scholarly journals Structural, Physical, and Mechanical Analysis of ZnO and TiO2 Nanoparticle-Reinforced Self-Adhesive Coating Restorative Material

Materials ◽  
2021 ◽  
Vol 14 (24) ◽  
pp. 7507
Author(s):  
Qura Tul Ain Idrees ◽  
Nazish Gul ◽  
Muhammad Amber Fareed ◽  
Salman Aziz Mian ◽  
Danish Muzaffar ◽  
...  
Keyword(s):  
Water Absorption ◽  
Anatase Phase ◽  
Hexagonal Phase ◽  
Mechanical Analysis ◽  
Control Group ◽  
Micro Hardness ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
Maximum Water ◽  
Hardness Values

This study aimed to modify an EQUIA coat (EC; GC, Japan) by incorporating 1 and 2 wt.% of zinc oxide (ZnO; EC-Z1 and EC-Z2) and titanium dioxide (TiO2; EC-T1 and EC-T2) nanoparticles, whereby structural and phase analyses were assessed using Fourier transform infrared spectroscopy (FTIR) and X-ray diffraction (XRD), respectively. Thermogravimetric analysis/differential scanning calorimetry, micro-hardness, and water absorption analyses were conducted, and the microstructure was studied by scanning electron microscopy/energy-dispersive spectroscopy. FTIR spectra showed a reduction in peak heights of amide (1521 cm−1) and carbonyl (1716 cm−1) groups. XRD showed peaks of ZnO (2θ~31.3°, 34.0°, 35.8°, 47.1°, 56.2°, 62.5°, 67.6°, and 68.7°) and TiO2 (2θ~25.3°, 37.8°, 47.9, 54.5°, 62.8°, 69.5°, and 75.1°) corresponding to a hexagonal phase with a wurtzite structure and an anatase phase, respectively. Thermal stability was improved in newly modified materials in comparison to the control group. The sequence of obtained glass transitions was EC-T2 (111 °C), EC-T1 (102 °C), EC-Z2 (98 °C), EC-Z1 (92 °C), and EC-C (90 °C). EC-T2 and EC-T1 showed the highest (43.76 ± 2.78) and lowest (29.58 ± 3.2) micro-hardness values. EC showed the maximum water absorption (1.6%) at day 7 followed by EC-T1 (0.82%) and EC-Z1 (0.61%). These results suggest that EC with ZnO and TiO2 nanoparticles has the potential to be used clinically as a coating material.

Micro-Hardness and Morphology of LDPE Influenced by Beta Radiation

2014 ◽  
Vol 606 ◽  
pp. 253-256 ◽  
Author(s):  
Martin Ovsik ◽  
Petr Kratky ◽  
David Manas ◽  
Miroslav Manas ◽  
Michal Stanek ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Hardness Test ◽  
Polymer Materials ◽  
Beta Radiation ◽  
Micro Hardness ◽  
X Ray Diffraction ◽  
Depth Sensing ◽  
Surface Layers ◽  
Hardness Values ◽  
Different Doses

This article deals with the influence of different doses of Beta radiation to the structure and mico-mechanical properties of Low-density polyethylene (LDPE). Hard surface layers of polymer materials, especially LDPE, can be formed by radiation cross-linking by β radiation with doses of 33, 66 and 99 kGy. Material properties created by β radiation are measured by micro-hardness test using the DSI method (Depth Sensing Indentation). Individual radiation doses caused structural and micro-mechanical changes which have a significant effect on the final properties of the LDPE tested. The highest values of micro-mechanical properties were reached at radiation dose of 66 and 99 kGy, when the micro-hardness values increased by about 21%. The changes were examined and confirmed by X-ray diffraction.

scholarly journals Relationship between the Stereocomplex Crystallization Behavior and Mechanical Properties of PLLA/PDLA Blends

Polymers ◽  
2021 ◽  
Vol 13 (11) ◽  
pp. 1851
Author(s):  
Hye-Seon Park ◽  
Chang-Kook Hong
Keyword(s):  
Mechanical Properties ◽  
Lactic Acid ◽  
Crystallization Behavior ◽  
Mechanical Analysis ◽  
X Ray Diffraction ◽  
Nucleation Agent ◽  
Scanning Calorimetry ◽  
Nucleation Sites ◽  
Wide Range ◽  
Degree Of Crystallization

