-D laser sintered techniques. A total of 36 Co-Cr alloy crown-copings were fabricated from an implant abutment. The marginal and internal fit were evaluated by measuring the weight of the silicone material, the vertical marginal discrepancy using a microscope, and the internal gap in the sectioned specimens. The data were statistically analyzed by One-way ANOVA (analysis of variance), a Scheffe’s test, and Pearson’s correlation at the significance level of p = 0.05, using statistics software. The silicone weight was significantly low in the casting group. The 3-D laser sintered group showed the highest vertical discrepancy, and marginal-, occlusal-, and average- internal gaps (p < 0.05). The CAD/CAM milled group revealed a significantly high axial internal gap. There are moderate correlations between the vertical marginal discrepancy and the internal gap variables (r = 0.654), except for the silicone weight. In this study, the 3-D laser sintered group achieved clinically acceptable marginal accuracy and internal fit. Full article
(This article belongs to the Section Manufacturing Processes and Systems)
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Open AccessFeature PaperArticle First-Row Transition Metal Doping in Calcium Phosphate Bioceramics: A Detailed Crystallographic Study
Materials 2017, 10(1), 92; https://doi.org/10.3390/ma10010092
Received: 30 November 2016 / Revised: 6 January 2017 / Accepted: 18 January 2017 / Published: 23 January 2017
Cited by 6 | PDF Full-text (5743 KB) | HTML Full-text | XML Full-text
Abstract
Doped calcium phosphate bioceramics are promising materials for bone repair surgery because of their chemical resemblance to the mineral constituent of bone. Among these materials, BCP samples composed of hydroxyapatite (Ca10(PO4)6(OH)2) and β-TCP (Ca3
[...] Read more.
Doped calcium phosphate bioceramics are promising materials for bone repair surgery because of their chemical resemblance to the mineral constituent of bone. Among these materials, BCP samples composed of hydroxyapatite (Ca10(PO4)6(OH)2) and β-TCP (Ca3(PO4)2) present a mineral analogy with the nano-multi-substituted hydroxyapatite bio-mineral part of bones. At the same time, doping can be used to tune the biological properties of these ceramics. This paper presents a general overview of the doping mechanisms of BCP samples using cations from the first-row transition metals (from manganese to zinc), with respect to the applied sintering temperature. The results enable the preparation of doped synthetic BCP that can be used to tailor biological properties, in particular by tuning the release amounts upon interaction with biological fluids. Intermediate sintering temperatures stabilize the doping elements in the more soluble β-TCP phase, which favors quick and easy release upon integration in the biological environment, whereas higher sintering temperatures locate the doping elements in the weakly soluble HAp phase, enabling a slow and continuous supply of the bio-inspired properties. An interstitial doping mechanism in the HAp hexagonal channel is observed for the six investigated cations (Mn2+, Fe3+, Co2+, Ni2+, Cu2+ and Zn2+) with specific characteristics involving a shift away from the center of the hexagonal channel (Fe3+, Co2+), cationic oxidation (Mn3+, Co3+), and also cationic reduction (Cu+). The complete crystallochemical study highlights a complex HAp doping mechanism, mainly realized by an interstitial process combined with calcium substitution for the larger cations of the series leading to potentially calcium deficient HAp. Full article
(This article belongs to the Special Issue Calcium Phosphate in Biomedical Applications)
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Open AccessArticle Idealized vs. Realistic Microstructures: An Atomistic Simulation Case Study on γ/γ Microstructures
Materials 2017, 10(1), 88; https://doi.org/10.3390/ma10010088
Received: 27 November 2016 / Revised: 14 January 2017 / Accepted: 16 January 2017 / Published: 23 January 2017
Cited by 5 | PDF Full-text (41321 KB) | HTML Full-text | XML Full-text | Supplementary Files
Abstract
Single-crystal Ni-base superalloys, consisting of a two-phase γ/γ microstructure, retain high strengths at elevated temperatures and are key materials for high temperature applications, like, e.g., turbine blades of aircraft engines. The lattice misfit between the γ and γ phases
[...] Read more.
Single-crystal Ni-base superalloys, consisting of a two-phase γ/ γ microstructure, retain high strengths at elevated temperatures and are key materials for high temperature applications, like, e.g., turbine blades of aircraft engines. The lattice misfit between the γ and γ phases results in internal stresses, which significantly influence the deformation and creep behavior of the material. Large-scale atomistic simulations that are often used to enhance our understanding of the deformation mechanisms in such materials must accurately account for such misfit stresses. In this work, we compare the internal stresses in both idealized and experimentally-informed, i.e., more realistic, γ/ γ microstructures. The idealized samples are generated by assuming, as is frequently done, a periodic arrangement of cube-shaped γ particles with planar γ/ γ interfaces. The experimentally-informed samples are generated from two different sources to produce three different samples—the scanning electron microscopy micrograph-informed quasi-2D atomistic sample and atom probe tomography-informed stoichiometric and non-stoichiometric atomistic samples. Additionally, we compare the stress state of an idealized embedded cube microstructure with finite element simulations incorporating 3D periodic boundary conditions. Subsequently, we study the influence of the resulting stress state on the evolution of dislocation loops in the different samples. The results show that the stresses in the atomistic and finite element simulations are almost identical. Furthermore, quasi-2D boundary conditions lead to a significantly different stress state and, consequently, different evolution of the dislocation loop, when compared to samples with fully 3D boundary conditions. Full article
(This article belongs to the Section Structure Analysis and Characterization)
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Open AccessArticle Self-Healing Materials for Ecotribology
Materials 2017, 10(1), 91; https://doi.org/10.3390/ma10010091
Received: 25 October 2016 / Revised: 17 January 2017 / Accepted: 17 January 2017 / Published: 22 January 2017
Cited by 6 | PDF Full-text (5908 KB) | HTML Full-text | XML Full-text
Abstract
Hydroxypropyl methylcellulose (HPMC) is a biopolymer that is biodegradable, environmentally friendly, and bio-friendly. Owing to its unique chemical structure, HPMC can reduce the coefficient of friction (COF) and frictional wear and thus possesses excellent lubrication properties. HPMC has good dissolvability in specific solvents.
[...] Read more.
