scholarly journals Thermal, Viscoelastic, Mechanical and Wear Behaviour of Nanoparticle Filled Polytetrafluoroethylene: A Comparison

Polymers ◽  
2020 ◽  
Vol 12 (9) ◽  
pp. 1940 ◽  
Author(s):  
Levente Ferenc Tóth ◽  
Patrick De Baets ◽  
Gábor Szebényi
Keyword(s):  
Room Temperature ◽  
Filler Content ◽  
Research Work ◽  
Tensile Modulus ◽  
Al2o3 Content ◽  
Wear Behaviour ◽  
X Ray ◽  
Mechanical Stirring ◽  
Wear Analysis ◽  
Sintering Method

In this research work, unfilled and mono-filled polytetrafluoroethylene (PTFE) materials were developed and characterised by physical, thermal, viscoelastic, mechanical, and wear analysis. The applied fillers were graphene, alumina (Al2O3), boehmite alumina (BA80), and hydrotalcite (MG70) in 0.25/1/4/8 and 16 wt % filler content. All samples were produced by room temperature pressing–free sintering method. All of the fillers were blended with PTFE by intensive dry mechanical stirring; the efficiency of the blending was analysed by Energy-dispersive X-ray spectroscopy (EDS) method. Compared to neat PTFE, graphene in 4/8/16 wt % improved the thermal conductivity by ~29%/~84%/~157%, respectively. All fillers increased the storage, shear and tensile modulus and decreased the ductility. PTFE with 4 wt % Al2O3 content reached the lowest wear rate; the reduction was more than two orders of magnitude compared to the neat PTFE.

scholarly journals Processing Analysis of Nanoparticle Filled PTFE: Restrictions and Limitations of High Temperature Production

Polymers ◽  
2020 ◽  
Vol 12 (9) ◽  
pp. 2044
Author(s):  
Levente Ferenc Tóth ◽  
Patrick De Baets ◽  
Gábor Szebényi
Keyword(s):  
Thermal Stability ◽  
Mass Loss ◽  
Room Temperature ◽  
Sintering Temperature ◽  
Research Work ◽  
Decomposition Analysis ◽  
High Thermal Stability ◽  
Al2o3 Content ◽  
Sintering Process ◽  
Sintering Method

In this research work, unfilled and monofilled polytetrafluoroethylene (PTFE) were investigated. The applied fillers were graphene, alumina (Al2O3), boehmite alumina (BA80) and hydrotalcite (MG70). Graphene and Al2O3 are already known in the literature as potential fillers of PTFE, while BA80 and MG70 are novel fillers in PTFE. Materials were produced by room temperature pressing—free sintering method with a maximum sintering temperature of 370 °C. The mass loss and decomposition analyses were carried out by thermogravimetric analysis (TGA) in two different ways. The first was a sensitivity analysis to gain a better view into the sintering process at 370 °C maximal temperature. The second was a heating from 50 °C up to 1000 °C for a full-scale decomposition analysis. BA80 is a suitable filler for PTFE, as most of its functional groups still existed after the sintering process. Both PTFE and Al2O3 had high thermal stability. However, when Al2O3 was incorporated in PTFE, a remarkable mass loss was observed during the sintering process, which indicated that the decomposition of PTFE was catalysed by the Al2O3 filler. The observed mass loss of the Al2O3-filled PTFE was increased, as the Al2O3 content or the applied dwelling time at a 370 °C sintering temperature increased.

PHASE STRUCTURE, PIEZOELECTRIC AND MULTIFERRIOC BEHAVIOR OF (K0.48Na0.52)NbO3-Co2O3 PIEZOELECTRIC CERAMICS

2011 ◽  
Vol 04 (03) ◽  
pp. 225-229 ◽  
Author(s):  
WENJUAN WU ◽  
DINGQUAN XIAO ◽  
JIAGANG WU ◽  
JING LI ◽  
JIANGUO ZHU
Keyword(s):  
Room Temperature ◽  
Sintering Temperature ◽  
Magnetic Behavior ◽  
Orthorhombic Phase ◽  
Piezoelectric Ceramics ◽  
X Ray Diffraction ◽  
Two Phase ◽  
X Ray ◽  
Solid State Sintering ◽  
Sintering Method

