Graphene oxide (GO) is grafted to chloropropyl trimethoxysilane, then it is grafted from N, N-dimethyldodecylamine to prepare a quaternised GO (QGO). The QGO is introduced to polyester (PET) fibre surface by immersion method. The results show that the QGO possesses good dispersibility, antibacterial activity and durability, the antibacterial rate of QGO-modified PET fibre against Staphylococcus aureus, Escherichia Coli and Bacillus subtilis are 99.5, 99.5 and 99.8%, respectively. In addition, the QGO-modified PET fibre shows a good chemical stability and corrosive resistance. It is convenient for preparing wearable textiles.

Layered double hydroxides (LDHs) are inorganic compounds with particle size ranging from micrometres to nanometres. On the nanoscale, particles tend to aggregate themselves; therefore, the synthesis of nanoparticles must consider a final step to passivate the surface avoiding aggregation. In this work, zinc/aluminium LDHs particles were synthesised in tomato juice as a reaction medium. This medium promoted the formation of 50 nm particles, which aggregated and simultaneously captured the lycopene in the juice, thus forming a precipitate. The precipitate is a composite material formed by LDH and 11% of organic matter according to an estimation done by thermogravimetric analysis. The organic fraction in the composite presented more thermal stability than that of the tomato flesh. The washing of this composite with ethanol removes lycopene as the main component according to infrared and visible spectroscopy data. As the metal cations in LDH can be selected to comply with food, cosmetic or pharmaceutical applications, the current method to produce lycopene/LDH composites is a promising route to easily obtain antioxidant additives for these industries.

Ti/TiO₂–RuO₂–La₂O₃ anodes were prepared by sol–gel process. The main aim of this work was to study nanostructured TiO₂–RuO₂–La₂O₃ coatings and the effect of electrolyte composition on their stability. For this purpose, coatings with different molar ratios applied on titanium substrate. Then, the morphology and electrochemical properties of the anodes in 0.5 M NaCl and 1 M H₂SO₄ solutions were studied using field emission scanning electron microscopy, energy dispersive X-ray spectroscopy, potentiostatic polarisation, cyclic voltammetry, and accelerated corrosion test (ACT). The results showed that the morphology of all the coatings was cracked-mud microstructure and cracks with a width of 50–500 nm produced in the coatings. It was also observed that corrosion resistance, stability, and electrocatalytic properties of the anodes improve with increased La₂O₃ content. Then, the optimum TiO₂–RuO₂–La₂O₃ composition is obtained with a molar ratio of 70:15:15. Besides, the lifetime and stability of the anodes in NaCl solution were higher than H₂SO₄, so that the reduction of active elements in the coating with a molar ratio of 70:15:15 after ACT was obtained about 64.7 and 77.4% of before ACT in NaCl and H₂SO₄, respectively.

In this study, Bi₂O₃ nanoparticles were employed as computed tomography (CT) contrast agents. In this regard, X-ray attenuation of Bi₂O₃ nanoparticles, prepared via DC arc discharge in water, was investigated. In addition, the optical, structural, morphology and cytotoxicity properties of afforded nanoparticles were also studied. The electric arc discharge was done via bismuth electrodes in a water medium. Then, to stabilise Bi₂O₃ nanoparticles, chitosan molecule was cross linked via glutaraldehyde around Bi₂O₃ nanoparticles. X-ray diffraction analysis demonstrated the monoclinic structure and field emission-scanning electron microscopy images clarified the average size of Bi₂O₃ as 40 nm. Fourier transform infrared analysis proved chitosan band formation around Bi₂O₃ nanoparticles. The 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay revealed no considerable toxicity after 72 h. Finally, X-ray CT of chitosan-coated Bi₂O₃ nanoparticles and Iohexol was carried out at concentrations of 1–6 mg/ml. The CT number of chitosan-coated Bi₂O₃ nanoparticles measured 16, 30, 49, 66, 75 and 85, as well as, respective numbers for Iohexol were 5, 14, 25, 34, 44 and 57. Therefore, it displayed that X-ray attenuation of chitosan-coated Bi₂O₃ nanoparticle was more in comparison with Iohexol at the same concentrations. Eventually, the results demonstrated that chitosan-coated Bi₂O₃ nanoparticles are a suitable candidate for commercial iodine contrast agent substitution.

