We detail the influence of tapered interfaces on the nanoscale morphologies of ion-doped poly(styrene-b-oligo-oxyethylene methacrylate) block polymers (BPs). Most significantly, the location of double-gyroid network phase window was found in ion-doped normal-tapered materials, and a similar window was not detectable in the corresponding non-tapered and inverse-tapered BPs. Additionally, the effective interaction parameters, χeff, were reduced substantially in the tapered materials in comparison with their non-tapered counterparts. Overall, this work demonstrates that tapering between polymer blocks provides unique control over BP morphologies and improves the material processability (due to lower χeff), potentially facilitating the development of future ion-conducting devices.

The thermal conductivities (κ) of bulk and thin-film α-Al2O3 are calculated from first principles using both the local density approximation (LDA) and the generalized gradient approximation (GGA) to exchange and correlation. The room temperature single-crystal LDA value ~39 W/m K agrees well with the experimental values ~35–39 W/m K, whereas the GGA values are much smaller ~26 W/m K. Throughout the temperature range, LDA is found to slightly overestimate κ, whereas GGA strongly underestimates it. We calculate the κ of crystalline α-Al2O3 thin films and observe a maximum of 79% reduction for 10 nm thickness.

We have used low-energy electron diffraction and microscopy to compare the growth of graphene on hydrogen-free Ge(111) and Ge(110) from an atomic carbon flux. Growth on Ge(110) leads to significantly better rotational alignment of graphene domains with the substrate. To explain the poor rotational alignment on Ge(111), we have investigated experimentally and theoretically how the adatom reconstructions of Ge interact with graphene. We find that the ordering transition of the Ge(111) adatom reconstruction is not significantly perturbed by graphene. Density functional theory calculations show that graphene on reconstructed Ge(110) has large-amplitude corrugations, whereas it is remarkably flat on reconstructed Ge(111). We argue that the absence of corrugations prevents graphene islands from locking into a preferred orientation.

This work presents an in-depth study of how the choice of boundary conditions can impact upon the calculated photovoltage and photocurrent in photoelectrochemical (PEC) devices. Utilizing a floating boundary condition for the electrostatic potential and pseudo-Schottky boundary conditions for the interfacial electron/hole currents, we show simultaneous calculation of photovoltage and photocurrent. We also explore the significance of capturing the photovoltage, with proper boundary conditions, to accurately replicate practical photocurrent along with the realistic band alignments. Finally, our results decouple the interfacial hole transfer from the recombination at the interface/space-charged region and suggest possible methods to engineer the mesoscopic transfer process at PEC electrodes.

We report on a novel processing route to prepare La0.8Ce0.2(Fe0.95Co0.05)11.8Si1.2/Cu bulk composites by low-temperature hot pressing. With increasing copper content, the compressive strength of the composites first decrease and then increase owing to the buffering effect of copper, but the magnetocaloric effect reduces to some extent. Copper addition improves the thermal conductivity of the composites, which compensates for the decrease in thermal conductivity due to porosity. A relatively large entropy change of 5.75–7.19 J/(kg K) at 2 T near the Curie temperature (249 K), good thermal conductivity of 7.51–15.55 W/(m·K), and improved compressive strength of 151.1–248.0 MPa make these composites attractive magnetic refrigeration materials.

While preclinical models such as orthotopic tumors generated in mice from patient-derived specimens are widely used to predict sensitivity or therapeutic interventions for cancer, such xenografts can be slow, require extensive infrastructure, and can make in situ assessment difficult. Such concerns are heightened in highly aggressive cancers, such as glioblastoma (GBM), that display genetic diversity and short mean survival. Biomimetic biomaterial technologies offer an approach to create ex vivo models that reflect biophysical features of the tumor microenvironment (TME). We describe a microfluidic templating approach to generate spatially graded hydrogels containing patient-derived GBM cells to explore drug efficacy and resistance mechanisms.

