scholarly journals Advancement in Microstructural, Optical, and Mechanical Properties of PVA (Mowiol 10-98) Doped by ZnO Nanoparticles

2014 ◽  
Vol 2014 ◽  
pp. 1-9 ◽  
Author(s):  
N. B. Rithin Kumar ◽  
Vincent Crasta ◽  
B. M. Praveen

The current paper explores the preparation of PVA nanocomposites by doping with zinc oxide (ZnO) nanoparticles using the method of coagulation and solvent casting technique. The dopant zinc oxide nanoparticle is prepared by simple precipitation method and is confirmed by the X-ray diffraction (XRD) studies. The XRD studies explore that the average particle size of the synthesized nanoparticles is 55 nm and show that the crystallinity factor of PVA nanocomposites is influenced by the interaction occurring between the PVA main chain and the ZnO nanoparticle. The FTIR spectroscopy suggests that the formulation of complexes occurring between the dopants and the PVA main chain is due to inter or intra molecular hydrogen bonding. UV-vis spectra explore the dramatic decrease in the optical energy gap of nanoparticles doped polymer composites and the variations of Urbach energy (Eu) related to crystallinity for various dopant concentrations. The mechanical properties of the PVA nanocomposites were explored using universal testing machine (UTM) that reflects that, for x=15% doping concentration, there is an increase in the tensile strength, stiffness, and Young’s modulus, whereas, for x=7.5% concentration, the percentage total elongation at fracture is found to be the maximum. The morphological behavior and homogenous nanoparticle distribution in the composites were examined by scanning electron microscopy (SEM) and energy-dispersive X-ray spectroscopy (EDAX).

2018 ◽  
Vol 4 (4) ◽  
pp. 135-141 ◽  
Author(s):  
V. Porkalai ◽  
B. Sathya ◽  
D. Benny Anburaj ◽  
G Nedunchezhian ◽  
S. Joshua Gnanamuthu ◽  
...  

Recently, transition metal (TM) and rare earth ion doped II–VI semiconductor nanoparticles have received much attention because such doping can modify and improve optical properties of II–VI semiconductor nanoparticles by large amount. In this study, undoped, La doped and La+Ag co-doped ZnO nano particles have been successfully synthesized by sol-gel method using the mixture of Zinc acetate dihydrate and ethanol solution. The powders were calcinated at 600 °C for 2 h. The effect of lanthanum and lanthanum-silver incorporation on the structure, morphology, optical and electrical conductivity were examined by X-ray diffraction (XRD), Scanning Electron Microscope (SEM), Energy Dispersive X-ray Absorption (EDAX), Fourier transform infrared spectroscopy (FTIR), UV and Photo Luminescence (PL) Characterization. The average particle size of the synthesized ZnO nanoparticles is calculated using the Scherrer formula and is found to be of less than 20 nm. Luminescences properties were found to be enhanced for the La and La+Ag co-doped ZnO nanoparticles.


Materials ◽  
2019 ◽  
Vol 12 (5) ◽  
pp. 821 ◽  
Author(s):  
H.S. Ali ◽  
Ali Alghamdi ◽  
G. Murtaza ◽  
H.S. Arif ◽  
Wasim Naeem ◽  
...  

In this work, microemulsion method has been followed to synthesize vanadium-doped Zn1−xVxO (with x = 0.0, 0.02, 0.04, 0.06, 0.08, and 0.10) nanoparticles. The prepared samples are characterized by several techniques to investigate the structural, morphology, electronic, functional bonding, and optical properties. X-ray diffractometer (XRD) analysis confirms the wurtzite phase of the undoped and V-doped ZnO nanoparticles. Variation in the lattice parameters ensures the incorporation of vanadium in the lattice of ZnO. Scanning electron microscopy (SEM) shows that by increasing contents of V ions, the average particle size increases gradually. X-ray Absorption Near Edge Spectroscopy (XANES) at the V L3,2 edge, oxygen K-edge, and Zn L3,2 edge reveals the presence and effect of vanadium contents in the Zn host lattice. Furthermore, the existence of chemical bonding and functional groups are also asserted by attenuated total reflection Fourier transform infrared spectroscopy (ATR-FTIR). UV–Visible analysis shows that by increasing V+ contents, a reduction up to 2.92 eV in the energy band gap is observed, which is probably due to an increase in the free electron concentration and change in the lattice parameters.


