Physical properties of the organic polymeric blend (PVA/PAM) modified with MgO nanofillers

2019 ◽  
Vol 53 (20) ◽  
pp. 2831-2847 ◽  
Author(s):  
S El-Gamal ◽  
Adel M El Sayed
Keyword(s):  
Physical Properties ◽  
Ac Conductivity ◽  
Nanocomposite Films ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
Mgo Nanoparticles ◽  
Maximum Value ◽  
Constant E ◽  
Direct Band ◽  
Equilibrium Swelling Ratio

Magnesium oxide/polyvinyl alcohol/polyacrylamide (MgO/PVA/PAM) nanocomposite films were prepared via a solution chemical method. The effect of PVA and MgO nanoparticles (NPs) loading on the physical properties of PAM is discussed. X-ray diffraction reveals that the average MgO crystallite size of the NPs is ∼25 nm, while adding PVA increases the crystallinity of PAM. FTIR spectra confirm the interaction between blend chains and MgO NPs. Differential scanning calorimetry thermograms illustrate the miscibility between the PVA and the PAM. The melting temperature, the glass transition, as well as the equilibrium swelling ratio, depend on the films' composition. PAM showed a transmittance of 87%, that increased to 90% after PVA addition, but decreased to 74% after MgO loading. Meaningful changes are observed in the extinction coefficient and indirect/direct band gap of PAM due to PVA blending and MgO addition. The influence of MgO NPs on the dielectric constant ( ɛ′) of the blend film is reported. The maximum value of AC conductivity of the blend is 4.77 × 10−3 Sm−1, which increased to 8.07 × 10−3 Sm−1 by increasing the MgO loading to 5.0 wt.%. The conduction mechanism changed from the correlated barrier hopping, in the blend, to the large Polaron tunneling with MgO loading. The observed improvements in optical properties and AC conductivity encourage the use of these nanocomposite films in the semiconductors industry.

scholarly journals Effect of Microwave Irradiation on the Physical Properties and Structures of Cotton Fabric

2018 ◽  
Vol 13 (2) ◽  
pp. 155892501801300
Author(s):  
Zhao Xue
Keyword(s):  
Microwave Irradiation ◽  
Physical Properties ◽  
Cotton Fabric ◽  
Chemical Structure ◽  
Irradiation Time ◽  
Morphological Structure ◽  
Microwave Treatment ◽  
Radio Waves ◽  
X Ray Diffraction ◽  
Scanning Calorimetry

Microwaves are high frequency radio waves which are capable of penetrating many materials and causing heat to be generated in the process. To investigate the effect of microwave irradiation on the physical properties, chemical structure, surface morphological structure and fine structure of cotton fabric, cotton fabric was treated with microwave irradiation under variety of conditions in terms of the power and the time of microwave treatment. The breaking strength, breaking elongation, and whiteness of the treated cotton fabric in wet state were investigated. The structures of the untreated and treated cotton were investigated with Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), differential scanning calorimetry (DSC) and X-ray diffraction (XRD). The results show that the physical properties of the treated cotton fabrics were changed with microwave irradiation time and power. The chemical structure and the surface morphological structure did not significantly change. Crystallinity of the treated cotton was changed.

Starch–PVA Nanocomposite Film Incorporated with Cellulose Nanocrystals and MMT: A Comparative Study

2016 ◽  
Vol 12 (1) ◽  
pp. 37-48 ◽  
Author(s):  
Nooshin Noshirvani ◽  
Babak Ghanbarzadeh ◽  
Hadi Fasihi ◽  
Hadi Almasi
Keyword(s):  
Thermal Properties ◽  
Food Packaging ◽  
Moisture Sorption ◽  
Water Vapor Permeability ◽  
Nanocrystalline Cellulose ◽  
Nanocomposite Films ◽  
Vapor Permeability ◽  
Mechanical And Thermal Properties ◽  
X Ray Diffraction ◽  
Scanning Calorimetry

