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Aluminium-doped zinc oxide thin films exhibit interesting optoelectronic properties, which make them suitable for fabrication of photovoltaic cell, flat panel display electrode, etc. It has been shown that aluminium dopant concentration and annealing treatment in reduced atmosphere are the major factors affecting the electrical and optical properties of aluminium doped zinc oxide (AZO) film. Here, the authors report the structural, optical and electrical properties of aluminium-doped zinc oxide thin films fabricated by dip coating technique and annealed in air atmosphere, thereby avoiding hazardous environments such as hydrogen. The aim of this paper was to systematically investigate the effect of annealing temperature on the electrical properties of dip-coated film.

Aluminium-doped ZnO thin films were prepared on corning substrates by dip coating method. Aluminium concentration in the film varied from 0.8 to 1.4 mol per cent. Films have been characterized by X-ray diffraction, scanning electron microscopy, atomic force microscopy, UV-visible spectroscopy and Hall measurements. The deposited films were heat treated at 450-600°C, in steps of 50°C for 1 h in air to study the improvement in electrical properties. Films were also prepared by annealing at 600°C in air for durations of 1, 2, 4 and 6 h. Envelope method was used to calculate the variation of the refractive index and extinction coefficient with wavelength.

The electrical resistivity is found to decrease considerably when the annealing time is increased from 1 to 4 h. The films exhibited high transmittance (>90 per cent) in the visible range, and the optical band gaps were found to change as per the Moss–Burstien effect, and this was consistent with the observed changes in the carrier concentration.

The study shows the effect of annealing in air, avoiding hazardous reduced environment, such as hydrogen, to study the improvement in electrical and optical properties of aluminum-doped zinc oxide films. Envelope method was used to calculate the variation of optical constants with wavelength.

This paper aims to prepare good waterborne light-diffusion dip-coatings (WLDDC) for the glass lampshade inner walls of LED lamp tubes, the effects of viscosities and viscous flow activation energies on these dip-coatings were investigated.

The WLDDC were prepared using white pigments, light-diffusion agents, additives and an acrylic emulsion. The dip-coatings were characterized by Fourier transform infrared spectroscopy, scanning electron microscopy and a digital rotational viscometer, respectively. The effects of shear rates, temperatures and solids contents on the viscosities of the dip-coatings were studied. The viscous flow activation energies of these dip-coatings and the emulsion were calculated, compared and studied, respectively.

The results showed that the non-Newtonian behaviors of these dip-coatings were more prominent than that of the acrylic emulsion. When the temperature was maintained to be a constant and the shear rate was increased, the viscosity decreased and the shear stress increased. When the shear rate was maintained to be a constant, the viscosity decreased with increasing temperatures. The viscous flow activation energies of these dip-coatings decreased with the increasing shear rates. The higher solid contents of WLDDC were, the more its viscosity would decrease with the increasing shear rates, the more prominent its non-Newtonian behaviors would show.

A sample of good WLDDC with balanced properties was illustrated.

This investigation benefits to investigate waterborne environment-friendly dip-coatings for the inner glass walls of lamp tubes. This research provides an approach to optimize the viscosity parameters of light-diffusion dip-coatings.

Wearable electronic devices have emerged which require compact, flexible power storage devices such as batteries and supercapacitors. Recently, energy storage devices have been developed based on supercapacitor threads. However, current supercapacitor energy storage threads which use electrolytes based on aqueous gels have a 1 V potential window. This is much lower than the voltage required by most electronic devices. This current contribution presents an approach for fabricating a multilayer supercapacitor working as a circuit unit, in which series combinations of the multiple layer structures can achieve a higher potential window, which can better meet the needs of wearable electronic devices.

Two-capacitive layer thread supercapacitors were fabricated using a semi-automatic dip coating method by coating two capacitive layers sequentially on a 50 μm stainless steel core wire, each capacitive layer includes ink, aqueous-based gel electrolyte and silver conductive paint layers.

Two capacitive layers of the single thread supercapacitor can work independently, or as combination circuits – parallel and series. Cyclic voltammograms showed that all flexible circuits have high electrochemical stability. For the case of series circuit configuration, with H₃PO-polyvinyl alcohol (PVA) gel electrolyte, a working potential window of 2 V was achieved.

A flexible single thread supercapacitor of multilayer structure, with working voltage above 1 V in H₃PO₄-PVA gel electrolyte, has not been reported before. A semi-automatic dip coating setup used to process the thread supercapacitor has high potential for transfer to an industrial environment for mass production.

