Harnessing the properties of imidazolium species, antimicrobial activity against Gram-negative and Gram-positive bacteria was attained by binary-grafting 2-hydroxyethyl methacrylate (HEMA) or N-isopropylacrylamide, followed by N-vinylimidazole onto polypropylene (PP) monofilaments (sutures) using 60Co γ-rays. Ulterior functionalization with methyl iodide was carried out to endow brushes with antimicrobial activity on the PP surface. The PP-grafted sutures were characterized by means of Fourier-transform infrared spectroscopy attenuated total reflection, scanning electron microscopy, differential scanning calorimetry, and thermogravimetric analysis, and regarding the mechanical properties and the responsiveness to pH and temperature. Tests were performed on Escherichia coli and Staphylococcus aureus achieving large inhibition zones.

Periodic lattice materials have been studied extensively in numerous science and engineering fields. Despite the vast knowledge that has emerged, the activities have been stove-piped within individual research communities, often in isolation from those in related fields. To bring this work into a holistic framework, the present article considers the elements needed to integrate the study of lattice materials into the processing–structure–properties paradigm that underpins materials science as an academic discipline. The emphasis is on concepts of structure involving topology, morphology, and defects of lattice materials, with illustrations of structure–property relations in the context of lattice strength.

Transparent high refractive index materials are of the central importance for the development of metasurface in visible range. Titanium dioxide (TiO2) has been considered as a perfect candidate due to its wide band gap and high refractive index. However, till now, it is still quite challenging to fabricate high-quality TiO2 films with high refractive indices and low losses. Here we demonstrate the fabrication of high-quality TiO2 film using an electron-beam evaporation method. We show that the post-annealing conditions play key roles in the microstructure crystallographic and the optical refractive index of the TiO2 films. A predominately oriented TiO2 film has been achieved by annealing at 700 °C in oxygen ambient. The refractive index is as high as 2.4, and the corresponding loss is negligible at 632 nm. Further studies on dielectric antennas show that our TiO2 film can be an ideal platform to fabricate metasurface in visible frequency range. We believe that our research will be important for the advances of all-dielectric metasurfaces.

Quantum simulations of oxygen incorporation at a Σ5 grain boundary in yttria-stabilized zirconia (YSZ), a common solid oxide fuel cells (SOFCs) electrolyte, show that the incorporation energy is reduced compared with YSZ with no grain boundaries. The simulation results are supported by electrochemical impedance spectroscopy (EIS) measurements conducted on a single crystalline YSZ substrate with nanogranular interlayered YSZ. EIS results showed that single crystalline YSZ membranes with nanogranular surface (i.e., high grain boundary densities) exhibit small electrode impedances than the reference single crystalline YSZ. The 20-nm-thick nanogranular YSZ interlayer was fabricated by atomic layer deposition and the performance for SOFCs with nanograined interlayer was increased by factor of 2 at operating temperatures between 350 and 450 °C.

The authors develop a computational approach that integrates machine learning (ML) and density functional theory (DFT) with experimental data to predict formable and thermodynamically stable iodine-containing apatites. This is an important problem because radioactive iodine is toxic and capturing it in solid waste forms have implications in remediation treatments. The authors train ML models using 336 compositions and screen 54 iodine-containing compounds in apatite stoichiometry. ML models predict 18 as formable and 24 as nonformable in the apatite structure; 12 compounds were identified to be uncertain. DFT convex hull predicted two to be thermodynamically stable, one as metastable, and nine as unstable.

Wearable healthcare technologies should be non-invasive, robust to daily activity/environments, easy to use, and comfortable to wear. Flexible substrate devices for biomarker monitoring can contribute to wearable diagnostic applications. Single-target biosensors have extensively been developed for health-monitoring applications; however, recently multiplex biomarker tests have generated clinical interest. Targeting multiple biomarkers in diagnostic systems (wearable or point of care) offers more focused diagnosis and treatment as changes in a single biomarker can be caused by a series of physiologic conditions. This review highlights flexible substrates that have been successfully demonstrated for multiplex biomarker detection with potential for healthcare monitoring.

We present a comparative ab initio study of surface diffusion of Li and Na on planar and curved graphene. The barrier for diffusion is ~0.1 eV lower for Na than for Li, and is changed significantly by curvature. The maximum change is similar for Li for Na, of the order of ±0.1 eV on the convex and concave sides. The difference in barrier for metal atoms adsorbed on the concave and convex sides can reach 0.2 eV. This modulation of the diffusion barrier by curvature is therefore expected to affect significantly the rate capability of graphene-based anodes.