Poly (l-lactic acid) (PLLA) is a promising biomedical polymer material with a wide range of applications. The diverse enantiomeric forms of PLLA provide great opportunities for thermal and mechanical enhancement through stereocomplex formation. The addition of poly (d-lactic acid) (PDLA) as a nucleation agent and the formation of stereocomplex crystallization (SC) have been proven to be an effective method to improve the crystallization and mechanical properties of the PLLA. In this study, PLLA was blended with different amounts of PDLA through a melt blending process and their properties were calculated. The effect of the PDLA on the crystallization behavior, thermal, and mechanical properties of PLLA were investigated systematically by thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), X-ray diffraction (XRD), polarized optical microscopy (POM), dynamic mechanical analysis (DMA), and tensile test. Based on our findings, SC formed easily when PDLA content was increased, and acts as nucleation sites. Both SC and homo crystals (HC) were observed in the PLLA/PDLA blends. As the content of PDLA increased, the degree of crystallization increased, and the mechanical strength also increased.

scholarly journals Effect of Sr2TiMnO6 fillers on mechanical, dielectric and thermal behaviour of PMMA polymer

2015 ◽  
Vol 05 (03) ◽  
pp. 1550018 ◽  
Author(s):  
P. Thomas ◽  
B. S. Dakshayini ◽  
H. S. Kushwaha ◽  
Rahul Vaish
Keyword(s):  
Coefficient Of Thermal Expansion ◽  
Thermo Gravimetric Analysis ◽  
Mechanical Analysis ◽  
Gravimetric Analysis ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
Melt Mixing ◽  
Transition Formula ◽  
Thermal Stability Of ◽  
Pmma Polymer

Composites of poly(methyl methacrylate) (PMMA) and [Formula: see text] (STMO) were fabricated via melt mixing followed by hot pressing technique. These were characterized using X-ray diffraction (XRD), thermo gravimetric analysis (TGA), differential scanning calorimetry (DSC), thermo mechanical analysis (TMA) and impedance analyser for their structural, thermal and dielectric properties. The coefficient of thermal expansion (CTE) was measured between 40°C and 100°C for pure PMMA is 115.2 ppm/°C, which was decreased to 78.58 ppm/°C when the STMO content was increased to 50 wt.% in PMMA. There was no difference in the glass transition ([Formula: see text]) temperature of the PMMA polymer and their composites. However, the FTIR analysis indicated possible interaction between the PMMA and STMO. The density and the hardness were increased as the STMO content increased in the PMMA matrix. Permittivity was found to be as high as 30.9 at 100 Hz for the PMMA+STMO-50 wt.% composites, indicating the possibility of using these materials for capacitor applications. The thermal stability of polymer was enhanced by incorporation of STMO fillers.

scholarly journals Microstructure Evolution and Performance Improvement of Hypereutectic Al–Mg2Si Metallic Composite with Ca or Sb

Materials ◽  
2020 ◽  
Vol 13 (12) ◽  
pp. 2714
Author(s):  
Min Zuo ◽  
Boda Ren ◽  
Zihan Xia ◽  
Wenwen Ma ◽  
Yidan Lv ◽  
...  
Keyword(s):  
Heat Treatment ◽  
Molar Ratio ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
Nucleation Behavior ◽  
X Ray ◽  
Primary Mg2si ◽  
Before And After ◽  
And Performance ◽  
Hardness Values

In this article, the modification effects on Al–Mg2Si before and after heat treatment were investigated with Ca, Sb, and (Ca + Sb). In comparison with single Ca or Sb, the samples with composition modifiers (Ca + Sb) had the optimal microstructure. The sample with a molar ratio for Ca-to-Sb of 1:1 obtained relatively higher properties, for which the Brinell hardness values before and after heat treatment were remarkably increased by 31.74% and 28.93% in comparison with bare alloy. According to differential scanning calorimetry analysis (DSC), it was found that the nucleation behavior of the primary Mg2Si phase could be significantly improved by using chemical modifiers. Some white particles were found to be embedded in the center of Mg2Si phases, which were deduced to be Ca5Sb3 through X-ray diffraction (XRD) and field-emission scanning electron microscope (FESEM) analyses. Furthermore, Ca5Sb3 articles possess a rather low mismatch degree with Mg2Si particles based on Phase Transformation Crystallography Lab software (PTCLab) calculation, meaning that the efficient nucleation capability of Ca5Sb3 for Mg2Si particles could be estimated.

The phase behaviour of lipid X at high water concentration

1990 ◽  
Vol 68 (1) ◽  
pp. 345-351 ◽  
Author(s):  
G. Lipka ◽  
H. Hauser
Keyword(s):  
Differential Scanning Calorimetry ◽  
Hexagonal Phase ◽  
Water Concentration ◽  
Critical Micellar Concentration ◽  
High Water ◽  
Phase Behaviour ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
Repeat Distance ◽  
X Ray

