Ab initio design of polymer nanocomposite materials for high breakdown strength requires prediction of localized trap states at the polymer–filler interface. Systematic first-principles calculations of realistic interfaces can be challenging, particularly for amorphous polymers and fillers that necessitate the calculation of ensembles of large unit cells with hundreds of atoms. We present a computational approach for automatically generating reasonable structures for amorphous polymer–filler interfaces, combining classical molecular dynamics and Monte Carlo simulations. We identify trap states by analyzing the localization of electronic eigenstates calculated using density functional theory on ensembles of interface structures, clearly distinguishing shallow trap states from delocalized band-edge states. Applying this approach to silica–polyethylene interfaces as an initial example, we find under-coordination and distorted coordination structures at amorphous silica surfaces contribute a combination of deep and shallow traps at these interfaces, whereas polyethylene does not generate localized interfacial states.

A novel photocatalyst Tm3+/Yb3+–co-doped bismuth molybdate (Bi2MoO6) were synthesized via the hydrothermal method. The samples were characterized through X-ray diffraction, field emission scanning electron microscopy, transmission electron microscopy, X-ray photoelectron spectroscopy (XPS), UV-vis diffuse reflectance spectra, and photoluminescence. XPS characterization confirmed the doped rare earth elements. Analysis of the optical properties explained the up-conversion process and its effect on the photocatalytic performance. The as-synthesized samples were employed to decompose Rhodamine B to value its photocatalytic activities under visible light irradiation. The doped samples showed an enhanced photocatalytic activity compared with the bare Bi2MoO6. When the ratio of Tm3+ and Yb3+ was 0.5:5, the degradation efficiency was the highest of 96.1% within 25 min, which was higher than that (74.9%) of pure Bi2MoO6. Moreover, the photocatalytic mechanism of improving the photocatalytic properties was discussed. Besides, the sample showed a super stability in photocatalytic activity. A novel catalyst for industrial pollutant degradation was proposed.

The development of GaN-on-diamond devices offers bright prospects for the creation of high-power density electronics. This article presents a process of fabricating GaN-on-diamond structure by depositing diamond films on dual sides, including heat dissipation diamond film and sacrificial carrier diamond film. Prior to heat dissipation diamond film layer preparation, aluminum nitride (AlN) is chosen as a dielectric layer and pretreated by nanodiamond (ND) particles, to enhance the nucleation density. Zeta potential measurements and X-ray photoelectron spectroscopy are used to analyze the AlN surface after each treatment. The results show that oxygen-terminated ND particles tend to adhere to an AlN surface because the oxygen-terminated NDs have –COOH and –OH groups, and hold a negative potential. On the contrary, fluorine-terminated AlN prefers to attract the hydrogen-terminated ND seeds, which resulted in higher diamond nucleation density. Based on this preliminary study, a dense high-quality GaN-on-diamond wafer is successfully produced by using AlN as the dielectric layer and a diamond film as the sacrificial carrier.

The unique properties of graphene have led to the use of this allotrope of carbon in a wide range of applications, including semiconductors, energy devices, diffusion barriers, heat spreaders, and protective overcoats. The synthesis of graphene by process methods that either directly or indirectly rely on physical vapor deposition, thermal annealing, laser irradiation, and ion/electron beam irradiation has drawn significant attention in recent years, mainly because they can provide high purity, low temperature, high throughput, and controllable growth of graphene on various substrates. This article provides a comprehensive assessment of these methods by grouping them into two main categories, i.e., indirect methods in which a carbon layer is first deposited on a substrate and then converted to graphene by some type of energetic post-treatment process and direct methods in which graphene is directly synthesized on a substrate surface by a process that uses a solid carbon source. The underlying growth mechanisms of these processes and the challenging issues that need to be overcome before further advances in graphene synthesis can occur are interpreted in the context of published results.