Hydroxypropyl methylcellulose (HPMC) is a biopolymer that is biodegradable, environmentally friendly, and bio-friendly. Owing to its unique chemical structure, HPMC can reduce the coefficient of friction (COF) and frictional wear and thus possesses excellent lubrication properties. HPMC has good dissolvability in specific solvents. The present research focuses on the reversible dissolution reaction subsequent to the film formation of HPMC, with a view to the healing and lubrication properties of thin films. Raman spectroscopy was used to test the film-forming properties of HPMC and the dissolution characteristics of various solvents. In this study, the solvents were water, methanol, ethanol, and acetone. The results showed that the HPMC film had the highest dissolvability in water. The ball-on-disk wear test was used to analyze the lubrication properties of HPMC, and the results showed that HPMC had the same COF and lubrication properties as the original film after being subjected to the water healing treatment. The HPMC film can be reused, recycled, and refilled, making it an ideal lubricant for next-generation ecotribology. Full article
(This article belongs to the Special Issue Selected Material Related Papers from ICI2016)
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Open AccessArticle Experimental Study on Influence of Trap Parameters on Dielectric Characteristics of Nano-Modified Insulation Pressboard
Materials 2017, 10(1), 90; https://doi.org/10.3390/ma10010090
Received: 9 October 2016 / Revised: 10 January 2017 / Accepted: 16 January 2017 / Published: 22 January 2017
Cited by 3 | PDF Full-text (8299 KB) | HTML Full-text | XML Full-text
Abstract
In order to study the influence of trap parameters on dielectric characteristics of nano-modified pressboards, pressboards were made using the nano doping method with different nanoparticle components. The dielectric characteristics of the modified pressboards were measured, and the trap parameters were investigated using
[...] Read more.
In order to study the influence of trap parameters on dielectric characteristics of nano-modified pressboards, pressboards were made using the nano doping method with different nanoparticle components. The dielectric characteristics of the modified pressboards were measured, and the trap parameters were investigated using the thermally stimulated current (TSC) method. The test results indicated that the conductivity initially declined and then rose with the increase of nano-Al2O3 content, whereas it solely rose with the increase of nano-SiC content. Moreover, the conductivity exhibited nonlinear characteristics with the enhancement of electric field stress at high nanoparticle content. The relative permittivity of modified pressboard declines initially and then rises with the increase of nanoparticle content. In addition, the breakdown strength of modified pressboards exhibited a pattern of incline followed by decline with the increase of nano-Al2O3 content, while it always declined with the increase of nano-SiC content. The analysis based on the energy band theory on trap parameters of the constructed multi-core model concludes that the nanoparticle components added in pressboard altered both the depth and density of traps. It is therefore concluded that trap parameters have significant influence on the dielectric characteristics of nano-modified insulation pressboard. Full article
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Open AccessArticle Combining Bioactive Multifunctional Dental Composite with PAMAM for Root Dentin Remineralization
Materials 2017, 10(1), 89; https://doi.org/10.3390/ma10010089
Received: 5 December 2016 / Revised: 16 January 2017 / Accepted: 17 January 2017 / Published: 22 January 2017
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Abstract
Objectives. The objectives of this study were to: (1) develop a bioactive multifunctional composite (BMC) via nanoparticles of amorphous calcium phosphate (NACP), 2-methacryloyloxyethyl phosphorylcholine (MPC), dimethylaminohexadecyl methacrylate (DMAHDM) and nanoparticles of silver (NAg); and (2) investigate the effects of combined BMC +
[...] Read more.
Objectives. The objectives of this study were to: (1) develop a bioactive multifunctional composite (BMC) via nanoparticles of amorphous calcium phosphate (NACP), 2-methacryloyloxyethyl phosphorylcholine (MPC), dimethylaminohexadecyl methacrylate (DMAHDM) and nanoparticles of silver (NAg); and (2) investigate the effects of combined BMC + poly (amido amine) (PAMAM) on remineralization of demineralized root dentin in a cyclic artificial saliva/lactic acid environment for the first time. Methods. Root dentin specimens were prepared and demineralized with 37% phosphoric acid for 15 s. Four groups were prepared: (1) root dentin control; (2) root dentin with BMC; (3) root dentin with PAMAM; (4) root dentin with BMC + PAMAM. Specimens were treated with a cyclic artificial saliva/lactic acid regimen for 21 days. Calcium (Ca) and phosphate (P) ion concentrations and acid neutralization were determined. The remineralized root dentin specimens were examined via hardness testing and scanning electron microscopy (SEM). Results. Mechanical properties of BMC were similar to commercial control composites (p = 0.913). BMC had excellent Ca and P ion release and acid-neutralization capability. BMC or PAMAM alone each achieved slight mineral regeneration in demineralized root dentin. The combined BMC + PAMAM induced the greatest root dentin remineralization, and increased the hardness of pre-demineralized root dentin to match that of healthy root dentin (p = 0.521). Significance. The excellent root dentin remineralization effects of BMC + PAMAM were demonstrated for the first time. BMC + PAMAM induced effective and complete root dentin remineralization in an acid challenge environment. The novel BMC + PAMAM method is promising for Class V and other restorations to remineralize and protect tooth structures. Full article
(This article belongs to the Section Biomaterials)
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Open AccessArticle Microstructure Evolution in High Purity Aluminum Single Crystal Processed by Equal Channel Angular Pressing (ECAP)
Materials 2017, 10(1), 87; https://doi.org/10.3390/ma10010087
Received: 3 November 2016 / Revised: 26 December 2016 / Accepted: 16 January 2017 / Published: 22 January 2017
Cited by 1 | PDF Full-text (4040 KB) | HTML Full-text | XML Full-text
Abstract
Aluminum single crystal with 99.999% purity was deformed at room temperature by equal channel angular pressing (ECAP) up to 16 passes. Grain size and misorientation of processed samples were quantitatively characterized by TEM and EBSD. The results show that the refinement efficiency of
[...] Read more.
