Analysis Of Thermal Properties Research Articles

A synergistic experimental and theoretical study elucidating the electronic and thermal properties in spinel CuInSnS4

Quaternary chalcogenides of different structure types continue to be of interest due to the novel physical properties they exhibit and for applications ranging from optoelectronics to energy-related technologies. Herein we report on the electronic and thermal properties of spinel CuInSnS4. UV–vis–NIR spectroscopy indicates strong absorption in the visible-light region with an indirect bandgap of 1.52 eV. First-principles computations corroborate our experimental data and reveal that the band-edge electronic properties are due to strong p−d and s−p hybridization and antibonding interactions. Analyses of temperature-dependent thermal properties together with first principles simulations reveal strong anharmonicity and low-lying optical branches that hybridize with the acoustic modes effectively suppressing thermal conductivity. This intrinsically very low thermal conductivity is much lower than that of related chalcogenides. Our findings are discussed in the light of ongoing interest in quaternary metal chalcogenide materials and may aid in the development of this and similar chalcogenides for applications of interest.

Comparative Analysis of Thermal Properties in Molybdenum Substrate to Silicon and Glass for a System-on-Foil Integration

Advanced electronics technology is moving towards smaller footprints and higher computational power. In order to achieve this, advanced packaging techniques are currently being considered, including organic, glass, and semiconductor-based substrates that allow for 2.5D or 3D integration of chips and devices. Metal-core substrates are a new alternative with similar properties to those of semiconductor-based substrates but with the added benefits of higher flexibility and metal ductility. This work comprehensively compares the thermal properties of a novel metal-based substrate, molybdenum, and silicon and fused silica glass substrates in the context of system-on-foil (SoF) integration. A simple electronic technique is used to simulate the heat generated by a typical CPU and to measure the heat dissipation properties of the substrates. The results indicate that molybdenum and silicon are able to effectively dissipate a continuous power density of 2.3 W/mm2 as the surface temperature only increases by ~15 °C. In contrast, the surface temperature of fused silica glass substrates increases by >140 °C for the same applied power. These simple techniques and measurements were validated with infrared camera measurements as well as through finite element analysis via COMSOL simulation. The results validate the use of molybdenum as an advanced packaging substrate and can be used to characterize new substrates and approaches for advanced packaging.

Numerical study of binary mixture and thermophoretic analysis near a solar radiative heat transfer

The main focus of the current article is to investigate the two-dimensional boundary layer flow of non-Newtonian fluid induced by a linear stretching surface in the streamwise direction. The flow features of non-Newtonian fluid (i.e. shear-thinning and thickening nature of the fluids) are explored with Carreau fluid model. In addition, thermophoresis, Brownian motion, thermal radiation (with Rosseland approximation), binary mixture and activation enthalpy are also incorporated in fluid model for better analysis of thermal and solutal properties. The mathematical modelling of under consider physical problem yields nonlinear partial differential system. The governing mathematical system is first simplified with scaling transformations for the high Reynolds number and then transformed into non-dimensional ordinary differential system by using the similarity variables. Since the governing mathematical system comprised on nonlinear boundary value problem, thus shooting method is utilized for the numerical solution of the fluid flow governing equations. The obtained results followed the qualitative manners of the previously reported data. The computed results for important physical quantities (i.e. velocity, temperature, and concentration) are presented through graphs and then interpreted physically. It is observed that the boundary layer thickness increased for shear thickening fluids (n>1) while it is reduced for shear thinning fluids (n<1). Also, the temperature of shear thinning fluid is higher than shear thickening fluid. In addition, heat generation and thermal radiations enhance the thermal boundary layer. Thermophoretic viscosity effect reduces the concentration profile significantly in the flow domain.

Electron paramagnetic resonance and luminescence spectroscopy of transition metal ion impurities and X-ray-induced radicals in brushite

Calcium phosphates hold paramount importance as the constituents of hard tissue of living organisms. Among them, brushite (CaHPO4·2H2O), also known as dicalcium phosphate dihydrate (DCPD), is a common precursor in phosphate synthesis and is becoming increasingly appealing as a biomaterial for bone regeneration applications. This study presents a comparative analysis of structural, morphological, thermal, and spectroscopic properties of synthetic brushite prepared by the wet precipitation method with several brushite products available from commercial vendors. Electron paramagnetic resonance (EPR) spectroscopy revealed that Mn2+ and Fe3+ ions are common trace impurities in commercial products. Following exposure to X-rays, EPR signals of several phosphorous-related radicals emerge. The annealing of the irradiated samples gives rise to broad thermally stimulated luminescence (TSL) signals in the 40-120 °C range, which correlates with the annealing kinetics of the radicals. The stability of radiation-induced EPR and TSL signals is limited by the phase transformation temperature from brushite to monetite (CaHPO4). The results of this study provide novel insights into the formation and stability of phosphorous-related radicals and demonstrate how minuscule amounts of impurity ions can strongly influence the spectroscopic properties of brushite.

