Oxidation Processes and Phase Changes in Metastable Al-Ti Mechanical Alloys

ABSTRACTOxidation of Al-Ti mechanical alloys with Ti concentrations from 5 to 25 at% was studied and compared to the oxidation of Al powders using thermal analysis in the temperature range of 300–1500 °C in oxygen. Differential scanning calorimetry (DSC) and differential thermal analysis (DTA) with simultaneous thermo-gravimetric analysis (TGA) were used to monitor phase changes and oxidation reactions. Intermediate reaction products were recovered at different temperatures and analyzed using x-ray diffraction (XRD) and scanning electron microscopy (SEM). Oxidation of all samples occurred stepwise. The temperature of the first oxidation step for Al-Ti mechanical alloys correlates with the exothermic formation of the Al3Ti intermetallic at T>700 °C and has a higher rate and greater degree of oxidation than the first oxidation step observed for pure aluminum. The second and third oxidation steps in mechanical alloys and aluminum occur at higher temperatures and both appear to be controlled by changes in the permeability of the Al2O3 films. The effect of the Al2O3 film becomes less noticeable at increased Ti concentrations.

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Study of Pseudoboehmite Synthesis by Sol-Gel Process

Advances in Science and Technology ◽

10.4028/www.scientific.net/ast.45.260 ◽

2006 ◽

Vol 45 ◽

pp. 260-265 ◽

Cited By ~ 19

Author(s):

Antônio Hortêncio Munhoz Jr. ◽

Leila Figueiredo de Miranda ◽

G.N. Uehara

Keyword(s):

Sol Gel ◽

Thermo Gravimetric Analysis ◽

Ammonium Hydroxide ◽

Gravimetric Analysis ◽

X Ray Diffraction ◽

Scanning Calorimetry ◽

X Ray ◽

Sol Gel Process ◽

Different Temperatures ◽

Sol Gel Synthesis

A pseudoboehmite was obtained by sol-gel synthesis using aluminum nitrate as precursor. It was used a 2n full factorial design for studying the effect of the temperature of synthesis, the concentration of ammonium hydroxide, and the radiation dose in the product of sol-gel synthesis. The product of the synthesis was analyzed by scanning electron microscopy, x-ray diffraction of the product (after firing the pseudoboehmite at different temperatures), and it was also analyzed the temperature of endothermic and exothermic transformations using the thermo gravimetric analysis (TG) and differential scanning calorimetry (DSC). The X-ray diffraction data show that α-alumina was obtained at 1100o C.

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DEVELOPMENT OF NANOEMULSION CONTAINING PELARGONIUM GRAVEOLENS OIL: CHARACTERIZATION AND STABILITY STUDY

International Journal of Pharmacy and Pharmaceutical Sciences ◽

10.22159/ijpps.2016v8i12.15108 ◽

2016 ◽

Vol 8 (12) ◽

pp. 271 ◽

Cited By ~ 3

Author(s):

Janice Luehring Giongo ◽

Rodrigo De Almeida Vaucher ◽

Aline Ourique ◽

MÍriam Steffler ◽

Clarissa Piccinin Frizzo ◽

...

Keyword(s):

