Thermo Gravimetric Analysis

< Nano composites of copper, capped by bis benzimidazole diamide ligand. < Such copper nano composites have not been used in conductivity studies before. < Conductance studies for these thus make this work unique. < The dc conductivity of these composites is much higher than normal.

The dependency on renewable resources of energy in power production is a necessary step that mankind has to take if we want our advances in life and technology to resume. In a century or two, fossil fuels will be depleted, and if we do not start to take action, Energy will be the most expensive and rare item on our planet. Biomass is one of the sources of renewable energy with an advantage of being the closest in characteristics to fossil fuels. The evolved gases are similar to fossil fuel gases which make it the easiest source to switch to, with the least infrastructure required. In this doctoral thesis, the experimental study of the Pyrolysis and gasification of chicken manure is presented. Both evolved gas analysis (EGA) and thermo-gravimetric analysis (TGA) have been investigated in details using different gasifying agents. In EGA, the concentrations and the mass flow rates of different evolved gases were presented and the mass flow rates were used to calculate the energy and carbon conversion efficiencies. Different gases including (N 2 , air, CO 2 , steam, and mixtures) were used as the gasifying agents, and the effect of temperature 600-1000 o C was tested. The effect of adding oxygen to steam gasification at 900 o C was studied and presented in details. In TGA, the degradation and rate of degradation of the mass were analyzed with different gases (N 2 , air, and CO 2 ) for iii various heating rates (5-40 o C/min.) using the extent of reaction, α. The order of reaction model was then used to find the chemical kinetic parameters for the different gases.

The present review concentrates on the fabrication of metal nanoparticles in polymer matrix by ion implantation. This approach is particularly promising for the development of optical composite materials in the production technology. Some examples on ion implantation into different polymer matrix are presented. Solid state and viscous polymer layers were irradiated by Ag + ions with doses up to 1.0 . 10 17 ion/cm 2 . The composites were examined by various methods: Rutherford backscattering (RBS), transmission electron microscopy (TEM) and optical spectroscopy. As follows from electron microscopy and electron microdiffraction data, ion implantation is suited for creation of silver nanoparticles in the near-surface polymer layer. The optical density spectra taken for some of these composites demonstrate that the silver nanoparticles exhibit unusually weak and wide plasmon resonance spectra. The formation of silver nanoparticles in solid polymer layers carbonized by ion irradiation is considered. Based on the Mie theory, optical extinction spectra for metal particles in the polymer and carbon matrices are simulated and compared with optical spectra for complex silver core-carbon sheath nanoparticles. It was shown that the implantation into viscous polymer leads to less carbonization of matrix than in the case of solid substrate. The physics behind experimental optical spectra of the composite is discussed.

Bio-nanomaterials are gaining increasing attention due to their renewable and ecofriendly characteristics. Among these, nanocrystalline cellulose (NCC) stands out as one of the most advanced options. NCC is a highly promising sustainable and renewable nanomaterial, offering different applications across chemistry, food, healthcare, medical components, composite material production, and beyond. In this study, nanocrystal cellulose (NCCs) was successfully extracted from cotton-based textile waste using a combination of chemical and mechanical methods. The cellulose fibres were first subjected to a dilute HCl acid solution for hydrolysis, followed by neutralization and drying. Morphological analysis using optical microscopy and scanning electron microscopy (SEM) revealed that the extracted material, microcrystalline cellulose (MCC), exhibited short fibre structures with diameters ranging from 7-15 µm and lengths up to 300 µm. To reduce the fibre size to the nanoscale, NaOH/urea solution was explored, which allowed for the successful extraction of nanocrystalline cellulose (NCC) in the supernatant, especially under room temperature conditions. Dynamic Light Scattering (DLS) analysis confirmed the presence of nanostructures, with average sizes ranging from 120 nm to 750 nm. Atomic Force Microscopy (AFM) analysis provided further evidence of nanocellulose production, revealing NCC fibres with diameters between 2-4 nm and lengths ranging from 200 nm to 1 µm. Fourier Transform Infrared (FTIR) spectroscopy revealed changes in the chemical structure of the cellulose during treatment, including the conversion of cellulose I to cellulose II, confirming the successful processing of the material into nanocrystalline cellulose.

