Materials

900 KiB

Open AccessArticle

Optimization of Injection Molding Parameters for HDPE/TiO₂ Nanocomposites Fabrication with Multiple Performance Characteristics Using the Taguchi Method and Grey Relational Analysis

by Hifsa Pervez, Mohammad S. Mozumder and Abdel-Hamid I. Mourad

Materials 2016, 9(8), 710; https://doi.org/10.3390/ma9080710 - 22 Aug 2016

Cited by 40 | Viewed by 6045

Abstract

The current study presents an investigation on the optimization of injection molding parameters of HDPE/TiO₂ nanocomposites using grey relational analysis with the Taguchi method. Four control factors, including filler concentration (i.e., TiO₂), barrel temperature, residence time and holding time, were [...] Read more.

The current study presents an investigation on the optimization of injection molding parameters of HDPE/TiO₂ nanocomposites using grey relational analysis with the Taguchi method. Four control factors, including filler concentration (i.e., TiO₂), barrel temperature, residence time and holding time, were chosen at three different levels of each. Mechanical properties, such as yield strength, Young’s modulus and elongation, were selected as the performance targets. Nine experimental runs were carried out based on the Taguchi L₉ orthogonal array, and the data were processed according to the grey relational steps. The optimal process parameters were found based on the average responses of the grey relational grades, and the ideal operating conditions were found to be a filler concentration of 5 wt % TiO₂, a barrel temperature of 225 °C, a residence time of 30 min and a holding time of 20 s. Moreover, analysis of variance (ANOVA) has also been applied to identify the most significant factor, and the percentage of TiO₂ nanoparticles was found to have the most significant effect on the properties of the HDPE/TiO₂ nanocomposites fabricated through the injection molding process. Full article

(This article belongs to the Special Issue Materials' 2016 (Montreal, Canada: June 20 - 24, 2016) - Advances and Trends in Engineering Materials and their Applications)

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2601 KiB

Open AccessArticle

Identification of Material Parameters for the Simulation of Acoustic Absorption of Fouled Sintered Fiber Felts

by Nicolas Lippitz, Christopher Blech, Sabine Langer and Joachim Rösler

Materials 2016, 9(8), 709; https://doi.org/10.3390/ma9080709 - 22 Aug 2016

Cited by 9 | Viewed by 5430

Abstract

As a reaction to the increasing noise pollution, caused by the expansion of airports close to residential areas, porous trailing edges are investigated to reduce the aeroacoustic noise produced by flow around the airframe. Besides mechanical and acoustical investigations of porous materials, the [...] Read more.

As a reaction to the increasing noise pollution, caused by the expansion of airports close to residential areas, porous trailing edges are investigated to reduce the aeroacoustic noise produced by flow around the airframe. Besides mechanical and acoustical investigations of porous materials, the fouling behavior of promising materials is an important aspect to estimate the performance in long-term use. For this study, two sintered fiber felts were selected for a long-term fouling experiment where the development of the flow resistivity and accumulation of dirt was observed. Based on 3D structural characterizations obtained from X-ray tomography of the initial materials, acoustic models (Biot and Johnson–Champoux–Allard) in the frame of the transfer matrix method were applied to the sintered fiber felts. Flow resistivity measurements and the measurements of the absorption coefficient in an impedance tube are the basis for a fouling model for sintered fiber felts. The contribution will conclude with recommendations concerning the modeling of pollution processes of porous materials. Full article

(This article belongs to the Special Issue Acoustic Waves in Advanced Materials)

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7787 KiB

Open AccessArticle

A New Superhard Phase and Physical Properties of ZrB₃ from First-Principles Calculations

by Gangtai Zhang, Tingting Bai, Yaru Zhao and Yanfei Hu

Materials 2016, 9(8), 703; https://doi.org/10.3390/ma9080703 - 22 Aug 2016

Cited by 30 | Viewed by 6723

Abstract

Using the first-principles particle swarm optimization algorithm for crystal structural prediction, we have predicted a novel monoclinic C2/m structure for ZrB₃, which is more energetically favorable than the previously proposed FeB₃-, TcP₃-, MoB₃-, [...] Read more.

Using the first-principles particle swarm optimization algorithm for crystal structural prediction, we have predicted a novel monoclinic C2/m structure for ZrB₃, which is more energetically favorable than the previously proposed FeB₃-, TcP₃-, MoB₃-, WB₃-, and OsB₃-type structures in the considered pressure range. The new phase is mechanically and dynamically stable, as confirmed by the calculations of its elastic constants and phonon dispersion curve. The calculated large shear modulus (227 GPa) and high hardness (42.2 GPa) show that ZrB₃ within the monoclinic phase is a potentially superhard material. The analyses of the electronic density of states and chemical bonding reveal that the strong B–B and B–Zr covalent bonds are attributed to its high hardness. By the quasi-harmonic Debye model, the heat capacity, thermal expansion coefficient and Grüneisen parameter of ZrB₃ are also systemically investigated. Full article

(This article belongs to the Special Issue Computational Multiscale Modeling and Simulation in Materials Science)

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11331 KiB

Open AccessArticle

Study on the Impact Resistance of Bionic Layered Composite of TiC-TiB₂/Al from Al-Ti-B₄C System

by Qian Zhao, Yunhong Liang, Zhihui Zhang, Xiujuan Li and Luquan Ren

Materials 2016, 9(8), 708; https://doi.org/10.3390/ma9080708 - 20 Aug 2016

Cited by 21 | Viewed by 6524

Abstract

Mechanical property and impact resistance mechanism of bionic layered composite was investigated. Due to light weight and high strength property, white clam shell was chosen as bionic model for design of bionic layered composite. The intercoupling model between hard layer and soft layer [...] Read more.

Mechanical property and impact resistance mechanism of bionic layered composite was investigated. Due to light weight and high strength property, white clam shell was chosen as bionic model for design of bionic layered composite. The intercoupling model between hard layer and soft layer was identical to the layered microstructure and hardness tendency of the white clam shell, which connected the bionic design and fabrication. TiC-TiB₂ reinforced Al matrix composites fabricated from Al-Ti-B₄C system with 40 wt. %, 50 wt. % and 30 wt. % Al contents were treated as an outer layer, middle layer and inner layer in hard layers. Pure Al matrix was regarded as a soft layer. Compared with traditional homogenous Al-Ti-B₄C composite, bionic layered composite exhibited high mechanical properties including flexural strength, fracture toughness, compressive strength and impact toughness. The intercoupling effect of layered structure and combination model of hard and soft played a key role in high impact resistance of the bionic layered composite, proving the feasibility and practicability of the bionic model of a white clam shell. Full article

(This article belongs to the Section Advanced Composites)

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1807 KiB

Open AccessArticle

Membrane Functionalization with Hyperbranched Polymers

by Agnes Schulze, Marco Went and Andrea Prager

Materials 2016, 9(8), 706; https://doi.org/10.3390/ma9080706 - 20 Aug 2016

Cited by 20 | Viewed by 6195

Abstract

Polymer membranes have been modified with hyperbranched polymers with the aim to generate a high density of hydrophilic functional groups at the membrane surface. For this purpose hyperbranched polymers containing amino, alcohol, and carboxylic acid end groups were used for membrane modification, respectively. [...] Read more.