Enhancements in thermal properties of binary alkali chloride salt by Al2O3 nanoparticles for thermal energy storage

The cost-effective molten chloride salts are promising heat transfer fluids for next-generation concentrating solar plants. However, their limited specific heat capacities and thermal conductivities hinder their applications. In this paper, molten salt-based nanofluids based on a binary chloride (50 mol.% NaCl, 50 mol.% KCl) with Al2O3 nanoparticles were proposed to enhance the thermal properties. Firstly, molecular dynamics simulations were employed to investigate the thermal properties of these nanofluids, focusing on various nanoparticle volume fractions within 1100∼1600 K. The findings reveal that as the nanoparticle fraction increases from 0% to 7%, the specific heat capacity and dynamic viscosity improve by ≈14.9% and 34.8%∼38.6%, respectively. Concurrently, the thermal conductivity increases by 10.0%∼16.5%. Then, microstructure evolution was analyzed to elucidate the enhancing mechanism of the thermal conductivity. Specifically, the negatively charged nanoparticle surface selectively attracts Na+ and K+, resulting in the formation of a compressed layer around the nanoparticle where the short-range order of ions was intensified. As a result, the compressed layer serves as a thermal conduit between the Al2O3 nanoparticle and the surrounding salt, resulting in the enhancement of the thermal conductivity. Furthermore, additional analyses of thermal diffusion properties and energy density distributions provide indirect evidence for the existence of the compressed layer where ionic motion is restricted, further validating the enhancing mechanism.

Investigation of Nanostructure of Schiff Base Copper (II) Complex: Synthesis, Characterization, Textural, and Thermal Property Analysis for Evaluating their Effectiveness as Cadmium Sensors with QCM-Based Sensing Method

Investigation of Nanostructure of Schiff Base Copper (II) Complex: Synthesis, Characterization, Textural, and Thermal Property Analysis for Evaluating their Effectiveness as Cadmium Sensors with QCM-Based Sensing Method

Advancing sustainable construction through comprehensive analysis of thermal, acoustic, and environmental properties in prefabricated panels with recycled PET materials

Acoustic and thermal insulation materials play a crucial role in the construction industry as they ensure high-performance applications. This study analyzes three recycled insulations (two derived from PET and one is EPS with graphite additives) for innovative prefabricated panels. A multiphysics, multiscale, and multiobjective approach was developed to analyze the performance of the individual materials and three prototype prefabricated panels incorporating them, combined with numerical analysis enabling the thermal transmittances assessment of a full-scale panel. Thermal investigations were conducted at both small and large scales to assess their performance. Additionally, acoustic sound insulation measurements at both scales and a LCA analysis were carried out. Thermal conductivity of the insulation layer ranges from 0.026 to 0.043 Wm−1K−1. Furthermore, the sound transmission loss exhibits a positive trend with increasing frequencies, reaching approximately 10 dB after 1600 Hz for the 15 cm thick PET insulation. EPS performs exceptionally well at low frequencies, with sound insulation peaks reaching almost 40 dB around 400 Hz. At the large scale, the weighted sound reduction index showed a 3.5 dB increase compared to the reference. The environmental assessment emphasized that 80 % of global warming potential comes from material extraction, stressing the importance of using recycled materials.