In this study, bio-based blends of thermoplastic starch (TPS) and polypropylene grafted with maleic anhydride (PP-g-MA) without and with organoclay, Cloisite 30B, were prepared in an internal mixer. A TPS-g-PP copolymer was successfully obtained in melt and its formation was confirmed by SEM. The establishment of this copolymer creates an interpenetrating network leading an intercalated/exfoliated clay nanocomposite. Several analytical, angle X-ray diffraction (XRD), scanning and transmission electron microscopy (SEM, STEM) and dynamic mechanical analysis (DMA) were used to characterize the prepared materials. The nanocomposites mechanical properties were improved, showing an increase of about 11% for the nanocomposite when compared with the neat blend. Biodegradation studies performed in compost revealed good percentage of weight loss for the copolymer with clay addition.

Nanoscale multilayer TiAlNyVN coatings were grown using combined cathodic arcyunbalanced magnetron deposition (arc bond sputtering, ABS) in an industrial-sized physical vapour deposition machine. The thermal behaviour of TiAlNyVN coatings in air was studied using thermo-gravimetric analysis, X-ray diffraction (XRD), scanning electron microscopy and transmission electron microscopy (TEM). Coatings were heat treated in air for 30 min at 550, 600, 638 and 672 8C. Surface oxidation occurred at 0550 8C at the coating surface. V O was found to form at 0600 8C by XRD. V O , TiO , AlVO were identified at 600 2 5 2 5 2 4 8C, with possible Al TiO and VO phases. TEM revealed a non-uniform oxideycoating interface, with preferential oxidation 2 5 2 along columnar grain boundaries, presumably because these provide a fast track for diffusion. At 672 8C, the entire coating volume was oxidised, and the coating spalled.

Nickel(II) complex of [NiL 2 ](ClO 4 ) 2 , where L is an unsymmetrical tridentate ligand of 2-(2-aminoethyl)imino-3-butanone oximehas been synthesized by a template condensation reaction. The complex was characterized on the basis of microanalytical, spectroscopic, and other physicochemical properties. X-ray diffraction study of the complex reveals nickel(II) center in a distorted octahedral environment through two amine nitrogen donors, two imine donors, and two nitrogen atoms of the oxime moieties of the ligand. The antibacterial activity of the complex has been tested against Gram(+) and Gram(-) bacteria. The results of the antibacterial screening indicated that the complex is effective against bacterial growth retardation activity to some extent and its effectiveness is higher forGram(+) bacteria.

Wood is a renewable, bio-based material with a mixture of different properties and qualities, used in numerous applications. Beside many species with high wood qualities several species suffer due to a number of disadvantages, where low hardness and abrasive resistance are characteristic for low-density species. This paper presents examples of on-going European research projects and industrial processes mostly related to wood densification methods. Wood densification is a classical thermohydro-mechanical (THM) wood treatment process, through which density is increased by mechanical compression of wood perpendicular to the grain, by impregnation of cell lumens or cell walls with solutions or melted substances (resins, waxes), or by a combination of both. The purpose is to produce newly designed and engineered materials and products with new property profiles, which would potentially find new markets. In general, the THM processes consist of three stages: plasticization of the wood cells, followed by the actual compression, and finally solidification of the compressed wood in order to prevent elastic spring-back and the moisture-induced set-recovery. The wood densification