Polymer membranes have been modified with hyperbranched polymers with the aim to generate a high density of hydrophilic functional groups at the membrane surface. For this purpose hyperbranched polymers containing amino, alcohol, and carboxylic acid end groups were used for membrane modification, respectively. Thus, surface potential and charges were changed significantly to result in attractive or repulsive interactions towards three different proteins (albumin, lysozyme, myoglobin) that were used to indicate membrane fouling properties. Our studies demonstrated that hydrophilization alone is not effective for avoiding membrane fouling when charged proteins are present. In contrast, electrostatic repulsion seems to be a general key factor. Full article

(This article belongs to the Section Porous Materials)

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3616 KiB

Open AccessArticle

Coating and Patterning Functional Materials for Large Area Electrofluidic Arrays

by Hao Wu, Biao Tang, Robert A. Hayes, Yingying Dou, Yuanyuan Guo, Hongwei Jiang and Guofu Zhou

Materials 2016, 9(8), 707; https://doi.org/10.3390/ma9080707 - 19 Aug 2016

Cited by 40 | Viewed by 5542

Abstract

Industrialization of electrofluidic devices requires both high performance coating laminates and efficient material utilization on large area substrates. Here we show that screen printing can be effectively used to provide homogeneous pin-hole free patterned amorphous fluoropolymer dielectric layers to provide both the insulating [...] Read more.

Industrialization of electrofluidic devices requires both high performance coating laminates and efficient material utilization on large area substrates. Here we show that screen printing can be effectively used to provide homogeneous pin-hole free patterned amorphous fluoropolymer dielectric layers to provide both the insulating and fluidic reversibility required for devices. Subsequently, we over-coat photoresist using slit coating on this normally extremely hydrophobic layer. In this way, we are able to pattern the photoresist by conventional lithography to provide the chemical contrast required for liquids dosing by self-assembly and highly-reversible electrofluidic switching. Materials, interfacial chemistry, and processing all contribute to the provision of the required engineered substrate properties. Coating homogeneity as characterized by metrology and device performance data are used to validate the methodology, which is well-suited for transfer to high volume production in existing LCD cell-making facilities. Full article

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143 KiB

Open AccessAddendum

Addendum: Bassan, J.C.; et al. Immobilization of Trypsin in Lignocellulosic Waste Material to Produce Peptides with Bioactive Potential from Whey Protein. Materials 2016, 9(5), 357

by Juliana Cristina Bassan, Thaís Milena De Souza Bezerra, Guilherme Peixoto, Clariana Zanutto Paulino Da Cruz, Julián Paul Martínez Galán, Aline Buda Dos Santos Vaz, Saulo Santesso Garrido, Marco Filice and Rubens Monti

Materials 2016, 9(8), 705; https://doi.org/10.3390/ma9080705 - 19 Aug 2016

Cited by 10 | Viewed by 3443

Abstract

The authors would like to add the following sentence to the “Acknowledgments” section of their article [1]:[...] Full article

799 KiB

Open AccessArticle

Hybrid Effect Evaluation of Steel Fiber and Carbon Fiber on the Performance of the Fiber Reinforced Concrete

by Weimin Song and Jian Yin

Materials 2016, 9(8), 704; https://doi.org/10.3390/ma9080704 - 18 Aug 2016

Cited by 88 | Viewed by 8335

Abstract

Fiber reinforcement is an important method to enhance the performance of concrete. In this study, the compressive test and impact test were conducted, and then the hybrid effect between steel fiber (SF) and carbon fiber (CF) was evaluated by employing the hybrid effect [...] Read more.

Fiber reinforcement is an important method to enhance the performance of concrete. In this study, the compressive test and impact test were conducted, and then the hybrid effect between steel fiber (SF) and carbon fiber (CF) was evaluated by employing the hybrid effect index. Compressive toughness and impact toughness of steel fiber reinforced concrete (SFRC), carbon fiber reinforced concrete (CFRC) and hybrid fiber reinforced concrete (HFRC) were explored at steel fiber volume fraction 0.5%, 1%, 1.5% and carbon fiber 0.1%, 0.2%, 0.3%. Results showed that the addition of steel fiber and carbon fiber can increase the compressive strength. SF, CF and the hybridization between them could increase the compressive toughness significantly. The impact test results showed that as the volume of fiber increased, the impact number of the first visible crack and the ultimate failure also increased. The improvement of toughness mainly lay in improving the crack resistance after the first crack. Based on the test results, the positive hybrid effect of steel fiber and carbon fiber existed in hybrid fiber reinforced concrete. The relationship between the compressive toughness and impact toughness was also explored. Full article

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9127 KiB

Open AccessArticle

Improvement in the Tensile Bond Strength between 3Y-TZP Ceramic and Enamel by Surface Treatments

by Seon-Mi Byeon, Yong-Seok Jang, Min-Ho Lee and Tae-Sung Bae

Materials 2016, 9(8), 702; https://doi.org/10.3390/ma9080702 - 18 Aug 2016

Cited by 5 | Viewed by 5583

Abstract

This study examined the effects of 3 mol % yttria-stabilized tetragonal zirconia polycrystal (3Y-TZP) ceramic surface treatments on the tensile bond strength and surface characteristics of enamel. To measure the tensile bond strength, the 3Y-TZP and tooth specimens were manufactured in a mini-dumbbell [...] Read more.