Effects of fatty acid esters on mechanical, thermal, microbial, and moisture barrier properties of carboxymethyl cellulose-based edible films

Fatty acid esters being biodegradable and environment friendly has been a sought-after class of molecule for various food grade applications. This work involves the incorporation of fatty acid esters namely cetyl-caprylate and cetyl-caprate in edible Carboxymethyl cellulose -based films. The esters were enzymatically synthesized by esterification of caprylic acid and capric acid respectively with cetyl alcohol at a molar ratio of 1:1, using Candida antarctica lipase B which was immobilized (10 % w/w) at 65 °C. Carboxymethyl cellulose films were prepared. To it, glycerol and by emulsification, cetyl-caprylate or cetyl-caprate esters were amalgamated. Film characterizations involved analysis of surface morphology, mechanical properties, and thermal properties. It was further characterized by X-Ray diffraction analysis, water vapor permeability, and moisture uptake. Barrier property carboxymethyl cellulose films showed significant improvement due to the incorporation of cetyl-caprylate or cetyl-caprate esters. However, when the film's melting point was measured, it was seen that glycerol influenced the thermal properties more prominently than cetyl-caprylate and cetyl-caprate esters. Thus, the addition of an optimized amount of glycerol and cetyl-caprylate or cetyl-caprate esters to the carboxymethyl cellulose films is required for improved mechanical strength and better thermal properties. Further, an antimicrobial well diffusion assay of both the esters established the antimicrobial property of the same, which thereby recommends the addition of the wax esters even more.

Design and characterization of novel Zr-Al-Fe-Y metallic glasses with nanoscale phase separation

We present a new phase-separated Zr-based metallic glass (MG) composition, free of toxic elements (Ni and Cu) prepared in a glass-forming system by alloying addition. The substitution of Y in Zr70-xAl12.5Fe17.5Yx (x = 0–15 at.%) results in phase separation, giving rise to nano-amorphous domains in a glassy matrix. A homogeneous MG feature is observed for low concentrations of Y up to x = 5. Microstructure and thermal property analysis indicate that the glasses with x = 10 and 15 at.% Y exhibit a typical liquid phase separation-induced two-glassy phase (Zr-rich and Y-rich) with droplet-like microstructures (nano-amorphous domains). With increasing Y addition, the domain size increases. The microstructural evolution arising due to phase separation in these alloys is confirmed by a combination of transmission electron microscopy (TEM) and atom probe tomography (APT) analysis. The formation of nanometer-size Y-enriched clusters is confirmed by APT for x = 15.

DFT analysis of mechanical, thermal, half-metallic, and thermoelectric properties of perovskites PrMnO3 and NdMnO3 ortho-manganite

In this study, we present a theoretical investigation of the structural, mechanical, thermal, electronic, magnetic and thermoelectric properties of orthorhombic rare earth perovskites RMnO3 (R=Pr- Nd). We used density functional theory (DFT) and the full-potential linearized augmented-plane wave method (FP-LAPW) as implemented in the WIEN2K package. We found that our proposed compounds are mechanically stable and elastically anisotropic materials. By examining the thermal characteristics of these compounds, we discovered that they exhibit low thermal conductivity, this feature has practical applications in thermal barrier coatings (TBC). Therefore, within both GGA and GGA + U approximations, we found that these materials are half-metal ferromagnetic (HMF) and maintaining their half-metallicity under stress, this suggests that orthorhombic rare earth perovskites RMnO3 might be appropriate for spintronic devices. Finally, we explored the thermoelectric properties as a function of temperatures using Boltzmann transport theory as implemented in the BoltzTrap code.

OH End-Capped Silicone as an Effective Nucleating Agent for Polylactide-A Robotizing Method for Evaluating the Mechanical Characteristics of PLA/Silicone Blends.

Current research on materials engineering focuses mainly on bio-based materials. One of the most frequently studied materials in this group is polylactide (PLA), which is a polymer derived from starch. PLA does not have a negative impact on the natural environment and additionally, it possesses properties comparable to those of industrial polymers. The aim of the work was to investigate the potential of organosilicon compounds as modifiers of the mechanical and rheological properties of PLA, as well as to develop a new method for conducting mechanical property tests through innovative high-throughput technologies. Precise dosing methods were utilized to create PLA/silicone polymer blends with varying mass contents, allowing for continuous characterization of the produced blends. To automate bending tests and achieve comprehensive characterization of the blends, a self-created workstation setup has been used. The tensile properties of selected blend compositions were tested, and their ability to withstand dynamic loads was studied. The blends were characterized through various methods, including rheological (MFI), X-ray (XRD), spectroscopic (FTIR), and thermal properties analysis (TG, DSC, HDT), and they were evaluated using microscopic methods (MO, SEM) to examine their structures.

