Effect Of Nanocoating Research Articles

Effect of Nanocoating (CuO Nanoparticles) on the Performance of Solar Evacuated Tube

In domestic solar water heating solar evacuated tubes have been widely used. Enhancement of solar energy absorption is the demand of time and CuO nanoparticles on account of their potential uses mainly in the field of solar energy applications. Cost effective sol-gel method is applied to synthesize CuO nanoparticles on solar evacuated glass tube. The synthesizing initiated from Cupric Acetate with the colloidal solution in water. A thin film has been prepared at room temperature nearly at 30 to 38 °C. The synthesized thin film had been annealed at 300 °C for one hour to give uniform grain structure and good surface morphological properties. For the structural study, the film was characterized by XRD-X-Ray diffraction, SEM-Scanning Electron Microscopy & TEM- Transmission Electron Microscopy. To exhibit the optical behavior of CuO nanoparticles on solar evacuated glass tube, UV-visible spectrum has been performed. By the calculations of an effective mass model, the size of particles determined as 2.26 nm, which supported and justified the TEM analysis. Coated CuO nanoparticles on borosilicate evacuated glass tube has been installed as a domestic solar water heater and working satisfactorily to generate hot water. For solar water heating system (domestic) application of nanotechnology is a novel concept. To develop durable nanocoating on 1800 mm long solar evacuated borosilicate glass tube itself it was a challenge. In this research it is shown that coating is working satisfactorily with energy enhancement. This paper opens the door for new nanocoating developments opportunities.

Antibacterial textile and the effect of incident light wavelength on its photocatalytic self-cleaning activity

Wool fabrics with antibacterial and photocatalytic self-cleaning functionalities were developed by applying TiO2/Pt, TiO2/Au and TiO2/Ag colloids to the fabrics surface. This study elucidates how light source type and wavelength range can affect the photo-induced self-cleaning property of the treated fabrics. The self-cleaning activity of fabrics was monitored based on the degradation of coffee stains under UVA (λmax: 365 nm), visible light (λmax: 435 nm), full spectrum simulated solar irradiation (λ: 250–800 nm) and filtered simulated solar irradiation (λ: 320–800 nm). In addition, the effect of nanocoatings on the antibacterial activity against Escherichia Coli (E. Coli) bacterium was examined. The incorporated metals synergistically affected the self-cleaning performance, and their efficiency was dependent on the dopants type, concentration, and light sources. It was observed that the filtered simulated sunlight was the most effective light source for inducing self-cleaning without causing any unwanted photo-yellowing damage in wool. Moreover, the coated fabrics containing silver and platinum led to a bactericidal effect, while gold additive did not re-produce this effectiveness.

Condensation of Humid Air on Superhydrophobic Surfaces: Effect of Nanocoatings on a Hierarchical Interface.

Vapor condensation is a well-known phase-change phenomenon observed in nature as well as in different industrial applications. Superhydrophobic surfaces (SHSs) with low hysteresis can efficiently drain off the condensate and rejuvenate the nucleation sites further. In this work, three distinct SHSs were fabricated by nanocoating three hydrophobic agents, viz., perfluoro-octyl-triethoxy-silane (PFOTS), perfluoro-octanoic-acid (PFOA), and commercial Glaco solution on a hierarchical aluminum surface. The surface morphology of all surfaces was investigated, and its effects on the wetting, droplet departure, and overall heat-transfer coefficient (HTC) during condensation phenomena in the humid air (>95% noncondensable gases) were analyzed. The contact angle hysteresis of all three surfaces was very low (∼5°); however, different wetting behaviors were observed during the condensation, depending on the adhesion of the condensate drop with nanoscale textures in the microcavities. Dropwise condensation (DWC) was observed in silane and Glaco-coated surfaces. A gravity-assisted sweeping mechanism removed the condensate from the silane-coated surface. In contrast, the condensate was ejected out of the plane of the Glaco-coated surface by droplet jumping. The PFOA-coated surface has shown DWC initially and floods in the later stages due to highly pinned condensed droplets. This study reports an enhancement of ∼35 to ∼110% in the HTC for the SHS-exhibiting gravity-assisted sweeping mechanism compared to the droplet-jumping mechanism. The present work will provide substantial insights into the fabrication of efficient hierarchical interfaces for water-energy nexus applications.

Effect of Nano-Coating on Microleakage of Different Capsulated Glass Ionomer Restoration in Primary Teeth: An In Vitro Study

Effect of Nano-Coating on Microleakage of Different Capsulated Glass Ionomer Restoration in Primary Teeth: An In Vitro Study

The Effect of Nanocoatings on Critical Heat Flux (CHF) under Pool Boiling Conditions

Abstract The effect of nanomaterial coating on heat transfer characteristics of a copper substrate during pool boiling with distilled water (>99.9 %) was studied. The peak on the pool boiling curve between nucleate and transition boiling is termed the critical heat flux. Multi-walled carbon nanotubes and graphene were used to obtain coatings on the copper substrate. Experiments were carried out at atmospheric pressure. The results showed enhanced critical heat flux for the coated substrates. Graphene-coated copper showed the highest critical heat transfer characteristics compared with that on bare and multi-walled carbon nanotube-coated substrates. The study has significant implications for the enhancement of heat transfer during quench heat treatment.