The comparative catalytic activities of iron phosphides, FexP (x = 1−3), have been established with phase-pure material grown by chemical vapor deposition (CVD) from singlesource organometallic precursors. This is the first report of the preparation of phase-pure thin films of FeP and Fe2P, and their identity was established with scanning-electron microscopy, X-ray photoelectron spectroscopy, and powder X-ray diffraction. All materials were deposited on fluorine-doped tin oxide (FTO) for evaluation of their activities toward the hydrogen evolution reaction (HER) of water splitting in 0.5 M H2SO4. HER activity follows the trend Fe3P &gt; Fe2P &gt; FeP, with Fe3P having the lowest overpotential of 49 mV at a current density of 10 mA cm−2. Density functional theory (DFT) calculations are congruent with the observed activity trend with hydrogen binding favoring the iron-rich terminating surfaces of Fe3P and Fe2P over the iron-poor terminating surfaces of FeP. The results present a clear...

4-Aminopyridinium oxalate is an organic crystal has been grown by slow evaporation solution growth technique. The solubility of 4-Aminopyridinium oxalate crystal increases with increasing temperature. The structure of 4-Aminopyridinium oxalate is confirmed by single crystal X-ray diffraction method. The title compound crystallizes in the monoclinic system and the space group is C2/c. The presence of various functional groups in the grown crystal is identified from FTIR analysis. The optical property such as transmittance of the grown 4-Aminopyridinium oxalate crystal is obtained from UV-Visible spectroscopic studies. The mechanical stability of the grown crystal has been studied by using Vickers microhardness test and it reveals that 4-Aminopyridinium oxalate crystal is soft category material. The dielectric constant and the dielectric loss of the specimen were also studied.

Carbon nanotubes have unique properties of interest for applications in aerospace, electronics, and biotechnology. However, the properties of different batches of carbon nanotubes can vary considerably depending on chemical purity and the nanotube types present (e.g., diameter and chirality distribution). Distinguishing the constituents of each nanotube batch is challenging, with many different techniques used in concert. Thermogravimetric analysis (TGA) provides one measure of nanotube purity by assessing the material's thermal stability (i.e., how it oxidizes with temperature). Unfortunately, however, TGA analysis requires a relatively large specimen for each measurement (several milligrams), making it inappropriate for rapid screening of incoming materials. Moreover, the measurement provides only an average purity for the analyzed sample, and variability can occur on a much finer level. As many applications will utilize only a small quantity of nanotubes, new approaches are needed to assess variability for a much smaller specimen size. This paper describes a new analysis method that uses a quartz crystal as a miniature microbalance for determining mass changes at elevated temperature. Thin nanotube coatings are spray deposited onto the crystals, and shifts in a crystal's resonance frequency are directly correlated with changes in coating mass during heating due to volatilization of different carbon species. By monitoring the response of the crystal at one or more temperatures, different nanotube specimens can be directly compared. This paper demonstrates concept feasibility by comparing quartz crystal results with conventional TGA analysis and discusses methods for applying the technique in process and quality control settings.

In this investigation, we report facile synthesis of cadmium(II)-thioacetamide nanocomposites in the presence and absence of polyvinyl alcohol under ultrasonic irradiations, using cadmium acetate dihydrate (Cd(CH 3 COO) 2 .2H 2 O), potassium iodide (KI), thioacetamide (TAA, CH 3 CSNH 2 ), and polyvinyl alcohol (PVA) as the starting materials. Results show that in the presence of polyvinyl alcohol sizes of the particles reduce. Characterization of the compounds was carried out by determination of melting point, scanning electron microscopy (SEM), energy dispersive X-ray analysis (EDAX), Fourier transform infrared (FT-IR) spectroscopy, 1 H-NMR spectroscopy and thermogravimetric-differential thermal analyses (TG/DTA). The thermal decomposition of the polymeric nanocomposite, Cd-thioacetamide/PVA in an autoclave under critical condition led to the formation of spherical cadmium sulfide nanoparticles with an average particle size of about 20 nm. The X-ray diffraction pattern at room temperature revealed that highly pure and crystallized CdS with hexagonal structure were obtained. The sonochemical method resulted in a significant reduction of reaction time, reaction temperature and particle size of the products.