One-dimensional magnesium oxysulphate MgSO₄·5Mg(OH)₂·2H₂O (abbreviated as 152MOS) with a high aspect ratio was prepared through the hydrothermal reaction route without granular fragments observed in the final products. Those parameters such as molar ratio of MgSO₄·7H₂O to NaOH solution, reaction temperature, reaction time, and dropping order between MgSO₄·7H₂O and NaOH that can influence the morphology, purity, and structure of 152MOS whiskers were taken into consideration. The results indicated that the high purity 152MOS whisker with a length of 170–210 μm can be obtained at 200°C for 15 h in an oven when dropping NaOH into MgSO₄ with the molar ratio of 1:1.5. The product characteristics were investigated by X-ray diffraction, Fourier transform-infrared, thermogravimetry, and scanning electron microscopy.

The study investigated how bending strain affected graphene field-effect transistors (GFETs) that had been fabricated on ultra-flat flexible polyimide (PI) film, and the instability of graphene from repeated bending strain. An ultra-flat surface of PI film was achieved by using varnish PI with gradually increasing temperature. The average surface roughness was reduced from 23.23 to 0.32 nm. Bending strain distorted the symmetric atomic structure of graphene, and thereby caused a shift of two-dimensional peak by −42.67 cm⁻¹/% in the Raman spectrum and acted such as uniaxial strain. Bending strain on the GFET increased its energy bandgap, and the increased energy bandgap decreased the ‘off’ current and increased the current on/off ratio. Bending strain increased carrier concentration and decreased carrier mobility. Repeated bending strain damaged graphene by increasing defects, and thereby increased its resistivity by ∼25%. The damage could be recovered by thermal annealing at 200°C.

The antimony doped tin oxide (Sb-SnO_2, ATO) nanopowders have been synthesised via a facile co-precipitation method using absolute methanol as a solvent at room temperature and followed by a calcination process. The calcination process of fabricated ATO from precursor is investigated by thermogravimetric analysis (TGA). The crystallite phase and morphological structure of ATO powder are examined by the X-ray diffraction and scanning electron microscopy. ATO material consisting of numerous sphere-like nanoparticles with the diameter of 40–60 nm were further measured by electrochemical workstation, exhibiting the ATO nanostructure is an high-conductivity electrode material with highly reversible features, good specific capacitance and good capacitance retention. The specific capacitance of the ATO electrode material shows 158.2 F g⁻¹ at current density of 1 A g⁻¹, and specific capacitance retention remained 72% when the current density increases up to 10 A g⁻¹, indicating the ATO nanostructures materials can be considered as a promising electrode material for supercapacitors.

The orthorhombic structure of Lanthanum orthoferrite (LaFeO₃) was synthesised by a facile hydrothermal method. The hydrothermal reaction time and potassium hydroxide (KOH) concentration play an important role in the formation of LaFeO₃ microcubes. The obtained samples were characterised by several analysis techniques such as X-ray diffraction, scanning electron microscope, ultraviolet–visible (UV–vis) absorption spectroscopy, and photoluminescence (PL) emission spectroscopy for identifying their structural and optical characteristics. On the basis of experimental results, it can be concluded that the obtained samples have been structurally characterised which confirms the orthorhombic LaFeO₃ structure. Meanwhile, the results depict that highly pure and monodisperse LaFeO₃ microcubes are successfully obtained when synthesised at the alkaline source of 4.5 g KOH and maintained at 240°C for 16 h, which have an average diameter of ∼7 μm. The subsequent plausible formation mechanism of the LaFeO₃ microstructure has been explained on the basis of the Ostwald ripening process. Subsequently, the optical properties of the prepared sample were investigated and optimised, and the UV–vis data showed that the microstructure was a visible light absorbing semiconductor with a narrow bandgap. In addition, PL spectra indicate that the LaFeO₃ microcubes synthesised by this technique can be considered as a photocatalytic material.

Carbon fibre reinforced polyetheretherketone (CF/PEEK) biocomposites were prepared by the method of hot casting under pressure. The influences of CF surface treatment methods on the tensile strength and modulus of CF/PEEK biocomposites were investigated. The results indicated that the CF modified with concentrated nitric acid was beneficial to improve the tensile strength of CF/PEEK composites. On the contrary, the surface of CF treated by KH-560 silane couple agent has a little or unfavourable influence on the tensile mechanical properties of CF/PEEK composite. Furthermore, the CF surface treatment methods and CF content have a synergistic effect on the mechanical properties of the biocomposites. With the CF content rising, the difference of the effect of different treatment methods on the tensile mechanical properties of CF/PEEK composites is more and more significant. Meanwhile, the tensile stress–strain relationship of the composites showed linear variation and the break strain of the CF/PEEK composites decreased with increasing CF content. The fracture mechanism of the biocomposites gradually changed from ductile to brittle fracture with the increase of CF content. The tensile strength of the biocomposites first increased and then decreased with the increasing CF content. However, the tensile modulus increased monotonically with CF content rising.

