Effect of Surface Modification by CuO on Surface Morphology, Electrical Properties and Gas Response of ZnO Thick Films

2019 ◽  
Vol 17 (12) ◽  
pp. 968-976
Author(s):  
M. K. Deore ◽  
V. B. Gaikwad ◽  
D. D. Kajale ◽  
J. H. Jain
Keyword(s):  
Surface Modification ◽  
Thick Films ◽  
Film Surface ◽  
Poor Response ◽  
Time Interval ◽  
Screen Printing Technique ◽  
Different Temperatures ◽  
Response And Recovery ◽  
Surface Modified ◽  
Gas Response

The screen printing technique was used for the preparation of ZnO thick films. The films were dipped into 0.01 M aq. solution of (CulCl2 · 2H2O) for 10, 15, 20 and 30 min time interval for the surface modification. The dispersed CuCl2 on the film surface oxidized during heating at 500 °C and converted into CuO. SEM coupled with EDAX analysis showed the morphology of surface and elemental composition of the films. The micrographs of the films dipped at different time interval show the very interesting changes. The EDAX result shows variation in Zn/O and Cu/Zn ratio with different concentration of Cu. The toxic gases such as Cl2, H2S, CO and LPG etc. were used to study the gas response of the films at different temperatures. The pure film shows the poor response to H2S gas at 300 °C while surface modified film shows a good response to the same gas at 100 °C temperature for 100 ppm level gas concentration. The main characteristics of the films such as the selectivity, response and recovery time were studied and are presented in this paper.

Surface Modification and Characterization of Photodegradable Polystyrene-TiO2 Nanocomposites

2013 ◽  
Vol 372 ◽  
pp. 128-131
Author(s):  
Achanai Buasri ◽  
Pornpimon Loakhonka ◽  
Tanaporn Benjapolchai ◽  
Nitchanan Chusripet ◽  
Vorrada Loryuenyong
Keyword(s):  
Surface Modification ◽  
Physical Properties ◽  
Thick Films ◽  
Compression Molding ◽  
Optical Bandgap ◽  
Molding Method ◽  
Surface Modified

In this study, polystyrene (PS) nanocomposites with TiO2 and surface-modified TiO2 nanoparticles were prepared by compression molding method. TiO2 nanoparticles were modified by 3-(methacryloxy) propyl trimethoxysilane (MPS). The resulting nanocomposite thick films were compared with pure polystyrene. It was found that MPS-modified TiO2 nanoparticles were better dispersed in PS matrix due to their hydrophobic characteristics. The addition of small amount of TiO2 nanoparticles could greatly decrease the optical bandgap of PS from 4.0 eV in pure PS to less than 3.0 eV in PS-TiO2 nanocomposite. The effects of surface modification and UVC irradiation on the physical properties and the degradation of nanocomposites were investigated.

scholarly journals Nano Ag-DopedIn2O3Thick Film: A Low-TemperatureH2SGas Sensor

2011 ◽  
Vol 2011 ◽  
pp. 1-8 ◽  
Author(s):  
D. N. Chavan ◽  
G. E. Patil ◽  
D. D. Kajale ◽  
V. B. Gaikwad ◽  
P. K. Khanna ◽  
...  
Keyword(s):  
Gas Sensing ◽  
Thick Films ◽  
Optimum Operating ◽  
Optimum Operating Temperature ◽  
Ethanol Vapour ◽  
Nano Silver ◽  
Sensitivity And Selectivity ◽  
Response And Recovery ◽  
Surface Modified ◽  
Sensing Performance

Thick films of AR grade In2O3were prepared by standard screen-printing technique. The gas sensing performances of thick films were tested for various gases. It showed maximum sensitivity to ethanol vapour at 350°C for 80 ppm concentration. To improve the sensitivity and selectivity of the film towards a particular gas, In2O3sensors were surface-modified by dipping them in a solution of 2% nanosilver for different intervals of time. Obtained results indicated that spherical nano-Ag grains are highly dispersed on the surface of In2O3sensor. The surface area of the nano-Ag/ In2O3sensor is several times larger than that of pure In2O3sensor. In comparison with pure In2O3sensor, all of the nano-Ag-doped sensors showed better sensing performance in respect of response, selectivity, and optimum operating temperature. The surface-modified (30 min) In2O3sensor showed larger sensitivity to H2S gas (10 ppm) at 100°C. Nano silver on the surface of the film shifts the reactivity of film from ethanol vapour to H2S gas. A systematic study of gas sensing performance of the sensor indicates the key role played by the nano silver species on the surface. The sensitivity, selectivity, response, and recovery time of the sensor were measured and presented.

