In this work, novel Cu–Co bimetal/reduce graphene oxide nanostructures with excellent catalytic activity were prepared by embedding Cu–Co bimetallic nanospheres into the interlayer of graphene. The composite materials were characterised by X-ray diffraction (XRD), Fourier transform infrared (FTIR), and scanning electron microscopy (SEM) etc. The characterisation results indicated that the diameters of the bimetallic nanospheres were controlled within ∼60 nm, which embedded uniformly in graphene. A series of electrochemical tests were carried out and the composites were found to exhibit excellent oxygen evolution properties under alkaline conditions. The excellent catalytic activity and stability make the composite have great potential for wide application and provide a basis for its industrial application.

In this work, the use of gold nanoparticles (AuNPs), synthesised using Curcuma mangga (CM) extract in photothermal killing of breast cancer (MCF-7) cells is demonstrated. CM-AuNPs showed higher photothermal heating efficiency compared to citrate-AuNPs upon irradiation with a 532 nm laser. In addition, treatment of MCF-7 cells with CM-AuNPs coupled with laser irradiation for 120 s was found to significantly reduce (72%) the cell viability compared to about 13%, obtained with citrate-AuNPs. Results from flow cytometry showed that the CM-AuNP-dependent photothermal-induced MCF-7 cells death was triggered mainly by apoptosis mechanism. All these results suggested the potential use of CM-AuNPs as therapeutic agents in cancer therapy.

In this study, ilmenite [iron titanate (FeTiO₃)] perovskite nanoparticles were synthesised by wet chemical method and sintered at two temperatures, namely 350°C (FT350) and 500°C (FT500). The phase structure, crystallinity, microstructure, particle size, and purity of the sintered samples were extensively studied. Electrochemical measurements such as cyclic voltammetric studies, electrochemical impedance spectroscopy (EIS), and discharge measurements were carried out. The results of the cyclic voltammetric studies showed that sample prepared at 500°C delivers high specific capacitance (42 F g⁻¹), which is significantly greater as compared to that of 350°C sample. Moreover, the results of the EIS study show that 500°C delivers better capacitance than 350°C. The FeTiO₃ samples sintered at 350 and 500°C used as cathodes in a novel Mg/FeTiO₃ cell delivered a discharge capacity of 129 and 90 mA h g⁻¹, respectively. According to the study's data, for the first time it has confirmed that FeTiO₃ is suitable for using it as a cathode material in Mg/FeTiO₃ primary cell. The discharge capacity of 500°C was found to be 70% higher when compared to 350°C. Thus, the proposed results show that the electrochemical behaviour of the sintered sample 500°C is superior to that of 350°C.

Naturally, some living things have non-wettable super-hydrophobic surfaces that depend on surface roughness and surface chemistry. Mimicking such super-hydrophobic surfaces has applications for pain reduction and improving the functionality of needles used in health care. This study prepared a stainless steel needle with a super-hydrophobic surface using ultrasonic etching for microstructure fabrication and surface fluorination. The as-prepared stainless steel needle was super-hydrophobic, as evidenced by a water contact angle of 151.3°. Investigations into the effect of ultrasonic etch time on wettability indicated that microstructures on the surface of the stainless steel needle were important for developing super-hydrophobicity. Resistance properties of the as-prepared stainless steel needle were also governed by surface morphology. Super-hydrophobic stainless steel needles have self-cleaning and low adhesion properties and a drag reduction effect that may reduce pain during a puncture process. Simultaneously, the bionic needle with super-hydrophobic property has more applications in biological antibacterial, and reducing retention of expensive reagents. Furthermore, this method can also be applied to micropipette tips, and inkjet or bio-printer heads, which will make breakthroughs in small droplets manipulation, biometric, and inkjet printing equipment.