Ti6Al4V is a commonly used titanium alloy with several applications in aerospace industry due to its excellent strength to weight ratio. But due to low thermal conductivity, it is categorized as “difficult to machine.” Though machinability can be improved with cutting fluids, it is not preferred due to associated problems. This study aims at eliminating the use of cutting fluid and finding an alternate solution to dry machining of Ti6Al4V. AlTiN coated tools provide good heat and oxidation resistance but have low lubricity. In the present work, graphene, which is known for lubricating properties, is added to the tools using five different methods (tool condition) to form graphene self-lubricated cutting tools.

Graphene-based self-lubricating tools are prepared by using five methods: dip coating (10 dips and 30 dips); drop casting; and filling of micro/macroholes. Performance of these tools is evaluated in terms of cutting forces, surface roughness and tool wear by machining Ti6Al4V and comparing with conventional coated cutting tool.

Self-lubricating tool with micro holes filled with graphene outperformed other tools and showed maximum decrease of 33.42% in resultant cutting forces, 35% in surface roughness (Ra) and 30% in flank wear compared to conventional cutting tool.

Analysis of variance for all forces show that tool condition and machining time have significant influence on all components of cutting forces and resultant cutting forces.

The purpose of this paper is to implement coating system by varying the amount of nano-sized titanium dioxide, (nano-TiO₂) combined with various organic binders and to study the coating effects on the performance of solar cell in terms of temperature and efficiency.

Nano-TiO₂ coatings are developed in two types of binder networks; the combination of methyltrimethoxy silane (MTMS) and nitric acid and the combination of 3-aminopropyl triethoxysilane (APTES) and MTMS. Overall, the formulations method was cost-effective, produces good transparency, clear and managed to dry at room temperature. The coating mixtures were applied onto the glass substrate by using the dip-coating method and the coated substrate were sent for several characterizations.

This study demonstrated that TiO₂ nanoparticle coating in APTES/MTMS matrix showed a thermal-decreasing result on solar cells, where the cell temperature is reduced to 46.81°C (T₂ coating type) from 55.74°C (without coating) after 1-h exposure under 1,000 W/m² irradiance in a solar simulator. Contrary to prior works where solar cell coatings were reported to reduce the cell temperature at the expense of the cell efficiency, the results from this study reported an improved fill factor (FF) of solar cells. From the photovoltaic (PV) characteristics study, the FF for solar cells is increased by approximately 0.2, i.e. 33.3 per cent, for all coatings compared to the non-coated cell.

Findings will be able to contribute in the development of temperature-reducing and efficiency-enhancing coating for PV panels.

A simple dip-coating method provides an even distribution of TiO₂ nanoparticle coating on the glass panel, which is cost-effective and time-efficient to reduce the temperature of solar cell while maintaining its efficiency.

The ability of nano-TiO₂ coatings with a simple fabrication method and the right solution to reduce the surface temperature of solar cells while improving the FF of the cells.

The main aim of this study was to examine the effects of chicken eggshell (CES) and rice husk ash (RHA) as fillers on the mechanical and the thermal insulation properties of polyurethane coatings.

CES and RHA were ground via ball milling set at different parameters, and the smallest particles size obtained were selected and used as fillers. Fillers of different weight proportions were mixed with other components such as binder, solvent and pigment to form various coating formulations and test samples were made via dip coating. A series of characterisations were conducted to analyse the thermal and mechanical properties of the coating.

The smallest particle size of CES and RHA was obtained after both of them had undergone grinding process at 400 rpm within 180 min. Morphological studies revealed that CES and RHA have irregular shape and high porosity. In crystallographic analysis, CES mainly composed of pure calcite crystal structure and RHA contained amorphous silica. Both of fillers were found thermally stable up to 520 and 710°C for RHA and CES, respectively. In RHA individual system, as the RHA proportion increases, the thermal conductivity of the coating declined. In contrast, in the CES coating system, the thermal conductivity demonstrated an opposite trend. Thermal gravimetric analysis results displayed that by adding hybrid fillers, the residue weight and the thermal stability of the coatings were increased. In addition, the adhesion strength of the coating was increased as the filler weight content increased.

Fillers with nano-range size were expected to be produced in this research for better performance of the coating. However, the obtained fillers were limited to micron size through dry grinding method. Another drawback in this research was the coating technique which is dip coating. The coated substrates do not have uniform coating thickness and this subsequently influenced the performance.

A novel attempt has been made to study the formulation coating system by mixing CES and RHA as fillers which is also known as a hybrid system.

