With the ever-increasing importance of nanoscale deformation phenomena in contemporary technologies, basic understanding of material behavior at the nanoscale has become of critical importance. Especially, nanomechanical testing that provides the capability to study fundamental nanoscale deformation and phase change phenomena in real time and under controlled loading conditions is essential for nanomaterial research. In this study, acoustic emission (AE) was used in situ to characterize nanoindentation-induced deformation, microfracture, and phase transformation processes intrinsic of bulk single-crystal MgO and polycrystalline Al, thin films of polycrystalline SiC, and thick films of austenitic TiNi shape-memory alloy. Scale-dependent plastic deformation and microfracture affected by the indenter tip radius and the applied normal load are interpreted in terms of the type and intensity of AE events revealed by abrupt displacement excursions in the loading response of the indented materials. The amplitudes of AE waveforms are used to examine characteristic deformation, microfracture, and phase change mechanisms in the time domain. Fast Fourier transformation and short-time Fourier transformation analyses provide further insight into the material behavior and structural changes due to indentation loading in the frequency and time-frequency domain, respectively. The methodology developed in this study represents an effective approach for nanomechanical testing and in situ characterization of nanoscale deformation, microfracture, and phase transformation phenomena.

Metal additive manufacturing (AM) provides a platform for microstructure optimization via process control, but establishing a quantitative processing-microstructure linkage necessitates an efficient scheme for microstructure representation and regeneration. Here, we present a deep learning framework to quantitatively analyze the microstructural variations of metals fabricated by AM under different processing conditions. The principal microstructural descriptors are extracted directly from the electron backscatter diffraction patterns, enabling a quantitative measure of the microstructure differences in a reduced representation domain. We also demonstrate the capability of predicting new microstructures within the representation domain using a regeneration neural network, from which we are able to explore the physical insights into the implicitly expressed microstructure descriptors by mapping the regenerated microstructures as a function of principal component values. We validate the effectiveness of the framework using samples fabricated by a solid-state AM technology, additive friction stir deposition, which typically results in equiaxed microstructures.

The initial steps of the thermal chemistry of Cu(I)-2-(tert-butylimino)-5,5-dimethyl-pyrrolidinate on metal surfaces were characterized using temperature-programmed desorption experiments and density functional theory (DFT). The relative stability of the initial dimer relative to its dissociation on metal surfaces was evaluated. Several molecular desorption temperatures were identified on Ni(110), but all correspond to dimers, either containing the initial Cu ions or after their removal; no monomer was ever detected. DFT calculations also indicated preferential bonding on Cu(110) as a dimer, albeit with a distorted configuration, via the Cu atoms and in registry with the lattice of the substrate. A potential dissociation pathway of the adsorbed dimer was identified involving the partial detachment of the ligands via the scission of one Cu–N bond at the time and migration to adjacent surface sites. This process is accompanied by the reduction of the Cu centers of the metal–organic complex, indicating that it may be the rate-limiting reaction that leads to further fragmentation of the ligands.

Lightweight, inexpensive and flexible electrodes are required for flexible technological applications. As polymers are generally low cost, flexible and have low density, they are potential candidates for use as flexible electrodes. However, polymers are not conductive and thus cannot be used as electrodes or current collectors. Polymers have been coated by metals/alloys to make them conductive for use in various applications including electromagnetic shielding and sensors. In this work, a flexible electrode was successfully fabricated by electrodeposition of Cu and Ni on polyester fabric for an energy storage application. The growth of metals was carried out in non-aqueous ionic liquid electrolyte, with the deposition condition of Cu and Ni studied by means of cyclic voltammetry. Non-electrochemical (FTIR, XRD, SEM and EDAX) characterizations of the metal-coated polyester are also presented. Modified flexible electrodes were transferred to an alkaline electrolyte for electrochemical characterization. The specific capacitance of Cu- and Ni-coated polyester reached 33.4 F/g and 50.2 F/g at the same scan rate of 5 mV/s. These results suggest an inexpensive and straightforward method for the fabrication of a flexible electrode for energy storage applications.