A ternary complex of Tb(SSA)₃Phen was synthesised based on terbium(III) (Tb³⁺) ion and the ligands including 1,10-phenanthroline (Phen) and 5-sulfosalicylic acid (SSA). Then a series of polylactic acid (PLA)/Tb(SSA)₃Phen composites were prepared by the melt-mixing process. The luminescent properties of PLA/Tb(SSA)₃Phen composite films were investigated by fluorescence spectrophotometry. The spectra of all composites indicated that PLA/Tb(SSA)₃Phen composites shown the characteristic bright green fluorescence which originated from Tb(SSA)₃Phen. Moreover, the energy absorption and transfers of Tb(SSA)₃Phen were slightly affected by the PLA matrix. The optical transmittance of the composites was measured by the UV–vis spectrometer. The results demonstrated that Tb(SSA)₃Phen can ameliorate the PLA film transparence, which well dispersed in the PLA matrix. Moreover, the thermal properties, crystal structure and the mechanical properties of PLA/Tb(SSA)₃Phen composite were also investigated to determine the potential usage as a green fluorescent material.

Hexagonal CdS and Fe-doped CdS nanorods were synthesised by a facile hydrothermal method and characterised by X-ray diffraction, energy dispersive X-ray spectroscopy, UV–vis absorption, photoluminescence, and X-ray photoelectron spectroscopy. The magnetic properties of undoped and Fe-doped CdS nanorods were investigated at room temperature. The experimental results demonstrate that the ferromagnetism of the Fe-doped CdS nanorods differs from that of the undoped CdS nanorods. The remanence magnetisation (M _r) and the coercive field (H _c) of the Fe-doped CdS nanorods were 4.9 × 10⁻³ emu/g and 270.6 Oe, respectively, while photoluminescence properties were not influenced by doping. First-principle calculations show that the ferromagnetism in Fe-doped CdS nanocrystal arose not only from the Fe dopants but also from the Cd vacancies, although the main contribution was due to the Fe dopants.

In this work, a model-based approach is proposed to validate the performance of aluminium nitride (AlN) piezoelectric material based ultrasonic MEMS transceiver for temperature sensing. This validation is performed based on the modelling of ultrasonic MEMS transceiver with AlN as piezoelectric material using COMSOL Multiphysics simulations. The output voltage values for different instances are evaluated by varying the input parameters of ultrasonic MEMS transceiver based temperature sensor. Moreover, the least square support vector machine (LSSVM) based regression model is used to estimate the output voltage from the input parameters ultrasonic MEMS transceiver. The results demonstrate that the LSSVM model successfully predicts the voltage with normalised correlation coefficient values of 0.9962, 0.9963 and 0.9780, respectively, using only transmitter section parameters, only receiver section parameters and, both transmitter and receiver sections parameters.

A novel frequency beam-scanning substrate integrated waveguide cavity-backed wide slot antenna with a wide-scanning angle and bandwidth is investigated. The wide slot etched on the metal substrate is not only the radiating element but also part of the feeding network, which makes the whole structure very compact. The experiment indicates that the design principle is correct. The measured results show that the antenna achieves an enhanced operating bandwidth of about 27% with the gain from 10.12 to 16.25 dBi and the corresponding scanning angle is from 12° to across the band. Good accordance is obtained between the simulated and the measured results.

Nanomaterials are playing more and more important roles in modern industry, while the large-scale fabrication and dispersibility still need to be addressed. This report explores the uniform fabrication and morphology control of ultrafine BaTiO₃ (BT) nanocrystals using a ‘TEG-sol’ method. By varying the reactant concentration, the obtained product sols, Ba/Ti ratios, structure and morphology of the nanocrystals are investigated. The results reveal that under low concentrations (0.4–0.8 mol/L), transparent sols with uniform BT nanocrystals are obtained. Increasing the concentration to higher than 1.0 mol/L, BT precipitates with abnormal large crystals are obtained. Moreover, the Ba/Ti ratio variation further reveals that the surface organics are critical to the control of crystal size and morphology. This investigation is potential to be extended to the synthesis of various perovskite nanocrystals.