Abstract The goal of this work was to compare the barrier, mechanical, and thermal properties of two types of starch–polyvinyl alcohol (PVA) nanocomposites. Sodium montmorillonite (MMT) and nanocrystalline cellulose were chosen as nanoreinforcements. X-ray diffraction (XRD) test showed well-distributed MMT in the starch–PVA matrix, possibly implying that the clay nanolayers formed an exfoliated structure. The moisture sorption, solubility and water vapor permeability (WVP) studies revealed that the addition of MMT and nanocrystalline cellulose reduced the moisture affinity of starch–PVA biocomposite. At the level of 7 % MMT, the nanocomposite films showed the highest ultimate tensile strength (UTS) (4.93 MPa) and the lowest strain to break (SB) (57.65 %). The differential scanning calorimetry (DSC) results showed an improvement in thermal properties for the starch–PVA–MMT nanocomposites, but not for the starch–PVA–NCC nanocomposites. Results of this study demonstrated that the use of MMT in the fabrication of starch–PVA nanocomposites is more favorable than that of nanocrystalline cellulose to produce a desirable biodegradable film for food packaging applications.

Studies on Metal Oxide Nanoparticle Doped PVP Polymer Nanocomposites

2017 ◽  
pp. 209-224
Author(s):  
Madhu B. J.
Keyword(s):  
Dielectric Constant ◽  
Dielectric Loss ◽  
Loss Tangent ◽  
Dielectric Loss Tangent ◽  
Ac Conductivity ◽  
Stoichiometric Composition ◽  
Magnesium Nitrate ◽  
Mgo Nanoparticles ◽  
Metal Oxide Nanoparticle ◽  
Constant E

Magnesium Oxide (MgO) nanoparticles have been synthesized by solution combustion technique using stoichiometric composition of magnesium nitrate as oxidizer and urea as fuel. Structure of the MgO was studied with the X-ray diffraction (XRD) using Cu-Ka radiation. MgO/polyvinylpyrrolidone (PVP) nanocomposites have been prepared by blending MgO nanoparticles with the polyvinylpyrrolidone. MgO/PVP nanocomposites were characterized by Fourier transform infrared (FTIR) spectroscopy. Frequency dependence of dielectric constant (e'), dielectric loss tangent (tand) and AC conductivity studies have been undertaken on the MgO/PVP nanocomposites in the frequency range 50Hz-5MHz at room temperature. Dielectric properties such as dielectric constant (e') and dielectric loss tangent (tand) are found to decrease with the increase in the frequency. Further, AC conductivity of MgO/PVP nanocomposites was found to increase with an increase in the frequency. Observed variation in the a. c. conductivity with the frequency has been understood on the basis of electron hopping model.

Study on Crystallization Behavior of Liquid Crystalline Polyacrylates Induced Isotactic Polypropylene

2012 ◽  
Vol 182-183 ◽  
pp. 302-306
Author(s):  
Qian Yang Chen
Keyword(s):  
Mass Fraction ◽  
Liquid Crystalline ◽  
Relative Content ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
X Ray ◽  
Nucleation Effect ◽  
Β Phase ◽  
Maximum Value ◽  
Pp Blends

A series of polypropylene (PP) blends were obtained by blending isotactic PP and different mass fraction of liquid crystalline polyacylates (LCP-A) at a proper process program. The effect of LCP-A as a new nucleator on crystallization behacior of isotactic PP has been investigated with wide angle X-ray diffraction (WAXD), polarized optical microscopy (POM) and differential scanning calorimetry (DSC). The experimental results showed that LCP-A in the PP played a role in the heterogeneous nucleation effect, supplied much crystal nucleus, enhanced the crystallization velocity and temperature, and the spherulites became smaller and more homogeneous. Moreover, β-phase in the PP was induced. In addition, the relative content of β-crystal (Kβ) increased with increasing LCP-A content or crystallization temperature, reached a maximum value, and then decreased as the temperature or LCP-A content further increased. Kβ of PP with 0.8% LCP-A isothermally crystallized at 125°C for 1h was 21%. POM results that showed the morphology of β and α spherulite disappeared at 156°C and 172°C, respectively.

New thermally stable poly(amide-imide)/montmorillonite reinforced nanocomposite based on N,N′-pyrromellitoyl-bis-l-valine: synthesis and characterization

2014 ◽  
Vol 21 (1) ◽  
pp. 1-6 ◽  
Author(s):  
Khalil Faghihi ◽  
Narges Dehnavi ◽  
Mohsen Hajibeygi
Keyword(s):  
Main Chain ◽  
Diphenyl Ether ◽  
Nanocomposite Films ◽  
X Ray Diffraction ◽  
Visible Spectroscopy ◽  
Scanning Calorimetry ◽  
Solution Intercalation ◽  
X Ray ◽  
Polymeric Chains ◽  
Uv Visible