In this work, a trans-scale precision positioning stage without guideway based on the inertial stick–slip driving is proposed, which can provide nano-scale resolution ratio and output long-range motion. The stage consists of an encapsulated piezoelectric actuator, a connection block, a base, a pair of ceramic bars, and magnets, and the volume is 25 mm × 17 mm × 13.5 mm. The structure and the principle are introduced in detail. To investigate the locomotion characteristics, a prototype is manufactured, and a series of experiments are carried out. The velocity can reach 13 mm/s when the driving frequency is 2.5 kHz and the resolution is 2 nm. The experimental results confirm that the prototype based on the inertial stick–slip driving is valid through magnets. The good linear relationships exist between the displacement curves and time under various driving voltages and frequencies.

A novel high breakdown voltage AlGaN/GaN high electron mobility transistor with a dipole layer (GaN DL-HEMT) is proposed in this work. The dipole layer (DL) is formed by AlGaN which is attached to the AlGaN barrier and located in the passivation layer between drain and gate electrodes. DL can improve significantly the breakdown voltage (BV) by modulating the distribution of electric field along the channel. The proposed GaN DL-HEMT exhibits a high BV of 1130 V, which increased from 496 V of conventional GaN HEMT with gate–drain distance of 5 μm, while on-state resistance keeps 0.48 Ω.mm and FOM at a high level of 2.67 GW/cm² is obtained. Meanwhile, the cutoff frequency maintains a large value as high as 32.4 GHz, which increases by 74% compared with GaN with a gate field plate. The novel GaN DL-HEMT shows great prospects in microwave power applications.

MoS₂ hierarchical nanoflowers are fabricated through a gelatin-assisted hydrothermal route. The obtained MoS₂ products are characterised by X-ray powder diffraction, scanning electronic microscopy, transmission electronic microscopy and X-ray photoelectron spectra. It is indicated that MoS₂ nanoflowers (MoS₂ NFs) are assembled by nanosheets as building blocks and gelatin plays a crucial role in the formation of these novel structures. Moreover, MoS₂ NF electrode exhibits an enhanced capacitive property because of its unique microstructure.

Zinc tungstate (ZnWO₄) is a self-activating phosphor and exhibits a broad band blue-green emission under ultraviolet excitation. When doped with Eu³⁺ ions, ZnWO₄ may emit white light due to the fact that WO₄ ²⁻ could effectively transfer energy to Eu³⁺ ion. In this work, ZnWO₄:Eu³⁺ phosphors were fabricated by the liquid precipitation method, and then X-ray diffraction, transmission electron microscopy, field emission scanning electron microscopy, and photoluminescence spectra were used to investigate the morphology, structure, and luminescent properties. The emission colour of synthesised ZnWO₄:Eu³⁺ phosphors can be tuned from pink to white with increasing the annealing temperature, which may be attributed to the change of the crystallinity and the crystal defects in ZnWO₄:Eu³⁺phosphors. What is more, ZnWO₄:Eu³⁺phosphors emit an idea white light with the Commission International de L'Eclairage coordinates (0.32, 0.32) after annealing at 900°C.

The quadrangular (QA) bismuth oxychloride nanoflakes (NFs) were synthesised by a simple solvothermal reaction. They were characterised by scanning electron microscope, transmission electron microscope and X-ray diffractometer. As catalysts, the square NFs exhibited excellent catalytic performance in the reduction of 4-nitrophenol (4-NP) and the degradation of rhodamine B (RhB). The complete reduction of 4-NP to 4-aminophenol was obtained in 30 s and the nearly complete degradation of RhB in 20 min.

Differential signalling is widely used in modern integrated circuits to guarantee signal integrity. In this work, differential carbon nanotube (CNT) interconnects are studied, with both voltage- and current-mode signalling schemes considered. An odd-mode half-circuit model of the differential CNT interconnects is developed, with transient response and time delay captured accurately. Finally, based on interval analysis, the effects of parameter variations on the differential CNT interconnects are investigated.