NOx Gas Sensing Properties of Fe-Doped ZnO Nanoparticles

2020 ◽  
Vol 12 (6) ◽  
pp. 908-914 ◽  
Author(s):  
Ahmad Umar ◽  
M. Alduraibi ◽  
Omar Al-Dossary
Keyword(s):  
Gas Sensors ◽  
Zno Nanoparticles ◽  
Gas Sensing ◽  
Hydrothermal Process ◽  
Gas Sensing Properties ◽  
Recovery Times ◽  
Different Temperatures ◽  
Response And Recovery ◽  
Doped Zno ◽  
Gas Response

Herein, NOx, i.e., nitric oxide (NO) and nitrogen dioxide (NO2), gas sensors were fabricated using iron (Fe)-doped ZnO nanoparticles prepared via the facile hydrothermal process. The synthesized Fe-doped ZnO nanoparticles were analyzed through several techniques that revealed the well-crystallinity and dense growth of nanoparticles with the typical diameters of 25 ± 5 nm. The synthesized nanoparticles were utilized as a prospective material for the fabrication of NOx gas sensors operating at different temperatures, i.e., 350 °C, 400 °C, and 450 °C. The detailed sensing performances revealed that the optimum and most suitable sensing temperature for the fabricated sensors is 400 °C. In presence of 10 ppm NO gas, the fabricated sensor exhibited the highest gas response of 1.35 with a response (tresponse) and recovery (trecovery) time of 44 s and 402 s, respectively. Similarly, the fabricated NO2 gas sensor, in presence of 10 ppm gas shows the highest gas response of 1.33 with a response and recovery times of 50 s and 281 s, respectively. The presented results demonstrate that Fe-doped ZnO nanomaterials are capable to fabricate efficient NOx gas sensors.

scholarly journals Facile Preparation of Efficient WO3Photocatalysts Based on Surface Modification

2015 ◽  
Vol 2015 ◽  
pp. 1-7 ◽  
Author(s):  
Min Liu ◽  
Hongmei Li ◽  
Yangsu Zeng
Keyword(s):  
Photocatalytic Activity ◽  
Surface Modification ◽  
Visible Light ◽  
Photoelectron Spectroscopy ◽  
Impregnation Method ◽  
Light Spectra ◽  
Simple Strategy ◽  
Visible Light Active ◽  
Efficient Charge ◽  
Surface Modified

Tungsten trioxide (WO3) was surface modified with Cu(II) nanoclusters and titanium dioxide (TiO2) nanopowders by using a simple impregnation method followed by a physical combining method. The obtained nanocomposites were studied by scanning electron microscope, X-ray photoelectron spectroscopy spectra, UV-visible light spectra, and photoluminescence, respectively. Although the photocatalytic activity of WO3was negligible under visible light irradiation, the visible light photocatalytic activity of WO3was drastically enhanced by surface modification of Cu(II) nanoclusters and TiO2nanopowders. The enhanced photocatalytic activity is due to the efficient charge separation by TiO2and Cu(II) nanoclusters functioning as cocatalysts on the surface. Thus, this simple strategy provides a facile route to prepare efficient visible-light-active photocatalysts for practical application.

scholarly journals Surface modification and adhesion improvement of polyester films

2013 ◽  
Vol 11 (1) ◽  
pp. 35-45 ◽  
Author(s):  
Aniello Cammarano ◽  
Giovanna Luca ◽  
Eugenio Amendola
Keyword(s):  
Free Energy ◽  
Surface Modification ◽  
Surface Free Energy ◽  
Self Assembly ◽  
Treatment Time ◽  
Solution Treatment ◽  
Film Surface ◽  
Critical Surface ◽  
Hydrolysis Time ◽  
Critical Surface Tension

AbstractFacile surface modification of polyester films was performed via chemical solutions treatment. Surface hydrolysis was carried out by means of sodium hydroxide solutions, leading to the formation of carboxylate groups. Three commercial polyester films of 100 μm in thickness were used in this work: AryLite™, Mylar™, and Teonex™, hydrolysis time being the main modification parameter. FTIR-ATR analysis, topography and contact angle (CA) measurements, surface free energy (SFE) and T-Peel adhesion tests were carried out to characterize the modified films. A quantitative estimate of the carboxylates surface coverage as a function of treatment time was obtained through a supramolecular approach, i.e. the ionic self-assembly of a tetracationic porphyrin chromophore onto the film surface. The surface free energy and critical surface tension of the hydrolyzed polyesters was evaluated by means of Zisman, Saito, Berthelot and Owens-Wendt methods. It was shown that NaOH solution treatment increases roughness, polarity and surface free energy of polymers. As a result, T-Peel strengths for modified Mylar™ and Teonex™ films were respectively 2.2 and 1.8 times higher than that for the unmodified films, whereas AryLite™ adhesion test failed.

scholarly journals Enhancement of the Congo Red Adsorption Capacity of Biochars by Surface Modification with MgCl2 Pretreatment