The present article reports on a comprehensive atomic-scale investigation on S-series precipitates in 2024 aluminum alloy. Cs-corrected high-angle annular dark-field scanning transmission electron microscopy is applied to reveal the fine atomic-scale structure of precipitates at early ageing state. Geometrics phase analysis is used for elucidating the induced strain field from precipitates. The precipitate sequence of S-series precipitates in 2024 Al alloy is identified as follows: super saturated solid solutions (s.s.s.s.) → clusters (GPB zone) → S′ phase → S phase. The interfaces between precipitates acting as precursor of S′ phase are well characterized. One typical characteristic of S-series phase precipitates is the coexistence of clusters and subsequent metastable phases. Transformation of metastable phases is characterized. Corresponding hardness structure relationship is revealed, and S′ phase is considered as the key strengthening structure in S-series precipitates in 2024 Al alloys.

A simple composition of TeO2–Yb2O3 binary glass was selected as the host glass matrix for discussing the structure of tellurite glass with increasing Yb2O3 content. Raman spectra were measured to investigate the structure of the binary tellurite glasses, and upconversion and downconversion fluorescence characteristics were employed for discussing the relationship between the structural units and the state of Yb3+ in the tellurite glasses. The results suggested that the decrease of TeO4/2 in the glasses would result in the formation of Yb3+ clusters and Yb3+–O2− couple in the tellurite glasses, and then results in the decrease of cooperative upconversion and downconversion fluorescence intensity.

We have synthesized graphene oxide (GO) using Hummer's method which was subsequently reduced (rGO) by hydrazine hydrate. The synthesized GO was coated with poly(3,4-ethylenedioxythiophene)-poly(styrenesulfonate) (PEDOT-PSS) conducting polymer (CP) to obtain CP-GO which was also further reduced using hydrazine hydrate to form CP-rGO. Scanning electron microscopy, Raman spectroscopy, X-ray diffraction, ultraviolet photoelectron spectroscopy, and X-ray photoelectron spectroscopy, X-ray absorption near-edge structure (XANES) techniques were used to study the electronic and structural properties of GO, rGO, CP-GO, and CP-rGO nanocomposites for biomedical applications. The superconducting quantum interference device method was used to investigate the magnetic properties of the nanocomposites. The electrical conductivity of the CP-GO nanocomposites was found to be ~104 times higher than that of GO due to an increase in sp2 content and subsequent decrease in oxygen functional groups. In rGO, we observed an improved paramagnetic saturation magnetization of approximately 5.6 × 0−3 emu/g at 2 K. The electronic and magnetic behavior of PEDOT-PSS-coated nanocomposites, as a result, were successfully tuned for potential biological and biomedical applications.

Recently, layered double hydroxides (LDHs) have attracted intensive research interest as the next-generation supercapacitor electrodes due to their unique two-dimensional (2D) hydrotalcite-like structure. However, the inevitable agglomeration significantly decreases the accessible surface areas and blocks the pseudocapacitive sites, thus severely hinders their electrochemical applications. Herein, we develop a facile one-step growth approach to fabricate porous agglomerate of NiCo-LDH nanosheets and reduced graphene oxide (rGO) nanoflakes. By adjusting feeding molar ratios, the obtained NiCo-LDH/rGO electrode delivers a high specific capacity of 879.5 C/g at a current density of 0.5 A/g and still remains 485 C/g at 20 A/g. Furthermore, the fabricated asymmetric supercapacitor (ASC) has demonstrated a superior energy density of 48.7 W h/kg at a power density of 401 W/kg. After 2000 cycles, the assembled ASC exhibits an improved capacity retention of 81% within a potential window of 1.6 V at 2 A/g.