Austenitic stainless steel is used in several industrial branches due to its mechanical and thermal properties, and to its good corrosion resistance. With low cost and biocompatibility, it is used to manufacture prostheses and devices for bone fixation. However, direct contact with body fluids may cause corrosion. Thin films of FeAlCr intermetallic alloy can be used to increase service life of prostheses and avoid replacement surgeries. The aim of this work was to cover the austenitic stainless steel to study the effect of target–substrate distance on the film characteristics. Coatings were performed using the magnetron sputtering technique with the substrate positioned at different distances from the target. The influence on film thickness, morphology, roughness, and adhesion to the substrate was investigated. The thin films of FeAlCr (160 nm thick deposited at 100 mm far from the substrate) were formed by smaller particles (11.2 nm long), densely packed (551,000 particles/mm2), with flat and regular appearance, and greater adherence to the substrate.

The LiCoO2 films were directly deposited on stainless steel (SS) using medium-frequency magnetron sputtering, and the effects of annealing parameters, such as ambiences, temperatures, holding times, and heating rates, were systematically compared based on surface morphologies, crystal structures, and electrochemical properties. The results demonstrate that an aerobic atmosphere with 3.5 Pa is the most important parameter to maintain the performance of LiCoO2 films. The influence of the annealing temperature (>550 °C) ranks second because the formed (101) or (104) planes of LiCoO2 facilitate Li+ migration. A short holding time of 20 min and a moderate heating rate of 3 °C/min are selected to reduce the oxidation or inter-diffusion between the LiCoO2 films and the SS substrate. Finally, the optimal annealing process is confirmed and corresponds to the initial discharge capacity of 37.56 μA h/(cm2 μm) and the capacity retention of 83.81% at the 50th cycle.

This article presents a brief review of our case studies of data-driven Integrated Computational Materials Engineering (ICME) for intelligently discovering advanced structural metal materials, including light-weight materials (Ti, Mg, and Al alloys), refractory high-entropy alloys, and superalloys. The basic bonding in terms of topology and electronic structures is recommended to be considered as the building blocks/units constructing the microstructures of advanced materials. It is highlighted that the bonding charge density could not only provide an atomic and electronic insight into the physical nature of chemical bond of materials but also reveal the fundamental strengthening/embrittlement mechanisms and the local phase transformations of planar defects, paving a path in accelerating the development of advanced metal materials via interfacial engineering. Perspectives on the knowledge-based modeling/simulations, machine-learning knowledge base, platform, and next-generation workforce for sustainable ecosystem of ICME are highlighted, thus to call for more duty on the developments of advanced structural metal materials and enhancement of research productivity and collaboration.

Pancreatic cancer is currently one of the most lethal tumors because of delayed diagnosis and treatment. Aminopeptidase N (CD13/APN), expressed in pancreatic cancer cells, is closely related to the malignant biological behavior, for instance, angiogenesis formation, tumor proliferation, and metastasis. In this study, asparagine–glycine–arginine (Asn–Gly–Arg, NGR), selectively binding to CD13 receptor, was modified to construct a novel contrast agent of QDs@Gd3+-NGR for targeted diagnosis and treatment of pancreatic cancer. It consists of QDs-unit for fluorescence imaging, Gd3+-unit for magnetic resonance imaging (MRI), and NGR for binding to CD13 receptor. PANC-1 cells labeled by QDs@Gd3+-NGR showed significant red fluorescence and high intensity on fluorescence and MR imaging, respectively. Besides, it was confirmed that QDs@Gd3+-NGR could inhibit theproliferation, metastasis, and invasion of PANC-1 cells, and increase reactive oxygen species production and death rate in vitro. Reasonably, we believe the targeted contrast agent of QDs@Gd3+-NGR can sensitively detect pancreatic cancer via MR-fluorescence dual-modality imaging, and plays an active role in inhibition of tumor progression. The promising results in this study provide integration of diagnostic and therapeutic strategy for the management of pancreatic cancer in future.