The cardiac contractile force is an important predictor of healthy and cardiovascular diseases. The changes of cardiomyocyte contractile force in response to American ginseng root water extract (AGRWE) detected by atomic force microscope have not been investigated yet. This study examined the effects of AGRWE on single beating cardiomyocytes extracted from a newborn rat. The same cardiomyocytes were incubated with AGRWE at a concentration of 50 μg/ml for about 30 min, and the cardiomyocytes’ contractile force increased from 1.74 ± 1.01 to 3.49 ± 1.53 nN. The mean value of the contractile strain calculated was 3.32 ± 1.55% for the cardiomyocyte before the treatment with AGRWE, while for the cardiomyocyte treated with AGRWE it increased to 4.60 ± 1.35%. The results also showed that the beating rate of the same single beating cardiomyocytes was decreased from 34 ± 11 beats/min (control, n = 10) to 20 ± 9 beats/min. In conclusion, the experimental results have shown clearly that the contractile forces and strain of single beating cardiomyocytes treated with AGRWE are significantly higher than the control group, while the heart rate was decreased. It suggests that ginseng agents are promising candidates in improving cardiac functions for treating heart failure.

An efficient modulation can be obtained by graphene due to its outstanding light-matter interaction, and many kinds of modulators based on graphene have been studied during the last couple of years. However, there still exist unsolved issues in graphene-based modulators, such as how to make a balance between modulation depth and modulation bandwidth. This work proposes a reflective modulator with relatively high-modulation depth and wide working bandwidth. The proposed modulator has a simple five-layered structure of graphene–silica–graphene–silicon-metal. They use an effective method of finite element method to simulate the performance of this modulator, and obtain a modulation depth of 96% with a low bias voltage of ∼4 V. Furthermore, they calculate the modulation speed by the equivalent circuit method, and obtain the maximum modulation speed of about 25 kHz and a wide broadband of 72 kHz from theoretical analysis. Therefore, this high-performance modulator provides an effective method for terahertz communication devices.

Development of stimuli-responsive nanocomposites for the delivery anticancer drug has attracted considerable attention. A magnetic/pH dual-responsive nanocomposite was synthesised by amide condensation reaction and developed for cancer therapy. The PEGylated citric-coated Fe₃O₄ (PCI)–graphene oxide (GO) nanocomposites was constructed by a three-step process. Fe₃O₄ magnetic nanoparticles were firstly coated with citric acid, and then covalently linked to aminated polyethylene glycol (NH₂–PEG–NH₂); lastly, the PCI was covalently conjugated to graphite oxide to obtain PCI–GO nanocomposites. The PCI–GO nanocomposites were characterised by X-ray diffraction, scanning electron microscopy, Fourier transform-infrared, ultraviolet–visible, and thermogravimetry. The magnetic of nanocomposites was confirmed by a vibrating sample magnetometer. Due to the hydrogen bond, π–π stacking and electrostatic interaction between the doxorubicin (DOX) hydrochloride and PCI–GO nanocomposites, the PCI–GO nanocomposites could load DOX effectively and with a high drug loading content (about 87.6%). The DOX-loaded PCI–GO (DOX/PCI–GO) nanocomposites exhibited pH-responsive release behaviour. The DOX/PCI–GO nanocomposites could effectively inhibit tumour growth in vitro, which was comparable to the antitumour effect of free DOX. The result indicates that the PCI–GO nanocomposites exhibit great potential for a magnetic targeted drug delivery system in multimodal and synergistic cancer therapy.

Micro-/nanoscale patterns are popular in many applications, and several techniques to transfer multiscale patterns have been developed. Ultraviolet nanoimprint lithography (UV-NIL) is the most promising method to quickly produce complex structures, and there is a need to understand the resist-flowing and cavity-filling processes because partial cavity filling may cause defects. One crucial element of a stamp is the layout of the multiscale cavities. They can induce some difficulties during the filling process. Five different stamps with various micro-/nanoscale features (one nano feature, one micro feature, one nano feature, and one micro feature, two nano features and one micro feature) were employed in this simulation study. The imprint results show that the neighbouring effect has major issues in the microscale cavity filling and minor issues in the nanoscale. The layout of complex cavities results in poor filling proportions, and longer imprint times and a symmetrical layout were needed to improve the imprint quality. The contact pressure between the stamp and the resist generally declined when the location approached the centre from both sides of the stamp. The overall physical performance of neighbouring micro-/nanoscale cavities was obtained, and this is essential for further understanding and improvements in the UV-NIL process.