There is a significant interest in developing the corrosion-resistant magnesium (Mg) alloy as a degradable biomaterial. In this work, the magnesium–zirconium (Zr = 1 wt%)–strontium (Sr = 2 wt%)–cerium (Ce = 0, 0.5 wt%) alloy was developed using the casting process. Effects of Ce addition on alloy microstructure, corrosion behavior, and biocompatibility were systematically investigated. Detailed microstructural analysis indicated that 0.5 wt% Ce addition refined the second phase (Mg17Sr2) in the Mg–2Sr–1Zr alloy. Furthermore, phase analysis of corrosion product showed the formation of stable CeO2 oxide layer on the corroded surface of the Mg alloy. Both the precipitate refinement and stable CeO2 layer formation significantly contributed toward enhanced corrosion resistance of the Mg–Sr–Zr–Ce alloy, as determined by both electrochemical and immersion corrosion in phosphate-buffered saline. Significantly higher osteoblast-like cell (MG-63) proliferation was observed in Ce-containing Mg alloy at both day 1 and day 3. Overall, the results showed that Ce addition could modulate degradation behavior and biocompatibility of the ternary Mg alloy.

Commercial chiral stationary phases (CSPs) are based mainly on polysaccharides supported on silica; however, the pharmaceutical industry shows a special interest on chiral separations, exhibiting high financial investment in the development of new CSPs. These can be structured by a new optically active compound or different support. Thus, metal–organic frameworks (MOFs) are crystalline materials that arise with great potential for support, due to its high porosity, the strong intermolecular force between the metal and the ligand selectivity, and high adsorption capacity. Interested in this, this work proposes a new CSP using the metal–organic structure ZIF-8 (Basolite Z1200) due to its high mechanical stability. To this end, it is proposed the modification of the ZIF-8 with the optically active compound, tris-3,5-dimethylphenylcarbamate amylose. Through characterization textural, structural, and physicochemical performed, it is possible to confirm the synthesis of the chiral compound (amylose carbamate), as well as the functionalization of the metal–organic structure with tris-3,5-dimethylphenylcarbamate amylose (ZIF-8-PEI-CA). In addition, as a validation technique, HPLC can detect the presence of enantiomers present in the racemic mixture of Troger bases.

The aim of this research was to develop the UV-cured epoxy/carbon composites. The rheological properties of the uncured neat epoxy and epoxy composite with graphite, graphene, and multi-walled carbon nanotube (MWCNT) were evaluated to observe the macroscopic flow behavior and the microstructure by shear force. The results showed that epoxy/carbon composites at high filler content exhibited shear-thinning behavior with a high yield stress value and epoxy/MWCNT at 30 phr showed this characteristic obviously. The fractured surface and particle dispersion in the epoxy matrix were evaluated by scanning electron microscopy and transmission electron microscopy, respectively. Epoxy/carbon composites at high filler content displayed rough fracture surface with particle agglomeration, thus the electrical conductivity increased. The result showed that the epoxy/MWCNT composites had high potential to use as a conductive adhesive with a 3D printing process due to high electrical conductivity with high viscosity that could be formed easily during processing.

This work demonstrates a double-step method, a simple chemical bath deposition and an in situ polymerization process, to synthesize the stable structure of a composite of Polyaniline/BiVO4/cellulose aerogel (PBC) in wastewater treatment. The poor stability of the carrier catalyst was improved significantly by forming a dense film of polyaniline (PANI) through polymerization on BiVO4/cellulose aerogel (BC). The developed three-dimensional porous structure enhanced photocatalytic stability. For instance, photocatalytic degradation of a dye, methylene blue, reached to 91.67% under the eight times successive irradiation of the visible light. The resulted fine performance could be owed to the strong adsorption of cellulose aerogel, uniform spreading of BiVO4, and the speedy electron separation efficiency of PBC. Moreover, the photocatalytic mechanisms including the role of the free radicals (•OH and •O2−) of the developed PBC were also discussed. The novel structure may present a new insight into the development of the carrier catalyst.