Mechanical properties of lightweight 3D-printed structures made with carbon-filled nylon

AbstractMaterial extrusion additive manufacturing is a widely used 3D-printing process involving depositing molten thermoplastic materials layer by layer to create a 3D object. Combining material extrusion with composites creates strong, lightweight, and functional parts with unique properties. This study uses chopped carbon fiber reinforcement to investigate polyamide's thermal, rheological, and mechanical properties. The study includes an analysis of the material's thermal properties via differential scanning calorimetry and its flow behavior via rotational rheometry. This study provides a comprehensive understanding of carbon-filled nylon PA material's economic and mechanical properties, which will help optimize its performance for various applications. Tensile and flexural tests were used to appraise the material's strength and stiffness under different loading conditions. A cost analysis was performed to compute the specimen cost as a function of orientation and infill density. The aim was to understand how the type and strategy of infill design impact the material's mechanical properties, helping optimize the performance of components and evaluating its cost.

Analysis of Mechanical and Thermal Properties of Polymer Materials Derived from Recycled Overprinted Metallized PP Films.

Polymer materials and their composites are one of the most frequently used materials in the packaging and food industries. This applies to both disposable and reusable packaging, layered films with barrier properties, as well as densely overprinted polymer films and metallized food wrap films. According to statistical data from Plastics Europe, approximately 40% of processed thermoplastics are used to produce packaging, including single- and multi-layer film packaging. Growing requirements and new EU directives require the use of recycled materials in new products, which is not easy because the properties of recyclates may differ significantly from those of the primary materials with which the former are mixed. This work attempts to analyze the properties of the primary material used to produce a film using the casting method in comparison with the industrial recyclate obtained by the processing of film made of the primary material and then overprinted and metallized. The process of obtaining re-granulates and preparing test samples was presented, and the mechanical, structural, and thermal properties of the tested materials were compared. The conducted research and the obtained results demonstrated the advisability of conducting advanced mechanical recycling, which leads to obtaining re-granulates with repeatable processing properties and thermal and mechanical properties comparable to the original material despite the impurities they contain.

Influence of size and crystallinity of nanohydroxyapatite (nHA) particles on the properties of Polylactic Acid/nHA nanocomposite scaffolds produced by 3D printing

Polylactic acid (PLA) and hydroxyapatite (HA) composite scaffolds have been widely studied for applications in bone tissue engineering (BTE) due to their bioactive and biocompatible properties. However, there is a need for more knowledge about the influence of size and crystallinity of HA nanoparticles (nHA) on the properties of PLA/nHA nanocomposite scaffolds produced by 3D printing. In this study, 3D printing was used to produce PLA nanocomposite scaffolds incorporated with nHA filler with different particle sizes and crystallinities. Initially, the nanocomposites were prepared by casting for 3D printing of scaffolds, which were characterized by analysis of thermal, morphological, physical-chemical, mechanical, and biological properties in vitro. The results showed that the size and crystallinity of nHA particles mainly influenced the scaffolds' mechanical properties, degradation rate, and bioactivity. Incorporating nHA provided a gain in compressive strength compared to pure PLA, superior to natural cancellous bone, which varies between 2 and 12 MPa. The lower crystallinity, 39.46 %, promoted a higher rate of degradation and bioactivity in vitro due to its solubility in the simulated fluid. All nanocomposite scaffolds showed cell viability above 90 %. The scaffolds showed suitable properties for BTE applications.

Multi-walled carbon nanotube reinforcement in polypropylene nanocomposites: comprehensive analysis of thermal behavior, mechanical properties, and dispersion characteristics

Multi-walled carbon nanotube reinforcement in polypropylene nanocomposites: comprehensive analysis of thermal behavior, mechanical properties, and dispersion characteristics

Synthesis and characterization of high-entropy carbide dispersed strengthening tungsten: Mechanical and thermal properties analysis

Carbide dispersion for reinforcement is an effective strategy to enhance the performance of tungsten (W). High-entropy carbides (HECs), when compared to conventional carbides, offer superior thermal stability, hardness, mechanical strength, creep resistance, and wear resistance. This study represents the first successful incorporation of (HfNbTaZr)C as a reinforcing phase into a W matrix, resulting in the formation of a W-HEC alloy. Compared to other carbides such as ZrC, HEC demonstrates improved coherency with the W matrix, resulting in a significant increase in plasticity and enhanced high-temperature stability. This innovative approach paves the way for alloy design in high-temperature applications such as nuclear fusion, providing fresh insights into the enhancement of mechanical properties and thermal stability.