Nanomaterials have been intensively studied over the past decades with many advantages over traditional bulk materials in many applications. Nanomaterials' properties are largely governed by their chemical compositions, sizes, shapes, dimensions, morphologies and structures, which are primarily controlled with the chemical and/or physical fabrication methods and processes. This prospective will highlight recent progress on the modifications of oxide nanomaterials' properties by hydrogenation, namely heat treatment under hydrogen or hydrogen plasma environment, for various applications.

The crystallization mechanism and kinetics of Cr2Ge2Te6 (CrGT) films were investigated by differential scanning calorimetry. The average Avrami exponent (na) analysis indicated that CrGT exhibits a growth-dominant crystallization in the range of heating rate (β) of 10–50°C/min. In comparison, Ge2Sb2Te5 (GST) showed a nucleation-dominant crystallization. The na of CrGT was about 3, and was majorly independent of β. The na of GST decreased with an increasing β, which asymptotically approached a value of around 3. The kinetic constant of CrGT was evaluated to be almost the same with that of GST, indicating that CrGT undergoes fast crystallization.

Planet–satellite-type supracolloidal clusters represent a comparably young class of nanomaterials, which are unique with regard to structural order. In this prospective article, different approaches for their synthesis are discussed and compared. These synthetic methods enable the engineering of supracolloidal structural and adaptive properties, which in turn enables different emerging applications, such as in sensing and catalysis. These possibilities are explored on the basis of selected recent examples. A perspective about possible future developments is given at the end of this article.

GaN nanowires are promising building blocks for future nanoelectronics, optoelectronic devices, and nanogenerators. Here, we report on strong piezoelectricity in individual single-crystal GaN nanowires revealed by direct measurement of the piezoelectric constant using piezoresponse force microscopy. Our experimental results show that individual c-axis GaN nanowires, with a characteristic dimension as small as 65 nm, show a shear piezoelectric constant of d15 ~ 10 pm/V, which is several times that measured in bulk. The revealed strong piezoelectricity could open promising opportunities for application of GaN nanowires in nanowire-based sensors and generators for self-powered nanodevices.

To evaluate whether the photocatalysis efficiency of titanium oxide (TiO2) increases under the shading of carbon aerogel (CA), super black CA/TiO2 composite sheets were directly fabricated by physical mixing of CA, TiO2 powder, and binder. It was found that the photocatalysis efficiency of composite sheets were higher than that of pure TiO2 sheet. We attribute this phenomenon to the hot electrons coupling between CA and TiO2. Besides the direct light absorption of TiO2, the hot electrons generating and indirect energy transfer from CA to TiO2 may enhance the photocatalysis efficiency of TiO2.

Three-dimensional cultures have exciting potential to mimic aspects of healthy and diseased brain tissue to examine the role of physiological conditions on neural biomarkers, as well as disease onset and progression. Hypoxia is associated with oxidative stress, mitochondrial damage, and inflammation, key processes potentially involved in Alzheimer's and multiple sclerosis. We describe the use of an enzymatically-crosslinkable gelatin hydrogel system within a microfluidic device to explore the effects of hypoxia-induced oxidative stress on rat neuroglia, human astrocyte reactivity, and myelin production. This versatile platform offers new possibilities for drug discovery and modeling disease progression.

Novel fluorine-doped zinc tin oxide (ZTO:F) thin-film transistors (TFTs) have been fabricated using an aqueous solution process. Exploiting hydrolysis and condensation reactions in an aqueous solution process, organic-free ZTO:F thin films were fabricated at a low temperature of 250 °C. The fabricated TFT device shows a field-effect mobility of 2.85 cm2/V s, on-to-off current ratios exceeding 107, and sub-threshold swings of 0.83 V/dec. The ZTO:F TFT also displays high operational stability of ΔVth = 1.73 V despite incorporation of a large amount of fluorine and use of a low-temperature annealing process. This is attributed to effective passivation of oxygen vacancy diffusion by metal fluoride bonds at the ZTO:F channel/gate dielectric interface.