An effective passive micromixer based on the principles of asymmetric split and recombine has been designed, developed, and investigated to enhance the mixing performance of the micromixer in a microfluidic system. The effects of geometrical parameters and the number of mixing units on mixing performance were studied at different Reynolds (Re) number (ranging from 1 to 80) via CFD software ANSYS CFX. The results revealed that the preferable number of mixing units is 6, and the optimal direction of reducer is opposite to the main channel flow; the D-shaped mixing channel forces the mixed fluid to produce the extended vortex and Dean vortices simultaneously which caused a strong collision at the confluence of fluids, thus leading to the superposition and enhancement of the vortex system; when Re number is 80 and the width ratio of mixing channel W2/W3 = 1, the mixing efficiency of micromixer can exceed 95%.

This work proposes an electroplating Ag/AgCl method to modify microelectrode arrays for the application of neural prosthesis. The conventional Ag/AgCl electrode is considered as a reference electrode due to its excellent long-term stability. However, the Ag/AgCl modified microelectrode is chosen as a working electrode in this work. The electrode with the surface area of 3.14 × 10⁻⁴ cm² was fabricated individually by electroplating silver. The surface of the electroplated silver was chemically chloridised to form the Ag/AgCl microelectrode. The experimental results show that the fabricated Ag/AgCl microelectrode exhibits higher charge storage capacity than the unmodified microelectrode. The impedance of the Ag/AgCl modified microelectrode at 0.1 Hz is 7447 Ω, which decreases with two orders of magnitude compared to the unmodified one. What is more, the Ag/AgCl modified microelectrode shows clearly enhanced transduction in ionic media and improved stability based on impedance spectroscopy results. Therefore, this functionalised Ag/AgCl can be deployed as a significant electrochemical modification material.

The work shows that a multi-walled carbon nanotube (MWCNT) film can be used as the sensing element of a low-cost sensor for the alcoholic concentration in liquid solutions. For this purpose, they investigate the electrical resistance of the film as a function of the isopropanol concentration in a water solution. The analysis reveals a growing resistance with increasing isopropanol concentration and a fast response. The sensing element is re-usable as the initial resistance value is restored once the solution has evaporated. The electrical resistance increases linearly when the MWCNT film is exposed to common beverages with increasing alcoholic content. This work paves the way for the development of low-cost, miniaturised MWCNT-based sensors for quality monitoring and control of alcoholic beverages and general liquid solutions.

Submicrometre-sized EuPO₄ hollow spheres were synthesised by utilising the colloidal spheres of Eu(OH)CO₃ as the sacrificial template, for the first time. The EuPO₄ hollow spheres were investigated by X-ray diffraction, scanning electron microscopy, transmission electron microscopy, and photoluminescence, respectively. The EuPO₄ hollow spheres exhibit red colour emission from ⁵D₀–⁷F _J (J = 1, 2, 3, 4) transitions of the Eu³⁺ ions. The obtained EuPO₄ hollow spheres may have potential applications in cell biology, drug release, diagnosis, due to the high chemistry stability and luminescence function.

The study investigated the anti-reflective properties of metal-coated nanopillar arrays with high-aspect ratio. Aluminium oxyhydroxide nanopillar arrays were prepared by using aluminium anodic oxidation, hydrothermal synthesis, and platinum sputtering on their surface. The anti-reflective properties were evaluated on four types of nanostructures such as nanolens and nanopillar arrays with aspect ratios of 1:0.5, 1:3, 1:9, and 1:14. The nanopillar arrays with an aspect ratio of 1:14 demonstrated extremely low reflectance <0.18% at 550 nm wavelength of all measured incident angles.

High-k spacer and gate insulator materials have been exhaustively studied nowadays for the enhancement of electrostatic control and reduction of short-channel effects in scaled devices. The work presents a high-performance and charge trap tolerant FinFET module at 10 nm gate length. Dual layer gate insulator (inner low-k and outer high-k) introduces to reduce charge trapping from the channel and outside into the gate oxide. It reduces the gate leakage current by 51.6% compared to conventional FinFET. Further, they demonstrate single charge trapping (SCT) induce effects and proposed optimised high-k spacer width of the SCT tolerant design. SCT analysis is presented in different high-k spacer materials and back-gate voltages. Process variation sources such as line edge roughness and line width roughness are also analysed for the circuit design.