Nanocrystalline metals possess high strength and outstanding resistance to irradiation damage. However, the high-density grain boundaries in nanocrystalline metals lead to low plasticity and poor thermal stability. In recent years, interface engineering has gradually become an important way to improve the comprehensive properties of nanocrystalline metals. In this paper, the interface structure, deformation mechanism, and physical properties of Cu–Nb nanolayered composites fabricated by physical vapor deposition and accumulative roll bonding are reviewed. Both Cu–Nb nanolayered composites possess semi-coherent interfaces. The nanolayered composites could achieve excellent resistance to irradiation damage since the interfaces are good sinks for the irradiation point defects. In addition, nanolayered metallic composites with abundant heterogeneous interfaces have better thermal stability compared to nanocrystalline metallic materials. Moreover, the interactions between dislocations and interfaces can be adjusted effectively through controlling the atomistic interface structure and alignment of slip systems across the interface, so as to achieve high strength and high plastic deformation ability simultaneously.

Cerium-doped lanthanum magnesium bulk aluminate (La1–xCexMgAl11O19, x = 0.03–0.50; abbreviated as LMA) was prepared via the Pechini sol–gel method after heating at 1200 °C for 2 h. The resulting single-phase ceramics was studied in terms of its structure using X-ray diffraction and optical properties using photoluminescence, its decay time, and radioluminescence spectroscopy. The diffraction and electron microscopy demonstrated LMA's plate-shaped nanocrystals with structure anisotropy and relatively broad particle size distribution. The optical measurements fully manifested the complexity of the LMA crystal structure. The radioluminescence study of cerium-doped LMA is here presented for the first time and, thus, contributes to the basic knowledge of Ce-doped materials. Additionally, the magnetic susceptibility exhibiting paramagnetic behavior of Ce3+ ions is presented. The magnetic data were interpreted in terms of local atomic Hamiltonian involving the crystal field and the Zeeman effect applied on the ground state J = 5/2 multiplet.

Electrochemical reduction of CO2 to formic acid is a good strategy to address both environmental and energy issues. However, some drawbacks including low activity, selectivity, and stability of electrocatalysts must be overcome. We propose a method for tailoring Bi2O2CO3-coated carbon fiber electrodes with higher selectivity and stability for electrochemical CO2 reduction to formic acid. We evaluated the effect of Bi2O2CO3 and Nafion contents on the electrocatalysts performance for CO2 reduction reaction (CO2RR). All electrodes produced only HCOO− in the liquid phase with a maximum faradaic efficiency (FE) of 69%. The electrocatalysts were stable under 24 h of continuous CO2RR operation. The FE increased with the increasing electrolyte concentration and cation radius size, which indicates that the anion stabilization in solution is critical for adequate formate generation. The CO2RR mechanism was proposed with basis on the literature. The structural carbonate of Bi2O2CO3 acts as an intermediate species in the formate production from CO2.

Silver/titanium dioxide (Ag/TiO2) membranes were successfully deposited on poly(sulfone amide) substrates by direct current magnetron sputtering and radio frequency magnetron sputtering techniques with pure silver (Ag) and TiO2 targets. The prepared membranes were systematically characterized by scanning electron microscopy X-ray diffraction, insulation tests, and Fourier transform infrared spectrometry. The dependence of the main sputtering parameters on optical and thermal properties of the film was investigated by an orthogonal analysis method. Optimal parameters of fabricate Ag/TiO2 membranes with better comprehensive performances could be obtained ultimately. The infrared reflection rate and temperature difference of the Ag/TiO2 film deposited with the optimized parameters were 81.6% and 90 °C, respectively. The high infrared reflection and excellent thermal conductivity properties of the Ag/TiO2 composite membrane make it a promising candidate for thermal insulating coatings on fabrics, and can be used for the development of high-performance protective garments in the future.

Traditional dip-assisted layer-by-layer (LbL) assembly produces robust and conformal coatings, but it is time-consuming. Alternatively, spray-assisted layer-by-layer (SA-LbL) assembly has gained interest due to rapid processing resulting from the short adsorption time. However, it is challenging to assemble anisotropic nanomaterials using this spray-based approach. This is because the standard approach for fabricating “all-polyelectrolyte” LbL films does not necessarily give rise to satisfactory film growth when one of the adsorbing components is anisotropic. Here, polymers are combined with a model anisotropic nanomaterial via SA-LbL assembly. Specifically, graphene oxide (GO) is investigated, and the effect of anchor layer, colloidal stability, charge distribution along the carbon framework, and concentration of polymer on the growth and the film quality is examined to gain insight into how to achieve pinhole-free, smooth polymer/GO SA-LbL coatings. This approach might be applicable to other anisotropic nanomaterials such as clays or 2D nanomaterials for future development of uniform coatings by spraying.