Particle Size ◽

Storage Temperature ◽

Thermo Gravimetric Analysis ◽

Physicochemical Characteristics ◽

Stability Study ◽

Gas Chromatography Mass Spectrometry ◽

Gravimetric Analysis ◽

Scanning Calorimetry ◽

Different Temperatures ◽

The Stability

Objective: To develop, characterize and evaluate the stability of nanoemulsions containing geranium oil (NEG) at different temperatures (4 °C, 25 °C and 45 °C) for 90 d.Methods: The quantification of oil in the nanostructure was performed by <a href="https://www.google.com.br/url?sa=t&rct=j&q=&esrc=s&source=web&cd=1&cad=rja&uact=8&ved=0ahUKEwiYjL3Niv7OAhVJI5AKHZ-_AeUQFggfMAA&url=https%3A%2F%2Fen.wikipedia.org%2Fwiki%2FGas_chromatography%25E2%2580%2593mass_spectrometry&usg=AFQjCNE3N9EyqMTXtw7u0lxolSlnU5zJfQ">gas chromatography–mass spectrometry</a> (GC-MS). The NEG was prepared in Ultra-Turrex and characterized by determining the particle size, polydispersity indices and pH. The thermo gravimetric analysis (TGA), differential scanning calorimetry (DSC) and transmission electron microscopy (TEM) to evaluate the thermal stability of the compounds, the thermal events and morphological analyses of NEG, respectively.Results: The results allow us to suggest that the use the ultra-turrax method is a strategy good to NEG preparation. The stability of the NEG was strongly influenced by storage temperature, with droplet size increasing rapidly at higher temperatures (45 °C), which was attributed to coalescence near the phase inversion temperature. The NEG submitted the low temperatures (4±2 °C) remained with the same particle size value (164 nm). However, the citronellol and geraniol showed a significant reduction throughout the test even in these conditions of temperature. Thermogram of NEG shows the crystallization peak at the cooling cycle in-20.1 °C and a melting was observed at 1.5 °C. TEM images indicated that NEG was spherical and nanometric.Conclusion: The proposed Ultra-Turrax method is simple which prevents volatilization of GO for the production of NEG. The formulations presented good physicochemical characteristics and stability for 90 d was only achieved in 4 °C.

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Biocomposites of Bio-Polyethylene Reinforced with a Hydrothermal-Alkaline Sugarcane Bagasse Pulp and Coupled with a Bio-Based Compatibilizer

Molecules ◽

10.3390/molecules25092158 ◽

2020 ◽

Vol 25 (9) ◽

pp. 2158

Author(s):

Nanci Vanesa Ehman ◽

Diana Ita-Nagy ◽

Fernando Esteban Felissia ◽

María Evangelina Vallejos ◽

Isabel Quispe ◽

...

Keyword(s):

Mechanical Properties ◽

3D Printing ◽

Water Absorption ◽

Sugarcane Bagasse ◽

Thermo Gravimetric Analysis ◽

Decomposition Temperature ◽

Gravimetric Analysis ◽

Scanning Calorimetry ◽

Cradle To Gate ◽

Bagasse Pulp

Bio-polyethylene (BioPE, derived from sugarcane), sugarcane bagasse pulp, and two compatibilizers (fossil and bio-based), were used to manufacture biocomposite filaments for 3D printing. Biocomposite filaments were manufactured and characterized in detail, including measurement of water absorption, mechanical properties, thermal stability and decomposition temperature (thermo-gravimetric analysis (TGA)). Differential scanning calorimetry (DSC) was performed to measure the glass transition temperature (Tg). Scanning electron microscopy (SEM) was applied to assess the fracture area of the filaments after mechanical testing. Increases of up to 10% in water absorption were measured for the samples with 40 wt% fibers and the fossil compatibilizer. The mechanical properties were improved by increasing the fraction of bagasse fibers from 0% to 20% and 40%. The suitability of the biocomposite filaments was tested for 3D printing, and some shapes were printed as demonstrators. Importantly, in a cradle-to-gate life cycle analysis of the biocomposites, we demonstrated that replacing fossil compatibilizer with a bio-based compatibilizer contributes to a reduction in CO2-eq emissions, and an increase in CO2 capture, achieving a CO2-eq storage of 2.12 kg CO2 eq/kg for the biocomposite containing 40% bagasse fibers and 6% bio-based compatibilizer.

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Synthesis, characterization and corrosion protection properties of polyN-(p-bromophenyl)-2-methacrylamide-co-glycidyl methacrylate on low nickel stainless steel

Journal of Polymer Engineering ◽

10.1515/polyeng.2011.042 ◽

2011 ◽

Vol 31 (2-3) ◽

Cited By ~ 2

Author(s):

Sakvai Mohammed Safiullah ◽

Deivasigamani Thirumoolan ◽

Kottur Anver Basha ◽

K. Mani Govindaraju ◽

Dhanraj Gopi ◽

...

