In recent years, titanium dioxide (TiO₂) has been commonly applied in the production of photoactive concrete materials capable of degrading a wide range of air contaminant such as nitric oxide (NO), VOC etc. It was confirmed that the photocatalytic activity of TiO₂ can be further enhanced by modifying the photocatalyst with non-metals such as nitrogen (N) or carbon (C). In view of this finding, several concrete/TiO₂ composites consisting of commercial concrete and raw anatase TiO₂ (supplied by Grupa Azoty Zakłady Chemiczne ‘POLICE’ S.A., Poland), previously modified with ammonia [N source] and/or 2-propanol [C source] have been manufactured. For reference, the additional concrete samples were prepared, containing unmodified TiO₂ and commercial titania P25 (Evonik). The NO degradation properties of prepared photoactive concrete materials were evaluated using laboratory test set-up. The measurements were conducted under constant temperature and humidity conditions, using ultraviolet light irradiation. Significant NO removal was recorded for the TiO₂/concrete composites containing N and/or C co-modified titania. The results were related to the improved photocatalytic activity of modified photocatalysts and probable, partial NO reduction to N₂, via the selective catalytic reduction process catalysed by TiO₂.

Micromixers are microfluidic components of critical importance in complex lab-on-chip devices. Passive devices in particular have attracted much attention over active ones due to their fabrication and operation simplicity. Staggered herringbone micromixers seem to be dominating the area of passive micromixers, and hence a lot of studies have been published on their optimisation, in terms of mixing efficiency (ME) and pressure drop. However, numerical simulations leveraging concentration-based models have not been convincingly accurate, owing to computational limitations and erroneous assumptions on diffusion coefficients that often are higher than those of large biomolecules in aqueous solutions. Accurate concentration-based models are a prerequisite in biochemical reaction studies. This work quantitatively shows how increasing mesh density increases solution accuracy, applying concentration-based modelling for biochemically realistic diffusivity. A numerical simulation methodology for obtaining less numerically diffusive results without further increasing mesh size is also given, leveraging quadratic discretisation and appropriate consistency stabilisation methods. They demonstrate that with the proposed approach, it is possible to obtain more accurate ME and pressure drop estimations for two different staggered herringbone micromixer variations, while at the same time limiting the usage of computational resources to a practical level.

This study reports the surface properties that a microelectromechanical system (MEMS)-based mechanical tacitle display can present. The display is composed of 3 by 3 large displacement MEMS actuators that comprise hydraulic displacement amplification mechanism and piezoelectric actuators. The control parameters of the display include the displacement, or driving voltage, vibration frequency, and spatial and temporal actuation patterns of the actuators. Roughness and hardness using the newly proposed sample comparison method have been investigated previously. In this study, methods investigating warmness, or thermal conductivity, wettability, or surface energy, and friction were considered. Correlation between the control parameters and the surface properties indicated that the mechanical tactile display is best at controlling the roughness of the surface.

Magnetic nanoparticles display a range of unique properties of interest to fields such as water treatment, drug delivery, catalysis, and many more. Widespread use of magnetic nanoparticles relies heavily on one's ability to separate them effectively from other media, for example in water treatment. In this work, an efficient method to separate magnetic nanoparticles from organic solvent using magnetic ionic liquids is demonstrated for the first time. Fourier transform infrared spectroscopy, ultraviolet–visible spectroscopy, and microscopy were employed to investigate the authors’ model system. This work will greatly impact future directions in the science of separating nanoparticles and applications of ionic liquids.

To describe and analyse mechanical structures due to external loads, equation of motion must be supplemented with appropriate boundary conditions. When nanomechanical structures (especially layered systems) are considered, satisfying the boundaries is more challenging. It may be essential to develop a specific methodology for any system in such scale and configuration. This work introduces a general approach for boundary conditions of monolayer graphene sheets as the most important part of future sensors and resonators in nanoelectromechanical systems. Comparing with the experiments, it has been demonstrated that the graphene sheets on the adhesive surfaces should be assumed as a hinged edge condition and not as a clamped one. As a result, inaccuracy of the commonly used rigid base as a clamped condition is proven due to comparison with a reported experiment. It is suggested that a flexible substrate can be replaced to have better accordance. A flexible silicon base with equilibrium distance equal to s = 2.5 Å and depth of potential well equal to ε = 0.02 eV is obtained as the best substrate for a square graphene sheet under doubly clamped edge conditions.

High-uniformity polyimide liner was successfully achieved in through silicon vias with aspect ratio and density as high as 15:1 and 2.8 × 10⁵ /cm², respectively. The liner is deposited by vacuum-assisted spin-coating approach, which used vacuum treatment to fully fill the via followed by spin coating to achieve uniform liner. The uniformity along the sidewall of via is evaluated with cross-sectional scanning electron microscopy images, and the results show that the thickness along sidewall from top to bottom has an average value of 530 nm and the achieved step coverage is above 33%. This liner deposition approach is completely compatible with complementary metal-oxide- semiconductor (CMOS) processes, and exhibits excellent uniformity, demonstrating the potential of the proposed technique in future advanced three-dimensional integration applications.

Synthesis of silver nanoparticles (NPs) has been performed using partially hydrolysed star-shaped graft copolymer of polyacrylamide to dextran as auxiliary capping agent. The star-branched copolymer proved to be a very good template for NP synthesis due to high local concentration of functional groups. Good biocompatibility of the copolymer was confirmed by phagocytic index value equal to 84%. In addition to this, the green synthesis approach was ensured using glucose as non-toxic reducing agent. Surface plasmon resonance spectra of the obtained NPs contained two characteristic bands situated at 270–300 and 420–450 nm. Transmission electron microscopy revealed that NPs synthesised in neutral solution (pH = 7) have average diameters equal 10–60 nm with a small portion of NP aggregates. Synthesis carried out at pH = 12 resulted in increased yield of NPs probably due to increased reducing power of glucose in alkaline medium. NPs synthesised in alkaline solution were sized from 20 to 300 nm and contained a large portion of NP aggregates.