2020 ◽  
Vol 42 (10) ◽  
pp. 472-481
Author(s):  
Hee So Oh ◽  
Jae-Soo Chang
Keyword(s):  
Surface Modification ◽  
Adsorption Isotherm ◽  
Adsorption Capacity ◽  
Congo Red ◽  
Raw Materials ◽  
Physicochemical Characteristics ◽  
Pine Sawdust ◽  
Adsorption Capacities ◽  
Initial Ph ◽  
Surface Modified

Objectives : The physicochemical characteristics of Mg-biochar composites derived from kelp and pine after pretreatment with MgCl2 were analyzed, and their adsorption capacities for an anionic dye, Congo red (CR), were evaluated.Methods : After pretreating 60 g of kelp and pine sawdust in 1 L of 0.1 M MgCl2･6H2O, the raw materials were pyrolyzed at 500℃ to produce Mg-biochar composites (kelp based KB-Mg and pine based PB-Mg). The fundamental physicochemical characteristics of the Mg-biochar composites were examined, and their adsorption capacities for CR were investigated using different initial pH values, adsorption kinetic models, and adsorption isotherm models.Results and discussion : The Mg-biochar composites showed the development of uniform deposits of Mg minerals primarily as MgO crystal on the surface by the surface modification with MgCl2. When the pristine biochars were surface-modified with MgCl2, their adsorption capacities for CR were significantly increased over the entire pH range tested. The CR adsorption process by all biochars was best described with the pseudo-first order kinetics model, and the adsorption isotherm characteristics were better described with the Langmuir isotherm model for all biochars. The Langmuir maximum adsorption capacities for KB-Mg and PB-Mg were 423.0 mg/g and 394.7 mg/g, respectively. It is suggested that the main mechanism for CR adsorption on the Mg-biochars is electrostatic attraction between CR and the biochars.Conclusions : The results showed that surface modification with MgCl2 could greatly enhance the CR adsorption capacity of biochars, and the results demonstrated the great potential of KB-Mg and PB-Mg for CR removal.

Surface modification of ferrite nanoparticles with dicarboxylic acids for the synthesis of 5-hydroxymethylfurfural: a novel and green protocol

RSC Advances ◽  
2016 ◽  
Vol 6 (80) ◽  
pp. 76795-76801 ◽  
Author(s):  
Melad Shaikh ◽  
Mahendra Sahu ◽  
Kiran Kumar Atyam ◽  
Kalluri V. S. Ranganath
Keyword(s):  
Surface Modification ◽  
Dicarboxylic Acids ◽  
Ferrite Nanoparticles ◽  
Solvent Free ◽  
Green Protocol ◽  
Flexible Ligand ◽  
Solvent Free Conditions ◽  
Surface Modified

5-Hydroxymethylfurfural (5-HMF) has been synthesized under solvent free conditions using surface modified ferrite nanoparticles. The flexible ligand modified ferrites showed higher activity than rigid modified ferrites.

Insights on the impact of photophysical processes and defect states evolution on the emission properties of surface-modified ZnO nanoplates for application in photocatalysis and hybrid LEDs

2021 ◽  
Author(s):  
Dhritiman Banerjee ◽  
Payal Banerjee ◽  
Asit Kumar Kar
Keyword(s):  
Zinc Oxide ◽  
Optical Properties ◽  
Surface Modification ◽  
Defect State ◽  
Defect States ◽  
Emission Properties ◽  
Photophysical Processes ◽  
State Densities ◽  
Surface Modified ◽  
The Impact

The effects of surface modification on the defect state densities, optical properties, photocatalytic and quantum efficiencies of zinc oxide (ZnO) nanoplates have been studied in this work. Here, the aim...

Articulating Biomaterials

2015 ◽  
pp. 218-267 ◽  
Author(s):  
Vamsi Krishna Balla ◽  
Mitun Das ◽  
Someswar Datta ◽  
Biswanath Kundu
Keyword(s):  
Surface Modification ◽  
Clinical Performance ◽  
Decisive Role ◽  
Surface Characteristics ◽  
Surface Modification Techniques ◽  
Biological Environment ◽  
Surface Modified ◽  
In Vivo Effects

This chapter examines the importance of surface characteristics such as microstructure, composition, crystallographic texture, and surface free energy in achieving desired biocompatibility and tribological properties thereby improving in vivo life of artificial articulating implants. Current implants often fail prematurely due to inadequate mechanical, tribological, biocompatibility, and osseointegration properties, apart from issues related to design and surgical procedures. For long-term in vivo stability, artificial implants intended for articulating joint replacement must exhibit long-term stable articulation surface without stimulating undesirable in vivo effects. Since the implant's surface plays a vital and decisive role in their response to biological environment, and vice versa, surface modification of implants assumes a significant importance. Therefore, overview on important surface modification techniques, their capabilities, properties of modified surfaces/implants are presented in the chapter. The clinical performance of surface modified implants and new surfaces for potential next-generation articulating implant applications are discussed at the end.

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