AbstractTwo new samples of poly(amide-imide) (PAI)/nanocomposites reinforced montmorillonite containing N,N′-pyrromelitoyl-bis-l-valine moiety in the main chain were synthesized by a solution intercalation technique. PAI 3 as a source of polymer matrix was synthesized by the direct polycondensation reaction of N,N′-pyrromelitoyl-bis-l-valine 1 with 4,4′-diamino diphenyl ether 2 in the presence of triphenyl phosphite, CaCl2, pyridine and N-methyl-2-pyrrolidone. The morphology and structure of the resulting PAI-nanocomposite films 4a and 4b with 5% and 10% silicate particles were characterized by Fourier transform infrared spectroscopy, X-ray diffraction and scanning electron microscopy. The effect of clay dispersion and the interaction between clay and polymeric chains on the properties of nanocomposites films were investigated by using UV-visible spectroscopy, thermogravimetric analysis and differential scanning calorimetry.

scholarly journals Synthesis and investigation of SiO2-MgO coated MWCNTs and their potential application

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Krisztian Nemeth ◽  
Nikolett Varro ◽  
Balazs Reti ◽  
Peter Berki ◽  
Balazs Adam ◽  
...  
Keyword(s):  
Sol Gel ◽  
Inorganic Nanoparticles ◽  
Mechanical And Thermal Properties ◽  
Melt Blending ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
Multiwalled Carbon ◽  
Mgo Nanoparticles ◽  
X Ray ◽  
Transmission Electron

Abstract In the present publication, multiwalled carbon nanotubes (MWCNT) coated with SiO2–MgO nanoparticles were successfully fabricated via sol–gel method to facilitate their incorporation into polymer matrices. Magnesium acetate tetrahydrate and tetraethyl orthosilicate were used as precursors. The coated MWCNTs were characterized by transmission electron microscopy (TEM), X–ray diffraction (XRD) and Raman spectroscopy methods. These investigation techniques verified the presence of the inorganic nanoparticles on the surface of MWCNTs. Surface coated MWCNTs were incorporated into polyamide (PA), polyethylene (PE) and polypropylene (PP) matrices via melt blending. Tensile test and differential scanning calorimetry (DSC) investigations were performed on SiO2–MgO/MWCNT polymer composites to study the reinforcement effect on the mechanical and thermal properties of the products. The obtained results indicate that depending on the type of polymer, the nanoparticles differently influenced the Young’s modulus of polymers. Generally, the results demonstrated that polymers treated with SiO2-MgO/MWCNT nanoparticles have higher modulus than neat polymers. DSC results showed that nanoparticles do not change the melting and crystallization behavior of PP significantly. According to the obtained results, coated MWCNTs are promising fillers to enhance mechanical properties of polymers.

scholarly journals Enhanced electrical conductivity in Zr-Doped (La0.7Ba0.3)(Mn0.5Fe0.5)O3 solid solutions

2020 ◽  
Vol 10 (06) ◽  
pp. 2050032
Author(s):  
Yogesh Kumar ◽  
Jaswinder Pal ◽  
Parambir Singh Malhi ◽  
Rakesh Kumar
Keyword(s):  
Electrical Conductivity ◽  
Solid Solutions ◽  
Ac Conductivity ◽  
Small Polaron ◽  
Negative Temperature ◽  
Solid State Reaction Method ◽  
X Ray Diffraction ◽  
X Ray ◽  
Maximum Value ◽  
Jonscher’S Power Law

The perovskite ([Formula: see text][Formula: see text]([Formula: see text][Formula: see text][Formula: see text]O3, where [Formula: see text] = 0.1, 0.2 and 0.3, ceramics were synthesized by solid-state reaction method. The introductory structural studies were followed through by X-ray diffraction technique and the results have disclosed that all the samples were crystallized into an isolated phase. The Zr substitution in the resulting solid solutions increases the electrical conductivity and the maximum value of ac conductivity has been found to be [Formula: see text]118.8 S [Formula: see text] cm[Formula: see text] for [Formula: see text] = 0.3 at 200[Formula: see text]C (at 1 MHz). The frequency dependence of ac conductivity data follows Jonscher’s power law. The variation of the exponent [Formula: see text] versus temperature follows the nonoverlapping small polaron tunneling (NSPT) model. The dielectric relaxation has been observed to be of non-Debye nature for all measuring temperatures (50–200[Formula: see text]C). The impedance spectroscopy reveals that all the samples exhibit negative temperature coefficient of resistance (NTCR) behavior. The prepared samples (for [Formula: see text] > 1) are supposed to be suitable for cathode materials in SOFCs.