2018 ◽  
Vol 24 (8) ◽  
pp. 5618-5623
Author(s):  
Lakkanna S Chougala ◽  
Mahantesh S Yatnatti ◽  
Ravi K Linganagoudar ◽  
Jagadish S Kadadevarmath

In this paper, we have reported the synthesis of zinc oxide (ZnO) nanoparticles by aqueous route method and its characterization. By X-ray diffraction pattern (XRD) study it reveals that ZnO has hexagonal wurtzite structure with average particle size of 16.5 nm. From the results of scanning electron microscope (SEM) and Atomic force microscope (AFM) images, particles were spherical in nature with good aggregation. Stoichiometric ratio of Zinc and oxygen were almost close which was revealed from energy dispersive analysis of X-ray (EDAX). From infrared spectroscopy (FTIR), peak of Zn–O bond appears at 433.43 cm−1. Direct band gap of ZnO was found to be 3.36 eV estimated from UV-Vis absorption spectra. The Photovoltaic properties of DSSC sensitized by Di-tetrabutylammonium cis-bis (isothiocyanato) bis (2,2′ -bipyridyl-4,4′-dicarboxylato) ruthenium(II) (N-719 dye) were obtained in which photo anode is prepared by synthesized ZnO. Photocurrent (I) and photovoltage (V) was measured using designed automated load variable solar simulator and optimum solar energy to electricity conversion efficiency (η) of 2.35% under AM 1.5 irradiation (1000 W/m2) was observed.


2013 ◽  
Vol 24 ◽  
pp. 123-132 ◽  
Author(s):  
S.M. Giripunje ◽  
Jyoti Ghushe

ZnO nanoparticles were prepared by chemical method using starch as capping agent. Also the polyaniline-zinc oxide (PANI-ZnO) nanocomposites were prepared by in-situ polymerization of aniline monomer with ZnO nanomaterials. The structure and morphology of the ZnO nanoparticles were investigated by X-ray diffraction and scanning electron microscopy. X-ray diffraction revealed the wurtzite structure of ZnO. Average particle size of the ZnO nanoparticles were also calculated from XRD. SEM micrographs showed the spherical shape of ZnO nanoparticles. Band gap energy of ZnO nanoparticles was determined from UV absorbance spectra and confirm quantum confinement. In UV-Vis spectra of PANI salt, two absorption peaks are observed at 320 and 630 nm. These absorption peaks arises due to excitation of the benzene segment including amine structures in polyaniline. A considerable large red shift at 360 nm from 320 nm has been observed for PANI-ZnO nanocomposites. This prominent red shift might occur due to the interaction between the hydroxyl groups of ZnO and the quinoid ring of emeraldine salt. Transport properties of PANI-ZnO nanocomposites were studied in terms of transport parameters such as DC electrical conductivity (σ), charge localization length (α-1), most probable hopping distance ® and hopping energy (w) using variable range hopping model as described by Ziller to conducting polymers.


2010 ◽  
Vol 93-94 ◽  
pp. 691-694 ◽  
Author(s):  
Pusit Pookmanee ◽  
Issara Attaveerapat ◽  
Jiraporn Kittikul ◽  
Sukon Phanichphant

Zinc oxide powder was prepared by a chemical co-precipitation method. Zinc nitrate and ammonium hydroxide were used as the starting precursors. The white precipitated powder was formed after adding ammonium hydroxide until the pH of final solution was 7-9. The powder was filtered and dried at 100 °C for 24h. The phase of zinc oxide powder was studied by X-ray diffractometer (XRD). Hexagonal single phase of zinc oxide was obtained without calcination step. The morphology of zinc oxide powder was investigated by scanning electron microscope (SEM). The particle was irregular in shape and highly agglomerated with an average particle size of 0.1 µm. The chemical composition of zinc oxide powder was determined by energy dispersive X-ray spectrometer (EDXS). The elemental composition of zinc oxide showed the characteristic X-ray energy value as follows: zinc of Lα = 1.012 keV, Kα = 8.630 keV and Kβ = 9.570 keV and oxygen of Kα = 0.525 keV, respectively.


Nanomaterials ◽  
2020 ◽  
Vol 10 (9) ◽  
pp. 1661 ◽  
Author(s):  
Muhammad Tayyab Noman ◽  
Michal Petrů

In this study, zinc oxide nanoparticles (nZnO) were synthesized, deposited, and successfully used for surface modification of cotton to enhance antimicrobial properties. An in situ ultrasonic acoustic method was applied to anchor nZnO on cotton. The results of scanning electron microscopy, energy dispersive X-ray spectroscopy, and X-ray diffraction confirmed the presence of nZnO on cotton. A homogenous distribution of nZnO with an average particle size 27.4 nm was found during the analysis of results. Antimicrobial performance of cotton-nZnO (C-nZnO) composites was evaluated against Gram-negative and Gram-positive microbes. The deposited amount of nZnO on C-nZnO composites was determined by volumetric titration through inductive couple plasma atomic emission spectroscopy. C-nZnO composites showed excellent antimicrobial performance especially against both Staphylococcus aureus (Gram-positive) and Escherichia coli. The durability and stability of C-nZnO composites were tested against leaching and washing. No significant fluctuation was found on deposited amount of nZnO before and after washing test for optimized sample. The results demonstrate that synthesized C-nZnO composite samples can be used as an alternative for antimicrobial bandages.