This study examined the effects of 3 mol % yttria-stabilized tetragonal zirconia polycrystal (3Y-TZP) ceramic surface treatments on the tensile bond strength and surface characteristics of enamel. To measure the tensile bond strength, the 3Y-TZP and tooth specimens were manufactured in a mini-dumbbell shape and divided into four groups based on the type of 3Y-TZP surface treatment: polishing (P), 110 µm alumina sandblasting (S), 110 µm alumina sandblasting combined with selective infiltration etching (SS), and 110 µm alumina sandblasting combined with MDP (10-methacryloyloxydecyl dihydrogen phosphate)-containing silane primer (SP). After surface treatment, the surface roughness, wettability, and surface changes were examined, and the tensile bond strength was measured. The mean values (from lowest to highest) for tensile bond strength (MPa) were as follows: P, 8.94 ± 2.30; S, 21.33 ± 2.00; SS, 26.67 ± 4.76; and SP, 31.74 ± 2.66. Compared to the P group, the mean surface roughness was significantly increased, and the mean contact angle was significantly decreased, while wettability was increased in the other groups. Therefore, surface treatment with 110 µm alumina sandblasting and MDP-containing silane primer is suitable for clinical applications, as it considerably improves the bond strength between 3Y-TZP and enamel. Full article

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3701 KiB

Open AccessArticle

Characterization of Mechanical and Bactericidal Properties of Cement Mortars Containing Waste Glass Aggregate and Nanomaterials

by Pawel Sikora, Adrian Augustyniak, Krzysztof Cendrowski, Elzbieta Horszczaruk, Teresa Rucinska, Pawel Nawrotek and Ewa Mijowska

Materials 2016, 9(8), 701; https://doi.org/10.3390/ma9080701 - 18 Aug 2016

Cited by 77 | Viewed by 8882

Abstract

The recycling of waste glass is a major problem for municipalities worldwide. The problem concerns especially colored waste glass which, due to its low recycling rate as result of high level of impurity, has mostly been dumped into landfills. In recent years, a [...] Read more.

The recycling of waste glass is a major problem for municipalities worldwide. The problem concerns especially colored waste glass which, due to its low recycling rate as result of high level of impurity, has mostly been dumped into landfills. In recent years, a new use was found for it: instead of creating waste, it can be recycled as an additive in building materials. The aim of the study was to evaluate the possibility of manufacturing sustainable and self-cleaning cement mortars with use of commercially available nanomaterials and brown soda-lime waste glass. Mechanical and bactericidal properties of cement mortars containing brown soda-lime waste glass and commercially available nanomaterials (amorphous nanosilica and cement containing nanocrystalline titanium dioxide) were analyzed in terms of waste glass content and the effectiveness of nanomaterials. Quartz sand is replaced with brown waste glass at ratios of 25%, 50%, 75% and 100% by weight. Study has shown that waste glass can act as a successful replacement for sand (up to 100%) to produce cement mortars while nanosilica is incorporated. Additionally, a positive effect of waste glass aggregate for bactericidal properties of cement mortars was observed. Full article

(This article belongs to the Section Advanced Composites)

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3986 KiB

Open AccessArticle

Identification of Specific Hydroxyapatite {001} Binding Heptapeptide by Phage Display and Its Nucleation Effect

by Jing Mao, Xin Shi, Ya-Bo Wu and Shi-Qiang Gong

Materials 2016, 9(8), 700; https://doi.org/10.3390/ma9080700 - 17 Aug 2016

Cited by 23 | Viewed by 6453

Abstract

With recent developments of molecular biomimetics that combine genetic engineering and nanotechnology, peptides can be genetically engineered to bind specifically to inorganic components and execute the task of collagen matrix proteins. In this study, using biogenous tooth enamel as binding substrate, we identified [...] Read more.

With recent developments of molecular biomimetics that combine genetic engineering and nanotechnology, peptides can be genetically engineered to bind specifically to inorganic components and execute the task of collagen matrix proteins. In this study, using biogenous tooth enamel as binding substrate, we identified a new heptapeptide (enamel high-affinity binding peptide, EHBP) from linear 7-mer peptide phage display library. Through the output/input affinity test, it was found that EHBP has the highest affinity to enamel with an output/input ratio of 14.814 × 10⁻⁷, while a random peptide (RP) displayed much lower output/input ratio of 0.00035 × 10⁻⁷. This binding affinity was also verified by confocal laser scanning microscopy (CLSM) analysis. It was found that EHBP absorbing onto the enamel surface exhibits highest normalized fluorescence intensity (5.6 ± 1.2), comparing to the intensity of EHBP to enamel longitudinal section (1.5 ± 0.9) (p < 0.05) as well as to the intensity of a low-affinity binding peptide (ELBP) to enamel (1.5 ± 0.5) (p < 0.05). Transmission electron microscopy (TEM), Attenuated total Reflection-Fourier transform infrared spectroscopy (ATR-FTIR), and X-ray Diffraction (XRD) studies further confirmed that crystallized hydroxyapatite were precipitated in the mineralization solution containing EHBP. To better understand the nucleation effect of EHBP, EHBP was further investigated on its interaction with calcium phosphate clusters through in vitro mineralization model. The calcium and phosphate ion consumption as well as zeta potential survey revealed that EHBP might previously adsorb to phosphate (PO₄³⁻) groups and then initiate the precipitation of calcium and phosphate groups. This study not only proved the electrostatic interaction of phosphate group and the genetically engineering solid-binding peptide, but also provided a novel nucleation motif for potential applications in guided hard tissue biomineralization and regeneration. Full article

(This article belongs to the Special Issue Calcium Phosphate in Biomedical Applications)

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6056 KiB

Open AccessArticle

Transverse Crack Detection in 3D Angle Interlock Glass Fibre Composites Using Acoustic Emission

by Matthieu Gresil, Mohamed Nasr Saleh and Constantinos Soutis

Materials 2016, 9(8), 699; https://doi.org/10.3390/ma9080699 - 16 Aug 2016

Cited by 21 | Viewed by 7008

Abstract

In addition to manufacturing cost and production rates, damage resistance has become a major issue for the composites industry. Three-dimensional (3D) woven composites have superior through-thickness properties compared to two-dimensional (2D) laminates, for example, improved impact damage resistance, high interlaminar fracture toughness and [...] Read more.

In addition to manufacturing cost and production rates, damage resistance has become a major issue for the composites industry. Three-dimensional (3D) woven composites have superior through-thickness properties compared to two-dimensional (2D) laminates, for example, improved impact damage resistance, high interlaminar fracture toughness and reduced notch sensitivity. The performance of 3D woven preforms is dependent on the fabric architecture, which is determined by the binding pattern. For this study, angle interlock (AI) structures with through-thickness binding were manufactured. The AI cracking simulation shows that the transverse component is the one that leads to transverse matrix cracking in the weft yarn under tensile loading. Monitoring of acoustic emission (AE) during mechanical loading is an effective tool in the study of damage processes in glass fiber-reinforced composites. Tests were performed with piezoelectric sensors bonded on a tensile specimen acting as passive receivers of AE signals. An experimental data has been generated which was useful to validate the multi-physics finite element method (MP-FEM), providing insight into the damage behaviour of novel 3D AI glass fibre composites. MP-FEM and experimental data showed that transverse crack generated a predominant flexural mode A0 and also a less energetic extensional mode S0. Full article

(This article belongs to the Special Issue Acoustic Waves in Advanced Materials)

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10069 KiB

Open AccessArticle

Fatigue Property of Open-Hole Steel Plates Influenced by Bolted Clamp-up and Hole Fabrication Methods

by Zhi-Yu Wang, Lihui Li, Yong-Jie Liu and Qing-Yuan Wang

Materials 2016, 9(8), 698; https://doi.org/10.3390/ma9080698 - 16 Aug 2016

Cited by 13 | Viewed by 5260

Abstract

Steel plates with open holes are commonly used in structural assemblies. The fatigue properties of such details are influenced by bolted clamp-up and hole fabrication methods. The fracture surface, stiffness degradation and fatigue life of test specimens are investigated in detail and compared [...] Read more.

