New Type Of Material Research Articles

Machinablility of titanium matrix composites (TMC) reinforced with multi-walled carbon nanotubes

Carbon nanotube (CNT) reinforced titanium matrix composite (TMC) is a type of new material with promising potentials in industry because of its superior properties such as low density and high elastic modulus. In this paper, the machinability of CNT-reinforced TMCs with different fabrication methods was studied experimentally. Multi-walled carbon nanotubes (MWCNTs) were dispersed in titanium (Ti) powder via different dispersive methods, and the Ti-MWCNTs powder mixtures were consolidated by spark plasma sintering (SPS) at different temperatures. The fabricated TMCs were machined by milling and electrical discharge machining (EDM), and their machinability was investigated by analysing the roughness, hardness, cutting forces and micro morphology of the machines surfaces. After milling, it was found that the machinability of the TMCs fabricated under different processing conditions was different, which was reflected by the difference in cutting force (values and frequecies), tool wear and facial morphology (roughness, hardness, flaws and element distribution). The main causes of these variances in machinability were attributed to the CNT agglomeration and presence of in situ formed titanium carbide (TiC) particles in Ti matrices. Also, the CNT agglomeration and TiC particles influenced the facial morphology of TMCs after EDM. The sizes and distribution of pores due to the erosion were different for the four TMCs. The results proved that the fabrication methods influence the properties of the TMCs which significantally impact their machinability.

High performance lithium-ion capacitors based on LiNbO3-arched 3D graphene aerogel anode and BCNNT cathode with enhanced kinetics match

High energy density remains difficult to achieve using current lithium ion capacitors (LICs) because of the mismatch of kinetics between the capacitor-type cathode and battery-type anode. To enhance the kinetic match, a graphene aerogel (GA) supported LiNbO3 nanoparticles (LiNbO3@GA) 3D conductive network is configured as a novel anode as well as a boron carbonitride nanotube (BCNNT) as cathode for LICs. Kinetics analysis of LiNbO3@GA anode and BCNNT cathode are conducted to further investigate the cation/anion storage behavior. Benefiting from the high pseudocapacitive contribution of LiNbO3 and the appealing features of 3D conductive framework, the LiNbO3@GA anode demonstrates enhanced kinetic properties and high-rate pseudocapacitive behaviors. Anion storage from both surface-controlled pseudocapacitive reaction and diffusion-limited intercalation/ deintercalation reaction in BCNNT electrode enables the cathode to exhibit fast charge-discharge capability, which greatly reduces the kinetic mismatch between cathode and anode. The assembled LiNbO3@GA//BCNNT LIC delivers the maximum energy density of 148 Wh kg−1 at the power density of 200 W kg−1 with a desirable cycling stability (82% after 7000 cycles). This strategy exploits a new type of material and widens the path for pseudocapacitive advanced high-rate devices in energy storage area.

Assessment of waste hardened cement mortar utilization as an alternative sorbent to remove SO2 in flue gas

Developing efficient low-cost absorbents has been recognized as a prerequisite for industrial application of wet flue gas desulfurization (WFGD). Herein, hardened cement mortar (HCM) particles developed from waste concrete blocks were used as an innovative absorbent for SO2. The results show that the SO2 in flue gas can be completely absorbed by the highly alkaline HCM slurry. Under optimum operating conditions, 0.8 g of SO2 was retained by per gram of HCM. Under acid conditions produced upon dissolving SO2 in water, the Ca-rich compounds in HCM particles can continuously release Ca2+ and OH− into the HCM slurry. The Ca2+ ions released can effectively combine with SO32−, resulting in the absorption of SO2 dissolved in water. The dissolution process of HCM particles is well described by the pseudo-second-order model. The desulphurization byproduct was characterized by X-Ray diffraction (XRD) analysis, scanning electron microscopy (SEM), Fourier transform infrared (FTIR) spectroscopy and energy dispersive spectrometry (EDS). The results show that the desulphurization product mainly consists of gypsum. The technology developed provides a type of new material for removing SO2 in waste flue gas. It also offers an innovative solution for the disposal of waste concrete which is also a global environmental concern.

Quasicrystal-related mosaics with periodic lattices interlaid with aperiodic tiles.

Quasicrystals, which have long-range orientational order without translational symmetry, are incompatible with the theory of conventional crystals, which are characterized by periodic lattices and uniformly repeated unit cells. Reported here is a novel quasicrystal-related solid state observed in two Al-Cr-Fe-Si alloys, which can be described as a mosaic of aperiodically distributed unit tiles in translationally periodic structural blocks. This new type of material possesses the opposing features of both conventional crystals and quasicrystals, which might trigger wide interest in theory, experiments and the potential applications of this type of material.