By inserting a carbon chain, the geometric structure and electronic properties of carbon nanotube (CNT) would undergo a significant change. Numerous studies have conducted to experimentally find the insertion effect of carbon chains on CNTs. This paper in a theoretical way studied the geometry of carbon chains inserted CNTs and analyzed the mechanism for conductivity change after insertion of carbon chains. Results indicate that carbon chains in the innermost channel of the tube are effective methods for transforming the electrical properties of the CNT, leading to the redistribution of electron and thereby causing the conductivity change in obtained configurations.

Conjugated polymers have been proposed as promising materials for scaffolds in tissue engineering applications. However, the restricted processability and biodegradability of conjugated polymers limit their use for biomedical applications. Here we synthesized a block-co-polymer of aniline tetramer and PCL (AT–PCL), and processed it into fibrous non-woven scaffolds by electrospinning. We showed that fibronectin (Fn) adhesion was dependent on the AT–PCL oxidative state, with a reduced Fn unfolding length on doped membranes. Furthermore, we demonstrated the cytocompatibility and potential of these membranes to support the growth and osteogenic differentiation of MC3T3-E1 cells over 21 days.

Akin to the natural tissues, soft artificial muscles possess a life cycle limited by aging and degradation phenomena. Here, we propose a rejuvenation method aimed at silicone-ethanol soft composite actuators, in which ethanol escape occurs during prolonged actuation, thus compromising their performance. The rejuvenation is achieved by immersion of the material–actuator in ethanol, allowing its diffusion into the silicone-based material until saturation. Repeatable rejuvenation of a soft robot, based on the soft material–actuator, resulted in retention of up to 100% of its functionality. Thus, we suggest that this method may be used for the rejuvenation of soft artificial muscles and material–actuators.

Graphene-based electronic DNA sequencing techniques have received significant attention over the past decade and are hoped to provide a new generation of portable, low-cost devices capable of rapid and accurate DNA sequencing. However, these devices are yet to demonstrate DNA sequencing. This is partly due to complex fabrication requirements resulting in low device yields and limited throughput. In this paper, we review the challenging fabrication of graphene-based electronic DNA sequencing devices. We will place a particular focus on common fabrication challenges and look toward the development of high-throughput, high-yield fabrication of these devices.

We report for the first time the hydrothermal growth of radially aligned ZnO nanorods on electrospun polyamide nanofibers, paving the way to the development of transparent, flexible, portable, solution processable, and low-cost thin-film photovoltaics. Polyamide nanofibers with mean diameters of 100 nm were prepared by electrospinning followed by a two-step hydrothermal growth method for fabricating ZnO nanorods. The loading ratio of ZnO nanorods were found to be 66 wt% by thermogravimetric analysis, significantly higher than the ZnO grown on cotton and nylon fabrics previously. A significant increase of UV absorption was observed. Superhydrophobicity, which is a desirable feature of self-cleaning photovoltaic devices, was achieved using 1-dodecanethiol modification.

Two semiconductors (Cu2O and TiO2) were chosen for the photocatalytic reduction of bicarbonate to formate in order to perform a systematic study on the effect of six different hole (h+) scavengers. The six h+ scavengers selected for the study include glycerol, ethylene glycol, 2-propanol, sodium sulfite, triethanolamine, and ethylenediaminetetraacetic acid. Glycerol proved to be the most efficient h+ scavenger, and TiO2 in glycerol showed the highest quantum efficiency of 5.04 ± 0.3%. This finding bodes well as a sustainable one because glycerol is environmentally benign, a low-cost material, and is derived from plants, as opposed to petroleum sources like 2-propanol or ethylene glycol.

Powering autonomous electronic devices is a key challenge toward the development of smart sensor networks. In this work, a state-of-the-art triboelectric nanogenerator is devised to enhance the output performance with an effective surface charge density of 70.2 µC/m2, which is 140 times higher than the initial results. Thin film Parylene-C material is deposited to increase charge accumulation by allowing the acceptance of more charges and enhance output performance by a factor of 10. By considering the merit of simple fabrication, we believe the effective charge inclusion layer will be an ideal energy source for low-power portable electronics.