Ab initio calculations are performed to investigate the structural, vibrational, electronic, and piezoelectric properties of functionalized single layers of TaS2. We find that single-layer TaS2 is a suitable host material for functionalization via fluorination and hydrogenation. The one-side fluorinated (FTaS2) and hydrogenated (HTaS2) single layers display indirect gap semiconducting behavior in contrast to bare metallic TaS2. On the other hand, it is shown that as both surfaces of TaS2 are saturated anti-symmetrically, the formed Janus structure is a dynamically stable metallic single layer. In addition, it is revealed that out-of-plane piezoelectricity is created in all anti-symmetric structures. Furthermore, the Janus-type single-layer has the highest specific heat capacity to which longitudinal and transverse acoustical phonon modes have contribution at low temperatures. Our findings indicate that single-layer TaS2 is suitable for functionalization via H and F atoms that the formed, anti-symmetric structures display distinctive electronic, vibrational, and piezoelectric properties.

In this work, four N-TiO2/bismuth oxyiodide (BiOI)/reduced graphene oxide (RGO) composite photocatalysts with different composite ratios were prepared using a hydrothermal method. The phase, surface structure, specific surface area, and light response were characterized by X-ray diffraction, X-ray photoelectron spectrum analysis, scanning electron microscopy, specific surface area and aperture analysis, and UV-vis diffuse reflection spectrum analysis. The results indicated that the N-TiO2/BiOI/RGO (NTGB) composite prepared with a mass ratio of 1:1:2 is a promising photocatalyst for the degradation of organic pollutants by using sunlight, with a specific surface area of 139.56 (m2/g), bandgap of 1.24 eV, and strong absorption with a smaller visible region. It has the best photocatalytic properties under visible light irradiation in the degradation of methylene blue (MB): the degradation rate of MB in the presence of light for 60 min reached 99.22%, and its photocatalytic performance was significantly higher than that of TiO2, N-TiO2, BiOI, N-TiO2/BiOI, BiOI/RGO, NTGB1, NTGB2, and NTGB4.

Hydrothermal carbon microsphere (HTC) is a carbon-based fluorescent material, which can be synthesized by hydrothermal carbonization of glucose. In this article, a series of 4ZnO·B2O3·H2O:Ln3+/HTC (where Ln = Eu or Tb) composites were prepared under hydrothermal conditions. The effects of the glucose concentration on the morphology, photoluminescence (PL) intensity and emission color of Zn3.64:Eu0.24[B2O7]·H2O/HTCx and Zn3.55:Tb0.3[B2O7]·H2O/HTCy were investigated. The relationship between morphology and PL intensity of composites was discussed. The results revealed that the presence of HTC did not change the original emission color of 4ZnO·B2O3·H2O:Ln3+ (where Ln = Eu or Tb) materials, but greatly increased their PL intensity, the sphere-like morphology composites have the strongest PL intensity. The Zn3.64:Eu0.24[B2O7]·H2O/HTCx and Zn3.55:Tb0.3[B2O7]·H2O/HTCy emit bright red light and green light, respectively, under respective excitation wavelengths. The present research suggests that the 4ZnO·B2O3·H2O:Ln3+/HTC (where Ln = Eu or Tb) composites may be candidates of red and green phosphors for display and lighting applications.