Skin Closure Tape and Surgical Staples in Primary Total Knee Arthroplasty: A Systematic Review and Meta-Analysis.

Background Staples closure technology has been widely used in total knee arthroplasty (TKA) and achieved good results. In recent years, a new type of material called skin closure tape (SCT) has been applied to TKA which also showed good treatment results. However, since it is still not clear yet which one is better, this paper collects literatures for statistical analysis so as to provide evidence for the use of SCT in TKA. Methods The comparative study on effects between SCT and staples is reviewed after the primary release of TKA in PubMed, the Cochrane library, and the EMBASE database up to March 2019. The two researchers independently screened the literature and evaluated the quality of the literature using bias risk tools. Results A total of four studies (3330 knees) have been included in our meta-analysis. For the main point, the results show that the SCT can reduce readmission rates compared to staples (RR 0.68, 95% CI 0.49–0.95, P=0.03), with no significant difference in complications (RR 0.85, 95% CI 0.27–2.64, P=0.77). Secondly, the results suggest that although there is no significant difference in removal time between the two groups, the SCT can reduce pains, save time and costs, and have a better cosmetic effect. Conclusions Our study indicates SCT as a closure method with fewer complications and faster speed compared with staples. Nevertheless, the cost and pain need to be further confirmed because of the small sample size included in this study.

Organic “receptor” fully covered few-layer organic–metal chalcogenides for high-performance chemiresistive gas sensing at room temperature

Organic-metal chalcogenides (OMCs) are proposed as a new family of two-dimensional (2D) chemiresistive sensing materials. Few-layer Ag(SPh-NH2), one of the OMCs, fully and orderly covered with predesigned -NH2 groups as "receptors", shows the highest sensitivity, excellent selectivity and reversibility in response to NO2 among all the reported 2D chemiresistive sensing materials at room temperature.

Investigation of CO2 Adsorption on Triethylenetetramine Modified Adsorbents of TETA(n)/Zr-TSCD

In the present study, a new type of material of Zr-TSCD was first synthesized and modified with different amounts of triethylenetetramine (TETA). The properties of the adsorbents were characterised with X-ray diffraction, UV-vis diffuse reflectance spectroscopy, FT-IR spectroscopy, X-ray photoelectron spectroscopy, Raman spectroscopy, N2 adsorption–desorption, energy dispersion spectrum, and thermogravimetric analysis. The results suggested that Zr-TSCD (TSCD=Na3C6H5O7·2H2O) was successfully synthesized through the coordination of Zr atoms from ZrOCl2·8H2O and O species in –COO– groups. After functionalization with TETA, the structure of Zr-TSCD was preserved and the adsorption capacity of CO2 was enhanced dramatically. At 75°C, TETA(30)/Zr-TSCD achieved a maximum absorption capacity of 175.1mg g−1 in a stream of 10mL min−1 CO2. The adsorption capacity ratio of CO2/N2, CO2/O2, and CO2/SO2 was 10.5, 7.4, and 1.2, respectively. In addition, the adsorption capacity of CO2 remained stable during 10 adsorption–desorption cycles.

Strategic Thinking on the Development of Electronic Ceramic Technology in China

Electronic ceramics are a type of new materials of strategic significance. They are the core materials of passive electronic components and an important technology frontier in the electronic information technology field. As the electronic information technology develops toward integration, intelligence, and miniaturization, passive electronic components have become a bottleneck restraining the development of electronic component technology. Therefore, the strategic position of electronic ceramic materials and their processing technologies is increasingly prominent. The field of electronic ceramic materials and components has formed a good industrial technology foundation in China. However, its competitiveness is still insufficient in high-end materials and components, and some key material, process, and equipment technologies are controlled by other countries. Facing the new situation, it is urgent to increase R & D investment, rationalize the system and mechanism, and strengthen the independence and innovation of the industrial chain.