The phase behaviour of lipid X at high water concentrations (> 60%) is studied using mainly differential scanning calorimetry (DSC) and X-ray diffraction. The critical micellar concentration (CMC) decreases from 8 × 10−5 M at −2 °C to 4 × 10−5 M at 20 °C. The critical micellar temperature (CMT) is 0 °C and decreases slightly with increasing lipid X concentration. Above the CMC and below the CMT, lipid X forms a lamellar gel phase (Lβ). Above 0 °C and at concentrations ranging from the CMC up to about 0.2 M (20%), lipid X forms small micelles. At even higher concentrations there is a transition to a hexagonal phase, probably hexagonal I. Addition of excess NaCl to lipid X dispersions at concentrations < 0.2 M (20%) has several effects on the phase behaviour of lipid X. (i) The lamellar phase is stabilized up to temperatures of ≈20 °C at [NaCl] ≥ 0.7 M. (ii) NaCl induces a tighter packing of the hydrocarbon chains. (iii) At concentrations > 0.7 M NaCl, the bilayer repeat distance decreases to about 43 Å (1 Å = 0.1 nm).Key words: lipid X, phase behaviour, effects of NaCl, differential scanning calorimetry, X-ray diffraction.

scholarly journals Effects of coating Populus nigra wood with nanoclay

BioResources ◽  
2020 ◽  
Vol 15 (4) ◽  
pp. 8026-8038
Author(s):  
Mostafa Emampour ◽  
Habibollah Khademieslam ◽  
Mohammad Mehdi Faezipour ◽  
Mohammad Talaeipour
Keyword(s):  
Contact Angle ◽  
Water Absorption ◽  
Abies Alba ◽  
Dip Coating ◽  
Populus Nigra ◽  
Control Group ◽  
Performance Parameters ◽  
X Ray Diffraction ◽  
X Ray ◽  
Flexural Resistance

This study evaluated the effects of coating Populus nigra wood with nanoclay by dip-coating and spin-coating. The samples were coated with nanoclay in concentrations of 3, 5, and 7%, and the products were compared with Abies alba wood as standard control for the morphological and moisture properties. Zycosil was also added into nanoclay as an adaptive material. The crystalline and morphological structures were investigated by X-ray diffraction (XRD) and scanning electron microscopy (SEM). Performance parameters including water absorption, contact angle, density, and flexural resistance were investigated. Water absorption was decreased, but the density, flexural resistance, and contact angle were increased in nanoclay treatments compared with the P. nigra control group (P<0.05). The best performance properties were observed at a concentration of 7%. In sum, the concentration of 7% nanoclay in dip-coating decreased water absorption by 250% and increased water angle by 150%, density by 113%, and flexural resistance by 145% compared to P. nigra control group.

scholarly journals Design of CNS-Li2SiO3 Permeable Protective Coatings and Effects on Mortar Matrix

Materials ◽  
2020 ◽  
Vol 13 (7) ◽  
pp. 1733
Author(s):  
Xu Li ◽  
Chonggen Pan ◽  
Dong Li ◽  
Jian Geng ◽  
Na Chen ◽  
...  
Keyword(s):  
Water Absorption ◽  
Sodium Silicate ◽  
Protective Coatings ◽  
Orthogonal Experiment ◽  
Chloride Ions ◽  
Lithium Silicate ◽  
Control Group ◽  
Strength Development ◽  
X Ray Diffraction ◽  
Mortar Matrix

In this paper, we prepared permeable protective coatings composed of lithium silicate (Li2SiO3), where the coating was modified by colloidal nano-silica (CNS). Three levels of lithium silicate (i.e., 30 wt. %; 40 wt. %; 50 wt. %), sodium silicate (i.e., 5 wt. %; 10 wt. %; 15 wt. %), and surfactant (i.e., 0.05 wt. %; 0.1 wt. %; 0.15 wt. %) were involved in this study. An orthogonal experiment design selected the optimal proportion basedon thestrength and water absorption requirements of mortar. The effects of CNS-Li2SiO3 coating on the resistance to permeability of chloride ions and carbonation of specimens were also studied. The outcomes were interpreted using scanning electron microscopy (SEM), X-ray diffraction (XRD), and mercury intrusion porosimetry (MIP) techniques. The results showed that the optimum mix formulation consisted of 40 wt. % of lithium silicate, 10 wt. % of sodium silicate and 0.1 wt. % of surfactant within the mixtures investigated. Meanwhile, compared tothe control group, after the specimens were coated at 21 days curing age of mortar, the strength development, 48-h water absorption, resistance to chloride ions penetration, and carbonation of CNS-Li2SiO3 coated specimenswere improved. This could be attributed to the second hydration, leading to a reduction of the content of Ca(OH)2 and an increase of the amount of C–S–H gel within specimens. Thus, the microstructure of mortar matrix was improved after coated with CNS-Li2SiO3 permeable protective coatings.