EFFECT OF ANNEALING AT DIFFERENT TEMPERATURES ON THE STRUCTURE AND HARDNESS OF AL85Y8NI5CO2 ALLOY AMORPHOUS STRIPS

2018 ◽  
pp. 60-67
Author(s):  
A. G. Igrevskaya ◽  
A. I. Bazlov ◽  
N. Yu. Tabachkova ◽  
D. V. Louzguine ◽  
V. S. Zolotorevskiy
Keyword(s):  
Heat Treatment ◽  
Amorphous Alloys ◽  
Amorphous Matrix ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
Maximum Value ◽  
Transmission Electron ◽  
Aluminum Solid Solution ◽  
Different Temperatures ◽  
Residual Amorphous Matrix

Aluminum-based metallic glasses are the new promising family of materials. However, the effect of heat treatment on the structure and properties of Al–Y–Ni–Co amorphous alloys has not been widely studied so far. In this paper, Al85Y8Ni5Co2 amorphous alloy strips were obtained by hardening on a rotary copper wheel. The effect of vacuum annealing at temperatures ranging from 100 to 500 °C for 30 minutes on the structure and hardness of these strips was investigated. Transmission electron microscopy, X-ray diffraction analysis, and differential scanning calorimetry were used to study changes in the structure of strips after heat treatment. Vickers microhardness was measured to investigate the effect of annealing on the mechanical properties of strips. The results obtained allowed for the conclusions made about changes in hardness depending on the Al85Y8Ni5Co2 alloy strip structure. It was found that as the temperature rises, strip microhardness increases reaching a maximum value of 575±7 HV after annealing at 350 °C, then it decreases with a further increase in the annealing temperature. It was shown that the Al85Y8Ni5Co2 alloy strips remain completely amorphous and no crystalline phases are detected in their structures after annealing at temperatures up to 250 °C for 30 minutes. A sharp increase in hardness after annealing at 350 °C is associated with 10–30 nm nanocrystals of an aluminum solid solution formed in the amorphous matrix and surrounded by a residual amorphous matrix, while further hardness decrease is associated with the increasing sizes of these crystals and Al3Y and Al19Ni5Y3 intermetallics formed in the structure.

Effect of chromium and phosphorus on the physical properties of iron and titanium-based amorphous metallic alloy films

1991 ◽  
Vol 6 (7) ◽  
pp. 1477-1483 ◽  
Author(s):  
S. DiStefano ◽  
R. Ramesham ◽  
D.J. Fitzgerald
Keyword(s):  
Physical Properties ◽  
Secondary Ion Mass Spectrometry ◽  
Metallic Alloy ◽  
X Ray Diffraction ◽  
Dc Magnetron Sputtering ◽  
Scanning Calorimetry ◽  
Alloy Films ◽  
X Ray ◽  
Polarization Technique ◽  
Secondary Ion

Amorphous iron and titanium-based alloys containing various amounts of chromium, phosphorus, and boron exhibit high corrosion resistance. We report some physical properties of Fe and Ti-based metallic alloy films deposited on a glass substrate by a dc-magnetron sputtering technique. The films were characterized using differential scanning calorimetry (DSC), stress analysis, scanning electron microscopy (SEM), x-ray diffraction (XRD), secondary ion mass spectrometry (SIMS), electron microprobe, and potentiodynamic polarization technique.

Microstructure and Physical Properties of Clay-Polymer Composites

2000 ◽  
Vol 628 ◽  
Author(s):  
T.N. Blanton ◽  
D. Majumdar ◽  
S.M. Melpolder
Keyword(s):  
Composite Materials ◽  
Physical Properties ◽  
Polymer Composites ◽  
Basal Plane ◽  
X Ray Diffraction ◽  
X Ray ◽  
Layered Clay

ABSTRACTClay-polymer nanoparticulate composite materials are evaluated by the X-ray diffraction technique. The basal plane spacing provided information about the degree of intercalation and exfoliation of the 2: 1 layered clay structure. Both intercalation and exfoliation are controlled by the identity of the polymer and the clay:polymer ratio.

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