Structures with several dimensional length-scales can be integrated with ceramic microsystems by using ceramic processing methods that produce components with novel functions. For example, structures optimized for heat transfer can be incorporated with structures designed for gas separation to produce microreactors in low cost, compact packages. Examples of incorporating multiple forming methods with, and without, one-step densification approaches will be described. This presentation will describe several examples of components incorporating multiscale structures. Typical applications are power electronic heat management, microreactors for chemical processing, and industrial heat exchangers. Features of design optimization methods that are unique to ceramic microsystems will be described. The objective of the presentation is to demonstrate the potential for ceramic microsystems in a broad range of applications and describe the benefits and challenges associated with their design, fa...

student project is described which involves both product and process design in the field of particle technology. This is predominantly a student view of both the technical and educational aspects of the dehydration of boric acid, in which the product specifications as well as the process were initially unknown. Although the final product proved insufficiently stable to moisture for commercial application, the exercise was judged a success by the students, academics and industrial sponsors.

The structural and optical modifications of polysulphone polymer under swift heavy ion (SHI) irradiation have been compared. Polysulphone films were irradiated with 45 MeV Li +3 ions and 120 MeV Ni +9 ions with fluence varying from 3×10 10 to 3×10 12 ions/cm 2 . Optical and structural modifications were characterized by UV-visible spectroscpy and X-ray diffraction (XRD) method. It is observed that optical absorption increases with increasing fluence and the absorption edge shifts towards the red end of the spectrum. The value of band gap shows a decreasing trend with increasing ion fluences of both the ions but a sharp decrease in band gap was observed in case of Ni ion. XRD analysis shows the decrease in peak intensity with increasing fluence.

Ethylene vinyl acetate (EVA) is a copolymer encapsulant used as an interlayer in the industrial photovoltaic module encapsulation process. EVA serves to provide the functions of structural support, electrical isolation, physical isolation/protection and thermal conduction for the solar cell circuit. This paper focuses on thermal properties of slow and fast cure EVA encapsulant material. Phase transition and thermal stability parameters of uncured EVA materials have been studied by employing thermo gravimetric analysis, thermal differential analysis and differential scanning calorimetric. EVA fast cure encapsulant material exhibits superior thermal stability in the range of operational cell temperature.

Biomass has the advantage of net zero carbon emissions and can even achieve negative carbon emission using oxy-fuel combustion with CO2 capture. More than ten million tons of Palm Empty Fruit Bunches (PEFB) annually produce in Indonesia and Malaysia as agricultural residues, which can be used as biofuel. Co-combustion of Palm empty fruit bunches (PEFB) and coal can make up for the adverse effects of high pollutant and high ash content of coal. Oxy-fuel combustion and CO2 capture from flue gases is a near-zero emission technology that can be adapted to both new and existing pulverized coal-fired power stations. In this study, the combustion characteristics of PEFB, Australian coal and their blend with various blending ratios are investigated. First, the feedstock is analyzed via proximate analysis, elemental analysis and calorimetry. The pyrolysis and combustion behavior of PEFB in the air and Oxy-fuel conditions are then investigated by thermogravimetric analysis (TGA). The combusti...

Nanostructured Cr/Co-Al coatings were deposited on Superni-718 substrate by DC/RF magnetron sputtering in the present work. Hot corrosion studies were conducted on bare substrate and the Cr/Co-Al coated Superni-718 after exposure to a molten salt environment of Na 2 SO 4 -60%V 2 O 5 at 900 • C under cyclic conditions. The weight change measurements were made to calculate the cyclic hot corrosion kinetics of the coatings at 900 • C. The microstructural features of the as deposited coatings were characterized by FE-SEM, AFM and XRD. It was observed that the corrosion rate of Cr/Co-Al coated superalloy is lower than that of the uncoated superalloy due to the formation of continuous, dense, adherent and protective oxide scale over the surface of the coatings. The protective oxide scales are basically the thin layer of Cr 2 O 3 , Al 2 O 3 , and CoCr 2 O 4 which has formed over the Cr/Co-Al coated superalloy substrate exposed to molten salt environment at temperature, 900 • C.