Comprehensive Analysis of Rheological, Mechanical, and Thermal Properties in Poly(lactic acid)/Oxidized Graphite Composites: Exploring the Effect of Heat Treatment on Elastic Modulus.

This study is focused on investigating the rheological and mechanical properties of highly oxidized graphite (GrO) incorporated into a poly (lactic acid) (PLA) matrix composite. Furthermore, the samples were annealed at 110 °C for 30 min to study whether GrO concentration has an effect on the elastic modulus (E') after treatment. The incorporation of GrO into PLA was carried out by employing an internal mixing chamber at 190 °C. Six formulations were prepared with GrO concentrations of 0, 0.1, 0.5, 1, 1.5, and 3 wt%. The thermal stability, thermomechanical behavior, and crystallinity of the composites were evaluated utilizing thermogravimetric analysis (TGA), dynamic mechanical analysis (DMA), and differential scanning calorimetry DSC, respectively. The thermal stability (according to Tmax) of the PLA/GrO composites did not change substantially compared with PLA. According to DSC, the crystallinity increased until the GrO concentration reached 1 wt% and afterward decreased. Regarding the heat treatment of the PLA/GrO composites, the E' increased (by two orders of magnitude) at 80 °C with the maximum value achieved at 1 wt% GrO compared with the non-heat-treated composites.

Understanding sensing mechanism of N-doped graphene-based toxic gas sensors using electronic, thermal, mechanical, electrical, and sensing properties:A DFT study

A facile and feasible protocol for the evolution of sensing characteristics of three dissimilar nitrogen-doped graphene (N-G)-based ethanol, methanol, and nitrogen-oxide gas sensors using first-principle calculations. Simulated X-ray diffraction (XRD) investigation demonstrates the sharp peak located at 7.9, 11, 13.8, and 15.4° represents (100), (111), (026), and (012) facets. Electronic properties calculations predict that toxic gas adsorption reduces the charge carrier concentration and induces internal resistance. Thermal properties analyses suggest that the nature of adsorption depends on changes in Gibbs free energy. Charge density and distribution analysis disclose that the adsorption of toxic gases leads to charge transfer between toxic gases and N-G. Mechanical properties analyses predict the mechanical superiority. The N-G's electrical conductivity and resistivity of are 49.95 × 103 Ω/m, and 2 × 10−5 Ω-m respectively. The electrical properties demonstrate that the adsorption of toxic gases would be a reason for the change in electrical conductivity and resistivity. The sensing response of N-G-M in terms of resistivity is 96.04 %. The sensing response of ethanol, NO are 17.12 %, and 5.95 %. Responses of N-G-E, N-G-M, N-G-N″-Z are 0.01, 0.06, 0.14 respectively.

Synthesis of Bis(cyclic carbonates) from Epoxy Resin under Microwave Irradiation: The Structural Analysis and Evaluation of Thermal Properties.

This article describes the use of microwave irradiation in the synthesis of bis(cyclo carbonate) compounds (BCCs) in bulk (without solvent) from carbon dioxide capture using an epoxidized compound-a commercial epoxy resin-and compares this process to the conventional method. CO2 cycloaddition to epoxides is an ecological and efficient method for the formation of bis(cyclic carbonates). Moreover, the introduction of gas into the reaction mixture was carried out at atmospheric pressure with a controlled flow rate, which is advantageous from an economic point of view. Progressive structural changes and the presence of characteristic chemical groups were monitored using attenuated total reflectance infrared spectroscopy with Fourier transform. The obtained crude products were purified to obtain three fractions, which were subjected to detailed structural analysis using FT-IR and 13CNMR. The formation of the main product with two cyclic carbonates was confirmed. The presence of monomers, dimers and trimers in individual fractions as well as their thermal stability were determined, and the molecular masses in individual fractions were determined using gel permeation chromatography (GPC).

Creation of a boron carbide-based Ti3AlBC (312) MAX phase: a route to novel MXenes for energy storage.

A novel boron carbide (B4C)-based Ti3AlBC (312) MAX phase was predicted for the first time via density functional theory (DFT). The stability of the MAX phase was confirmed by mechanical and thermal property analyses. The computational details revealed the attractive properties of Ti3AlBC, indicating its potential as an advanced material with improved characteristics. Its thermodynamic properties are reported as a function of temperature, indicating its potential for energy storage applications.