A new type of drug carrier with thermo-sensitivity is reported. The system consisted of poly(N-isopropylacrylamide) (PNIPAAm) and polyurethane (PU) and two kinds of polymer were spun into core–sheath nanofibres without bead defects by coaxial electrospinning technique. Poor soluble nifedipine was used as a model drug to evaluate the release behaviour of drug from nanofibre carriers. Results showed that the diameter and diameter distribution of nanofibres varied with the ratios of the outer flow rate to the inner flow rate. PNIPAAm/PU core–sheath electrospun nanofibres maintained the thermo-sensitivity of PNIPAAm and the wettability of the electrospun nanofibres could be adjusted effectively by the change of the temperature. In-vitro release of nifedipine from nanofibre carriers showed that core–sheath electrospun nanofibres as the drug carrier could slow down the release rate of nifedipine compared with that of PNIPAAm/PU composite electrospun nanofibres, and then could effectively achieve the controlled release of nifedipine, avoiding the concentrated release of drug and reduce the toxicity.

A novel Pb-electrodeposited porous graphite (PG)/Pb conductive net skeleton was prepared by electroplating. The PG/Pb was also used as a negative electrode to study its electrochemical performance. The morphologies of skeleton and negative electrode were characterised by scanning electron microscopy and energy-dispersive spectrometry. Results showed that the skeleton and electrode had a three-dimensional porous structure and that the lead-based active material evenly covered the surface, which can improve electrochemical performance. Cyclic voltammetry and charge–discharge tests were then performed to study electrochemical performance. Results showed markedly restrained hydrogen evolution and a wide working-potential range (−1.05 to −1.3 V versus Hg/Hg₂SO₄). The PG, which had a high specific surface area and increased capacitance, acted as a buffer and enforced the charge and discharge acceptance, thereby enabling the electrode to discharge 271, 103 and 48 s at current densities of 3.4, 8.6 and 17.2 A/g, respectively. After 50 cycles, specific capacity almost did not decrease, which effectively restrained the irreversible sulphation and improved battery capacity and lifespan. The prepared electrode had excellent electrochemical performance and can be used as a novel negative electrode in lead-acid batteries.

In this work, a way to achieve effective directional transport of water on superhydrophobic surface is presented. An aluminium (Al) superhydrophobic surface was prepared by chemical etching method. After being treated by cold nitrogen plasma jet, a superhydrophilic track pattern corresponding to the mask was then fabricated. The vein-like structure of the liquid transport platform was composed of a trunk and several branches, both having wedge angles. Driven by surface tension, water droplets at any location of the dripping area can be transported against gravity. This method is reusable and could be widely used in the directional transportation and water recycling.

The role of capping ligand concentration on the microstructural characteristics of strontium titanate (SrTiO₃ or STO) nanoparticles has been investigated. Capping the surface of primary particles with ligand having long alkyl chain protects the increase in nanoparticle size by hindering the agglomeration. Therefore, in the present work the role of ligands namely cetyltrimethyl ammonium bromide (CTAB) and polyvinylpyrrolidone (PVP) on the structure and surface morphology of STO have been studied by varying their concentrations from 0.01 to 0.08 M and 0.001 to 0.008 M respectively. The structure of STO was determined using the X-ray diffraction (XRD) and transmission electron microscopy (TEM) techniques. The surface morphologies of the different STO samples were viewed through the field emission scanning electron microscopy (FESEM). A cubic crystalline phase formation of STO has been observed as revealed from the XRD and TEM images. The typical crystallite size, strain and dislocation density determined for PVP capped STO are 29 nm, 2.08 × 10⁻⁰³ and 1.194 × 10¹⁵ m⁻², respectively. FESEM images manifested a decrease in the grain size as a result of increase in the concentration of CTAB to 0.05 M and PVP to 0.005 M. Nearly spherical grains with some sort of fusing have been observed at lower and higher concentrations of the CTAB and PVP in both the cases.

Three-dimensional (3D) urchin-like zinc oxide (ZnO)/titanium dioxide (TiO₂) composite micronanostructures were first successfully synthesised using a facile electrochemical deposition method by depositing TiO₂ into the surface of as-prepared 3D urchin-like ZnO, and polydienes dimethylammonium chloride as polycation solution. Photoelectric properties of the single 3D urchin-like ZnO and the composite micronanostructures as dye-sensitised solar cell (DSSC) anodes were investigated. During the deposition reaction, the TiO₂ was exactly densely anchored onto the surface of 3D urchin-like ZnO with uniform size, which were characterised by scanning electron microscopy, X-ray diffraction, and energy dispersive X-ray spectroscopy. The effects of different molar ratios of TiO₂ and ZnO for the composite structure's morphology and photocatalytic activity were investigated systematically. The results indicated that the composite micronanostructures exhibited a larger adsorption range (−450 nm) and higher photoelectric conversion efficiency due to the synergistic effects, planar heterojunction, and mesoporous structure. When used as photoanodes for DSSCs, the I–V curve showed the photoelectric conversion efficiency of the novel composite was increased by 17.7% of that compared with the single 3D urchin-like ZnO. These features collectively demonstrated the composite has a considerable potential for various applications in photocatalysis materials.