Nickel–molybdenum (Ni–Mo) materials are widely used functional oxide catalysts for the hydrogen evolution reaction. In this work, we investigate the high activity of Ni–Mo by depositing size-controlled Ni nanocrystals (NCs) onto Mo substrates. We observe a synergistic increase in catalytic activity that does not scale with the Ni–Mo interface length. This evidence points to a bulk electronic interaction of the two metals that is separate from the mechanism of enhancement seen in conventionally co-deposited Ni–Mo electrocatalysts. In addition to elucidating the catalytic behavior of the Ni–Mo system, this work offers a general NC-based paradigm for investigating fundamental interactions and synergistic effects in electrocatalytic materials.

In this study, we investigate spray pyrolysis as an approach to synthesis of tunnel structure sodium manganese oxide, as it is a cost-effective and scalable technology. The powders synthesized with Na/Mn ratio of 0.50 displayed a pure tunnel structure, and demonstrated the best electrochemical performance, with a discharge capacity of 115 mAh/g. The material also showed good cycleability and rate capability. Noticeable decay in performance was seen in materials with Na/Mn ratios other than 0.50, indicating that this material is sensitive to minor compositional deviations. This study has demonstrated that spray pyrolysis is a promising synthesis method for this material.

We report that a hexagonal closed-packed (HCP) phase with high cobalt content precipitates in Al0.5CoCrFeNi high entropy alloy (HEA) after 650 °C/8 h heat-treatment. The precipitate with the shape of plate is completely located at the interdendritic region. Results of electron diffraction and high resolution transmission electron microscopy show that the HCP phase was transformed from the body-centered cubic phase through a simple shear and the two phase obey an orientation relationship. The thermodynamic stability of Al0.5CoCrFeNi HEA should be carefully reevaluated, especially at the vulnerable temperature.

The extraordinary electronic, thermal, and mechanical properties of carbon nanotubes (CNTs) make them attractive materials for incorporation into polymer films. However, retaining these outstanding properties of CNTs during processing can be difficult due to the attractive forces that cause the nanotubes to bundle together. In this study, six different hydrophobically modified linear poly(ethylenimine) (LPEI) polymers are evaluated and effectively used as aqueous nanotube dispersants. This study also shows that the polymers are bifunctional in nature as aqueous polymer/nanotube mixtures can be cross-linked into CNT-impregnated hydrogels.

We synthesized two types of ZnO nanoparticles (NPs) for comparison, the first NPs were produced using a Zn(Ac)2.2H2O solution in distilled water and the second were produced using a Zn(Ac)2.2H2O solution in an aqueous extract of Mentha (mint). The x-ray diffraction patterns were indexed on the basis of a hexagonal (wurtzite) structure. The samples illustrate the high crystalline quality, and the average crystal sizes of the NPs were calculated to be 50 and 60 nm for GS and NS, respectively. ZnO nanorods were produced for the first time by using green synthesis method.

A novel, alloy-agnostic, nanofunctionalization process has been utilized to produce metal matrix composites (MMCs) via additive manufacturing, providing new geometric freedom for MMC design. MMCs were produced with the addition of tungsten carbide nanoparticles to commercially available AlSi10Mg alloy powder. Tungsten carbide was chosen due to the potential for coherent crystallographic phases that were identified utilizing a lattice-matching approach to promote wetting and increase dislocation interactions. Structures were produced with evenly distributed strengthening phases leading to tensile strengths >385 MPa and a 50% decrease in wear rate over the commercially available AlSi10Mg alloy at only 1 vol% loading of tungsten carbide.

This study investigated a new strategy for fabricating porous scaffolds with the self-folding ability and controlled release of growth factors (GFs) via 3D printing. The scaffolds were a bilayer structure comprising a poly(D,L-lactide-co-trimethylene carbonate) scaffold for providing the shape morphing ability and a gelatin methacrylate scaffold for encapsulating and delivering GF. The structure, shape morphing behavior, GF release, and its effect on stem cell behavior were studied for new scaffolds. The results suggest that these scaffolds have great potential for regenerating tissues such as blood vessels. This work also contributes to developments of 3D printing in tissue engineering.