scholarly journals Multifunctional Flax Fibres Based on the Combined Effect of Silver and Zinc Oxide (Ag/ZnO) Nanostructures

Nanomaterials ◽  
2018 ◽  
Vol 8 (12) ◽  
pp. 1069 ◽  
Author(s):  
Sofia Costa ◽  
Diana Ferreira ◽  
Armando Ferreira ◽  
Filipe Vaz ◽  
Raul Fangueiro
Keyword(s):  
Zinc Oxide ◽  
Smart Materials ◽  
Low Cost ◽  
Combined Effect ◽  
Zno Nanostructures ◽  
X Ray Diffraction ◽  
Flax Fibres ◽  
Conductive Surface ◽  
New Findings ◽  
Wash Durability

Cellulosic fibre-based smart materials exhibiting multiple capabilities are getting tremendous attention due to their wide application areas. In this work, multifunctional flax fabrics with piezoresistive response were developed through the combined functionalization with silver (Ag) and zinc oxide (ZnO) nanoparticles (NPs). Biodegradable polyethylene glycol (PEG) was used to produce AgNPs, whereas ZnONPs were synthetized via a simple and low-cost method. Flax fabrics with and without NPs were characterized by Ground State Diffuse Reflectance (GSDR), Field Emission Scanning Electron Microscopy (FESEM), Energy Dispersive Spectroscopy (EDS), X-ray Diffraction (XRD), Attenuated Total Reflectance-Fourier Transform Infrared Spectroscopy (ATR-FTIR), and Thermogravimetric analysis (TGA). After creating a conductive surface by flax functionalization with AgNPs, ZnONPs were synthetized onto these fabrics. The developed fibrous systems exhibited piezoresistive response and the sensor sensitivity increased with the use of higher ZnO precursor concentrations (0.4 M). Functionalized fabrics exhibited excellent antibacterial activity against Gram-negative (Escherichia coli) and Gram-positive (Staphylococcus aureus) bacteria, higher hydrophobicity (WCA changed from 00 to >1000), UV radiation resistance, and wash durability. Overall, this work provides new insights regarding the bifunctionalization of flax fabrics with Ag/ZnO nanostructures and brings new findings about the combined effect of both NPs for the development of piezoresistive textile sensors with multifunctional properties.

scholarly journals Sensing Performance of Al and Sn Doped ZnO for Hydrogen Detection

Proceedings ◽  
2019 ◽  
Vol 14 (1) ◽  
pp. 39
Author(s):  
Zahira. El khalidi ◽  
Maryam Siadat ◽  
Elisabetta. Comini ◽  
Salah. Fadili ◽  
Philippe. Thevenin
Keyword(s):  
Zinc Oxide ◽  
Chemical Sensor ◽  
Low Cost ◽  
Zinc Powder ◽  
Health Condition ◽  
Vibration Modes ◽  
X Ray Diffraction ◽  
Grain Sizes ◽  
Pure Oxide ◽  
Doped Zno

Chemical gas sensors were studied long ago and nowadays, for the advantageous role they provide to the environment, health condition monitoring and protection. The recent studies focus on the semiconductors sensing abilities, especially of non toxic and low cost compounds. The present work describes the steps to elaborate and perform a chemical sensor using intrinsic and doped semiconductor zinc oxide. First, we synthesized pure oxide using zinc powder, then, two other samples were established where we introduced the same doping percentage of Al and Sn respectively. Using low cost spray pyrolysis, and respecting the same conditions of preparation. The obtained samples were then characterized by X Ray Diffraction (XRD) that revealed the hexagonal wurzite structure and higher crystallite density towards the direction (002), besides the appearance of the vibration modes related to zinc oxide, confirmed by Raman spectroscopy. SEM spectroscopy showed that the surface morphology is ideal for oxidizing/reduction reactions, due to the porous structure and the low grain sizes, especially observed for the sample Sn doped ZnO. The gas testing confirms these predictions showing that the highest response is related to Sn doped ZnO compared to ZnO and followed by Al doped ZnO. The films exhibited responses towards: CO, acetone, methanol, H2, ammonia and NO2. The concentrations were varied from 10 to 500 ppm and the working temperatures from 250 to 500°C, the optimal working temperatures were 350 and 400 °C. Sn doped ZnO showed a high response towards H2 gas target, with a sensitivity reaching 200 at 500 ppm, for 400 °C.