The corrosion performance of ceramic films of SiO₂‐Al₂O₃ prepared by the sol‐gel processing of organometallic compounds and deposited by dip‐coating technique on 1008 steel foils has been evaluated. Two kinds of procedures were developed to produce the sol‐gel coatings. The influence of the coatings on the chemical corrosion of the substrate has been measured by using potentiodynamical polarization curves in 0.5 M H₂SO₄ and 1 M HCl solutions at room temperature. Sol‐B showed the best behaviour in protective corrosion, in addition to the fact that the number of applications does not influence the resistant corrosion. Protection of coatings was limited by the growing of film cracking due to residual stress between coating and substrate. The results were supplemented by SEM analysis.

A widespread focus on the plant-based antimicrobial cotton fabric finishes has been accomplished with notable importance in recent times. The antimicrobials prevent microbial dwelling in fabrics, which causes severe infections to the fabric users. Chemical disinfectants were conventionally used in fabrics to address this challenge; however, they were found to be toxic to humans. Thus, the present study aims to deal with the utilization of phytochemical extracts from different parts of Pongamia pinnata as antimicrobial coatings in cotton fabrics.

The root, bark and stem were collected and washed several times using tap water. Then, the leaves were dried at room temperature and the root and bark were dried using an oven at 40ºC. After drying, they were ground into fine powder and extracted with ethanol using the Soxhlet apparatus. After that the extract was coated on the fabric tested for antimicrobial studies.

The results reported that the leaf extract of P. pinnata-coated fabric exhibited enhanced antibacterial property towards gram-negative Escherichia coli bacteria, followed by root, bark and stem. The wash durability test in the extract-coated fabric samples revealed that dip-coating retained antibacterial activity until five washes. Thus, the current study clearly suggests that the leaf extract from P. pinnata is highly useful to develop antibacterial cotton fabrics as health-care textiles.

The novelty of the present work is to obtain the crude extract from the leaves, bark, root and stem of P. pinnata and evaluate their antibacterial activity against E. coli, upon being coated on cotton fibres. In addition, the extracts were subjected to wash durability analysis to study the coating efficiency of the phytochemicals in cotton fabrics and a probable mechanism for the antibacterial activity of P. pinnata extracts was also presented.

This paper aims to figure out the conundrum that the corrosion resistance longevity of steel wires for bridge cables was arduous to meet the requirements.

The “two-step” hot-dip coating process for cable steel wires was developed, which involved first hot-dip galvanizing and then hot-dip galvanizing of aluminum magnesium alloy. The corrosion rate, polarization curve and impedance of Zn–6Al–1Mg and Zn–10Al–3Mg alloy-coated steel wires were compared through acetate spray test and electrochemical test, and the corrosion mechanism of Zn–Al–Mg alloy-coated steel wires was revealed.

The corrosion resistance of Zn–10Al–3Mg alloy-coated steel wires had the best corrosion resistance, which was more than seven times that of pure zinc-coated steel wires. The corrosion current of Zn–10Al–3Mg alloy-coated steel wires was lower than that of Zn–6Al–1Mg alloy-coated steel wires, whereas the capacitive arc and impedance value of the former were higher than that of the latter, making it clear that the corrosion resistance of Zn–10Al–3Mg was better than that of Zn–6Al–1Mg alloy coating. Moreover, the Zn–Al–Mg alloy-coated steel wires for bridge cables had the function of coating “self-repairing.”

Controlling the temperature and time of the hot dip galvanizing stage can reduce the thickness of transition layer and solve the problem of easy cracking of the transition layer in the Zn–Al–Mg alloy coating due to the Sandelin effect.

The paper aims to design the optimum formulation of the nano-titanium dioxide (TiO2) hydrophilic coating system using the synthetic polypropylene glycol (PPG), which can create the reflection and absorption property.

TiO2 nanoparticles are used as fillers, and PPG has been blended at the proper ratio of 1PPG: 0.2TiO2. The prepared resin has been applied onto the glass substrate at different numbers of glass immersions during the dip-coating fabrication process. One-time glass immersion is labeled as T1 coating, two-time glass immersion is labeled as T2 coating and three-time glass immersion is labeled as T3 coating. All the prepared coating systems were left dry at ambient temperature.

T3 coating showed the lowest reading of WCA value at 40.50°, due to higher surface energy at 61.73 mN/m. The T3 coating also shows the greatest absorbance property among the prepared coating systems among the prepared coating. In terms of reflectance property, the T2 coating system has great reflectance in UV region and near-infrared region, which is 16.47% and 2.77 and 2.73%, respectively. The T2 coating also has great optical transmission about 75.00% at the visible region.

The development of thermal insulation coating by studying the relationship between convection heat and reflectance at different wavelengths of incident light.

The developed coating shows high potential for glass window application.

The application of the hydrophilic coating on light absorption, reflectance and transmission at different wavelengths.