PRODUCTION OF THERMAL INSULATION MATERIAL BASED ON VOLCANIC ASH DEPOSITS OF PRIMAGADANYA

Modern technologies are not standing still, and scientists are trying not only to invent new building materials, but also to find non-standard use of various raw materials that were previously considered unsuitable for use. Innovative technologies are actively used for modern construction of buildings, in particular, some types of new materials are used in the construction of various facilities. This is especially true in areas where it is not possible to import or use ordinary building materials for various reasons. Often, when designing a building, developers are wondering whether it is worth making the house warm during construction, and which insulation for the walls of the house is better to choose. This article addresses the question of which insulation for walls is most suitable for construction. The most common are mineral insulation, which are represented on the market today in the form of basalt slabs, fiberglass, etc. They have such advantages as low thermal conductivity, good thermal insulation and vapor permeability. The article presents a table with comparative performance characteristics of a mineral wool stone slab and a fiberglass slab. Stone or basalt wool has several advantages. It is able to withstand significant temperatures and temperature changes, the mats are easy to transport, convenient to install. In our opinion, a serious alternative to basalt in the production of thermal insulation materials is volcanic ash. One of the main features of volcanic ash are its building qualities, such as good thermal insulation and an environmentally friendly composition. Since here we are considering the possibility of producing insulation materials based on volcanic ash, we performed a thermal calculation of the enclosing structures. Also in the tables are the costs of transportation of volcanic ash from the field to the point of the proposed production of insulating material. Volcanic ash can be widely used in countries with high volcanic activity as an inexpensive raw material for the manufacture of building materials. It does not require additional processing and has a number of useful properties.

Research status on soil and water pollution remediation and environmental impact of nanomaterials

Nanomaterials are a new type of materials, which have been widely used in many fields. In the field of environmental governance and restoration, nanomaterials are highly concerned by scholars all over the world. Due to the small particle size, strong reducing ability, high surface activity and large specific surface area, nanomaterials have obvious advantages in the rehabilitation and treatment of contaminated soil and water. At the same time, due to the characteristics of small particle size, low solubility and weak degradation ability, nanomaterials will have adverse effects on the ecological environment. In this paper, through literature research, the application of nanomaterials in soil and water pollution remediation and treatment is summarized, and the repair mechanism and influencing factors are briefly described. At the same time, the impact of nanomaterials on ecological environment is also summarized. On this basis, this paper points out that further research on measures to reduce the impact of nanomaterials on ecological environment should be carried out in the aspects of soil and water pollution rehabilitation and treatment.

Micro-mechanical properties of new alternative binders for cemented carbides: CoCrFeNiWx high-entropy alloys

High-entropy alloys are a new type of materials with excellent properties that offer a great variety of possibilities due to the large degree of freedom in element composition. In particular, CoCrFeNiW alloys have recently attracted a lot of attention due to their potential use in solving the long-standing problem of substituting cobalt in the cemented carbide industry. The lack of experimental and theoretical studies on these multi-components alloys hinders their optimal development. In this work, we aim at filling in this gap by studying their mechanical properties employing first-principles alloy theory and experimental techniques. By using the calculated elastic parameters, we analyzed the mechanical stability, elastic anisotropy, Debye temperature, and derived polycrystalline moduli. Moreover, we fabricated CoCrFeNi and (CoCrFeNi)0.96W0.04 and analyzed them by means of X-ray diffraction and electron backscatter diffraction. The hardness and the Young’s modulus were measured. The Young’s moduli and the lattice parameters were compared to first principles calculations and good agreement was obtained. Hardness increases with the increment of W composition.

Perovskite Structured Nanomaterials: An Advanced Key for Global Development of Nanotechnology

Starting with a history of the fundamental science, currently, the perovskite structures exemplify the extensive manifestation of crystal chemistry which is associated with the smart synthesis techniques to develop a new type of material. The perovskite structures exhibit the most efficient single accomplished ceramic host. Perovskite structured nanomaterials had originated from CaTiO3. They are made up by the assembling of distinct materialistic components and follow the general configuration ABX3. Perovskite type metal oxide nanomaterial shows a wide range of ferroelectric, piezoelectric, and pyroelectric properties along with numerous optoelectrical effects. They get the facility to the various advanced technical applications due to the excellency in their properties. The photocatalytic activity may be one of the plausible and impulsive applications of that very special type of materials. Most elements in the periodic table are able to take part in designing the perovskite-type materials. Perovskite structured nanoparticles (NPs) are applying rapidly for global development because of their higher responsiveness and degree of function, large surface area, size-dependent properties etc and unfold the new possibilities in the field of nanotechnology.

Preparation of Magneto Electric (Bafe12o19 / Bifeo3) Composites using Sol-Gel Auto Combustion Method

The coexistence of ferromagnetic and ferroelectric properties in single phase material leads to the existence of new type of material known as magnetoelectric. In present work, magneto electric composites BaFe12O19 / BiFeO3 with different mass percentage of BiFeO3 (0, 25%, 50%, 75% and 100 %) were prepared. BaFe12O19 (BHF) and BiFeO3 (BiF) ferrites were prepared separately using Sol-gel auto combustion method and then physically mixed. Prepared composite samples were characterized using FTIR, XRD, SEM and VSM. XRD spectra reveal the mixed hexaferrite and bismuth ferrite phases. SEM micrograph of showed the formation of porous clusters of non uniform grains in the composites. Saturation magnetization of BaFe12O19 / BiFeO3 composites decreased gradually with increasing in BiFeO3 content and there is no systematic change in coercivity values.