Aluminum single crystal with 99.999% purity was deformed at room temperature by equal channel angular pressing (ECAP) up to 16 passes. Grain size and misorientation of processed samples were quantitatively characterized by TEM and EBSD. The results show that the refinement efficiency of high purity aluminum single crystal was poor in the initial stage. Extrusion by fewer ECAP passes (n ≤ 8) resulted in only elongated grains containing a large number of subgrains and small misorientations between grains. Stable microstructures of nearly equiaxed grains with high misorientations were obtained by 15 passages, indicating that the initial extremely coarse grains and highly uniform grain orientation are not conducive to the accumulation of strain energy. The initial state of high purity aluminum has a significant effect on the refining efficiency of the ECAP process. Full article
(This article belongs to the Section Structure Analysis and Characterization)
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Open AccessArticle Synthesis of Graphene Based Membranes: Effect of Substrate Surface Properties on Monolayer Graphene Transfer
Materials 2017, 10(1), 86; https://doi.org/10.3390/ma10010086
Received: 19 September 2016 / Revised: 10 January 2017 / Accepted: 17 January 2017 / Published: 21 January 2017
Cited by 2 | PDF Full-text (9957 KB) | HTML Full-text | XML Full-text | Supplementary Files
Abstract
In this work, we report the transfer of graphene onto eight commercial microfiltration substrates having different pore sizes and surface characteristics. Monolayer graphene grown on copper by the chemical vapor deposition (CVD) process was transferred by the pressing method over the target substrates,
[...] Read more.
In this work, we report the transfer of graphene onto eight commercial microfiltration substrates having different pore sizes and surface characteristics. Monolayer graphene grown on copper by the chemical vapor deposition (CVD) process was transferred by the pressing method over the target substrates, followed by wet etching of copper to obtain monolayer graphene/polymer membranes. Scanning electron microscopy (SEM), atomic force microscopy (AFM), and contact angle (CA) measurements were carried out to explore the graphene layer transferability. Three factors, namely, the substrate roughness, its pore size, and its surface wetting (degree of hydrophobicity) are found to affect the conformality and coverage of the transferred graphene monolayer on the substrate surface. A good quality graphene transfer is achieved on the substrate with the following characteristics; being hydrophobic (CA > 90°), having small pore size, and low surface roughness, with a CA to RMS (root mean square) ratio higher than 2.7°/nm. Full article
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Open AccessArticle An Extended Damage Plasticity Model for Shotcrete: Formulation and Comparison with Other Shotcrete Models
Materials 2017, 10(1), 82; https://doi.org/10.3390/ma10010082
Received: 7 December 2016 / Revised: 10 January 2017 / Accepted: 12 January 2017 / Published: 21 January 2017
Cited by 5 | PDF Full-text (604 KB) | HTML Full-text | XML Full-text | Correction
Abstract
The aims of the present paper are (i) to briefly review single-field and multi-field shotcrete models proposed in the literature; (ii) to propose the extension of a damage-plasticity model for concrete to shotcrete; and (iii) to evaluate the capabilities of the proposed extended
[...] Read more.
The aims of the present paper are (i) to briefly review single-field and multi-field shotcrete models proposed in the literature; (ii) to propose the extension of a damage-plasticity model for concrete to shotcrete; and (iii) to evaluate the capabilities of the proposed extended damage-plasticity model for shotcrete by comparing the predicted response with experimental data for shotcrete and with the response predicted by shotcrete models, available in the literature. The results of the evaluation will be used for recommendations concerning the application and further improvements of the investigated shotcrete models and they will serve as a basis for the design of a new lab test program, complementing the existing ones. Full article
(This article belongs to the Special Issue Numerical Analysis of Concrete using Discrete Elements)
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Open AccessArticle On the Injection Molding Processing Parameters of HDPE-TiO2 Nanocomposites
Materials 2017, 10(1), 85; https://doi.org/10.3390/ma10010085
Received: 24 September 2016 / Revised: 9 November 2016 / Accepted: 11 November 2016 / Published: 20 January 2017
Cited by 3 | PDF Full-text (7531 KB) | HTML Full-text | XML Full-text
Abstract
In recent years, the development and use of polymeric nanocomposites in creating advanced materials has expanded exponentially. A substantial amount of research has been done in order to design polymeric nanocomposites in a safe and efficient manner. In the present study, the impact
[...] Read more.
In recent years, the development and use of polymeric nanocomposites in creating advanced materials has expanded exponentially. A substantial amount of research has been done in order to design polymeric nanocomposites in a safe and efficient manner. In the present study, the impact of processing parameters, such as, barrel temperature, and residence time on the mechanical and thermal properties of high density polyethylene (HDPE)-TiO2 nanocomposites were investigated. Additionally, scanning electron microscopy and X-ray diffraction spectroscopy were used to analyze the dispersion, location, and phase morphology of TiO2 on the HDPE matrix. Mechanical tests revealed that tensile strength of the fabricated HDPE-TiO2 nanocomposites ranged between 22.53 and 26.30 MPa, while the Young’s modulus showed a consistent increase as the barrel temperature increased from 150 °C to 300 °C. Moreover, the thermal stability decreased as the barrel temperature increased. Full article
(This article belongs to the Section Manufacturing Processes and Systems)
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Open AccessArticle Synthesis of Magnetic Microspheres with Sodium Alginate and Activated Carbon for Removal of Methylene Blue
Materials 2017, 10(1), 84; https://doi.org/10.3390/ma10010084
Received: 26 November 2016 / Revised: 31 December 2016 / Accepted: 15 January 2017 / Published: 20 January 2017
Cited by 8 | PDF Full-text (4762 KB) | HTML Full-text | XML Full-text
Abstract
Based on the adsorption performance of composite microspheres with activated carbon (AC) and sodium alginate (SA), as well as the magnetic property of Fe3O4, we designed and explored an efficient strategy to prepare a unique, multifunctional Fe3O
[...] Read more.
Based on the adsorption performance of composite microspheres with activated carbon (AC) and sodium alginate (SA), as well as the magnetic property of Fe3O4, we designed and explored an efficient strategy to prepare a unique, multifunctional Fe3O4/AC/SA composite absorbent (MSA-AC) that extracted dye from aqueous solution. The composite exhibited the following advantages: rapid and simple to prepare, environmentally friendly process, low-cost, recyclability, and multi-functionality. The physicochemical properties of the prepared magnetic microspheres were measured, and methylene blue (MB) was selected to investigate the performance of the magnetic absorbent. The results showed a maximum adsorption capacity of 222.3 mg/g for MB. Adsorption studies revealed that the data of adsorption isotherms and kinetics fit the pseudo-second-order kinetic model and Langmuir isotherm model. Full article
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Open AccessFeature PaperArticle Bioactive Glass Fiber-Reinforced PGS Matrix Composites for Cartilage Regeneration
Materials 2017, 10(1), 83; https://doi.org/10.3390/ma10010083
Received: 8 December 2016 / Revised: 12 January 2017 / Accepted: 13 January 2017 / Published: 20 January 2017
Cited by 7 | PDF Full-text (6716 KB) | HTML Full-text | XML Full-text
Abstract
Poly(glycerol sebacate) (PGS) is an elastomeric polymer which is attracting increasing interest for biomedical applications, including cartilage regeneration. However, its limited mechanical properties and possible negative effects of its degradation byproducts restrict PGS for in vivo application. In this study, a novel PGS–bioactive
[...] Read more.