In this work, a mesoporous structure TiO₂/SiO₂ (M-TS) composite with excellent adsorption and photocatalytic properties was fabricated by a sol–gel process combined with calcination. The structure of the samples was characterised by scanning electron microscopy and Brunauer–Emmett–Teller analysis. The factors influencing the adsorption behaviours of methylene blue (MB) onto M-TS, including ingredient, dosage, initial concentration and temperature were investigated. The M-TS was produced by removing poly(vinylpyrrolidone) from the precursor gel was vital to the excellent adsorption capacity. Furthermore, the isotherm and kinetic data were fitted by using Langmuir and Freundlich isotherm models, pseudo-first-order and pseudo-second-order equations, and the intra-particle diffusion model. The Langmuir isotherm model and the pseudo-second-order kinetics were the most suitable models for describing the adsorption of MB onto M-TS. It was also found that the adsorption capacity of cationic dyes on M-TS is better than that of anionic dyes. The experimental results of adsorption and photodegradation proved that improvement of adsorption capacity enhances the decolourisation efficiency. This work shows that the M-TS could be used as an effective adsorbent and photocatalyst to remove cationic dyes from wastewater.

Cu₂O thin film solar cells have attracted the interest of many researchers owing to their non-toxic and earth-abundant properties. High-quality pure-phase Cu₂O thin films were prepared by using a simple low-vacuum thermal annealing technique. The growth temperatures of the Cu₂O thin films were varied from 400 to 1000°C. X-ray diffraction (XRD) and scanning electron microscopy were used to characterise the structural and morphological changes of the thin films. The XRD results suggested that all the films were pure-phase Cu₂O; thus, no second-phase CuO was observed. The detailed evolution of the surface morphology was investigated. The electron dispersion spectrum (EDS) results show that the atomic ratio of Cu and O were changed with the annealing temperature, the ratio change from around 2:1 to 1.84:1 with the turning temperature of 800°C, indicating copper vacancy formed during annealing temperature higher than 800°C. EDS results well matched the d-spacing changes of the XRD results.

Revealing the physical interactions between biomedical devices and human skin requires a scalable phantom with physical properties as close as possible to those of human skin. In this work, the authors developed an artificial phantom for the simulation of human skin. The proposed device comprises a gelatin membrane, a layer of SU-8 photoresist, and microholes, respectively, mimicking the epidermis, stratum corneum, and sweat pores/ducts. A prototype was fabricated using microelectromechanical system and laser ablation techniques. The proposed structure includes microholes with a diameter of 20 µm and a depth of 57 µm distributed at a surface density of 620/cm² to simulate pores and sweat ducts. The mechanical and electrical properties of the fabricated phantom were compared with those of human skin. The electrical properties, such as resistivity and impedance, can be adjusted simply by varying the content of sodium chloride. 3T3 cells cultivated on the artificial phantom demonstrate their biocompatibility. The authors believe that the proposed phantom model and associated manufacturing scheme could be used to facilitate the testing of wearable and attachable bioelectronic devices.

Copper oxides (CuO and Cu₂O), having narrow bandgap and a variety of chemophysical properties, are attractive in many fields such as solar cells, energy conversion, optoelectronic devices, and catalyst. In this work, these copper oxides are synthesised via co-precipitation method and spin coating and annealed in various temperatures. Then, samples are characterised by X-ray powder diffraction, scanning electron microscopy (SEM) and ultraviolet–visible light absorption spectra. From the SEM images of sample annealed at 450°C, the diameter and lengths range of the rod-shaped particles were 30–70 and 200–300 nm, respectively. Finally, to investigate the photocatalytic activity of oxides, methyl orange (MeO) degradation by copper oxides under UV irradiation was studied. Pure CuO with bandgap energy 1.37 eV and specific surface areas 91.3 m²/g had a greater efficiency of MeO degradation value 87.8%.

A novel graphene oxide (GO) nanomaterial, which was rapidly and simply synthesised and conjugated with low-molecular-weight chitosan (CS), was used to develop a simple, sensitive GO biosensor system for glucose detection by fluorescence resonance energy transfer. The GO-CS was used to detect low concentrations of glucose based on competitive binding with maltose-binding protein (MBP). The α-subunit of recombinant phycocyanin (rPC), which emits far-red fluorescence, was used to label MBP (MBP-rPC). The rPC emission was quenched by binding between GO-CS and MBP. However, in the presence of glucose, GO-CS was out-competed for binding to MBP, leading to rPC fluorescence. Glucose was sensitively and selectively detected with this biosensor, with a linear detection range of 0.1–1 mg glucose/ml. The limit of detection for glucose was ∼0.05 mg/ml.