Steel plates with open holes are commonly used in structural assemblies. The fatigue properties of such details are influenced by bolted clamp-up and hole fabrication methods. The fracture surface, stiffness degradation and fatigue life of test specimens are investigated in detail and compared with the contemporary test data. The analysis results show that the presence of draglines greatly influences the fatigue crack initiation at the open-hole cut by laser. The bolted clamp-up condition greatly enhances the stiffness and the fatigue life of the open-hole details. A discussion is also made from a comparison with the referred fatigue life of hole fabrication details, such as the influence of plate thickness and plasma cutting, drilling and oxy-fuel gas cutting, with the details studied herein. This work could enhance the understanding of the fatigue property and design of such details. Full article

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4386 KiB

Open AccessArticle

Tailorable Burning Behavior of Ti14 Alloy by Controlling Semi-Solid Forging Temperature

by Yongnan Chen, Wenqing Yang, Haifei Zhan, Fengying Zhang, Yazhou Huo, Yongqing Zhao, Xuding Song and Yuantong Gu

Materials 2016, 9(8), 697; https://doi.org/10.3390/ma9080697 - 16 Aug 2016

Cited by 11 | Viewed by 5569

Abstract

Semi-solid processing (SSP) is a popular near-net-shape forming technology for metals, while its application is still limited in titanium alloy mainly due to its low formability. Recent works showed that SSP could effectively enhance the formability and mechanical properties of titanium alloys. The [...] Read more.

Semi-solid processing (SSP) is a popular near-net-shape forming technology for metals, while its application is still limited in titanium alloy mainly due to its low formability. Recent works showed that SSP could effectively enhance the formability and mechanical properties of titanium alloys. The processing parameters such as temperature and forging rate/ratio, are directly correlated with the microstructure, which endow the alloy with different chemical and physical properties. Specifically, as a key structural material for the advanced aero-engine, the burn resistant performance is a crucial requirement for the burn resistant titanium alloy. Thus, this work aims to assess the burning behavior of Ti14, a kind of burn resistant alloy, as forged at different semi-solid forging temperatures. The burning characteristics of the alloy are analyzed by a series of burning tests with different burning durations, velocities, and microstructures of burned sample. The results showed that the burning process is highly dependent on the forging temperature, due to the fact that higher temperatures would result in more Ti₂Cu precipitate within grain and along grain boundaries. Such a microstructure hinders the transport of oxygen in the stable burning stage through the formation of a kind of oxygen isolation Cu-enriched layer under the burn product zone. This work suggests that the burning resistance of the alloy can be effectively tuned by controlling the temperature during the semi-solid forging process. Full article

(This article belongs to the Special Issue Physical Metallurgy of High Performance Alloys)

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2757 KiB

Open AccessArticle

Nature of the Electrochemical Properties of Sulphur Substituted LiMn₂O₄ Spinel Cathode Material Studied by Electrochemical Impedance Spectroscopy

by Monika Bakierska, Michał Świętosławski, Roman Dziembaj and Marcin Molenda

Materials 2016, 9(8), 696; https://doi.org/10.3390/ma9080696 - 16 Aug 2016

Cited by 13 | Viewed by 6969

Abstract

In this work, nanostructured LiMn₂O₄ (LMO) and LiMn₂O_3.99S_0.01 (LMOS1) spinel cathode materials were comprehensively investigated in terms of electrochemical properties. For this purpose, electrochemical impedance spectroscopy (EIS) measurements as a function of state of charge [...] Read more.

In this work, nanostructured LiMn₂O₄ (LMO) and LiMn₂O_3.99S_0.01 (LMOS1) spinel cathode materials were comprehensively investigated in terms of electrochemical properties. For this purpose, electrochemical impedance spectroscopy (EIS) measurements as a function of state of charge (SOC) were conducted on a representative charge and discharge cycle. The changes in the electrochemical performance of the stoichiometric and sulphur-substituted lithium manganese oxide spinels were examined, and suggested explanations for the observed dependencies were given. A strong influence of sulphur introduction into the spinel structure on the chemical stability and electrochemical characteristic was observed. It was demonstrated that the significant improvement in coulombic efficiency and capacity retention of lithium cell with LMOS1 active material arises from a more stable solid electrolyte interphase (SEI) layer. Based on EIS studies, the Li ion diffusion coefficients in the cathodes were estimated, and the influence of sulphur on Li⁺ diffusivity in the spinel structure was established. The obtained results support the assumption that sulphur substitution is an effective way to promote chemical stability and the electrochemical performance of LiMn₂O₄ cathode material. Full article

(This article belongs to the Special Issue Amorphous and Nanocrystalline Materials for Electrochemical Energy Storage)

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3730 KiB

Open AccessArticle

Effects of Rapid Thermal Annealing on the Structural, Electrical, and Optical Properties of Zr-Doped ZnO Thin Films Grown by Atomic Layer Deposition

by Jingjin Wu, Yinchao Zhao, Ce Zhou Zhao, Li Yang, Qifeng Lu, Qian Zhang, Jeremy Smith and Yongming Zhao

Materials 2016, 9(8), 695; https://doi.org/10.3390/ma9080695 - 13 Aug 2016

Cited by 19 | Viewed by 7856

Abstract

The 4 at. % zirconium-doped zinc oxide (ZnO:Zr) films grown by atomic layer deposition (ALD) were annealed at various temperatures ranging from 350 to 950 °C. The structural, electrical, and optical properties of rapid thermal annealing (RTA) treated ZnO:Zr films have been evaluated [...] Read more.