Electrospun membranes have potential applications in the field of waterproof and breathable textile products. However, challenges still exist to improve the breathability, and waterproof and mechanical properties of these microporous membranes. In this paper, a novel hydrophobic microporous nanofiber membrane was prepared via side-by-side electrospinning of fluorosilane-modified silica nanoparticles (F–SiO2) blended with synthesized polyurethane (PU) solution and composited with the polyacrylonitrile (PAN) solution. To prepare F–SiO2, SiO2 nanoparticles were hydrophobically modified by fluorosilane. Composite nanofiber membranes with different blending ratios of PU(F–SiO2)/PAN were fabricated via side-by-side electrospinning by controlling the extruding speed of two spinnerets. Experimental results indicated that regarding F–SiO2 as hydrophobic inorganic particle can improve the hydrophobic properties of PU nanofiber membrane. The prepared PAN/(F–SiO2/PU) nanofiber microporous membranes exhibit relatively excellent waterproof and mechanical properties as that robust tensile strength (19.5 MPa), preferable water vapor permeability [10.3 kg/(m2 d)], favorable water contact angle (137.2°), and superior mechanical properties. It was believed that the reinforced PAN/(F–SiO2/PU) nanofibrous composite membranes have potential applications in chemical protective clothing, army combat uniforms, self-cleaning materials, and other medical products.

Grain boundary (GB) motions, such as migration, sliding and rotation, have been shown to play a vital role in the mechanical performance of polycrystalline metals. Despite extensive efforts have been made on the pure polycrystalline metals, few attentions have been paid to those in alloys. In this work, taking conventional nanoscale Cu–Al binary alloy system as an example, we intend to shed some light on understanding its GB motions under shear loading by means of molecular dynamics (MD) simulations. It is found that either shear-coupled GB migration or sliding motion can be observed, depending on GB tilt angles, temperatures and Al solute concentrations. By systematical MD simulations, the Al concentration required for transition between shear-coupled migration and sliding is found to decrease with increasing tilt angles (θ ≤ 50°) at fixed temperature, whereas it switches to the opposite trend for larger tilt angles. Furthermore, the GBs migrate much slower comparing with those in pure Cu, which shows the drag effects of the Al solutes in the alloy form. Moreover, the critical stress during shear loading shows a linear dependence on 2/3 power of the temperature.

To advance the utilization of solar thermal energy, a novel solar-driven microcapsule was designed by the combination of high-performance CuS nanoconverter and the microencapsulated n-Eicosane with a brookite TiO2 shell via in situ sol–gel method. The resultant n-Eicosane@TiO2/CuS microcapsules possessed excellent thermal properties with high latent heat density (171.7 J/g), high encapsulation efficiency (71.7%), and increased thermal conductivity (0.730 W/(m K)). SEM analysis clearly verified that CuS nanoparticles exhibited a uniform distribution on the surfaces. Most of all, the addition of CuS not only enlarged the absorption spectra from the UV to the visible and NIR region but also achieved high solar-to-thermal conversion efficiency (94.41%). Due to the high heat storage capability and solar irradiation utilization efficiency, this solar-driven microcapsule possesses great potential for the solar energy utilization.

In this study, we report a simple one-pot synthesis of iron oxide nanoparticles (IONPs) modified with thermoresponsive polymers potentially applicable for nucleic acid capture. Ferrous (Fe2+) and ferric (Fe3+) ions were coprecipitated to a dispersion of previously prepared poly(N-isopropylacrylamide-co-2-aminoethyl methacrylate) P(NIPAAm-co-AEM) for in situ synthesis of magnetite (Fe3O4) and concurrent surface modification of Fe3O4 with the polymer to obtain magnetic nanocomposites. Fourier-transform infrared (FTIR) spectroscopy analysis reveals the surface modification of Fe3O4 with P(NIPAAm-co-AEM) and P(NIPAAm) as functional and control polymers, respectively. Fe3O4@P(NIPAAm-co-AEM) and Fe3O4@P(NIPAAm) nanocomposites’ surfaces contain 7.5 and 2.3 wt% of immobilized polymers, respectively. Vibrating sample magnetometry (VSM) result indicates a high saturation of magnetization value, 75 emu/g, for Fe3O4@P(NIPAAm-co-AEM) nanocomposites. The hydrodynamic diameter of Fe3O4@P(NIPAAm-co-AEM) in water changes depending on pH and temperature. A study for deoxyribonucleic acid (DNA) capture ability of Fe3O4@P(NIPAAm-co-AEM) nanocomposites shows a maximum 18.5 mg/g of DNA can be adsorbed on Fe3O4@P(NIPAAm-co-AEM).