Optimization of production parameters of geopolymer mortar and concrete: A comprehensive experimental study

Geopolymers are a new type of material offered as an alternative to traditional Portland cement. Geopolymers, produced by activation of natural and waste pozzolans with alkali activators such as NaOH (SH) and Na2O·3SiO2 (SS) solutions, have been widely supported and investigated due to environmental and economic advantages. In this study, a detailed experimental program was conducted to investigate the influence of activator type, activator concentration and curing temperature on mechanical and microstructural properties of volcanic tuff based geopolymer mortar (GPM) and concrete (GPC) samples. A total of 1080 GPM and GPC samples were produced and a number of parameters were investigated with 360 combinations. Maximum compressive strength was obtained as 37.09 MPa in 90-day samples in which the SH concentration was 16 M, activator/binder (a/b) ratio was 0.45 and the curing temperature was 120 °C. As a result of optimization of the production parameters, a considerable development in mechanical and microstructural properties of GPM and GPC samples was obtained. Experimental results demonstrated that alkali activation with sole SH bring about superior characteristics compared to alkali activation with SH + SS. Higher a/b ratio led to higher UPV values because of more dense and compact microstructure resulting from increase in gopolymerization reactions. This is also supported by compressive strength and microstructure findings.

Electron Beam Patterning of Polymerizable Ionic Liquid Films for Application in Photonics.

Planar photonic components can be fabricated with high resolution by electron beam patterning of polymer thin films on solid substrates such as silicon and glass. However, polymer films are normally formed by spin-coating lithographic resists containing not only polymers but also volatile solvents, which is a serious environmental and health issue. Therefore, we investigate a new type of material for planar structure fabrication (i.e., room-temperature ionic liquids (RTILs) with a polymerizable allyl group) that is electron-beam-curable, solvent-free, and thus potentially interesting for processing materials with weak resistance to solvents. We fabricate planar polymer microstructures by electron beam patterning of RTIL thin films in vacuum, which is possible because of the negligible volatility of ionic liquids. Three different polymerizable ionic liquids {i.e., [Allmim][Cl] (1-allyl-3-methylimidazolium chloride), [Allmim][NTf2] (1-allyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide), and [Allmmim][NTf2] (1-allyl-2,3-dimethylimidazolium bis(trifluoromethylsulfonyl)imide)} are compared in terms of the quality of the fabricated microstructures. We demonstrate that the shape of the more viscous RTIL with the Cl- anion is less distorted during electron-beam-activated polymerization than the shape of the less viscous RTILs with a large NTf2- anion. Furthermore, the surface tension of the NTf2-based ionic liquid decreases significantly with temperature as compared to that of the Cl-based ionic liquid. Thus, we suggest that the thermocapillary effect, that is, the Marangoni flow caused by a temperature gradient, might be responsible for the differences in the shape of the RTIL-derived microstructures. Also, we analyze the chemistry of the electron-beam-activated polymerization of RTIL by the use of Fourier-transform infrared spectroscopy (FTIR) and conclude that because of the disappearance of C═C bonds the free radical polymerization is a probable reaction mechanism. Finally, we show that polymerized microstructures are potentially attractive as planar photonic components because of good optical properties such as a high refractive index.

Composite Materials with Combined Electronic and Ionic Properties

Summary In this work, we develop a new type of composite material that combines both electrocatalytic and ionic properties, by doping a silver metal catalyst with an anion-conducting ionomer at the molecular level. We show that ionomer entrapment into the silver metallic structure is possible, imparting unique properties to the catalytic character of the metallic silver. The novel composite material is tested as the cathode electrode of fuel cells, showing significant improvement in cell performance as compared with the undoped counterpart. This new type of material may then replace the current design of electrodes in advanced fuel cells or other electrochemical devices. The possibility to merge different properties into one composite material by molecular entrapment in metals can open the way to new materials, leading to unexplored fields and applications.