The 4 at. % zirconium-doped zinc oxide (ZnO:Zr) films grown by atomic layer deposition (ALD) were annealed at various temperatures ranging from 350 to 950 °C. The structural, electrical, and optical properties of rapid thermal annealing (RTA) treated ZnO:Zr films have been evaluated to find out the stability limit. It was found that the grain size increased at 350 °C and decreased between 350 and 850 °C, while creeping up again at 850 °C. UV–vis characterization shows that the optical band gap shifts towards larger wavelengths. The Hall measurement shows that the resistivity almost keeps constant at low annealing temperatures, and increases rapidly after treatment at 750 °C due to the effect of both the carrier concentration and the Hall mobility. The best annealing temperature is found in the range of 350–550 °C. The ZnO:Zr film-coated glass substrates show good optical and electrical performance up to 550 °C during superstrate thin film solar cell deposition. Full article

(This article belongs to the Special Issue Physical Metallurgy of High Performance Alloys)

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6179 KiB

Open AccessArticle

Generalized Effective Medium Theory for Particulate Nanocomposite Materials

by Muhammad Usama Siddiqui and Abul Fazal M. Arif

Materials 2016, 9(8), 694; https://doi.org/10.3390/ma9080694 - 13 Aug 2016

Cited by 27 | Viewed by 5942

Abstract

The thermal conductivity of particulate nanocomposites is strongly dependent on the size, shape, orientation and dispersion uniformity of the inclusions. To correctly estimate the effective thermal conductivity of the nanocomposite, all these factors should be included in the prediction model. In this paper, [...] Read more.

The thermal conductivity of particulate nanocomposites is strongly dependent on the size, shape, orientation and dispersion uniformity of the inclusions. To correctly estimate the effective thermal conductivity of the nanocomposite, all these factors should be included in the prediction model. In this paper, the formulation of a generalized effective medium theory for the determination of the effective thermal conductivity of particulate nanocomposites with multiple inclusions is presented. The formulated methodology takes into account all the factors mentioned above and can be used to model nanocomposites with multiple inclusions that are randomly oriented or aligned in a particular direction. The effect of inclusion dispersion non-uniformity is modeled using a two-scale approach. The applications of the formulated effective medium theory are demonstrated using previously published experimental and numerical results for several particulate nanocomposites. Full article

(This article belongs to the Section Advanced Composites)

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1474 KiB

Open AccessArticle

Improvement of the Mechanical Properties of 1022 Carbon Steel Coil by Using the Taguchi Method to Optimize Spheroidized Annealing Conditions

by Chih-Cheng Yang and Chang-Lun Liu

Materials 2016, 9(8), 693; https://doi.org/10.3390/ma9080693 - 12 Aug 2016

Cited by 24 | Viewed by 6378

Abstract

Cold forging is often applied in the fastener industry. Wires in coil form are used as semi-finished products for the production of billets. This process usually requires preliminarily drawing wire coil in order to reduce the diameter of products. The wire usually has [...] Read more.

Cold forging is often applied in the fastener industry. Wires in coil form are used as semi-finished products for the production of billets. This process usually requires preliminarily drawing wire coil in order to reduce the diameter of products. The wire usually has to be annealed to improve its cold formability. The quality of spheroidizing annealed wire affects the forming quality of screws. In the fastener industry, most companies use a subcritical process for spheroidized annealing. Various parameters affect the spheroidized annealing quality of steel wire, such as the spheroidized annealing temperature, prolonged heating time, furnace cooling time and flow rate of nitrogen (protective atmosphere). The effects of the spheroidized annealing parameters affect the quality characteristics of steel wire, such as the tensile strength and hardness. A series of experimental tests on AISI 1022 low carbon steel wire are carried out and the Taguchi method is used to obtain optimum spheroidized annealing conditions to improve the mechanical properties of steel wires for cold forming. The results show that the spheroidized annealing temperature and prolonged heating time have the greatest effect on the mechanical properties of steel wires. A comparison between the results obtained using the optimum spheroidizing conditions and the measures using the original settings shows the new spheroidizing parameter settings effectively improve the performance measures over their value at the original settings. The results presented in this paper could be used as a reference for wire manufacturers. Full article

(This article belongs to the Special Issue Selected Papers from ICASI 2016)

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Open AccessArticle

High Pressure Properties of a Ba-Cu-Zn-P Clathrate-I

by Juli-Anna Dolyniuk and Kirill Kovnir

Materials 2016, 9(8), 692; https://doi.org/10.3390/ma9080692 - 12 Aug 2016

Cited by 2 | Viewed by 5136

Abstract

The high pressure properties of the novel tetrel-free clathrate, Ba₈Cu_13.1Zn_3.3P_29.6, were investigated using synchrotron powder X-ray diffraction. The pressure was applied using a diamond anvil cell. No structural transitions or decomposition were detected in the [...] Read more.

The high pressure properties of the novel tetrel-free clathrate, Ba₈Cu_13.1Zn_3.3P_29.6, were investigated using synchrotron powder X-ray diffraction. The pressure was applied using a diamond anvil cell. No structural transitions or decomposition were detected in the studied pressure range of 0.1–7 GPa. The calculated bulk modulus for Ba₈Cu_13.1Zn_3.3P_29.6 using a third-order Birch-Murnaghan equation of state is 65(6) GPa at 300 K. This bulk modulus is comparable to the bulk moduli of Ge- and Sn-based clathrates, like A₈Ga₁₆Ge₃₀ (A = Sr, Ba) and Sn_19.3Cu_4.7P₂₂I₈, but lower than those for the transition metal-containing silicon-based clathrates, Ba₈T_xSi_46−x, T = Ni, Cu; 3 ≤ x ≤ 5. Full article

(This article belongs to the Special Issue Inorganic Clathrate Materials)

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6743 KiB

Open AccessArticle

Synthesis and Characterization of Reduced Graphene Oxide-Supported Nanoscale Zero-Valent Iron (nZVI/rGO) Composites Used for Pb(II) Removal

by Mingyi Fan, Tongjun Li, Jiwei Hu, Rensheng Cao, Qing Wu, Xionghui Wei, Lingyun Li, Xuedan Shi and Wenqian Ruan

Materials 2016, 9(8), 687; https://doi.org/10.3390/ma9080687 - 12 Aug 2016

Cited by 73 | Viewed by 8797

Abstract

Reduced graphene oxide-supported nanoscale zero-valent iron (nZVI/rGO) composites were prepared by chemical deposition method and were characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD), Raman spectroscopy, N₂-sorption and X-ray photoelectron spectroscopy (XPS). Operating parameters for the removal process of Pb(II) [...] Read more.