Low Cost Environmental Sensors Using Zinc Oxide Nanowires and Nanostructures

2012 ◽  
Vol 1439 ◽  
pp. 139-144 ◽  
Author(s):  
Nima Mohseni Kiasari ◽  
Saeid Soltanian ◽  
Bobak Gholamkhass ◽  
Peyman Servati
Keyword(s):  
Zinc Oxide ◽  
Metal Oxide ◽  
High Performance ◽  
Low Cost ◽  
Chemical Vapor ◽  
Environmental Sensors ◽  
X Ray Diffraction ◽  
Zinc Oxide Nanowires ◽  
Oxide Nanowires ◽  
Current Voltage

ABSTRACTZinc oxide (ZnO) nanowires (NW) are grown on both silicon and sapphire substrates using conventional chemical vapor deposition (CVD) system. As-grown nanostructures are characterized by scanning electron microscope (SEM), X-ray diffraction (XRD) as well as energy dispersive spectroscopy (EDS) and the results confirm high-quality c-axis growth of single-crystalline zinc oxide nanowires. Nanowire are dispersed in solvent and then placed between micro-patterned gold electrodes fabricated on silicon wafers using low cost and scalable dielectrophoresis (DEP) process for fabrication of oxygen and humidity sensors. These sensors are characterized in a vacuum chamber connected to a semiconductor analyzer. Current-voltage characteristics of each device are systematically investigated under different hydrostatic pressure of various gaseous environments such as nitrogen, argon, dry and humid air. It is observed that the electrical conductivity of the nanowires is significantly dependent on the number of oxygen and water molecules adsorbed to the surface of the metal oxide nanowire. These results are critical for development of low cost metal oxide sensors for high performance ubiquitous environmental sensors of oxygen and humidity.

Improvement of Heat Sink Effect Using Zinc Oxide Nanostructure

2020 ◽  
Vol 20 (11) ◽  
pp. 6980-6984
Author(s):  
Yun Guang Li ◽  
Hyun Jin Yoo ◽  
Changyoon Baek ◽  
Junhong Min
Keyword(s):  
Thermal Conductivity ◽  
Zinc Oxide ◽  
Reaction Time ◽  
Surface Area ◽  
Heat Sink ◽  
Heat Sinks ◽  
Zno Nanostructures ◽  
X Ray Diffraction ◽  
Precision Temperature ◽  
Polymerase Chain

Heat sinks that dissipate heat effectively play a significant role in devices with high-precision temperature control, such as thermal cyclers for polymerase chain reaction (PCR). This study was carried out to develop a heat sink with a high thermal conductivity to dissipate heat effectively. To increase the surface area of the heat sink, zinc oxide (ZnO) nanostructures were fabricated on an aluminum plate. ZnO nanostructures were fabricated by hydrothermal method and confirmed by scanning electron microscopy and X-ray diffraction. With the increase in the concentration of the precursors, the length of the nanorods increased, and with longer reaction time, nanostructures connected with higher stability and larger surface area. Thermal conductivity is increased by ZnO nanostructures and is affected by the concentration of precursors and the reaction time. Thermal conductivity of an optimal ZnO-coated Al plate is 2 times higher than that of a bare one. This technology can be applied to portable PCR devices to reduce weight, size, and power consumption.

Analysis of Sputtered Zinc Oxide Films

1980 ◽  
Vol 38 ◽  
pp. 416-417
Author(s):  
T. A. Emma ◽  
M. P. Singh
Keyword(s):  
Electron Microscopy ◽  
Zinc Oxide ◽  
Piezoelectric Materials ◽  
Oxide Films ◽  
Optical Quality ◽  
Zno Films ◽  
Rf Power ◽  
X Ray Diffraction ◽  
Sputtered Films ◽  
Zinc Oxide Films

Optical quality zinc oxide films have been characterized using reflection electron diffraction (RED), replication electron microscopy (REM), scanning electron microscopy (SEM), and X-ray diffraction (XRD). Significant microstructural differences were observed between rf sputtered films and planar magnetron rf sputtered films. Piezoelectric materials have been attractive for applications to integrated optics since they provide an active medium for signal processing. Among the desirable physical characteristics of sputtered ZnO films used for this and related applications are a highly preferred crystallographic texture and relatively smooth surfaces. It has been found that these characteristics are very sensitive to the type and condition of the substrate and to the several sputtering parameters: target, rf power, gas composition and substrate temperature.

scholarly journals Preparation of Zn-MOFs by microwave-assisted ball milling for removal of tetracycline hydrochloride and Congo red from wastewater

2021 ◽  
Vol 10 (1) ◽  
pp. 125-133
Author(s):  
Qinhui Ren ◽  
Fuhua Wei ◽  
Hongliang Chen ◽  
Ding Chen ◽  
Bo Ding
Keyword(s):  
Ball Milling ◽  
Congo Red ◽  
Low Cost ◽  
Metal Organic Framework ◽  
Tetracycline Hydrochloride ◽  
Infrared Spectrometry ◽  
X Ray Diffraction ◽  
Wastewater Purification ◽  
Microwave Assisted ◽  
Metal Organic