Keyword(s):

Stainless Steel ◽

Corrosion Protection ◽

Glycidyl Methacrylate ◽

Electrochemical Impedance ◽

Thermo Gravimetric Analysis ◽

Gel Permeation Chromatography ◽

Gravimetric Analysis ◽

Scanning Calorimetry ◽

Protection Efficiency ◽

Ft Ir

Abstract The synthesis of copolymers from different feed ratios of N-(p-bromophenyl)-2- methacrylamide (PBPMA) and glycidyl methacrylate (GMA) was achieved by using free radical solution polymerization technique and characterized using FT-IR, 1H and 13C NMR spectroscopy. The thermal stability of the synthesized copolymers was studied using thermo-gravimetric analysis (TGA) and differential scanning calorimetry (DSC). The molecular weight of the copolymer is determined by gel permeation chromatography (GPC). The corrosion performances of low nickel stainless steel specimens dip coated with different composition of copolymers were investigated in 0.5 M H2SO4 using potentiodynamic polarization and electrochemical impedance spectroscopic (EIS) techniques. The polarization and impedance measurements showed different corrosion protection efficiency with change in composition of the copolymers. It was found that the corrosion protection properties are owing to the barrier effect of the polymer layer covered on the low nickel stainless steel surfaces. However, it is observed that the mole ratio of PBPMA and GMA plays a major role in the protective nature of the copolymer.

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Graphene Nanoplates Filled Nylon 6,6 Nanocomposites, Morphological, Thermal, Mechanical and Solvent Uptake Study

Journal of the chemical society of pakistan ◽

10.52568/000762/jcsp/41.03.2019 ◽

2019 ◽

Vol 41 (3) ◽

pp. 388-388

Author(s):

Khalid Saeed Khalid Saeed ◽

Tariq Shah and Ahmad Hassan Tariq Shah and Ahmad Hassan

Keyword(s):

Thermo Gravimetric Analysis ◽

Neutral Red ◽

Gravimetric Analysis ◽

Scanning Calorimetry ◽

Nucleation Effect ◽

Morphological Studies ◽

Solvent Uptake ◽

Nylon 6,6 ◽

Dsc Analyses ◽

Graphene Nanoplates

Effect of graphene nanoplates (GNPs) on the properties of Nylon 6,6 (Nyl 6,6) is investigated in present study. The morphological studies presented that the GNPs were dispersed inside the Nyl 6,6 matrix. The thermo gravimetric analysis (TGA) illustrated that the thermal degradation of nanocomposites samples were started at the range of 350-393 oC, which was appreciably higher than neat Nyl 6,6 (360 oC). The differential scanning calorimetry (DSC) analyses revealed that the crystallization temperature (Tc) of GNPs/Nyl 6,6 increased as increased the addition of GNPs, which might be due to the nucleation effect of GNPs. The mechanical properties of Nyl 6,6 was enhanced by incorporation of GNPs upto the addition of an optimal quantity of filler (5%wt GNPs) into the polymer matrix. The stress yield and Young’s modulus of 5%wt GNPs/Nyl 6,6 was 96.79 and 1.54, N/nm2, respectively. Both Nyl 6,6 and nanocomposites samples were also used for the adsorption of Neutral red chloride (NRC) dye, which significantly remove the dye from the aqueous solution. The neat nylon 6,6 and GNPs (5 and 10 wt%)/Nyl 6,6 adsorbed about 88.49, 93.15, and 93.60% within 2 h, respectively.

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Characterization of Novel Solid Dispersions of Moringa oleifera Leaf Powder Using Thermo-Analytical Techniques

Processes ◽

10.3390/pr9122230 ◽

2021 ◽

Vol 9 (12) ◽

pp. 2230

Author(s):

Nontsikelelo Noxolo Tafu ◽

Victoria A. Jideani

Keyword(s):