Reduced graphene oxide-supported nanoscale zero-valent iron (nZVI/rGO) composites were prepared by chemical deposition method and were characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD), Raman spectroscopy, N₂-sorption and X-ray photoelectron spectroscopy (XPS). Operating parameters for the removal process of Pb(II) ions, such as temperature (20–40 °C), pH (3–5), initial concentration (400–600 mg/L) and contact time (20–60 min), were optimized using a quadratic model. The coefficient of determination (R² > 0.99) obtained for the mathematical model indicates a high correlation between the experimental and predicted values. The optimal temperature, pH, initial concentration and contact time for Pb(II) ions removal in the present experiment were 21.30 °C, 5.00, 400.00 mg/L and 60.00 min, respectively. In addition, the Pb(II) removal by nZVI/rGO composites was quantitatively evaluated by using adsorption isotherms, such as Langmuir and Freundlich isotherm models, of which Langmuir isotherm gave a better correlation, and the calculated maximum adsorption capacity was 910 mg/g. The removal process of Pb(II) ions could be completed within 50 min, which was well described by the pseudo-second order kinetic model. Therefore, the nZVI/rGO composites are suitable as efficient materials for the advanced treatment of Pb(II)-containing wastewater. Full article

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1463 KiB

Open AccessFeature PaperArticle

Effect of Guest Atom Composition on the Structural and Vibrational Properties of the Type II Clathrate-Based Materials A_xSi₁₃₆, A_xGe₁₃₆ and A_xSn₁₃₆ (A = Na, K, Rb, Cs; 0 ≤ x ≤ 24)

by Dong Xue, Charles W. Myles and Craig Higgins

Materials 2016, 9(8), 691; https://doi.org/10.3390/ma9080691 - 11 Aug 2016

Cited by 7 | Viewed by 5030

Abstract

Type II clathrates are interesting due to their potential thermoelectric applications. Powdered X-ray diffraction (XRD) data and density functional calculations for Na_xSi₁₃₆ found a lattice contraction as x increases for 0 < x < 8 and an expansion as x [...] Read more.

Type II clathrates are interesting due to their potential thermoelectric applications. Powdered X-ray diffraction (XRD) data and density functional calculations for Na_xSi₁₃₆ found a lattice contraction as x increases for 0 < x < 8 and an expansion as x increases for x > 8. This is explained by XRD data that shows that as x increases, the Si₂₈ cages are filled first for x < 8 and the Si₂₀ cages are then filled for x > 8. Motivated by this work, here we report the results of first-principles calculations of the structural and vibrational properties of the Type II clathrate compounds A_xSi₁₃₆, A_xGe₁₃₆, and A_xSn₁₃₆. We present results for the variation of the lattice constants, bulk moduli, and other structural parameters with x. These are contrasted for the Si, Ge, and Sn compounds and for guests A = Na, K, Rb, and Cs. We also present calculated results of phonon dispersion relations for Na₄Si₁₃₆, Na₄Ge₁₃₆, and Na₄Sn₁₃₆ and we compare these for the three materials. Finally, we present calculated results for the elastic constants in Na_xSi₁₃₆, Na_xGe₁₃₆, and Na_xSn₁₃₆ for x = 4 and 8. These are compared for the three hosts, as well as for the two compositions. Full article

(This article belongs to the Special Issue Inorganic Clathrate Materials)

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3836 KiB

Open AccessArticle

Synthesis of Acylated Xylan-Based Magnetic Fe₃O₄ Hydrogels and Their Application for H₂O₂ Detection

by Qing-Qing Dai, Jun-Li Ren, Feng Peng, Xiao-Feng Chen, Cun-Dian Gao and Run-Cang Sun

Materials 2016, 9(8), 690; https://doi.org/10.3390/ma9080690 - 11 Aug 2016

Cited by 24 | Viewed by 6914

Abstract

Acylated xylan-based magnetic Fe₃O₄ nanocomposite hydrogels (ACX-MNP-gels) were prepared by fabricating Fe₃O₄ nanoctahedra in situ within a hydrogel matrix which was synthesized by the copolymerization of acylated xylan (ACX) with acrylamide and N-isopropylacrylamide under ultraviolet irradiation. [...] Read more.

Acylated xylan-based magnetic Fe₃O₄ nanocomposite hydrogels (ACX-MNP-gels) were prepared by fabricating Fe₃O₄ nanoctahedra in situ within a hydrogel matrix which was synthesized by the copolymerization of acylated xylan (ACX) with acrylamide and N-isopropylacrylamide under ultraviolet irradiation. The size of the Fe₃O₄ fabricated within the hydrogel matrix could be adjusted through controlling the crosslinking concentrations (C). The magnetic hydrogels showed desirable magnetic and mechanical properties, which were confirmed by XRD, Raman spectroscopy, physical property measurement system, SEM, TGA, and compression test. Moreover, the catalytic performance of the magnetic hydrogels was explored. The magnetic hydrogels (C = 7.5 wt %) presented excellent catalytic activity and provided a sensitive response to H₂O₂ detection even at a concentration level of 5 × 10⁻⁶ mol·L⁻¹. This approach to preparing magnetic hydrogels loaded with Fe₃O₄ nanoparticles endows xylan-based hydrogels with new promising applications in biotechnology and environmental chemistry. Full article

(This article belongs to the Section Porous Materials)

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8796 KiB

Open AccessArticle

Thermo-Mechanical Characterization of Friction Stir Spot Welded AA7050 Sheets by Means of Experimental and FEM Analyses

by Gianluca D’Urso and Claudio Giardini

Materials 2016, 9(8), 689; https://doi.org/10.3390/ma9080689 - 11 Aug 2016

Cited by 12 | Viewed by 5141

Abstract

The present study was carried out to evaluate how the friction stir spot welding (FSSW) process parameters affect the temperature distribution in the welding region, the welding forces and the mechanical properties of the joints. The experimental study was performed by means of [...] Read more.

The present study was carried out to evaluate how the friction stir spot welding (FSSW) process parameters affect the temperature distribution in the welding region, the welding forces and the mechanical properties of the joints. The experimental study was performed by means of a CNC machine tool obtaining FSSW lap joints on AA7050 aluminum alloy plates. Three thermocouples were inserted into the samples to measure the temperatures at different distance from the joint axis during the whole FSSW process. Experiments was repeated varying the process parameters, namely rotational speed, axial feed rate and plunging depth. Axial welding forces were measured during the tests using a piezoelectric load cell, while the mechanical properties of the joints were evaluated by executing shear tests on the specimens. The correlation found between process parameters and joints properties, allowed to identify the best technological window. The data collected during the experiments were used to validate a simulation model of the FSSW process, too. The model was set up using a 2D approach for the simulation of a 3D problem, in order to guarantee a very simple and practical solution for achieving results in a very short time. A specific external routine for the calculation of the thermal energy due to friction acting between pin and sheet was developed. An index for the prediction of the joint mechanical properties using the FEM simulations was finally presented and validated. Full article

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2425 KiB

Open AccessArticle

Synthesis and Mechanical Characterisation of an Ultra-Fine Grained Ti-Mg Composite

by Markus Alfreider, Jiwon Jeong, Raphael Esterl, Sang Ho Oh and Daniel Kiener

Materials 2016, 9(8), 688; https://doi.org/10.3390/ma9080688 - 11 Aug 2016

Cited by 7 | Viewed by 4949

Abstract

The importance of lightweight materials such as titanium and magnesium in various technical applications, for example aerospace, medical implants and lightweight construction is well appreciated. The present study is an attempt to combine and improve the mechanical properties of these two materials by [...] Read more.