TiO2-(B)/SnO2 nanostructured composites have been prepared by the combination of an oil-in-water (O/W) microemulsion reaction method (MRM) and a hydrothermal method. Its electrochemical properties were investigated as anode materials in lithium-ion battery, and characterization was carried out by XRD, BET, Raman, FE-SEM, EDXS, and TEM. The as-prepared composites consisted of monoclinic phase TiO2-(B) nanoribbons decorated with cassiterite structure SnO2 nanoparticles. The electrochemical performance of the TiO2-(B)/SnO2 50/50 nanocomposite electrode showed higher reversible capacity of 265 mAh/g than that of the pure SnO2 electrode, 79 mAh/g, after 50 cycles at 0.1 C in a voltage range of 0.01-3.0 V at room temperature. In addition, the coulombic efficiency of the TiO2-(B)/SnO2 50/50 nanocomposite remains at an average greater than 90% from the 2nd to the 50th cycles. The TiO2-(B)/SnO2 50/50 nanocomposite presented the best balance between the mechanical support effect provided by TiO2-(B) that also contributes to the LIB capacity and the SnO2 that provides high specific capacity.

The measurement of thin film mechanical properties free from substrate influence remains one of the outstanding challenges in nanomechanics. Here, a technique based on indentation of a supported film with a flat punch whose diameter is many times the initial film thickness is introduced. This geometry generates a state of confined uniaxial strain for material beneath the punch, allowing direct access to intrinsic stress versus strain response. For simple elastic–plastic materials, this enables material parameters such as elastic modulus, bulk modulus, Poisson's ratio, and yield stress to be simultaneously determined from a single loading curve. The phenomenon of confined plastic yield has not been previously observed in thin films or homogeneous materials, which we demonstrate here for 170 -470 nm thick polystyrene (PS), polymethyl-methacrylate (PMMA) and amorphous Selenium films on silicon. As well as performing full elastic -plastic parameter extraction for these materials at room temperature, we used the technique to study the variation of yield stress in PS to temperatures above the nominal glass transition of 100 °C.

A de novo drug delivery nanosystem based on gold nanoparticles (GNPs), decorated poly(ethylene glycol) (PEG), and folate (FA)-conjugated graphene oxide (GO) was designed and developed successfully. Initially, the graphite (G) powder was oxidized to the GO, and then functionalized with chloroacetic acid to afford a carboxylated graphene oxide (GO–COOH). The obtained GO–COOH was functionalized with an amine end-caped PEG, FA, as well as 3-amino-1-propanethiol to produce a GO–PEG–FA–SH. In another experimental section, GNPs were synthesized through a citrate-mediated reduction approach, and subsequently decorated onto/into GO–PEG–FA–SH through the formation of Au–S bond to afford a GO–PEG–FA/GNP nanosystem. The resultant nanosystem was loaded with doxorubicin hydrochloride (DOX) as a model anticancer drug, and its drug-loading capacity as well as pH-dependent drug release behavior were investigated. The anticancer activity of the developed theranostic nanomedicine was extensively evaluated using MTT assay against human breast cancer cells (MCF7). The developed GO–PEG–FA/GNPs–DOX theranostic nanomedicine exhibited an excellent cancer chemotherapy feature. In addition, this nanomedicine can be used in chemo-photothermal therapy of solid tumors because of the presence of GO and GNPs in its structure.

Continuous hBN films have been grown by means of a radio-frequency-sputtering technology, and their material properties have been investigated. The prepared hBN films can achieve good smoothness in a large area. The surface morphologies and compositions of the hBN films on Si substrate and Al film have been characterized, indicating that there is no difference. The 101-phase peak of hBN film is the strongest, and the optical band gap of the fabricated film is 5.84 eV. An attempt on the fabrication of the hBN based resistive switching (RS) device has been made by using an Ag/hBN/Al structure, leading to the observation of a clear and stable RS behavior. The device exhibits a resistance window (high-resistivity state/low-resistivity state) of around 102, and the RS behaviors of hBN film prepared by sputtering were first observed. It has been found that the opening voltage for the device is changed when a different cycle voltage is applied because of the built-in electric field increasing with the increase of applied cycle voltage. The mechanism of the RS behavior has been analyzed, which lay a foundation for the application of hBN as RS material in resistive random access memory to improve the storage density.