N, N-Bis (2-hydroxy ethyl) neem fatty amide (HENFA) was prepared by reacting neem oil with diethanolamine in the presence of zinc oxide as catalyst. HENFA was used as curing agent with acid functional acrylic resin to prepare thermosetting coating compositions. Certain compositions were found to have comparable performance to that of conventional coating system cured by melamine formaldehyde resin.

37 Abstract— This work focused on investigating the thermal behavior of the coniferous tree (beech) and broadleaf tree (beefwood) that are abundantly available in Vietnam during a low-oxygen combustion condition. Pyrolysis in 100% Nitrogen atmosphere, char oxidation and combustion in 3% Oxygen atmosphere were conducted using a Macrothermogravimetric analyzer, from room temperature to 900C. Results showed that, regarding pyrolysis and char oxidation processes, beech biomass has the initial mass loss and the maximum mass loss at higher temperatures compared to beefwood biomass. For the overall combustion process, two stages could be clearly observed in differential thermal analysis curves, which correspond to devolatilization and char oxidation. However, the maximum combustion rate temperature and the char burnout temperature were sharply lower than in the case of pyrolysis and char oxidation that were carried out independently. This is likely due to volatile combustion of gaseous pro...

This study examined the dielectric properties of linear low density polyethylene (LLDPE)/organo-clay nanocomposites including the same amount of maleic anhydride grafted polyethylene (PE-g-MA) and oxidized polyethylene (OxPE) as compatibilizer at different frequencies (10 -1 -10 +7 Hz) and temperatures (237-373 K). The dielectric constant of natural LLDPE remained constant at around 1.5, depending on the temperature rise and frequency while that of LLDPE-PE-g-MA/clay and LLDPE-OxPE/clay nanocomposites increased up to 4.8 and 2.8, respectively, linearly with increasing temperature. Especially in the low frequency region, a Maxwell-Wagner-Sillars polarization was observed in composite structures with an increase in temperature due to the dipolar effect. It has been concluded that the clay in the polymer matrix was more homogeneously dispersed than OxPE due to the compatibilizing effect of PE-g-MA and that different polarization mechanisms were at play for each compatibilizer.

Massive samples of self-standing, well packed, vertically aligned and very long multiwall carbon nanotubes (average diameter 50 nm; length exceeding 3 mm) were synthesized on uncoated silicon by a very efficient thermal chemical vapor deposition (CVD) process. The deposition involves the co-evaporation of camphor and ferrocene in a nitrogen atmosphere and subsequently the pyrolysis of the precursors at 850 °C. The average growth rate was 500 nm/s (1.8 mm/h), with a conversion of approximately 30% in weight of the total hydrocarbon feedstock. The morphology and physical properties of the nanotube forest were characterized by electron microscopy and spectroscopy techniques, thermo-gravimetric analysis and mechanical tests. The analysis showed the presence of negligible amount of carbonaceous by-products and about 6% in weight of ferromagnetic iron clusters. Moreover, the as-grown carpet showed good thermal stability, very interesting mechanical properties, such as elasticity and resistance under compression, and was fully hydrophobic.

In this paper, Ag 2 S nanocrystals were synthesized by the colloidal method at room temperature. The synthesized Ag 2 S nanocrystals were spherical in shape with a diameter of about 10-20 nm and high crystallinity, which were confirmed by the high resolution transmission electron microscope images and selected-area electron diffraction patterns. In order to investigate the electrical properties of the Ag 2 S nanocrystals, a backgate thin film transistor (TFT) device structure was fabricated on SiO 2 /Si substrates. The drain current of TFT composed of Ag 2 S was increased according to the increase in the voltages of drain-source and gate, revealing n-type semiconductor properties. The phase of the Ag 2 S nanocrystals, which is related to their electrical properties, was proved to be α-phase by thermo-gravimetric analysis, differential thermal analysis, and X-ray diffraction.