( K 0.48 Na 0.52) NbO 3-x% Co 2 O 3 (x = 0, 0.03 and 0.05) (KNN-x% Co2O3 ) lead-free piezoelectric ceramics were prepared by the conventional solid-state sintering method. An orthorhombic phase was observed for all KNN-x% Co2O3 ceramics at room temperature, and two phase transitions were confirmed by the high temperature X-ray diffraction and the temperature dependence of the dielectric constant. The Co2O3 greatly improves the density and decreases the sintering temperature of KNN ceramics. The KNN-0.05 mol%Co2O3 ceramic exhibits good properties (d33 = 120 pC/N , k p = 0.41, Q m = 213 and T c = 407°C) and a good age stability. The multiferroic behavior was also observed at room temperature for the KNN-0.05 mol%Co2O3 ceramic, as confirmed by P–E loops and magnetic behavior.

Preparation of Calcium Citrate Malate Using Citric Acid and Malic Acid with Calcium Hydroxide Synthesized from Duck Eggshell

2021 ◽  
Vol 897 ◽  
pp. 117-123
Author(s):  
Ronald Allan S. Delos-Reyes ◽  
Marc Andre D. Mecaydor ◽  
Angelu R. Pesito ◽  
Mariah Shaira A. Razon
Keyword(s):  
Citric Acid ◽  
Empirical Model ◽  
Design Of Experiment ◽  
Malic Acid ◽  
Room Temperature ◽  
Research Work ◽  
Calcium Citrate ◽  
X Ray Diffraction ◽  
X Ray ◽  
Main Effects

This research work presents an optimum setting at which the production of calcium citrate malate would have the highest yield. The factors that were varied are temperature and the concentrations of citric acid and malic acid. Duck eggshells were used as the source of calcium. The temperature settings were at room temperature (25°C) and at 80°C, the concentrations of citric acid at 1.5 M and 1.7 M and that of malic acid at 2.2 M and at 2.5 M. Using 23 factorial design of experiment (8 settings), the main effects and the interaction effects were plotted to derive an empirical model to predict the yield of calcium citrate malate. Furthermore, a comparison of x-ray diffraction graphs was conducted to evaluate the final product.

Sintering, Microstructure and Electrical Properties of MnO2 and CuO-Doped [Na0.515K0.485]0.94Li0.06(Nb0.99Ta0.01)O3 Ceramics

2013 ◽  
Vol 770 ◽  
pp. 258-261
Author(s):  
Pornsuda Bomlai
Keyword(s):  
Dielectric Constant ◽  
Grain Size ◽  
Room Temperature ◽  
Secondary Recrystallization ◽  
Lead Free ◽  
Reaction Sintering ◽  
X Ray Diffraction ◽  
X Ray ◽  
Co Doping ◽  
Sintering Method

Ceramics with formula (1-x-y)[Na0.515K0.485]0.94Li0.06(Nb0.99Ta0.01)O3 (NKLNT) xMnO2yCuO (when x, y = 0, 0.005 and 0.01) were prepared by a reaction sintering method. The effects of doping level on sinterability and properties of NKLNT ceramics were studied. The results indicated that the co-doping of MnO2 and CuO was effective in promoting the densification of ceramics. Grain growth during secondary recrystallization was also affected, leading to larger grain size with x, y = 0.01 sample. X-ray diffraction data showed that the orthorhombic tetragonal morphotropic phase boundary existed in all the samples. At room temperature, the dielectric properties of NKLNT ceramics were improved by doping of appropriate MnO2 and CuO content. The temperature dependence of dielectric constant showed a decrease slightly in Curie temperature (TC) with increasing MnO2 and CuO content. The composition with x = 0.005, y = 0 exhibited favorable properties for the promising lead-free piezoelectric candidate material.

Preparation and analysis of polypropylene composites with maleated tea dust particles

2018 ◽  
Vol 25 (2) ◽  
pp. 373-381 ◽  
Author(s):  
Shital R. Lanjewar ◽  
Pravin S. Bari ◽  
Dharmesh P. Hansora ◽  
Satyendra Mishra
Keyword(s):  
Mechanical Properties ◽  
Filler Content ◽  
Research Work ◽  
Tensile Modulus ◽  
Dust Particles ◽  
Swelling Properties ◽  
Polypropylene Composites ◽  
Increasing Trend ◽  
Pp Composites ◽  
Waste Tea