Silver nanoparticles are excellent antibacterial materials with wide application. However, it is extremely unstable associated with easy aggregation and colour changes. Although a great number of carriers have been developed for stable silver nanoparticles, it is never ending to broaden silver carrier to meet varying applications. Herein, delaminated hectorite was developed as an alternative silver carrier. The structure of silver-loaded delaminated hectorite was confirmed by X-ray diffraction, X-ray photoelectron spectroscopy and scanning electron microscopy/energy-dispersive X-ray studies. Silver (8.69 wt%) was loaded onto the hectorite nanoparticles by cationic ionic change and surface coating. The silver-loaded hectorite showed fast bacterial killing ability (kill more than 94% Escherichia coli and 83% Staphylococcus aureus at 50 ppm within 1 h) by destroying bacterial cell wall.

Instead of a conventional wireless transceiver system that requires batteries and complex circuits, the surface acoustic wave (SAW) sensor enables wireless passive measurement. A sensor consisting of an SAW device and external impedance sensing element is analysed. Since the reflection coefficient of the reflective grating on the SAW device depends on the load impedance, the echo characteristics are influenced by the change in the impedance of external sensing element. A resistance sensor or a capacitive sensor is selected as the external sensing element. The two different types of sensors are simulated using coupling-of-mode (COM) modelling, and the relationships between amplitude and phase with load impedance are analysed. On the basis of COM theory, a wireless impedance-loaded SAW sensor is fabricated by the lift-off process and tested by a network analyser to verify the simulation results. It is observed that the test results agree well with the simulation results. The phase change is more sensitive than the amplitude based on the results obtained. The sensitivity is 0.274°/Ω for the sensor with resistance and the sensitivity of the sensor with capacitance is 1.096°/pF. These results can guide the design of the high sensitivity impedance-loaded SAW sensors in the future.

In this paper, the effect of environmental humidity on the mechanical removal of potassium dihydrogen phosphate (KDP) crystal was preliminarily investigated using an environment control atomic force microscope at the nanoscale. The results reveal that the pre-wear storage time in humid environments has nearly no impact on the removal of KDP crystal with ∼50 nm wear depth whereas the post-wear storage time imposes remarkable influence. Moreover, the material removal volume gradually increases from 29 × 10⁵ to 127 × 10⁵ nm³ when the relative humidity (RH) increases from 0 to 60%. Such significant increment is mainly attributed to the synergism of mechanical force and deliquescence. More specifically, mechanical force-enhanced deliquescence is achieved by the acceleration of the deliquescence rate in the plastic deformation zone probably due to the high concentrations of catalytically active sites for water molecules adsorption; deliquescence-enhanced mechanical force is achieved by the formation of a thin deliquescence layer with much reduced mechanical strength and the resultant promotion of the material removal. With the increase of RH, more water molecules will be adsorbed on the KDP crystal surface, leading to the continuous mutual promotion between mechanical force and deliquescence, and thereby the material removal volume greatly increases in a high RH environment.

In this work, the novel method of generating fluorocarbon quantum dots (FQDs) in aqueous solution is demonstrated. The FQDs were synthesised by milk at high temperature and high-pressure hydrothermal method, which were the only raw material. They synthesised high fluorescence, green FQDs. The Fe³⁺ was added to FQDs, the fluorescence signal was quenched effectively. The fluorescence of FQDs showed a good linear relationship with the change of Fe³⁺ concentration (50–700 μmol/l), and FQDs selected Fe³⁺ to complete detection. Finally, the authors applied the prepared FQDs to the real samples to detect the Fe³⁺ in the water. The iron ions belong to the Yellow River water, which is detected about 90.6–107%, and it is indicated that this method can be applied to detect iron ions in actual water samples. They successfully used milk to synthesis the FQDs, and it had high selectivity for Fe³⁺. So the authors’ think the FQDs has great potential in the field.