The importance of lightweight materials such as titanium and magnesium in various technical applications, for example aerospace, medical implants and lightweight construction is well appreciated. The present study is an attempt to combine and improve the mechanical properties of these two materials by forming an ultra-fine grained composite. The material, with a composition of 75 vol% (88.4 wt%) Ti and 25 vol% (11.4 wt%) Mg , was synthesized by powder compression and subsequently deformed by high-pressure torsion. Using focused ion beam machining, miniaturised compression samples were prepared and tested in-situ in a scanning electron microscope to gain insights into local deformation behaviour and mechanical properties of the nanocomposite. Results show outstanding yield strength of around 1250 MPa, which is roughly 200 to 500 MPa higher than literature reports of similar materials. The failure mode of the samples is accounted for by cracking along the phase boundaries. Full article

(This article belongs to the Section Advanced Composites)

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4019 KiB

Open AccessArticle

Template-Free Synthesis of Monoclinic BiVO₄ with Porous Structure and Its High Photocatalytic Activity

by Pengyu Dong, Xinguo Xi, Xinjiang Zhang, Guihua Hou and Rongfeng Guan

Materials 2016, 9(8), 685; https://doi.org/10.3390/ma9080685 - 11 Aug 2016

Cited by 20 | Viewed by 6544

Abstract

Monoclinic BiVO₄ photocatalysts with porous structures were synthesized by a two-step approach without assistance of any templates. The as-prepared samples were characterized by X-ray diffraction pattern (XRD), scanning electron microscopy (SEM), Brunauer–Emmett–Teller (BET), ultraviolet–visible (UV–vis) diffuse reflectance spectroscopy (DRS), photocurrent responses, and [...] Read more.

Monoclinic BiVO₄ photocatalysts with porous structures were synthesized by a two-step approach without assistance of any templates. The as-prepared samples were characterized by X-ray diffraction pattern (XRD), scanning electron microscopy (SEM), Brunauer–Emmett–Teller (BET), ultraviolet–visible (UV–vis) diffuse reflectance spectroscopy (DRS), photocurrent responses, and electrochemical impedance spectra (EIS). It is found that the as-prepared BiVO₄ samples had a porous structure with aperture diameter of 50–300 nm. Moreover, the BET specific surface area of the porous BiVO₄-200 °C sample reaches up to 5.69 m²/g, which is much higher than that of the sample of BiVO₄ particles without porous structure. Furthermore, a possible formation mechanism of BiVO₄ with porous structure was proposed. With methylene blue (MB) as a model compound, the photocatalytic oxidation of organic contaminants in aqueous solution was investigated under visible light irradiation. It is found that the porous BiVO₄-200 °C sample exhibits the best photocatalytic activity, and the photocatalytic rate constant is about three times of that of the sample of BiVO₄ particles without porous structure. In addition, the photocurrent responses and electrochemical impedance spectra strongly support this conclusion. Full article

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8300 KiB

Open AccessFeature PaperArticle

On the Mechanism of Microwave Flash Sintering of Ceramics

by Yury V. Bykov, Sergei V. Egorov, Anatoly G. Eremeev, Vladislav V. Kholoptsev, Ivan V. Plotnikov, Kirill I. Rybakov and Andrei A. Sorokin

Materials 2016, 9(8), 684; https://doi.org/10.3390/ma9080684 - 11 Aug 2016

Cited by 67 | Viewed by 8314

Abstract

The results of a study of ultra-rapid (flash) sintering of oxide ceramic materials under microwave heating with high absorbed power per unit volume of material (10–500 W/cm³) are presented. Ceramic samples of various compositions—Al₂O₃; Y₂O [...] Read more.

The results of a study of ultra-rapid (flash) sintering of oxide ceramic materials under microwave heating with high absorbed power per unit volume of material (10–500 W/cm³) are presented. Ceramic samples of various compositions—Al₂O₃; Y₂O₃; MgAl₂O₄; and Yb(LaO)₂O₃—were sintered using a 24 GHz gyrotron system to a density above 0.98–0.99 of the theoretical value in 0.5–5 min without isothermal hold. An analysis of the experimental data (microwave power; heating and cooling rates) along with microstructure characterization provided an insight into the mechanism of flash sintering. Flash sintering occurs when the processing conditions—including the temperature of the sample; the properties of thermal insulation; and the intensity of microwave radiation—facilitate the development of thermal runaway due to an Arrhenius-type dependency of the material’s effective conductivity on temperature. The proper control over the thermal runaway effect is provided by fast regulation of the microwave power. The elevated concentration of defects and impurities in the boundary regions of the grains leads to localized preferential absorption of microwave radiation and results in grain boundary softening/pre-melting. The rapid densification of the granular medium with a reduced viscosity of the grain boundary phase occurs via rotation and sliding of the grains which accommodate their shape due to fast diffusion mass transport through the (quasi-)liquid phase. The same mechanism based on a thermal runaway under volumetric heating can be relevant for the effect of flash sintering of various oxide ceramics under a dc/ac voltage applied to the sample. Full article

(This article belongs to the Collection Spark-Plasma Sintering and Related Field-Assisted Powder Consolidation Technologies)

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4725 KiB

Open AccessArticle

Effects of Sputtering Parameters on AlN Film Growth on Flexible Hastelloy Tapes by Two-Step Deposition Technique

by Bin Peng, Dongdong Gong, Wanli Zhang, Jianying Jiang, Lin Shu and Yahui Zhang

Materials 2016, 9(8), 686; https://doi.org/10.3390/ma9080686 - 10 Aug 2016

Cited by 13 | Viewed by 5636

Abstract

AlN thin films were deposited on flexible Hastelloy tapes and Si (100) substrate by middle-frequency magnetron sputtering. A layer of Y₂O₃ films was used as a buffer layer for the Hastelloy tapes. A two-step deposition technique was used to prepare [...] Read more.