Abstract In this study, we prepared Zn-MOFs as an ordinary, low-cost, and efficiency method taking advantage of zinc(ii) acetate monohydrate and 1,3,5-benzenetricarboxylic acid in microwave-assisted ball milling. The Zn-MOFs were measured via scanning electron microscopy, infrared spectrometry, X-ray diffraction, and thermogravimetry. We explored its use as a photocatalyst for the degradation of tetracycline hydrochloride and Congo red from aqueous solutions. The results demonstrate that the kinetic model was appropriate for the removal of organic pollutants. In general, it is feasible, inexpensive, and effective to use metal organic framework (MOF) to treat waste liquid. Therefore, our findings indicate that Zn-MOFs have broad application vista in wastewater purification.

scholarly journals Multidimensional Ln-Aminophthalate Photoluminescent Coordination Polymers

Materials ◽  
2021 ◽  
Vol 14 (7) ◽  
pp. 1786
Author(s):  
Carla Queirós ◽  
Chen Sun ◽  
Ana M. G. Silva ◽  
Baltazar de Castro ◽  
Juan Cabanillas-Gonzalez ◽  
...  
Keyword(s):  
Water Content ◽  
Coordination Polymers ◽  
Metal Ion ◽  
Low Cost ◽  
Microwave Assisted Synthesis ◽  
X Ray Diffraction ◽  
X Ray ◽  
Wide Range ◽  
Ft Ir ◽  
Ft Ir Spectroscopy

The development of straightforward reproducible methods for the preparation of new photoluminescent coordination polymers (CPs) is an important goal in luminescence and chemical sensing fields. Isophthalic acid derivatives have been reported for a wide range of applications, and in addition to their relatively low cost, have encouraged its use in the preparation of novel lanthanide-based coordination polymers (LnCPs). Considering that the photoluminescent properties of these CPs are highly dependent on the existence of water molecules in the crystal structure, our research efforts are now focused on the preparation of CP with the lowest water content possible, while considering a green chemistry approach. One- and two-dimensional (1D and 2D) LnCPs were prepared from 5-aminoisophthalic acid and Sm3+/Tb3+ using hydrothermal and/or microwave-assisted synthesis. The unprecedented LnCPs were characterized by single-crystal X-ray diffraction (SCRXD), powder X-ray diffraction (PXRD), Fourier transform infrared (FT-IR) spectroscopy and scanning electron microscopy (SEM), and their photoluminescence (PL) properties were studied in the solid state, at room temperature, using the CPs as powders and encapsulated in poly(methyl methacrylate (PMMA) films, envisaging the potential preparation of devices for sensing. The materials revealed interesting PL properties that depend on the dimensionality, metal ion, co-ligand used and water content.

scholarly journals Investigation of Flexible Arrayed Lactate Biosensor Based on Copper Doped Zinc Oxide Films Modified by Iron–Platinum Nanoparticles

Polymers ◽  
2021 ◽  
Vol 13 (13) ◽  
pp. 2062
Author(s):  
Yu-Hsun Nien ◽  
Zhi-Xuan Kang ◽  
Tzu-Yu Su ◽  
Chih-Sung Ho ◽  
Jung-Chuan Chou ◽  
...  
Keyword(s):  
Zinc Oxide ◽  
Response Time ◽  
Platinum Nanoparticles ◽  
Electrochemical Impedance ◽  
Rf Sputtering ◽  
X Ray Diffraction ◽  
Average Sensitivity ◽  
Iron Platinum ◽  
Zinc Oxide Films ◽  
Paste Electrode

Potentiometric biosensors based on flexible arrayed silver paste electrode and copper-doped zinc oxide sensing film modified by iron-platinum nanoparticles (FePt NPs) are designed and manufactured to detect lactate in human. The sensing film is made of copper-doped zinc oxide (CZO) by a radio frequency (RF) sputtering system, and then modified by iron-platinum nanoparticles (FePt NPs). The surface morphology of copper-doped zinc oxide (CZO) is analyzed by scanning electron microscope (SEM). FePt NPs are analyzed by X-ray diffraction (XRD) and Fourier transform infrared spectroscopy (FTIR). The average sensitivity, response time, and interference effect of the lactate biosensors are analyzed by voltage-time (V-T) measurement system. The electrochemical impedance is analyzed by electrochemical impedance spectroscopy (EIS). The average sensitivity and linearity over the concentration range 0.2 mM–5 mM are 25.32 mV/mM and 0.977 mV/mM, respectively. The response time of the lactate biosensor is 16 s, with excellent selectivity.