The vibration propagated in polymer components is related to the interfacial fusion in ultrasonic bonding process, which can be employed to be reference variables to control the ultrasonic energy. In this paper, an ultrasonic precise bonding method controlled by characteristic waveform from the wavelet decomposition of the ultrasonic propagation is proposed. The vibration propagated from ultrasonic horn, through polymer components, to the anvil finally is analysed by wavelet packet decomposition. The node signal in the frequency band of 109,375–125,000 Hz, which contains more information related to the interfacial fusion behaviour, is reconstructed as the characteristic waveform. The ultrasonic bonding control procedure is designed by the recognition of two characteristic points on the characteristic waveform. Results indicate that, at the second characteristic point, high-quality interfacial fusion bonding is achieved without overflow out of the edge.

The demand to fabricate membranes much cheaper than usual expensive methods creates an opportunity to find low-cost and more available modifying agents for synthesising an appropriate membrane for membrane distillation (MD) process. In this work, reactive ethylene terpolymer was applied to modify a commercial polyvinylidene fluoride (PVDF) membrane for using in the desalination process. Elvaloy4170 with a hydrophobic structure containing three different functional groups was coated (different contents of 0.5, 1, 1.5 and 2 wt%) on the top surface of the microporous commercial PVDF membrane and the resultant membranes were analysed under air-gap MD process. The fabricated membrane structures were determined by scanning electron microscopy and atomic force microscopy to investigate their elemental and topographical properties. After experiments, the membrane with 1.5 wt% of Elvaloy4170 showed water vapour flux of 1.93 kg/m²h and salt rejection of >99.7 which confirmed its suitability to be used in the desalination process. Moreover, to assess the anti-fouling properties of the membranes, real seawater was used as feed solution, and as a result the membrane with 1.5 wt% of Elvaloy4170 presented flux recovery of 87% indicating its enhanced anti-fouling properties compared with the commercial PVDF membrane (flux recovery of 71%).

The mesoporous Cu(II)-1,4-benzenedicarboxylate (CuBDC) microplate was synthesised by using a mineral, atacamite [Cu₂(OH)₃Cl] microbricks as a precursor under room condition based on the acid–base reaction. The CuBDC microplates transformed from Cu₂(OH)₃Cl microbricks displayed a higher ability for the adsorption of methylene blue in comparison with Cu₂(OH)₃Cl microbricks and the CuBDC synthesised in solution.

An enhancement of heat capacity (C _v) of nanoconfined liquid is reported using equilibrium molecular dynamics simulations using Lennard–Jones type solid–liquid molecular model. Liquid molecules are confined in between two solid surfaces with separation distance varying from 0.6 to 17.55 nm and temperature 100 K to 140 K. The obtained heat capacity of the bulk liquid is in excellent agreement with the published literature. However, in case of nanoconfined liquid, for a particular temperature and gap thickness band, a significant enhancement of heat capacity results in. For 100 K temperature and a gap thickness of 4 nm, the obtained molar heat capacity of the nanoconfined liquid is 46.45 J/mol K, i.e. the heat capacity is enhanced by 133% compared to its bulk counterpart (19.95 J/mol K). However, this broad maximum value of heat capacity shifts to a lower value at a higher temperature. At 120 and 140 K, the maximum heat capacity becomes 29.56 and 26.97 J/mol.K and the enhancement becomes 51% and 40%, respectively. The enhancement of heat capacity is attributed to the variation in density distribution, ballistic transport of thermal phonons, reduced molecular motion and a larger contribution of interfacial thermal resistance.