Paper transistors are indispensable devices for paper-based electronic biosensing systems. Existing paper transistors mainly use paper as a mechanical support in a passive fashion. By taking advantage of the cellulose fibers in paper, here we report a transistor-in-paper where paper is employed as an essential part to allow for low-voltage operation, which addresses the long-standing challenge of high-voltage operation with existing paper transistors. Such a low-threshold voltage is because of the ion gel/cellulose fiber composite dielectric formed by modifying the paper with ion gels. We further developed paper-based inverters as examples of logic gates and an integrated tactile sensing mat based on a transistor array–enabled multiplexing device. The results collectively indicate that the ion gel–modified paper leads to a class of flexible, low-voltage transistors and integrated electronic devices, which hold promise in many applications.

In this study, the glass forming ability, thermal stability, and room-temperature mechanical behavior of a high Zr-containing Zr71Cu11Ni10.5Al7Ti0.5 bulk glassy alloy were investigated. The glassy alloy exhibits a high glass-forming ability with a critical casting diameter of 5 mm using copper mold injection casting, and its critical cooling rate is estimated to be smaller than 40 K/s. A small kinetic fragility index m of 32 indicates its good thermodynamic stability and glass-forming ability. Compressive tests indicate that the glassy alloy displays a significant average plastic strain of 12.3%, a high fracture strength of 1592 MPa, and Young's modulus of 74.5 GPa. The good ductility is attributed to the introduction of more free volume and local compositional inhomogeneity with increasing Zr addition. This finding may provide useful guidelines for the development of novel high Zr-containing glassy alloys.

Thermochemical interactions between calcium–magnesium–aluminosilicate (CMAS) glass and an environmental barrier coating of ytterbium disilicate (Yb2Si2O7) and ytterbium monosilicate (Yb2SiO5) were investigated. Top coats were deposited by plasma spray-physical vapor deposition onto silicon carbide substrates. CMAS powder was prepared as a glass and cast into a tape to yield a CMAS loading of ~29 mg/cm2. Samples were heat treated with CMAS at 1300 °C for 1–10 h or at 1400 °C for 1 h in air. Polished specimen cross-sections were characterized using scanning electron microscopy, X-ray diffraction, X-ray energy-dispersive spectroscopy, and transmission electron microscopy to evaluate resulting microstructures, phases, and compositions at CMAS/Yb2Si2O7 interfaces. Coatings exposed at 1300 °C—10 h and 1400 °C—1 h were fully infiltrated and compromised by CMAS. Dissolution of ytterbium silicate into molten CMAS followed by precipitation of cyclosilicate, silicocarnotite, and Yb2Si2O7 at 1300 °C and Yb2Si2O7 at 1400 °C enabled CMAS to effectively infiltrate top coats, rendering the predominantly Yb2Si2O7 coating ineffective at arresting molten CMAS degradation.

The thermal expansion coefficient (TEC) of nano-B4C having 50 nm mean particle size was measured as a function of applied direct current (DC) electric field strength varying from 0 to 12.7 V/mm and over a temperature range from 298 K up to 1273 K. The TEC exhibits a linear variation with temperature despite being measured over a range that is well below 50% of B4C’s normal melting temperature. The zeroth- and first-order TEC coefficients under zero-field condition are 4.8220 ± 0.009 × 10−6 K−1 and 1.462 ± 0.004 × 10−9 K−1, respectively. Both TECs exhibit applied DC electric field dependence. The higher the applied field strength, the steeper the linear thermal expansion response in nano-B4C, which suggests that the applied field affects the curvature of the interatomic potentials at the equilibrium bond length at a given temperature. No anisotropic thermal expansion with and without applied electric field was observed, although nano-B4C has a rhombohedral unit cell symmetry. The rhombohedral unit cell angle was determined as δR= 65.7046° (0.0007), and it remains unaffected by a change in temperature and applied electric field strength, which we attribute to B4C nanoparticle size and its carbon saturation.