Mechanical Properties of Ti-Fe-Sn Biomedical Alloys with or without Aging Treatment

2014 ◽  
Vol 783-786 ◽  
pp. 2423-2428 ◽  
Author(s):  
Hideki Hosoda ◽  
Kenta Kasuya ◽  
Masaki Tahara ◽  
Tomonari Inamura ◽  
Shuichi Miyazaki
Keyword(s):  
Mechanical Properties ◽  
Single Phase ◽  
Volume Fraction ◽  
Solution Treatment ◽  
Aging Treatment ◽  
Aging Effect ◽  
Mechanical Analysis ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
Α Phase

In order to develop new β (bcc) Ti alloys, the Ti-Fe-Sn system was focused and phase constitution, microstructure, mechanical properties of Ti-5mol%Fe-6mol%Sn and Ti-6mol%Fe-3mol%Sn were clarified in addition to aging effect. It was estimated by differential scanning calorimetry (DSC) that α phase is formed at temperature from 773-779K and that β transus temperature is 1019K in both the alloys. X-ray diffraction analysis revealed that, in both alloys, β single phase is formed after the solution treatment (ST) at 1273K followed by water quenching, while α phase is formed after the aging at 773K and 873K for 3.6ks. The formation of α phase is also confirmed by optical microscopy. The volume fraction of α phase reaches to 90% in Ti-5Fe-6Sn and 80% in Ti-6Fe-3Sn after the aging at 873K for 3.6ks. The 0.2% proof stress was increased by aging at 873K from 550MPa to 650MPa in Ti-5Fe-6Sn and 500MPa to 690MPa in Ti-6Fe-3Sn. Besides, apparent Young’s modulus measured by dynamic mechanical analysis was raised by the aging treatment. These changes in the mechanical properties were discussed in connection with α phase precipitation.

The solid solution between platinum and palladium in nature

2013 ◽  
Vol 77 (3) ◽  
pp. 269-274 ◽  
Author(s):  
L. Bindi ◽  
F. Zaccarini ◽  
G. Garuti ◽  
N. Angeli
Keyword(s):  
Solid Solution ◽  
Single Crystal ◽  
Structural Data ◽  
Micro Hardness ◽  
Metallic Elements ◽  
X Ray Diffraction ◽  
X Ray ◽  
Complete Solid Solution ◽  
Hardness Values ◽  
Palladium Platinum

AbstractChemical and structural data are reported for platinum–palladium intermediates from two nuggets found at Córrego Bom Sucesso, Minas Gerais, Brazil. Three grains with simple stoichiometries (i.e. PtxPd1−x with x ∼0.67, ∼0.5 and ∼0.33, which correspond to Pt2Pd, PtPd and PtPd2, respectively) were characterized by single-crystal X-ray diffraction and electron-probe microanalysis. In the absence of single-crystal data it might be tempting to hypothesize that such simple stoichiometries represent distinct mineral species, however structural analyses show that all of the phases are cubic and crystallize in space group Fmm. They are, therefore, natural intermediates in the palladium–platinum solid solution. Reflectance and micro-hardness values are reported for the samples and a comparison with the pure metallic elements made. On the basis of information gained from the chemical and structural characterization it can be concluded that there is a complete solid solution between Pt and Pd in nature. These findings corroborate results from experiments on synthetic compounds.

scholarly journals Mg65Ni20Y15–XAgX (X = 1, 2, 3, 5) alloys prepared via atmosphere controlled induction system

2018 ◽  
Vol 96 (7) ◽  
pp. 810-815 ◽  
Author(s):  
Celal Kursun ◽  
Musa Gogebakan ◽  
Yunus Azakli ◽  
Sezgin Cengiz ◽  
Hasan Eskalen ◽  
...  
Keyword(s):  
Hardness Measurement ◽  
Microstructural Properties ◽  
Micro Hardness ◽  
X Ray Diffraction ◽  
X Ray ◽  
Induction System ◽  
Quantitative Results ◽  
Hardness Values ◽  
Vickers Micro Hardness ◽  
Scanning Electron

In this work, Mg65Ni20Y15–XAgX (X = 1, 2, 3, 5) alloys were manufactured by atmosphere controlled induction system. The effect of Ag ratio on the microstructural properties, micro-hardness, density, and homogeneity of the Mg–Ni–Y alloys were investigated. These alloys were characterized by X-ray diffraction (XRD), optical microscopy, scanning electron microscopy with energy dispersive X-ray (SEM-EDX) and Vickers micro-hardness measurement. According to XRD results, Ni3Y and Mg6Ni phases were observed as well as AgY and Ag17Mg54 phases, which were obtained in alloys. The quantitative results of EDX analysis confirm that the chemical composition of the obtained phases is very close and their homogeneities are so high. The average micro-hardness values of the ingot alloys were measured between 208 and 266 HV for matrix. The elastic modulus and densities of the Mg65Ni20Y15–XAgX (X = 1, 2, 3, 5) alloys increased by increasing Ag in the alloys and they were determined in the range of 58.18–68.12 GPa and 3.14–3.53 g/cm3, respectively.

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