In this work, the performance of the nano bow-tie arrays for biosensing applications has been investigated. Since the geometrical parameters of the device such as the bow-tie length and gap size have major effects on the system's optical response, a parametric study based on finite-difference time-domain (FDTD) method has been conducted. In order to enhance the sensitivity, two bow-tie shaped nanoparticles in the form of 2 × 1 and 2 × 2 arrays have been developed. In the case of TM polarisation, a sensitivity up to 923 nm/RIU with a figure of merit (FOM) of 5.5 has been obtained for 2 × 2 nano bow-tie array. Moreover, the performance of the proposed nanoparticles for TE polarisation has been evaluated and a FOM exceeding 15.9 has been achieved for single nano bow-tie. According to this study, the proposed nano bow-tie structures have a great potential for sensing and detection applications.

Zeolite P with the pseudo-spherical form was successfully synthesised from low-grade fly ash via alkali-dissolving hydrothermal synthesis method. These samples were characterised by X-ray diffraction, scanning electron microscope, X-ray fluorescence, Fourier-transform infrared spectroscopy, thermogravimetry-differential scanning calorimeter (TG-DSC) and Brunauer–Emmett–Teller. The textural properties of zeolite P were further studied by N₂ adsorption–desorption technique. In addition, the TG-DSC study confirmed that the bound water content of zeolite P is 19.7% and the phase transition temperature of zeolite P is 400°C. Moreover, this thermal stability study approach not only extends the application of zeolite P but can be further extended to other zeolite materials as well.

This work has developed a facile strategy to create magnetically separable, core-shell structured composites consisting of a magnetic Ag nanowires (NWs)/Fe₃O₄ cores and an outer mesoporous TiO₂ (mTiO₂) shell using a sol–gel process and subsequent hydrothermal treatment. Benefiting from the mesoporous anatase TiO₂ as well as the unique structures of the composite, the resulting Ag NWs/Fe₃O₄@mTiO₂ composite was employed as a catalyst for removal of the organic contaminants through a colorimetric photocatalytic degradation assay using methylene blue (MB) as a model contaminant. Moreover, the photocatalysts can be easily separated and recycled with an external magnetic field and possess prominent recoverability.

Green nanomaterial production techniques are desired for medicinal applications because of their biocompatibility and lack of toxic by-products. This work reports the biological synthesis of silver nanoparticles (AgNPs) from silver nitrate solutions using the cell-free extract of Polysiphonia alga as a reducing agent. The visible yellow-brown colour formation and surface plasmon resonance at 420 nm by ultraviolet–visible spectroscopy indicates the reduction of silver nitrate and biosynthesis of AgNPs. For more characterisation of green synthesised AgNPs, Fourier-transform infrared (FTIR) spectroscopy analysis is used and the results confirmed the presence of functional groups capping in the AgNPs. The scanning electron microscopy and transmission electron microscopy images showed mostly spherical AgNPs with a size range between 5 and 25 nm and the concentration of 3.1 × 10⁶ particles/ml. The results of energy-dispersive X-ray analysis confirmedthe presence of Ag in the synthesised nanoparticles. The MTT assay and flow cytometry are used to determine the toxicity of AgNPs against breast cancer MCF-7 cell line and the results showed the best inhibitory activity at 100 µg/ml. Generally, green synthesis of anticancer AgNPs using filamentous red alga Polysiphonia extract can easily be scaled up for many biomedical applications such as defence against the cancerous cells.

The organic-intercalated clay composites have aroused attractable interest due to their tremendous application in industry. As a new type of the layered-structure material, halloysite nanotubes (HNTs) were employed to explore the intercalation relationship between the interlayer property and intercalating agents, which were more significant for the potential application. For this purpose, this work systematically studied the intercalation behaviours of dimethyl sulphoxide, potassium acetate, N-methylformamide, methanol, and acrylamide in the layered-structure HNTs, respectively. The organics-intercalated HNT composites were determined by a series of characterisations.