AlN thin films were deposited on flexible Hastelloy tapes and Si (100) substrate by middle-frequency magnetron sputtering. A layer of Y₂O₃ films was used as a buffer layer for the Hastelloy tapes. A two-step deposition technique was used to prepare the AlN films. The effects of deposition parameters such as sputtering power, N₂/Ar flow rate and sputtering pressure on the microstructure of the AlN thin films were systematically investigated. The results show that the dependency of the full width at half maximum (FWHM) of AlN/Y₂O₃/Hastelloy on the sputtering parameters is similar to that of AlN/Si (100). The FWHM of the AlN (002) peak of the prepared AlN films decreases with increasing sputtering power. The FWHM decreases with the increase of the N₂/Ar flow rate or sputtering pressure, and increases with the further increase of the N₂/Ar flow rate or sputtering pressure. The FWHM of the AlN/Y₂O₃/Hastelloy prepared under optimized parameters is only 3.7° and its root mean square (RMS) roughness is 5.46 nm. Based on the experimental results, the growth mechanism of AlN thin films prepared by the two-step deposition process was explored. This work would assist us in understanding the AlN film’s growth mechanism of the two-step deposition process, preparing highly c-axis–oriented AlN films on flexible metal tapes and developing flexible surface acoustic wave (SAW) sensors from an application perspective. Full article

(This article belongs to the Special Issue Thin-Film Deposition, Characterization and Advanced Surface Engineering)

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3007 KiB

Open AccessArticle

Metals Recovery from Artificial Ore in Case of Printed Circuit Boards, Using Plasmatron Plasma Reactor

by Jakub Szałatkiewicz

Materials 2016, 9(8), 683; https://doi.org/10.3390/ma9080683 - 10 Aug 2016

Cited by 25 | Viewed by 9103

Abstract

This paper presents the investigation of metals production form artificial ore, which consists of printed circuit board (PCB) waste, processed in plasmatron plasma reactor. A test setup was designed and built that enabled research of plasma processing of PCB waste of more than [...] Read more.

This paper presents the investigation of metals production form artificial ore, which consists of printed circuit board (PCB) waste, processed in plasmatron plasma reactor. A test setup was designed and built that enabled research of plasma processing of PCB waste of more than 700 kg/day scale. The designed plasma process is presented and discussed. The process in tests consumed 2 kWh/kg of processed waste. Investigation of the process products is presented with their elemental analyses of metals and slag. The average recovery of metals in presented experiments is 76%. Metals recovered include: Ag, Au, Pd, Cu, Sn, Pb, and others. The chosen process parameters are presented: energy consumption, throughput, process temperatures, and air consumption. Presented technology allows processing of variable and hard-to-process printed circuit board waste that can reach up to 100% of the input mass. Full article

(This article belongs to the Section Manufacturing Processes and Systems)

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1896 KiB

Open AccessFeature PaperArticle

Optical and Electrical Performance of MOS-Structure Silicon Solar Cells with Antireflective Transparent ITO and Plasmonic Indium Nanoparticles under Applied Bias Voltage

by Wen-Jeng Ho, Ruei-Siang Sue, Jian-Cheng Lin, Hong-Jang Syu and Ching-Fuh Lin

Materials 2016, 9(8), 682; https://doi.org/10.3390/ma9080682 - 10 Aug 2016

Cited by 4 | Viewed by 5190

Abstract

This paper reports impressive improvements in the optical and electrical performance of metal-oxide-semiconductor (MOS)-structure silicon solar cells through the incorporation of plasmonic indium nanoparticles (In-NPs) and an indium-tin-oxide (ITO) electrode with periodic holes (perforations) under applied bias voltage. Samples were prepared using a [...] Read more.

This paper reports impressive improvements in the optical and electrical performance of metal-oxide-semiconductor (MOS)-structure silicon solar cells through the incorporation of plasmonic indium nanoparticles (In-NPs) and an indium-tin-oxide (ITO) electrode with periodic holes (perforations) under applied bias voltage. Samples were prepared using a plain ITO electrode or perforated ITO electrode with and without In-NPs. The samples were characterized according to optical reflectance, dark current voltage, induced capacitance voltage, external quantum efficiency, and photovoltaic current voltage. Our results indicate that induced capacitance voltage and photovoltaic current voltage both depend on bias voltage, regardless of the type of ITO electrode. Under a bias voltage of 4.0 V, MOS cells with perforated ITO and plain ITO, respectively, presented conversion efficiencies of 17.53% and 15.80%. Under a bias voltage of 4.0 V, the inclusion of In-NPs increased the efficiency of cells with perforated ITO and plain ITO to 17.80% and 16.87%, respectively. Full article

(This article belongs to the Special Issue Selected Papers from ICASI 2016)

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4621 KiB

Open AccessArticle

Nitrogen-Rich Energetic Metal-Organic Framework: Synthesis, Structure, Properties, and Thermal Behaviors of Pb(II) Complex Based on N,N-Bis(1H-tetrazole-5-yl)-Amine

by Qiangqiang Liu, Bo Jin, Qingchun Zhang, Yu Shang, Zhicheng Guo, Bisheng Tan and Rufang Peng

Materials 2016, 9(8), 681; https://doi.org/10.3390/ma9080681 - 10 Aug 2016

Cited by 38 | Viewed by 11308

Abstract

The focus of energetic materials is on searching for a high-energy, high-density, insensitive material. Previous investigations have shown that 3D energetic metal–organic frameworks (E-MOFs) have great potential and advantages in this field. A nitrogen-rich E-MOF, Pb(bta)·2H₂O [N% = 31.98%, H₂ [...] Read more.

The focus of energetic materials is on searching for a high-energy, high-density, insensitive material. Previous investigations have shown that 3D energetic metal–organic frameworks (E-MOFs) have great potential and advantages in this field. A nitrogen-rich E-MOF, Pb(bta)·2H₂O [N% = 31.98%, H₂bta = N,N-Bis(1H-tetrazole-5-yl)-amine], was prepared through a one-step hydrothermal reaction in this study. Its crystal structure was determined through single-crystal X-ray diffraction, Fourier transform infrared spectroscopy, and elemental analysis. The complex has high heat denotation (16.142 kJ·cm⁻³), high density (3.250 g·cm⁻³), and good thermostability (T_dec = 614.9 K, 5 K·min⁻¹). The detonation pressure and velocity obtained through theoretical calculations were 43.47 GPa and 8.963 km·s⁻¹, respectively. The sensitivity test showed that the complex is an impact-insensitive material (IS > 40 J). The thermal decomposition process and kinetic parameters of the complex were also investigated through thermogravimetry and differential scanning calorimetry. Non-isothermal kinetic parameters were calculated through the methods of Kissinger and Ozawa-Doyle. Results highlighted the nitrogen-rich MOF as a potential energetic material. Full article

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