Effect of Nano-coating on Molten Salts for Turbine Blades

The purpose of this study is to optimize hot corroded pack coated Ni-based superalloy K417G using grey relational analysis. Optimization of the pack cementation parameters was performed using quality characteristics of diffusion coatings for pack cementation process, i.e., salt activator, Nano-powders master alloy powder, and wt.% Y2O3. Analysis of variance (ANOVA) was used for observing the most influencing pack cementation parameters on the quality characteristics, i.e., Na2So4-6% wt. V2O5 (kp1), 100 wt% NaSO4 (kp2), and 75 wt. % NaSO4-25 wt % NaCl (kp3). The optimal process parameters were calculated using a grey relation grade and a confirmation test was performed. Based on the analysis of variance results, the wt.% Y2O3 is the most significant controllable diffusion coating factor for the hot corroded pack coated K417G at optimum setting conditions (A2, B3, C3) i.e., activator (NaCl), master alloy (94Cr-6Al), and wt.%Y2O3 (4%). according to the quality characteristics. Grey relational analysis was successfully applied to the optimization of hot corroded pack coated K417G using multi-performance characteristics.

Natural-convection heat transfer enhancement of aluminum heat sink using nanocoating by electron beam method

The high power density and compactness of the next generation electronic devices necessitate efficient and effective cooling methods for heat dissipation in order to maintain the temperature at an acceptable safety level. In the present work, aluminum nanocoating was employed in a heat sink to study the heat transfer performance under natural-convection conditions. The nanocoating was achieved using an electron beam method while the characteristics of nanocoated surfaces were analysed using SEM, an energy dispersive X-ray spectroscopy, surface roughness profilometry equipment and by X-ray diffraction techniques. The heat dissipation from heat sink with and without nanocoating under natural-convection has been experimentally studied at different controllable surrounding temperatures. A uniform increase in the surface roughness by the nanocoating was seen in all cases. The conclusion from several experimental results was that the effect of nanocoating in augmenting the heat transfer is more pronounced only when there is a sufficient temperature driving potential.

Investigation of Metal and Metal Oxide nanocoating on Fins in HPHE with Silver Water NanoFluid

An improvement of energy saving and the heat transfer characteristics via introducing nanocoating of fins is a new method in HVAC systems. ANSYS software is the preferred choice to design a model for nanocoating on fins in Thermosyphon Heat Exchangers. The investigation of thermal resistance and temperature distribution are presented. The influence of enhancing the working system is examined using different nanocoating metal and metal oxide materials of fins (Ag, Cu, AL, BeO, Al2O3 and CuO) in heat pipe. The effect of Nanocoating by metals is explored in which the maximum improvement occurred at the evaporator section in transient operation condition with 71.9585 for AL, 71.383 for Cu and 70.708 for Ag while, the effect of Nanocoating by metal oxide is (73.79 for CuO, 73,41 for AL2O3 and 71.96 for BeO). The obtained results showed that the best nanocoat material for this purpose is the aluminum for metals and copper oxide for metal oxides. The calculations give important indication that using the nanocoating just in the evaporator section to reduce the cost. The large amount of heat transfer occur in the evaporator section according to the result of thermal resistance in this section then large benefit of latent heat of the air is guiding to increase the energy saving when using HPHE in HVAC systems.

The effect of nano-coatings with α-tocopherol and xanthan gum on shelf-life and browning index of fresh-cut “Red Delicious” apples

The objective of this study was to prepare nanoparticles and nanocapsules using the emulsification–diffusion method, and then evaluate the effectiveness of several systems made with dl-α-tocopherol on the browning index and firmness in fresh-cut apples. Poly-ε-caprolactone was used as a biopolymer to form the membrane of nanocapsules and the matrix of nanospheres. To provide greater functionality to the coating, xanthan gum was added to some of the systems tested. Changes in the treated fruit were monitored during 18 days of cold storage. The micrographs obtained give evidence of the presence of capsular entities. Particle size was 174 to 240 nm, and the zeta potential was − 44 to − 56 mV, which indicates that the systems were stable. With respect to the browning index, nanocapsules proved to be the most effective system, followed by nanospheres. Firmness changes were reduced by applying nanocapsules and nanospheres, both of which limited variations in firmness to below 15% (6.1 and 6.3 N, respectively). These results confirm that the use of nanoparticle systems does indeed help maintain the quality of fresh-cut apples. This study shows the advantages of using edible coatings containing nanosystems to preserve fresh cut fruits in particular the apple. The results show clearly that nanotechnological coatings decrease the browning index and preserve the firmness by longer times compared with the xanthan gum and control. Nanocapsules containing dl-α-tocopherol were the best system followed by nanoemulsions and nanospheres. The systems were prepared by the emulsion–diffusion method from acceptable food materials. This process is efficient, versatile and of simple implementation to industrial level. On the other hand, the nanosystems can be easily applied by dipping or spraying as conventional coatings in production lines, and they do not require special equipment. Apparently the effect of nanosystems is attributed to their high superficial area and the modification of membrane permeability due to their lipophilic nature. Furthermore, the food industry is continuously growing, so that the application of antioxidants in a nanocapsule form is a choice of easy application, in accordance with current systems of conservation of fresh-cut fruit, helping to increase the shelf life of apples and other products of high marked demand, thereby reducing product losses.

Effect of Nano-Coatings on Waste-to-Energy (WTE) plant : A Review

Effect of Nano-Coatings on Waste-to-Energy (WTE) plant : A Review

Effect of Nano-Coating on the Thermal Conductivity of Microporous Thermal Insulations

Effect of Nano-Coating on the Thermal Conductivity of Microporous Thermal Insulations