AbstractIn this research work, the recycling of waste tea dust particles was done by preparing the injection moulded polypropylene (PP) composites using different (10–40 wt.%) loadings of tea dust particles as a filler. The tea dust particles were treated with maleic anhydride (MA) and its esterification effect was studied on physico-mechanical (morphology, mechanical, thermal and swelling) properties of tea dust:polypropylene (TD:PP) composites. Surface modification of tea dust particles was observed due to the MA treatment i.e. the esterification effect. The surface morphology of the composites showed better interfacial bonding between the maleated tea dust particles and PP than the untreated particles. The mechanical properties of the maleated TD:PP composites were found to be improved (200–300% higher tensile strength, 250% higher tensile modulus, 43% higher flexural strength and 10% higher hardness) as compared to untreated TD:PP composites. Crystallinity and thermal properties of the maleated TD:PP composites showed increasing trend with increase in filler content. Water absorption tests showed that maleated TD:PP composites absorb less water than that of untreated one. The increment in all these properties is due to the greater compatibility in tea dust particles and PP by MA treatment. Thus, tea dust particles can be suggested for preparation of composite materials.

Sulfur Nanoparticles Improves Root and Shoot Growth of Tomato

2016 ◽  
Vol 8 (4) ◽  
pp. 179 ◽  
Author(s):  
Nidá M. Salem ◽  
Luma S. Albanna ◽  
Amany O. Abdeen ◽  
Qusay I. Ibrahim ◽  
Akl M. Awwad
Keyword(s):  
Room Temperature ◽  
Shoot Growth ◽  
Research Work ◽  
Inhibitory Effect ◽  
X Ray Diffraction ◽  
X Ray ◽  
Green Route ◽  
Root And Shoot Growth ◽  
Temperature Scanning ◽  
Sulfur Nanoparticles

<p>The objective of this research work is to synthesize sulfur nanoparticles by green route and to investigate the beneficial effect on root and shoot growth of tomato. Sulfur nanoparticles (SNPs) synthesized using aqueous extract of <em>Ailanthus altissima</em> leaves at room temperature. Scanning electron microscopy (SEM) and X-ray diffraction (XRD) inspections indicated that nanoparticles are spherical and polydispersed with diameters ranging between 5 and 80 nm. The potential of sulfur nanoparticles for enhancing tomato’s growth, increasing the concentration of sulfur nanoparticles from 100 ppm to 300 ppm cause an increase in root and shoot lengths, while higher concentration 400 ppm and 600 ppm induced an inhibitory effect. Results of this study reveal that SNPs have the potential to enhance root and shoot growth of tomato and the effect is concentration dependent.</p>

scholarly journals Solid gas and electrochemical hydrogenation properties of the R1-xR’xMgNi4-yCoy (R, R’ = Y, La, Ce) alloys

2020 ◽  
Vol 21 (3) ◽  
pp. 503-509
Author(s):  
Yu. V. Verbovytskyy ◽  
I. Yu. Zavaliy ◽  
V. V. Berezovets ◽  
P. Ya. Lyutyy
Keyword(s):  
Room Temperature ◽  
Electrode Materials ◽  
High Rate ◽  
X Ray Diffraction ◽  
Hydrogen Storage Properties ◽  
X Ray ◽  
Powder Sintering ◽  
Related Compounds ◽  
Sintering Method ◽  
Storage Properties

New R1-xR’xMgNi4-yCoy (R, R’ = Y, La, Ce; x = 0.5; y = 0, 1, 2) alloys have been synthesized by powder sintering method, and their crystal structure and hydrogen storage properties have been studied. X-ray diffraction analysis showed that R1-xR’xMgNi4-yCo alloys belong to the MgCu4Sn-type structure. The synthesized alloys absorb hydrogen at room temperature and hydrogen pressure 0.1-10 bar. For some of the studied compounds, the formation of hydrides with cubic and orthorhombic structures was found. Highest hydrogen content is found for the Co-rich compounds: La0.5Y0.5MgNi2Co2H5.18 and La0.5Ce0.5MgNi2Co2H6.48. Electrochemical studies showed that Y-based electrode materials exhibit better electrochemical performance comparing with Ce-doped ones. Highest discharge capacity of 292 mА∙h/g was observed for La0.5Y0.5MgNi3Co, but the best cyclic stability after 50th cycle of 92% was seen for La0.5Y0.5MgNi2Co2. Additionally, obtained results of the electrochemical properties were compared with related compounds. High rate dischargeability of Co-free alloys at I = 1 A/g were twice higher than ones containing cobalt.