Solid Dispersion ◽

Moringa Oleifera ◽

Solid Dispersions ◽

Intermolecular Hydrogen Bond ◽

Thermo Gravimetric Analysis ◽

Analytical Techniques ◽

Gravimetric Analysis ◽

Scanning Calorimetry ◽

Hydrogen Bond Interactions ◽

Leaf Powder

Moringa oleifera leaf powder (MOLP) has been identified as the most important functional ingredient owing to its rich nutritional profile and healthy effects. The solubility and functional properties of this ingredient can be enhanced through solid dispersion technology. This study aimed to investigate the effects of polyethylene glycols (PEGs) 4000 and 6000 as hydrophilic carriers and solid dispersion techniques (freeze-drying, melting, solvent evaporation, and microwave irradiation) on the crystallinity and thermal stability of solid-dispersed Moringa oleifera leaf powders (SDMOLPs). SDMOLPs were dully characterized using powder X-ray diffraction (PXRD), differential scanning calorimetry (DSC), thermo-gravimetric analysis (TGA), and Fourier transform infrared spectroscopy (FTIR). The PXRD results revealed that the solid dispersions were partially amorphous with strong diffraction peaks at 2θ values of 19° and 23°. The calorimetric and thermogravimetric curves showed that PEGs conferred greater stability on the dispersions. The FTIR studyrevealed the existence of strong intermolecular hydrogen bond interactions between MOLP and PEG functional groups. MOLP solid dispersions may be useful in functional foods and beverages and nutraceutical formulations.

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Decellularized liver-regenerative 3D printing biomaterials for cell-based liver therapies via a designed procedure combined with papain-containing reagent treatments and supercritical fluids

Bio-Medical Materials and Engineering ◽

10.3233/bme-211303 ◽

2021 ◽

pp. 1-8

Author(s):

Ching-Cheng Huang

Keyword(s):

3D Printing ◽

Thermo Gravimetric Analysis ◽

Extraction Process ◽

Gravimetric Analysis ◽

Collagen Scaffolds ◽

Scanning Calorimetry ◽

Porcine Liver ◽

Good Thermal Stability ◽

Decellularized Liver ◽

Liver Collagen

BACKGROUND: The biologic scaffolds derived from decellularized tissues and organs have been successfully developed in a variety of preclinical and/or clinical studies. OBJECTIVE: The new decellularized liver-regenerative 3D printing biomaterials were designed and prepared for cell-based liver therapies. METHODS: An extraction process was employed to remove the tissue and cellular molecules from porcine liver via pretreatment of supercritical fluid of carbon dioxide (ScCO2). Varying porosities of the decellularized liver tissues were created using papain-containing reagent treatments after ScCO2. RESULTS: The resulting liver-regenerative 3D printing biomaterials of decellularized liver collagen scaffolds were characterized by Fourier transform infrared spectroscopy, thermo-gravimetric analysis, differential scanning calorimetry and scanning electron microscopy. CONCLUSIONS: The decellularized liver collagen scaffolds with good thermal stability (>150 °C) were obtained and employed as liver-regenerative 3D printing biomaterials for cell-based liver therapies.

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The Influence of Nickel Oxide Nanoparticle Dispersion on the Thermo Stability of Lubricant Oil

International Journal of Nanoscience ◽

10.1142/s0219581x18500448 ◽

2019 ◽

Vol 19 (01) ◽

pp. 1850044

Author(s):

K. Ramachandran ◽

P. Navaneethakrishnan ◽

M. Sivaraja

Keyword(s):

Thermo Gravimetric Analysis ◽

Gravimetric Analysis ◽

Nanoparticle Dispersion ◽

Nio Nanoparticles ◽

Scanning Calorimetry ◽

Lubricant Oil ◽

Nickel Oxide Nanoparticle ◽

Nanoparticles Dispersion ◽

Thermo Stability

The homogeneous and substantial dispersion of nanoparticles into base fluids is vital since the final properties of any nanolubricant are estimated by their quality of stability. This paper addresses the effect of NiO nanoparticles dispersion into SN500 lubricant oil and its nonisothermal thermo stability. The dispersion of NiO nanoparticles is achieved by ultrasonication method. The thermo stability is estimated by Thermo Gravimetric Analysis (TGA), Differential Thermal Analysis (DTA) and Differential Scanning Calorimetry (DSC). The result shows that the thermo stability of base fluid enhances up to 0.3[Formula: see text]wt.% particle concentration then it decreases due to agglomeration of dispersed nanoparticles. The findings recommend that 0.1[Formula: see text]wt.% and 0.3[Formula: see text]wt.% of NiO-nanolubricant can be used for the temperature-dependent applications up to 200∘C.