Poly(glycerol sebacate) (PGS) is an elastomeric polymer which is attracting increasing interest for biomedical applications, including cartilage regeneration. However, its limited mechanical properties and possible negative effects of its degradation byproducts restrict PGS for in vivo application. In this study, a novel PGS–bioactive glass fiber (F18)-reinforced composite was developed and characterized. PGS-based reinforced scaffolds were fabricated via salt leaching and characterized regarding their mechanical properties, degradation, and bioactivity in contact with simulated body fluid. Results indicated that the incorporation of silicate-based bioactive glass fibers could double the composite tensile strength, tailor the polymer degradability, and improve the scaffold bioactivity. Full article
(This article belongs to the Special Issue Bioceramics 2016)
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Open AccessArticle Metal-Organic Framework of Lanthanoid Dinuclear Clusters Undergoes Slow Magnetic Relaxation
Materials 2017, 10(1), 81; https://doi.org/10.3390/ma10010081
Received: 3 December 2016 / Revised: 12 January 2017 / Accepted: 16 January 2017 / Published: 20 January 2017
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Abstract
Lanthanoid metal-organic frameworks (Ln-MOFs) can adopt a variety of new structures due to the large coordination numbers of Ln metal ions, and Ln-MOFs are expected to show new luminescence and magnetic properties due to the localized f electrons. In particular, some Ln metal
[...] Read more.
Lanthanoid metal-organic frameworks (Ln-MOFs) can adopt a variety of new structures due to the large coordination numbers of Ln metal ions, and Ln-MOFs are expected to show new luminescence and magnetic properties due to the localized f electrons. In particular, some Ln metal ions, such as Dy(III) and Tb(III) ions, work as isolated quantum magnets when they have magnetic anisotropy. In this work, using 4,4′,4″-s-triazine-2,4,6-triyl-tribenzoic acid (H3TATB) as a ligand, two new Ln-MOFs, [Dy(TATB)(DMF)2] (1) and [Tb(TATB)(DMF)2] (2), were obtained. The Ln-MOFs contain Ln dinuclear clusters as secondary building units, and 1 underwent slow magnetic relaxation similar to single-molecule magnets. Full article
(This article belongs to the Special Issue Advances in Molecular Magnets and related Phenomena)
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Open AccessArticle Cellulose Nanocrystals (CNCs) from Corn Stalk: Activation Energy Analysis
Materials 2017, 10(1), 80; https://doi.org/10.3390/ma10010080
Received: 15 November 2016 / Revised: 15 January 2017 / Accepted: 16 January 2017 / Published: 20 January 2017
Cited by 1 | PDF Full-text (3681 KB) | HTML Full-text | XML Full-text
Abstract
Cellulose nanocrystals (CNCs) were isolated from corn stalk using sulfuric acid hydrolysis, and their morphology, chemical structure, and thermal stability properties were characterized. The CNCs had an average length of 120.2 ± 61.3 nm and diameter of 6.4 ± 3.1 nm (L/D =
[...] Read more.
Cellulose nanocrystals (CNCs) were isolated from corn stalk using sulfuric acid hydrolysis, and their morphology, chemical structure, and thermal stability properties were characterized. The CNCs had an average length of 120.2 ± 61.3 nm and diameter of 6.4 ± 3.1 nm (L/D = 18.7). The degree of crystallinity of the CNCs increased to 69.20% from the 33.20% crystallinity of raw corn stalk fiber, while the chemical structure was well kept after sulfuric acid hydrolysis. Thermal stability analysis showed that the degradation temperature of the CNCs reached 239.5 °C, which was higher than that of the raw fiber but lower than that of the extracted cellulose. The average activation energy values for the CNCs, evaluated using the Friedman, Flynn-Wall-Ozawa (F-W-O) and Coats-Redfern methods, were 312.6, 302.8, and 309 kJ·mol−1 in the conversion range of 0.1 to 0.8. The isolated CNCs had higher values of activation energy than did the purified cellulose, which was attributed to the stronger hydrogen bonds present in the crystalline domains of CNCs than in those of cellulose. These findings can help better understand the thermal properties of polymer/CNC composites. Full article
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Open AccessArticle Methodology for Fast and Facile Characterisation of Carbon-Based Electrodes Focused on Bioelectrochemical Systems Development and Scale Up
Materials 2017, 10(1), 79; https://doi.org/10.3390/ma10010079
Received: 7 December 2016 / Revised: 12 January 2017 / Accepted: 13 January 2017 / Published: 20 January 2017
Cited by 1 | PDF Full-text (5709 KB) | HTML Full-text | XML Full-text | Supplementary Files
Abstract
The development and practical implementation of bioelectrochemical systems (BES) requires an in-depth characterisation of their components. The electrodes, which are critical elements, are usually built from carbon-based materials due to their high specific surface area, biocompatibility and chemical stability. In this study, a
[...] Read more.
The development and practical implementation of bioelectrochemical systems (BES) requires an in-depth characterisation of their components. The electrodes, which are critical elements, are usually built from carbon-based materials due to their high specific surface area, biocompatibility and chemical stability. In this study, a simple methodology to electrochemically characterise carbon-based electrodes has been developed, derived from conventional electrochemical analyses. Combined with classical electrochemical theory and the more innovative fractal geometry approach, our method is aimed at comparing and characterising the performance of carbon electrodes through the determination of the electroactive surface and its fractal dimension. Overall, this methodology provides a quick and easy method for the screening of suitable electrode materials to be implemented in BES. Full article
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Open AccessArticle Investigation of γ-(2,3-Epoxypropoxy)propyltrimethoxy Silane Surface Modified Layered Double Hydroxides Improving UV Ageing Resistance of Asphalt
Materials 2017, 10(1), 78; https://doi.org/10.3390/ma10010078
Received: 1 October 2016 / Revised: 13 January 2017 / Accepted: 13 January 2017 / Published: 19 January 2017
Cited by 5 | PDF Full-text (10949 KB) | HTML Full-text | XML Full-text
Abstract
γ-(2,3-Epoxypropoxy)propyltrimethoxy silane surface modified layered double hydroxides (KH560-LDHs) were prepared and used to improve the ultraviolet ageing resistance of asphalt. The results of X-ray photoelectron spectrometry (XPS) indicated that KH560 has been successfully grafted onto the surface of LDHs. The agglomeration of LDHs
[...] Read more.