scholarly journals Investigations of Damping Capacity and Fretting Wear Behaviour of AlTiN Coated Friction Damper

2020 ◽  
Author(s):  
Maqusud Alam ◽  
Kutubuddin Ansari ◽  
Sunil Kumar Sharma
Keyword(s):  
High Temperature ◽  
Physical Vapor Deposition ◽  
Room Temperature ◽  
Industrial Applications ◽  
Fretting Wear ◽  
Wear Behaviour ◽  
Damping Capacity ◽  
Friction Damper ◽  
Wear Analysis ◽  
Altin Coating

The concept of friction damper is widespread technique and used to reduce the structural vibrations in many industrial applications. These friction dampers are generally coated with low wear rate materials to reduce the fretting wear. This paper investigates the use of physical vapor deposition (PVD) nitride based AlTiN coating material applied over the stainless steel friction damper to enhance the damping capacity and to reduce the fretting wear. A friction test rig has been developed to measure the dynamic hysteresis characteristics of friction damper at high temperature (700 &deg;C). The damping capacity and fretting wear analysis is carried out at room temperature, 300 &deg;C and 600 &deg;C. The force versus displacment characterisitcs curve is used to predict the damping capacity and fretting wear analysis is carried out at microscopic level for the comparision. It is observed that at room temperature AlTiN coated friction damper has not much influence to improve the damping capacity and to reduce the fretting-wear. However, at high temperature it has better damping capacity and less wear in comparision to uncoated friction damper. Wear behaviour in coated and uncoated damper is different at room temperature and at elevated temperature.

Electron Microscopy of Human Gallstones

1971 ◽  
Vol 29 ◽  
pp. 296-297
Author(s):  
C. Wolpers ◽  
R. Blaschke
Keyword(s):  
Electron Microscopy ◽  
Room Temperature ◽  
Bile Pigment ◽  
X Ray Diffraction ◽  
Triclinic Crystal System ◽  
X Ray ◽  
Follow Up Study ◽  
Infra Red ◽  
Main Components

Scanning microscopy was used to study the surface of human gallstones and the surface of fractures. The specimens were obtained by operation, washed with water, dried at room temperature and shadowcasted with carbon and aluminum. Most of the specimens belong to patients from a series of X-ray follow-up study, examined during the last twenty years. So it was possible to evaluate approximately the age of these gallstones and to get information on the intensity of growing and solving.Cholesterol, a group of bile pigment substances and different salts of calcium, are the main components of human gallstones. By X-ray diffraction technique, infra-red spectroscopy and by chemical analysis it was demonstrated that all three components can be found in any gallstone. In the presence of water cholesterol crystallizes in pane-like plates of the triclinic crystal system.

Opening images of synaptic vesicles and calcium localization by means of microwave fixation method

1990 ◽  
Vol 48 (2) ◽  
pp. 182-183
Author(s):  
Vinci Mizuhira ◽  
Hiroshi Hasegawa
Keyword(s):  
Synaptic Vesicles ◽  
Room Temperature ◽  
Osmium Tetroxide ◽  
Sampling Procedure ◽  
Fixation Method ◽  
Potassium Oxalate ◽  
X Ray ◽  
Cacodylate Buffer ◽  
Ultrathin Sections ◽  
Microwave Fixation

Microwave irradiation (MWI) was applied to 0.3 to 1 cm3 blocks of rat central nervous system at 2.45 GHz/500W for about 20 sec in a fixative, at room temperature. Fixative composed of 2% paraformaldehyde, 0.5% glutaraldehyde in 0.1 M cacodylate buffer at pH 7.4, also contained 2 mM of CaCl2 , 1 mM of MgCl2, and 0.1% of tannic acid for conventional observation; and fuether 30-90 mM of potassium oxalate containing fixative was applied for the detection of calcium ion localization in cells. Tissue blocks were left in the same fixative for 30 to 180 min after MWI at room temperature, then proceeded to the sampling procedure, after postfixed with osmium tetroxide, embedded in Epon. Ultrathin sections were double stained with an useal manner. Oxalate treated sections were devided in two, stained and unstained one. The later oxalate treated unstained sections were analyzed with electron probe X-ray microanalyzer, the EDAX-PU-9800, at 40 KV accelerating voltage for 100 to 200 sec with point or selected area analyzing methods.

Sign in / Sign up

Export Citation Format

Share Document