2020 ◽  
Vol 17 (6) ◽  
pp. 823-829
Author(s):  
Ernest Mbamalu Ezeh ◽  
O.D. Onukwuli

Purpose The purpose of this paper is to observe the effect of cheap cow horn ash particles (CHAp) filler as a possible replacement for expensive fillers on the mechanical properties of polyester-banana peduncle fibre (BPF) composites were evaluated using standard procedures. Design/methodology/approach Composite was developed using CHAp as a filler component, polyester resin and BPF, with the filler of varying percentage weights (5%, 10%, 15% and 20%), at particle sizes of 125 µm, using hand lay-up technique. The physicochemical properties of CHAp were examined through x-ray fluorescence (XRF), X-ray diffractometer (XRD), transmission electron microscopy, scanning electron microscope, energy dispersion spectrometric analysis (EDS) and density. Mechanical properties of the developed composites were also examined. Findings The results showed that the tensile properties and impact strength of the composites reduced marginally with the incorporation of the cow horn ash particle as a filler. However, the flexural strength of the composites increased progressively with the incorporation of BPF as the fibre loading increased. The major constituents of CHAp were CaO from XRF study, calcite (CaCO3) from XRD study and Ca in EDS study in accordance with the analytical parameter, which showed a major component of calcium. The high value of CaCO3 in CHAp improved flexural and impact strengths of the composites. CHAp presented around solid and irregular shape particle characteristic of most fillers with an average particle size of 98.13 nm. The tensile and flexural strengths of the polyester matrix composites obtained at 7.5% BPF: 7.5% CHAp was 117.87 MPa depicting satisfactory mechanical characteristics. Originality/value Generally, cow horn ash particle exhibited adequate filler component potential in composite production in keeping with its property effects on the mechanical properties of polyester-BPF composites.


2017 ◽  
Vol 17 ◽  
pp. 101-105 ◽  
Author(s):  
V. Porkalai ◽  
B. Sathya ◽  
Durairaj Benny Anburaj ◽  
G. Nedunchezhian ◽  
R. Meenambika

Zinc oxide has been receiving an enormous attention due to its potential applications in a variety of field such as optoelectronics, spintronics and sensors. Ag and In co-doped ZnO nanoparticles with different doping concentration 0.1M, 0.2M and 0.3M were prepared by sol-gel method via microwave irradiation followed by calcinations at 600°C for 2h. The structure and morphology were examined by X-ray diffraction (XRD), and Scanning Electron Microscope (SEM), respectively. Elemental composition has been estimated by Energy Dispersive X-ray Absorption (EDAX), while chemical properties are studied by Fourier transform infrared spectroscopy (FTIR) and X-ray Photoelectron Spectroscopy (XPS) . The average particle size of the synthesized ZnO nanoparticles was calculated using the Scherrer formula and is found to be of less than 20 nm. Also the effect on the structure and the morphological properties of ZnO when co-doped with silver and Indium is examined. As the process is simple and low cost, it has the potential to be produced on a large scale.


2014 ◽  
Vol 2014 ◽  
pp. 1-10 ◽  
Author(s):  
K. A. Athmaselvi ◽  
C. Kumar ◽  
M. Balasubramanian ◽  
Ishita Roy

This study evaluates the physical properties of freeze dried tropical (guava, sapota, and papaya) fruit powders. Thermal stability and weight loss were evaluated using TGA-DSC and IR, which showed pectin as the main solid constituent. LCR meter measured electrical conductivity, dielectric constant, and dielectric loss factor. Functional groups assessed by FTIR showed presence of chlorides, and O–H and N–H bonds in guava, chloride and C–H bond in papaya, and chlorides, and C=O and C–H bonds in sapota. Particle size and type of starch were evaluated by X-ray diffraction and microstructure through scanning electronic microscopy. A semicrystalline profile and average particle size of the fruit powders were evidenced by X-ray diffraction and lamellar/spherical morphologies by SEM. Presence of A-type starch was observed in all three fruits. Dependence of electric and dielectric properties on frequency and temperature was observed.


2014 ◽  
Vol 968 ◽  
pp. 63-66 ◽  
Author(s):  
Fei Zhao ◽  
Zhan Ling Zhang ◽  
Jun Shuai Li ◽  
Cui Ye ◽  
Ni Li

The microstructure and mechanical properties of the four spring steels with different Si content treated by Q-I-Q-T process were studied by metallographic microscope, MTS, impact testing machine and X-ray stress analyzer. The results show that the tensile strength and yield strength is first increased and then decreased with the increase of Si content, the volume fraction of retained austenite and elongation are fist decreased and then increased when the Si content is less than 2.1%, and the microstructure become finer and homogeneous. When Si content reaches 2.1%, the comprehensive properties of 60Si2CrVA spring steel is the best.


Sign in / Sign up

Export Citation Format

Share Document