γ-(2,3-Epoxypropoxy)propyltrimethoxy silane surface modified layered double hydroxides (KH560-LDHs) were prepared and used to improve the ultraviolet ageing resistance of asphalt. The results of X-ray photoelectron spectrometry (XPS) indicated that KH560 has been successfully grafted onto the surface of LDHs. The agglomeration of LDHs particles notably reduced after KH560 surface modification according to scanning electron microscopy (SEM), which implied that the KH560 surface modification was helpful to promote the dispersibility of LDHs in asphalt. Then, the influence of KH560-LDHs and LDHs on the physical and rheological properties of asphalt before and after UV ageing was thoroughly investigated. The storage stability test showed that the difference in softening point (ΔS) of LDHs modified asphalt decreased from 0.6 °C to 0.2 °C at an LDHs content of 1% after KH560 surface modification, and the tendency became more pronounced with the increase of LDH content, indicating that KH560 surface modification could improve the stability of LDHs in asphalt. After UV ageing, the viscous modulus (G’’) of asphalt significantly reduced, and correspondingly, the elastic modulus (G’) and rutting factor (G*/sin δ) rapidly increased. Moreover, the asphaltene increased and the amount of “bee-like” structures of the asphalt decreased. Compared with LDHs, KH560-LDHs obviously restrained performance deterioration of the asphalt, and helped to relieve the variation of the chemical compositions and morphology of asphalt, which suggested that the improvement of KH560-LDHs on UV ageing resistance of asphalt was superior to LDHs. Full article
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Open AccessErratum Erratum: Myoung, S.C.; Su-Tae, K.; Bang, Y.L.; Kyeong-Taek, K.; Gum-Sung, R. Improvement in Predicting the Post-Cracking Tensile Behavior of Ultra-High Performance Cementitious Composites Based on Fiber Orientation Distribution. Materials 2016, 9, 829
Materials 2017, 10(1), 63; https://doi.org/10.3390/ma10010063
Received: 11 January 2017 / Accepted: 11 January 2017 / Published: 19 January 2017
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Abstract
1.The authors wish to remove the symbol “†”, which indicates the equal contribution from each author. The correct authorship is shown below:[...] Full article
Open AccessArticle Facile Synthesis of V2O5 Hollow Spheres as Advanced Cathodes for High-Performance Lithium-Ion Batteries
Materials 2017, 10(1), 77; https://doi.org/10.3390/ma10010077
Received: 14 December 2016 / Revised: 13 January 2017 / Accepted: 16 January 2017 / Published: 18 January 2017
Cited by 6 | PDF Full-text (3652 KB) | HTML Full-text | XML Full-text
Abstract
Three-dimensional V2O5 hollow structures have been prepared through a simple synthesis strategy combining solvothermal treatment and a subsequent thermal annealing. The V2O5 materials are composed of microspheres 2–3 μm in diameter and with a distinct hollow interior.
[...] Read more.
Three-dimensional V2O5 hollow structures have been prepared through a simple synthesis strategy combining solvothermal treatment and a subsequent thermal annealing. The V2O5 materials are composed of microspheres 2–3 μm in diameter and with a distinct hollow interior. The as-synthesized V2O5 hollow microspheres, when evaluated as a cathode material for lithium-ion batteries, can deliver a specific capacity as high as 273 mAh·g−1 at 0.2 C. Benefiting from the hollow structures that afford fast electrolyte transport and volume accommodation, the V2O5 cathode also exhibits a superior rate capability and excellent cycling stability. The good Li-ion storage performance demonstrates the great potential of this unique V2O5 hollow material as a high-performance cathode for lithium-ion batteries. Full article
(This article belongs to the Special Issue Materials for Electrochemical Capacitors and Batteries)
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Open AccessFeature PaperReview On the Selective Laser Melting (SLM) of the AlSi10Mg Alloy: Process, Microstructure, and Mechanical Properties
Materials 2017, 10(1), 76; https://doi.org/10.3390/ma10010076
Received: 21 October 2016 / Revised: 10 January 2017 / Accepted: 12 January 2017 / Published: 18 January 2017
Cited by 30 | PDF Full-text (41922 KB) | HTML Full-text | XML Full-text
Abstract
The aim of this review is to analyze and to summarize the state of the art of the processing of aluminum alloys, and in particular of the AlSi10Mg alloy, obtained by means of the Additive Manufacturing (AM) technique known as Selective Laser Melting
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The aim of this review is to analyze and to summarize the state of the art of the processing of aluminum alloys, and in particular of the AlSi10Mg alloy, obtained by means of the Additive Manufacturing (AM) technique known as Selective Laser Melting (SLM). This process is gaining interest worldwide, thanks to the possibility of obtaining a freeform fabrication coupled with high mechanical properties related to a very fine microstructure. However, SLM is very complex, from a physical point of view, due to the interaction between a concentrated laser source and metallic powders, and to the extremely rapid melting and the subsequent fast solidification. The effects of the main process variables on the properties of the final parts are analyzed in this review: from the starting powder properties, such as shape and powder size distribution, to the main process parameters, such as laser power and speed, layer thickness, and scanning strategy. Furthermore, a detailed overview on the microstructure of the AlSi10Mg material, with the related tensile and fatigue properties of the final SLM parts, in some cases after different heat treatments, is presented. Full article
(This article belongs to the Special Issue Metals for Additive Manufacturing)
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Open AccessArticle XPS Study on the Stability and Transformation of Hydrate and Carbonate Phases within MgO Systems
Materials 2017, 10(1), 75; https://doi.org/10.3390/ma10010075
Received: 7 November 2016 / Revised: 23 December 2016 / Accepted: 9 January 2017 / Published: 18 January 2017
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Abstract
MgO cements have great potential for carbon sequestration as they have the ability to carbonate and gain strength over time. The hydration of reactive MgO occurs at a similar rate as ordinary Portland cement (PC) and forms brucite (Mg(OH)2, magnesium hydroxide),