Applications of High-Pressure Technology for High-Entropy Alloys: A Review

High-entropy alloys are a new type of material developed in recent years. It breaks the traditional alloy-design conventions and has many excellent properties. High-pressure treatment is an effective means to change the structures and properties of metal materials. The pressure can effectively vary the distance and interaction between molecules or atoms, so as to change the bonding mode, and form high-pressure phases. These new material states often have different structures and characteristics, compared to untreated metal materials. At present, high-pressure technology is an effective method to prepare alloys with unique properties, and there are many techniques that can achieve high pressures. The most commonly used methods include high-pressure torsion, large cavity presses and diamond-anvil-cell presses. The materials show many unique properties under high pressures which do not exist under normal conditions, providing a new approach for the in-depth study of materials. In this paper, high-pressure (HP) technologies applied to high-entropy alloys (HEAs) are reviewed, and some possible ways to develop good properties of HEAs using HP as fabrication are introduced. Moreover, the studies of HEAs under high pressures are summarized, in order to deepen the basic understanding of HEAs under high pressures, which provides the theoretical basis for the application of high-entropy alloys.

Hydration Behavior of Magnesium Oxysulfate Cement with Fly Ash via Electrochemical Impedance Spectroscopy

A new type of material, magnesium oxysulfate cement (MOSC), has attracted widespread attention as an environmentally friendly and low-energy inorganic green cementitious material due to its outstanding performance. In this study, electrochemical impedance spectroscopy (EIS) and in situ X-ray diffraction (XRD) were used to characterize the hydration behavior and process of MOSC. EIS was also used to investigate the effect of fly ash (FA) on the hydration behavior of MOSC. Mercury intrusion porosimetry (MIP), backscattered scanning electron microscopy (BSE), and scanning electron microscopy (SEM) were used to study the evolution of the pore structure and micromorphology of MOSC incorporated with FA. The results show that the resistance values (R1) in the equivalent circuit for MOSC increase with increasing curing time. The incorporation of FA can affect the resistance values for each element in the equivalent circuit. In the early stages of hydration (1 day and 2 days), high-volume FA can reduce the degree of hydration of MOSC paste. At the later stages of hydration, the resistance values (R1) increase with increasing FA content. The MIP, BSE, and SEM results also show that the porosity of MOSC decreases with increasing FA content; the incorporation of FA can significantly improve the morphology of MOSC, resulting in a denser microstructure. This study shows that the electrochemical impedance spectroscopy is a powerful technique to investigate the hydration behavior and process of MOSC, and the results also indicate that FA is a good mineral admixture used as a partial substitute for MOSC cementitious materials.

Polyethylenimine "Snow": An Emerging Material for Efficient Carbon Removal.

Amine-functionalized solid adsorbents are one of the most promising alternatives to the conventional "amine scrubbing" for carbon capture with a number of prominent examples being reported. However, their widespread application in industry is unfulfilled due to their overall performance and complex fabrication, which relies on a porous support. In this "proof of concept" study, we report an approach for generating a new type of material called polyethylenimine (PEI) 'snow', which can be prepared for use in under 15 min. The material does not require a support, and the resulting CO2 uptake is the highest reported to date for PEI-functionalized materials. This was achieved through a rigorous material program that identified conditions where a material with the requisite properties could be generated. From experimental measurements, the virtual dryness of the PEI snow results in fast CO2 absorption kinetics, which is comparable to conventional solid adsorbents, but its CO2 uptake (451.5 mg CO2/g PEI) is the highest reported so far. Breakthrough curves demonstrate the outstanding CO2 selectivity over N2 and CH4 (above 1000), with the potential for post-combustion capture and natural gas sweeting. This strategy can be applied in affordable and efficient gas treatment for various large point sources.

Adsorption characteristics of formaldehyde on nitrogen doped graphene-based single atom adsorbents: A DFT study

Formaldehyde (CH2O) is the most common volatile organic pollutant in the indoor environment, which can directly cause respiratory system diseases of humans. As a new type of material, graphene-based single atom adsorbent has the advantages of large specific surface and high adsorption activity, which can provide a new direction for formaldehyde removal. In this paper, the adsorption characteristics of formaldehyde on graphene-based single atom adsorbents were investigated through density functional theory (DFT) calculations. According to the analysis of geometric structure, electron transfer and density of states (DOS), the adsorption of formaldehyde belongs to a stable chemisorption and the largest adsorption energy of formaldehyde is −2.27 eV, which is a combined action of electron transfer and hybridization effect. Formaldehyde will be preferentially adsorbed on single atom adsorbent in side-on model. The effect of N doping and desorption temperature were studied through searching for linear relationship and Gibbs free energy calculation, respectively. Doping N atoms into graphene plane can significantly improve the adsorption strength of formaldehyde through modulating the charge of metal atoms. The charge of metal atoms can be an efficient descriptor for adsorption energy of formaldehyde. CH2O plays a dominant role in competitive adsorption between O2, N2 and CH2O. We expect that this theoretical study can lay a foundation for the experimental investigations.