The glass surfaces used for optical devices are necessary to have high transparency. Here we propose to take advantage of tube-like SiO2 textures to trap lubricant liquid inside aiming to prepare novel slippery liquid-infused porous surfaces (SLIPS). As a consequence, SLIPS with high transparency were synthesized on glass substrate successfully. The capillary action of unique tubular structure induces the ion migration of adjacent Krytox 100, thus endowing SLIPS with the self-healing property. Moreover, the remarkable slip behavior enables these surfaces to possess the self-cleaning and anti-biofouling performances. The current work might provide a promising candidate for long-term transparent optical devices.

In this work, we investigated the interactions of human mesenchymal stem cells (hMSCs) with three-dimensional (3D) printed scaffolds displaying different scaffold architectures. Pressure-assisted microsyringe system was used to fabricate scaffolds with square (SQR), hexagonal (HEX), and octagonal (OCT) architectures defined by various degrees of curvatures. OCT represents the highest degree of curvature followed by HEX, and SQR is composed of linear struts without curvature. Scaffolds were fabricated from poly(L-lactic acid) and poly(tyrosol carbonate). We found that hMSCs attached and spread by taking the shape of the individual struts, exhibiting high aspect ratios (ARs) and mean cell area when cultured on OCT scaffolds as compared with those cultured on HEX and SQR scaffolds. In contrast, cells appeared bulkier with low AR on SQR scaffolds. These significant changes in cell morphology directly correlate with the stem cell lineage commitment, such that 80 ± 1% of the hMSCs grown on OCT scaffolds differentiated into osteogenic lineage, compared with 70 ± 4% and 62 ± 2% of those grown on HEX and SQR scaffolds, respectively. Cells on OCT scaffolds also showed 2.5 times more alkaline phosphatase activity compared with cells on SQR scaffolds. This study demonstrates the importance of scaffold design to direct stem cell differentiation, and aids in the development of novel 3D scaffolds for bone regeneration.

A method of fabricating oriented single-crystalline SrRuO3 nanowire arrays using a bottom-up approach relying on diffusion-controlled self-organization is demonstrated. DyScO3 substrates exhibiting an ordered striped phase of DyO and ScO2 chemical termination are used as a template for pulsed laser deposition growth of SrRuO3. Here SrRuO3 preferentially nucleates on one type of termination. The resulting nanowires are single crystalline, conducting and isolated from each other, typically 100 nm wide and 5–10 nm high. This preferential growth is studied using a kinetic Monte Carlo model, which provides a guide to optimize growth conditions and tune the dimensions of the nanowires.

Hollow mesoporous polydopamine (HMPDA) microcapsules were prepared by a template method using silica nanoparticles as the templates. The template method was also used for the formation of mesoporous polydopamine (PDA), which is driven by π–π interactions of trimethylbenzene and PDA, in which the PDA wall with mesoporous structure can be obtained after template removal by extraction. Because of its surface mesoporous structure and large central cavity structure, HMPDA microcapsules have unique adsorption properties. Compared with other porous materials, PDA has better biosafety because dopamine itself is a bionic material. The above properties are of great significance for the application of HMPDA microcapsules in the field of biologic medicine, especially in drug carriers.

We show that the optical response of ultrathin metallic films of finite lateral size and thickness can feature peculiar magneto-optical effects resulting from the spatial confinement of the electron motion. In particular, the frequency dependence of the magnetic permeability of the film exhibits a sharp resonance structure shifting to the red as the film aspect ratio increases. The films can also be negatively refractive in the IR frequency range under proper tuning. We show that these magneto-optical properties can be controlled by adjusting the film chemical composition, plasmonic material quality, the aspect ratio, and the surroundings of the film.

The authors have shown recently that the neurite extension by neuronal PC12 cells is greatly impacted by aerogel topography. Indeed, the average neurite length of PC-12 cells grown on aerogels is greater than that in cells cultured on control substrates. Here, the authors report on the first experimental study focused on the design and development of a plasmonic photo-patterning technique for collagen-coated mesoporous aerogel biomaterials. Herein, the authors have produced specific patterns on silica aerogels by performing precise plasmonic photo-patterning on liquid crystal-coated aerogels. The authors report the methodology employed to create a collagen–liquid crystal gel mixture imprinted with precise plasmonic photo-patterns. PC12 cells plated on these patterns did attach and survive and followed the spatial cues of the pattern to align themselves in a similar pattern.