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MgO cements have great potential for carbon sequestration as they have the ability to carbonate and gain strength over time. The hydration of reactive MgO occurs at a similar rate as ordinary Portland cement (PC) and forms brucite (Mg(OH)2, magnesium hydroxide), which reacts with CO2 to form a range of hydrated magnesium carbonates (HMCs). However, the formation of HMCs within the MgO–CO2–H2O system depends on many factors, such as the temperature and CO2 concentration, among others, which play an important role in determining the rate and degree of carbonation, the type and stability of the produced HMCs and the associated strength development. It is critical to understand the stability and transformation pathway of HMCs, which are assessed here through the use of X-ray photoelectron spectroscopy (XPS). The effects of the CO2 concentration (in air or 10% CO2), exposure to high temperatures (up to 300 °C) and curing period (one or seven days) are reported. Observed changes in the binding energy (BE) indicate the formation of different components and the transformation of the hydrated carbonates from one form to another, which will influence the final performance of the carbonated blends. Full article
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Open AccessArticle Supercritical CO2-Assisted Spray Drying of Strawberry-Like Gold-Coated Magnetite Nanocomposites in Chitosan Powders for Inhalation
Materials 2017, 10(1), 74; https://doi.org/10.3390/ma10010074
Received: 29 July 2016 / Revised: 21 November 2016 / Accepted: 11 January 2017 / Published: 18 January 2017
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Abstract
Lung cancer is one of the leading causes of death worldwide. Therefore, it is of extreme importance to develop new systems that can deliver anticancer drugs into the site of action when initiating a treatment. Recently, the use of nanotechnology and particle engineering
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Lung cancer is one of the leading causes of death worldwide. Therefore, it is of extreme importance to develop new systems that can deliver anticancer drugs into the site of action when initiating a treatment. Recently, the use of nanotechnology and particle engineering has enabled the development of new drug delivery platforms for pulmonary delivery. In this work, POXylated strawberry-like gold-coated magnetite nanocomposites and ibuprofen (IBP) were encapsulated into a chitosan matrix using Supercritical Assisted Spray Drying (SASD). The dry powder formulations showed adequate morphology and aerodynamic performances (fine particle fraction 48%–55% and aerodynamic diameter of 2.6–2.8 µm) for deep lung deposition through the pulmonary route. Moreover, the release kinetics of IBP was also investigated showing a faster release of the drug at pH 6.8, the pH of lung cancer. POXylated strawberry-like gold-coated magnetite nanocomposites proved to have suitable sizes for cellular internalization and their fluorescent capabilities enable their future use in in vitro cell based assays. As a proof-of-concept, the reported results show that these nano-in-micro formulations could be potential drug vehicles for pulmonary administration. Full article
(This article belongs to the Special Issue Selected papers from ISN2A2016)
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Open AccessArticle Properties of a Laser Shock Wave in Al-Cu Alloy under Elevated Temperatures: A Molecular Dynamics Simulation Study
Materials 2017, 10(1), 73; https://doi.org/10.3390/ma10010073
Received: 2 October 2016 / Revised: 2 December 2016 / Accepted: 3 January 2017 / Published: 18 January 2017
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Abstract
The laser shock wave (LSW) generated by the interaction between a laser and a material has been widely used in laser manufacturing, such as laser shock peening and laser shock forming. However, due to the high strain rate, the propagation of LSW in
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The laser shock wave (LSW) generated by the interaction between a laser and a material has been widely used in laser manufacturing, such as laser shock peening and laser shock forming. However, due to the high strain rate, the propagation of LSW in materials, especially LSW at elevated temperatures, is difficult to study through experimental methods. A molecular dynamics simulation was used in this study to investigate the propagation of LSW in an Al-Cu alloy. The Hugoniot relations of LSW were obtained at different temperatures and the effects of elevated temperatures on shock velocity and shock pressure were analyzed. Then the elastic and plastic wave of the LSW was researched. Finally, the evolution of dislocations induced by LSW and its mechanism under elevated temperatures was explored. The results indicate that the shock velocity and shock pressure induced by LSW both decrease with the increasing temperatures. Moreover, the velocity of elastic wave and plastic wave both decrease with the increasing treatment temperature, while their difference decreases as the temperature increases. Moreover, the dislocation atoms increases with the increasing temperatures before 2 ps, while it decreases with the increasing temperatures after 2 ps. The reason for the results is related to the formation and evolution of extended dislocations. Full article
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Open AccessFeature PaperCommunication Preparation of Advanced CuO Nanowires/Functionalized Graphene Composite Anode Material for Lithium Ion Batteries
Materials 2017, 10(1), 72; https://doi.org/10.3390/ma10010072
Received: 15 November 2016 / Revised: 11 January 2017 / Accepted: 11 January 2017 / Published: 17 January 2017
Cited by 4 | PDF Full-text (5658 KB) | HTML Full-text | XML Full-text | Supplementary Files
Abstract
The copper oxide (CuO) nanowires/functionalized graphene (f-graphene) composite material was successfully composed by a one-pot synthesis method. The f-graphene synthesized through the Birch reduction chemistry method was modified with functional group “–(CH2)5COOH”, and the CuO nanowires (NWs) were well
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The copper oxide (CuO) nanowires/functionalized graphene (f-graphene) composite material was successfully composed by a one-pot synthesis method. The f-graphene synthesized through the Birch reduction chemistry method was modified with functional group “–(CH2)5COOH”, and the CuO nanowires (NWs) were well dispersed in the f-graphene sheets. When used as anode materials in lithium-ion batteries, the composite exhibited good cyclic stability and decent specific capacity of 677 mA·h·g−1 after 50 cycles. CuO NWs can enhance the lithium-ion storage of the composites while the f-graphene effectively resists the volume expansion of the CuO NWs during the galvanostatic charge/discharge cyclic process, and provide a conductive paths for charge transportation. The good electrochemical performance of the synthesized CuO/f-graphene composite suggests great potential of the composite materials for lithium-ion batteries anodes. Full article
(This article belongs to the Special Issue Microwave Absorbing and Energy Storage Materials)
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Open AccessFeature PaperArticle Inspection of Piezoceramic Transducers Used for Structural Health Monitoring
Materials 2017, 10(1), 71; https://doi.org/10.3390/ma10010071
Received: 14 September 2016 / Revised: 24 December 2016 / Accepted: 5 January 2017 / Published: 16 January 2017
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Abstract