Hydroxyapatite powders characterized by ionic substitutions both in anionic and cationic sites were successfully prepared by synthesis in aqueous medium. The process parameters were set up to allow the simultaneous substitution of the foreign ions, namely carbonate, magnesium and silicon in the crystallographic site of calcium and phosphorus, keeping in count the competition which arises between atoms destined to occupy the same crystallographic site. The chemico-physical properties of the powders were investigated through several analytical techniques, i.e. X-ray diffraction, infrared spectroscopy, atomic emission spectroscopy and thermo-gravimetric analysis. The results show that the utilization of sodium hydrogen-carbonate as a reactant allows the entering of carbonate into the HA structure, mainly in phosphate position, while sodium is eliminated during the process of the powder washing. The entering of silicon in the HA structure progressively reduces its crystallinity, as also carbonate ions do. Silicate and carbonate ions can enter simultaneously into the HA structure, in biological-like amounts, although they compete for the occupation of the phosphate site; the powder crystallinity is strongly reduced as the content of the two substituting ions increases, so that a limit molar concentration exists where the apatite structure collapses and an amorphous phase forms with the simultaneous formation of crystalline calcium carbonate. Solubility tests, carried out at physiological conditions, reveal an increased calcium release in the HA powders containing silicon compared to the silicon-free HA; the solubility behaviour of the multi-substituted HA powders at physiological conditions makes these materials promising as bioactive bone scaffold, as they are able to continuously supply ions which are essential for the process of bone reconstruction.

Previously we showed that pure struvite could be recovered from wastewater at neutral pH. This omits the need for adding alkalinity to the process. However, at a neutral pH value the reaction is relatively slow making it practically not a good system from an engineering point of view. In this study, electrochemical deposition was evaluated as a means to improve the formation of pure struvite at a neutral pH value. An electrolytic cell with an inert Pt (or graphite) anode and a nickel cathode was set up for the experiment. The generation of OH -via electrochemical reduction of dissolved oxygen slightly increased the interfacial pH near the cathode, resulting in rapid formation of the precipitates. The structure, morphology, composition and thermal properties of the harvested precipitate were analyzed by X-ray diffraction (XRD), scanning electron microscopy (SEM), microscopic analysis, infrared (IR) spectra, energy-dispersive spectrometry (EDS), element analysis (EA) and thermo-gravimetric analysis (TGA). All the analyses support formation of pure struvite in the precipitate.

This paper presents procedures for determining the fractions, chemical compositions and combustion characteristics of Heavy Fuel Oil (HFO). This chemical characterization is requisite for better prediction of thermodynamics behavior of multicomponent fuel such as HFO which consist of thousands of different components. Detailed chemical and physical compositions, molecular weight range and mean molecular weight of individual fractions of fuel enable to use more advanced approaches such as continuous thermodynamics for simulation and modelling. Sequential elution solvent chromatography was used to separate HFO into Saturates, Aromatics, Resins and Asphaltenes (SARA) as gas chromatographic analysis was unsatisfactory to reveal the overall composition of HFO, due to the insufficient 2 volatility in most of the heavy compounds. Subsequent mass spectrometric and elemental analysis showed a wide range of molecular weight distributions for the fractions. The results also indicate that the saturates fraction contains cyclic structures with aliphatic side chains while the aromatics fraction contains tetracyclic aromatic rings with aliphatic side chains. The degree of difference between the Thermo-Gravimetric Analysis (TGA) scans of the fractions in inert and oxidizing atmospheres observed at high temperatures also increases with the degree of functionality of the fractions due to the presumably greater extent of free radical chemistry occurring in an oxidizing environment. The Infrared spectra of the fractions are consistent with what would be expected from a consideration of the solvents used to elute them in column chromatography and supported the classification of the fractions.