Thermal conversion of CBD grown ZnS thin films to ZnO

2020 ◽  
Vol 0 (0) ◽  
Author(s):  
Kooliyankal Naseema ◽  
Kaniyamkandy Ribin ◽  
Nidiyanga Navya ◽  
Prasoon Prasannan
Keyword(s):  
Thin Films ◽  
Low Cost ◽  
Thermal Conversion ◽  
X Ray Diffraction ◽  
Xrd Pattern ◽  
Glass Substrates ◽  
Anion Substitution ◽  
Nano Crystalline ◽  
Before And After ◽  
Uv Visible

AbstractNano crystalline zinc sulfide thin films were deposited onto glass substrates by chemical bath deposition method. One of the samples was annealed at 300 °C for 2 h in air using a muffle furnace. The prepared thin films were investigated by X-ray diffraction (XRD), UV–visible spectroscopy (UV–vis), photoluminescence spectroscopy (PL), scanning electron microscopy (SEM) and Raman spectroscopy (FT-R) studies before and after annealing. The analysis confirmed the thermal-induced anion substitution and conversion of ZnS crystal to ZnO wurtzite crystal. XRD pattern showed that these films were phase pure and polycrystalline in nature. Optical band gap was found to be 3.86 eV for ZnS and 3.21 eV for ZnO. The films prepared by this simple, low-cost technique are suitable for photovoltaic and optoelectronic applications.

Core–Shell Chain-Like Cu@Ni Composite with Dual Absorption Peaks to Improve Microwave Absorption Properties

NANO ◽  
2018 ◽  
Vol 13 (05) ◽  
pp. 1850052
Author(s):  
Yuanyuan Zhou ◽  
Jianying Deng ◽  
Shimei Li ◽  
Zefeng Li
Keyword(s):  
Hydrothermal Reaction ◽  
Low Cost ◽  
Electromagnetic Properties ◽  
Formation Mechanisms ◽  
Core Shell ◽  
The Novel ◽  
Redox Potentials ◽  
X Ray Diffraction ◽  
Ni Alloy ◽  
Absorbing Material

Core–shell Cu@Ni chains were successfully synthesized through a mild hydrothermal reaction. The morphology, structure and microwave electromagnetic properties of the composite were then characterized by X-ray diffraction, energy-dispersive spectroscopy, scanning electron microscopy and vector network analysis. The formation mechanisms of the core–shell structure and one-dimensional chains were ascribed to the varying redox potentials of Cu and Ni ions and the magnetic dipole–dipole attraction. Furthermore, a minimal reflection loss (RL) of [Formula: see text]20.7[Formula: see text]dB was observed at 9.6[Formula: see text]GHz with a thickness of 2.0[Formula: see text]mm and the effective absorption ([Formula: see text]10[Formula: see text]dB, 90% microwave attenuation) bandwidth can be adjusted between 5.2[Formula: see text]GHz and 16.6[Formula: see text]GHz for the thin absorber thickness of 2.0–4.0[Formula: see text]mm. The novel core–shell chain-like Cu@Ni alloy can be used as a promising absorbing material because it shows numerous features such as thin thickness, strong absorption, low cost and lightweight.

Figures of Merit of Low-Cost CuAl0.9Fe0.1O2 Thermoelectric Material Prepared at Different Solid State Reaction Sintering Temperatures

2015 ◽  
Vol 659 ◽  
pp. 185-189
Author(s):  
Aparporn Sakulkalavek ◽  
Rungnapa Thonglamul ◽  
Rachsak Sakdanuphab
Keyword(s):  
Figure Of Merit ◽  
Sintering Temperature ◽  
Low Cost ◽  
Uniaxial Pressure ◽  
Rhombohedral Structure ◽  
Second Phase ◽  
X Ray Diffraction ◽  
High Purity Grade ◽  
Average Grain Size ◽  
Xrd Patterns

In this study, we investigated a CuAl0.9Fe0.1O2 compound prepared at two different sintering temperatures in order to find out the effect of sintering temperature on the compound's figure of merit of thermoelectric properties. The thermoelectric CuAl0.9Fe0.1O2 compound was prepared from high purity grade Cu2O, Al2O3 and Fe2O3 powders. The mixture of these powders were ground and then pressed with uniaxial pressure into pellets. The pellets obtained were sintered in the air at 1423 K and 1473 K. X-ray diffraction (XRD) patterns showed a single phase of CuAl0.9Fe0.1O2 with rhombohedral structure, , along with a trace of CuO second phase. Moreover, the XRD peaks of the sample sintered at 1423 K indicated that more Fe3+ atoms replaced Al3+ atoms in this sample than they did in the sample sintered at 1473 K. The average grain size of the CuAl0.9Fe0.1O2 compound prepared increased with increasing sintering temperature, whereas its mean pore size and porosity decreased with increasing sintering temperature. The dispersed small pores markedly decreased the thermal conductivity of the compound, while the Fe3+ substitution of Al3+ increased its electrical conductivity. The highest figure of merit (ZT) found was 0.021 at 973 K in the CuAl0.9Fe0.1O2 sample sintered at 1423 K. Our findings show that this low-cost material with a reasonable figure of merit is a good candidate for thermoelectric applications at high-temperature.

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