The use of piezoelectric wafer active sensors (PWAS) for structural health monitoring (SHM) purposes is state of the art for acousto-ultrasonic-based methods. For system reliability, detailed information about the PWAS itself is necessary. This paper gives an overview on frequent PWAS faults and
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The use of piezoelectric wafer active sensors (PWAS) for structural health monitoring (SHM) purposes is state of the art for acousto-ultrasonic-based methods. For system reliability, detailed information about the PWAS itself is necessary. This paper gives an overview on frequent PWAS faults and presents the effects of these faults on the wave propagation, used for active acousto-ultrasonics-based SHM. The analysis of the wave field is based on velocity measurements using a laser Doppler vibrometer (LDV). New and established methods of PWAS inspection are explained in detail, listing advantages and disadvantages. The electro-mechanical impedance spectrum as basis for these methods is discussed for different sensor faults. This way this contribution focuses on a detailed analysis of PWAS and the need of their inspection for an increased reliability of SHM systems. Full article
(This article belongs to the Special Issue Advances in Structural Health Monitoring for Aerospace Structures)
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Open AccessArticle Conjugation Length Effect on TPA-Based Optical Limiting Performance of a Series of Ladder-Type Chromophores
Materials 2017, 10(1), 70; https://doi.org/10.3390/ma10010070
Received: 20 October 2016 / Revised: 11 January 2017 / Accepted: 12 January 2017 / Published: 16 January 2017
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Abstract
Nonlinear optical properties of a series of newly-synthesized ladder-type chromophores containing oligo-p-phenylene moiety with different π-conjugated lengths were theoretically studied by numerically solving the rate equations and the field intensity equation with an iterative predictor-corrector finite-difference time-domain technique. Ab initio calculation
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Nonlinear optical properties of a series of newly-synthesized ladder-type chromophores containing oligo-p-phenylene moiety with different π-conjugated lengths were theoretically studied by numerically solving the rate equations and the field intensity equation with an iterative predictor-corrector finite-difference time-domain technique. Ab initio calculation results show that the compounds can be described by the three-level model. Based on the two-photon absorption mechanism, highly efficient optical limiting performances are demonstrated in the chromophores, which strongly depend on the π-conjugated length of the molecule. Special attention has been paid to the dynamical two-photon absorption, indicating that the parameter of the medium can affect the dynamical two-photon absorption cross section. Our numerical results agree well with the experimental measurements. It reveals that the increase in the π-conjugated length of ladder-type oligo-p-phenylene for these chromophores leads to enhanced nonlinear optical absorption. The results also provide a method to modulate the optical limiting and dynamical two-photon absorption of the compounds by changing the molecular density and thickness of the absorber. Full article
(This article belongs to the Special Issue Nonlinear Optical Material)
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Open AccessArticle Novel AlN/Pt/ZnO Electrode for High Temperature SAW Sensors
Materials 2017, 10(1), 69; https://doi.org/10.3390/ma10010069
Received: 7 November 2016 / Revised: 26 December 2016 / Accepted: 9 January 2017 / Published: 16 January 2017
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Abstract
In order to develop a film electrode for the surface acoustic wave (SAW) devices working in high temperature, harsh environments, novel AlN/Pt/ZnO multilayers were prepared using pulsed laser deposition (PLD) systems on langasite (LGS) substrates. The AlN film was used as a protective
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In order to develop a film electrode for the surface acoustic wave (SAW) devices working in high temperature, harsh environments, novel AlN/Pt/ZnO multilayers were prepared using pulsed laser deposition (PLD) systems on langasite (LGS) substrates. The AlN film was used as a protective layer and the ZnO buffer layer was introduced to improve the crystal quality of Pt films. The results show that the resistances of Pt and AlN/Pt film electrodes violently increase above 600 °C and 800 °C, respectively, while the resistances of AlN/Pt/ZnO electrodes have more stable electrical resistance from room temperature to 1000 °C. The AlN/Pt/ZnO electrode, where the ZnO film was deposited at 600 °C, has the best temperature stability and can steadily work for 4 h at 1000 °C. The mechanism underlying the stable resistance of the AlN/Pt/ZnO electrode at a high temperature was investigated by analyzing the microstructure of the prepared samples. The proposed AlN/Pt/ZnO film electrode has great potential for applications in high temperature SAW sensors. Full article
(This article belongs to the Section Structure Analysis and Characterization)
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Open AccessArticle Electrospun Nanofibers Made of Silver Nanoparticles, Cellulose Nanocrystals, and Polyacrylonitrile as Substrates for Surface-Enhanced Raman Scattering
Materials 2017, 10(1), 68; https://doi.org/10.3390/ma10010068
Received: 12 November 2016 / Revised: 2 January 2017 / Accepted: 9 January 2017 / Published: 14 January 2017
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Abstract
Nanofibers with excellent activities in surface-enhanced Raman scattering (SERS) were developed through electrospinning precursor suspensions consisting of polyacrylonitrile (PAN), silver nanoparticles (AgNPs), silicon nanoparticles (SiNPs), and cellulose nanocrystals (CNCs). Rheology of the precursor suspensions, and morphology, thermal properties, chemical structures, and SERS sensitivity
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Nanofibers with excellent activities in surface-enhanced Raman scattering (SERS) were developed through electrospinning precursor suspensions consisting of polyacrylonitrile (PAN), silver nanoparticles (AgNPs), silicon nanoparticles (SiNPs), and cellulose nanocrystals (CNCs). Rheology of the precursor suspensions, and morphology, thermal properties, chemical structures, and SERS sensitivity of the nanofibers were investigated. The electrospun nanofibers showed uniform diameters with a smooth surface. Hydrofluoric (HF) acid treatment of the PAN/CNC/Ag composite nanofibers (defined as p-PAN/CNC/Ag) led to rougher fiber surfaces with certain pores and increased mean fiber diameters. X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS) results confirmed the existence of AgNPs that were formed during heat and HF acid treatment processes. In addition, thermal stability of the electrospun nanofibers increased due to the incorporation of CNCs and AgNPs. The p-PAN/CNC/Ag nanofibers were used as a SERS substrate to detect p-aminothiophenol (p-ATP) probe molecule. The results show that this substrate exhibited high sensitivity for the p-ATP probe detection. Full article