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Optimization of Curing Conditions and Nanofiller Incorporation for Production of High Performance Laminated Kevlar/Epoxy Nanocomposites

Volume 6A: Materials and Fabrication ◽

10.1115/pvp2018-85067 ◽

2018 ◽

Author(s):

Abdel-Hamid I. Mourad ◽

Mouza S. Al Mansoori ◽

Lamia A. Al Marzooqi ◽

Farah A. Genena ◽

Nizamudeen Cherupurakal

Keyword(s):

Oil And Gas ◽

Mechanical Performance ◽

Thermo Gravimetric Analysis ◽

Applied Pressure ◽

Curing Temperature ◽

Gravimetric Analysis ◽

Epoxy Nanocomposites ◽

Scanning Calorimetry ◽

Curing Conditions ◽

Weight Percentage

Kevlar composite materials are getting scientific interest in repairing of oil and gas pipelines in both offshore and onshore due to their unique properties. Curing is one of the major factor in deciding the final mechanical performance of laminated Kevlar/epoxy nanocomposites. The parameters such as curing time, temperature and applied pressure during the hot pressing will affect chemistry of crosslinking of the epoxy matrix and interaction of epoxy with the Kevlar fiber. The present study is carried out to evaluate the optimal curing conditions of the Kevlar/epoxy nanocomposites. Three different nanofillers (namely Multi walled Carbon nanotubes (MWCNT), Silicon Carbide (SiC) and Aluminum Oxide (Al2O3)) are incorporated in different weight percentage. Differential Scanning Calorimetry (DSC) and Thermo-Gravimetric Analysis (TGA) tests are carried out to determine the thermal stability and optimal curing conditions. Mechanical performance is investigated by conducting flexure, and drop weight tests. The results show that, the optimal curing temperature for maximizing the mechanical properties is at 170°C. Peeling off the Kevlar layers are observed for nanocomposite samples cured under 100°C. Mechanical strength of the composites is enhanced by optimizing the curing conditions and nanofiller contents.

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3D Printed Silicone Meniscus Implants: Influence of the 3D Printing Process on Properties of Silicone Implants

Polymers ◽

10.3390/polym12092136 ◽

2020 ◽

Vol 12 (9) ◽

pp. 2136

Author(s):

Eric Luis ◽

Houwen Matthew Pan ◽

Anil Kumar Bastola ◽

Ram Bajpai ◽

Swee Leong Sing ◽

...

Keyword(s):

Photoelectron Spectroscopy ◽

Weight Bearing ◽

Thermo Gravimetric Analysis ◽

Silicone Implants ◽

Osteoarthritis Of The Knee ◽

Gravimetric Analysis ◽

Scanning Calorimetry ◽

Hydrogel Scaffolds ◽

Custom Made ◽

3D Printed

Osteoarthritis of the knee with meniscal pathologies is a severe meniscal pathology suffered by the aging population worldwide. However, conventional meniscal substitutes are not 3D-printable and lack the customizability of 3D printed implants and are not mechanically robust enough for human implantation. Similarly, 3D printed hydrogel scaffolds suffer from drawbacks of being mechanically weak and as a result patients are unable to execute immediate post-surgical weight-bearing ambulation and rehabilitation. To solve this problem, we have developed a 3D silicone meniscus implant which is (1) cytocompatible, (2) resistant to cyclic loading and mechanically similar to native meniscus, and (3) directly 3D printable. The main focus of this study is to determine whether the purity, composition, structure, dimensions and mechanical properties of silicone implants are affected by the use of a custom-made in-house 3D-printer. We have used the phosphate buffer saline (PBS) absorption test, Fourier transform infrared (FTIR) spectroscopy, surface profilometry, thermo-gravimetric analysis (TGA), X-ray photoelectron spectroscopy (XPS), differential scanning calorimetry (DSC), and scanning electron microscopy (SEM) to effectively assess and compare material properties between molded and 3D printed silicone samples.

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