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Open AccessArticle Bonding to Different PEEK Compositions: The Impact of Dental Light Curing Units
Materials 2017, 10(1), 67; https://doi.org/10.3390/ma10010067
Received: 29 November 2016 / Revised: 15 December 2016 / Accepted: 10 January 2017 / Published: 14 January 2017
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Abstract
This study investigated the impact of different light curing units (LCUs) for the polymerization of adhesive system visio.link (VL) on the tensile bond strength (TBS) of different PEEK compositions. For TBS measurements, 216 PEEK specimens with varying amounts of TiO2 (PEEK/0%, PEEK/20%,
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This study investigated the impact of different light curing units (LCUs) for the polymerization of adhesive system visio.link (VL) on the tensile bond strength (TBS) of different PEEK compositions. For TBS measurements, 216 PEEK specimens with varying amounts of TiO2 (PEEK/0%, PEEK/20%, PEEK/>30%) were embedded, polished, air abraded (Al2O3, 50 µm, 0.4 MPa), conditioned using VL, and polymerized using either a halogen LCU (HAL-LCU) or a LED LCU (LED-LCU) for chairside or labside application, respectively. After thermocycling (5000×, 5/55 °C), TBS was measured, and fracture types were determined. Data was analyzed using a 2-way ANOVA followed by Tukey–HSD, Kruskal–Wallis H and Mann–Whitney U tests as well as a Chi2-test and a Ciba–Geigy table (p < 0.05). Globally, the light curing units, followed by PEEK composition, was shown to have the highest impact on TBS. The HAL-LCUs, compared to the LED-LCUs, resulted in a higher TBS for all PEEK compositions—without significant differences between chairside and labside units. Regarding the different PEEK compositions, PEEK/20%, compared to PEEK/0%, resulted in a higher TBS when both, HAL-LCUs or LED-LCUs were used for labside application. In comparison with PEEK/>30%, PEEK/20% resulted in a higher TBS after using HAL-LCU for labside application. No significant differences were found between PEEK/0% and PEEK/>30%. HAL-LCU with PEEK/20% for labside application showed a higher TBS than HAL-LCU with PEEK/20% for chairside application, whereas LED-LCU with PEEK/>30% for chairside application showed a higher TBS than LED-LCU with PEEK/>30% for labside application. Full article
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Open AccessArticle Scaling-Up Techniques for the Nanofabrication of Cell Culture Substrates via Two-Photon Polymerization for Industrial-Scale Expansion of Stem Cells
Materials 2017, 10(1), 66; https://doi.org/10.3390/ma10010066
Received: 17 October 2016 / Revised: 5 January 2017 / Accepted: 10 January 2017 / Published: 13 January 2017
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Abstract
Stem-cell-based therapies require a high number (106–109) of cells, therefore in vitro expansion is needed because of the initially low amount of stem cells obtainable from human tissues. Standard protocols for stem cell expansion are currently based on chemically-defined
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Stem-cell-based therapies require a high number (106–109) of cells, therefore in vitro expansion is needed because of the initially low amount of stem cells obtainable from human tissues. Standard protocols for stem cell expansion are currently based on chemically-defined culture media and animal-derived feeder-cell layers, which expose cells to additives and to xenogeneic compounds, resulting in potential issues when used in clinics. The two-photon laser polymerization technique enables three-dimensional micro-structures to be fabricated, which we named synthetic nichoids. Here we review our activity on the technological improvements in manufacturing biomimetic synthetic nichoids and, in particular on the optimization of the laser-material interaction to increase the patterned area and the percentage of cell culture surface covered by such synthetic nichoids, from a low initial value of 10% up to 88% with an optimized micromachining time. These results establish two-photon laser polymerization as a promising tool to fabricate substrates for stem cell expansion, without any chemical supplement and in feeder-free conditions for potential therapeutic uses. Full article
(This article belongs to the Special Issue Materials for Hard and Soft Tissue Engineering: Novel Approaches)
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Open AccessArticle Laser Sintered Magnesium-Calcium Silicate/Poly-ε-Caprolactone Scaffold for Bone Tissue Engineering
Materials 2017, 10(1), 65; https://doi.org/10.3390/ma10010065
Received: 14 November 2016 / Revised: 10 January 2017 / Accepted: 11 January 2017 / Published: 13 January 2017
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Abstract
In this study, we manufacture and analyze bioactive magnesium–calcium silicate/poly-ε-caprolactone (Mg–CS/PCL) 3D scaffolds for bone tissue engineering. Mg–CS powder was incorporated into PCL, and we fabricated the 3D scaffolds using laser sintering technology. These scaffolds had high porosity and interconnected-design macropores and structures.
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In this study, we manufacture and analyze bioactive magnesium–calcium silicate/poly-ε-caprolactone (Mg–CS/PCL) 3D scaffolds for bone tissue engineering. Mg–CS powder was incorporated into PCL, and we fabricated the 3D scaffolds using laser sintering technology. These scaffolds had high porosity and interconnected-design macropores and structures. As compared to pure PCL scaffolds without an Mg–CS powder, the hydrophilic properties and degradation rate are also improved. For scaffolds with more than 20% Mg–CS content, the specimens become completely covered by a dense bone-like apatite layer after soaking in simulated body fluid for 1 day. In vitro analyses were directed using human mesenchymal stem cells (hMSCs) on all scaffolds that were shown to be biocompatible and supported cell adhesion and proliferation. Increased focal adhesion kinase and promoted cell adhesion behavior were observed after an increase in Mg–CS content. In addition, the results indicate that the Mg–CS quantity in the composite is higher than 10%, and the quantity of cells and osteogenesis-related protein of hMSCs is stimulated by the Si ions released from the Mg–CS/PCL scaffolds when compared to PCL scaffolds. Our results proved that 3D Mg–CS/PCL scaffolds with such a specific ionic release and good degradability possessed the ability to promote osteogenetic differentiation of hMSCs, indicating that they might be promising biomaterials with potential for next-generation bone tissue engineering scaffolds. Full article
(This article belongs to the Special Issue 3D Printing for Biomedical Engineering)
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