Analysis Of Thermal Properties Research Articles

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.

Mechanical and Thermal Properties Analysis on Bitumen Mixture with Additives: HDPE, PP and Lignin

Mechanical and Thermal Properties Analysis on Bitumen Mixture with Additives: HDPE, PP and Lignin

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.

Characterisation of Bio composites for Bio-Manufacturing: Jute-reinforced Bacterial Cellulose for Construction

This research investigates the biological, mechanical and thermal characterisation of the jute-reinforced bacterial cellulose biocomposites to forecast their potential and performance in bio-manufacturing for architectural construction. The experimental trial-and-error-based methodology involves seven stages: Material formulation, manufacturing of biocomposite samples, mechanical testing, scanning electron microscopy analysis, thermogravimetric analysis, and biodegradation assessment. The results indicated that the use of biobased construction materials has a potential to reduce carbon footprint, while the addition of jute fibres resulted in enhanced mechanical properties such as higher elasticity and desirable stiffness compared to pure bacterial cellulose. Moreover, slight distinctions in thermal property analysis and biodegradation assessments across the specimens are observed. The findings contribute valuable data for material selection, design optimization, and structural considerations in the integration of these biopolymers into construction practices. Overall, this research aligns with the broader objective of advancing ecological construction starting from the material formulations, thus addressing the scalability of these materials, considering their potential for large-scale adoption in the construction industry.

Energizing the Thermal Conductivity and Optical Performance of Salt Hydrate Phase Change Material Using Copper (II) Oxide Nano Additives for Sustainable Thermal Energy Storage

Due to intermittent nature of solar energy, scientists and researchers are working to develop thermal energy storage (TES) systems for effectively use the solar energy. One promising avenue involves utilizing phase change materials (PCMs), but primary challenge lies in their limited thermal conductivity, which results in slower heat transfer rate and lower thermal energy storage density. The present research work demonstrates, to develop and explore a PCM composite by embedding salt hydrate and coper (II) oxide to enhance the heat transfer mechanism for potential utilization of TES material. The optical behavior, and thermal conductivity were analyzed by using Ultraviolet visible spectrum, and thermal property analyzer. The developed copper oxide dispersed PCM composite displayed the thermal conductivity was energized up to 71.5 % without affecting the other properties. Also, the optical absorptance was remarkably enhanced and the transmittance reduced to 87 %. Increasing the concentration of copper oxide nanoparticles in the salt hydrate PCM improves the optical absorptivity and heat conductivity. With these extraordinary abilities the nanocomposite could play a significant role in progress of sustainable TES with significance to contribute towards sustainable development goal of affordable and clean energy and climate change.

Comparative Analysis of Mechanical and Thermal Properties of Lime Concrete Blocks Made with Pigeon Pea and Carrot Grass Plants as Partial Replacement of Fine Aggregates

Comparative Analysis of Mechanical and Thermal Properties of Lime Concrete Blocks Made with Pigeon Pea and Carrot Grass Plants as Partial Replacement of Fine Aggregates

Analysis of thermal properties of main sedimentary rocks in the Beijing area

The Beijing area is abundant in geothermal resources, yet there has been limited research on the thermal properties of rocks and their influencing factors. This paper focuses on the thermal properties of sedimentary rocks in the region, conducting experimental analysis to investigate these properties and their influencing factors. The experiment involved collecting primary sedimentary rock outcrop samples from around Beijing, testing the thermophysical parameters of 48 samples using a Hot Disk thermal constant analyzer. By combining this data with the standard stratum profile and historical information about Beijing, the thermal conductivity of the formation was calculated using the harmonic mean method, allowing for an analysis of the thermal properties of primary sedimentary rocks in the study area. The results indicate that overall distribution of thermal conductivity for sedimentary rocks in the Beijing area ranges from 1.48 to 6.55 W/(m·K), while thermal diffusivity ranges from 0.76 × 10−6 to 4.04 × 10−6 m2/s, and specific heat distribution ranges from 0.57 to 2.52MJ/(m3·K). Furthermore, according to harmonic mean calculations, it was found that Jixian formation exhibits the highest thermal conductivity value, whereas Triassic formation displays the lowest. This study on the thermal properties of sedimentary rocks provides valuable insights for the geothermal field research in the Beijing area.

Cellulose-based sustainable packaging of leafy vegetables: an experimental study on the shelf life of baby spinach

A novel bio-based and compostable cellulose film (NF) was studied for the packaging of fresh baby spinach, with results compared to a petroleum-derived non-biodegradable polypropylene (PP) film, currently used to market the same product. Baby spinach is a leafy vegetable with high metabolic activity. A preliminary analysis of the product respiration rate was conducted to select the cellulose film grade. The chosen NF film ensures the optimal O2 and CO2 concentration in the headspace, performing even better than the conventional PP film. In fact, when the leafy vegetable is packed within PP, after 15 days of storage, no equilibrium value of gas concentration was reached, which, upon longer storage, might cause anaerobic conditions and off-odor development. Baby spinach leaves packed with NF film showed a slower decrement in texture properties and total antioxidant capacity during storage with respect to control samples, but also a larger weight loss, mostly due to the high-water permeability of the cellulose. However, water condensation upon storage was noted for both packaging materials. Analysis of mechanical, thermal, and barrier properties of the NF film before, during, and after use probed no deterioration of material properties, confirming the potentiality of this polymer for sustainable packaging of fresh leafy vegetables.

Effect of processing on thermal properties of pentaglycerine-based solid-solid phase change materials

Plastic crystals hold great potential for compact and cost-effective thermal energy storage (TES) systems due to their solid-solid transitions, high latent heat, and tunable transition temperatures. However, the impact of processing on their thermal properties remains underexplored. Pentaglycerine (PG)-based composites, suitable for TES applications at 80 °C, doped with two sizes of expanded graphite (EG) are investigated in this work. Effects of pressing and casting and common processing methods are evaluated. A comprehensive analysis of key thermal properties characterizing phase change materials was conducted. Specifically, the research focuses on the evaluation of thermal conductivity in both radial and axial directions, performing a thorough study of latent heats and subcooling using differential scanning calorimetry, conducting in situ characterization through solid-state nuclear magnetic resonance, and assessing solid-solid transition kinetics. This study highlights the significant influence of processing on the thermal properties of organic plastic crystals. Adequate processing enhances the effectiveness of EG in addressing the low thermal conductivity of plastic crystals and preventing latent heat drops associated with nanoconfinement effects. Additionally, notable reductions in subcooling can be achieved in PG-based composites simply through this processing, by reducing grain size and consequently lowering the activation energies in the plastic-to-crystal transitions.

Synthesis and fabrication of lightweight microcellular thermoplastic polyimide foams using supercritical CO2 foaming

Polyimide foams (PIFs) are usually synthesized by solution polymerization, followed by chemical foaming to prepare thermosetting foam. In this research, lightweight microcellular thermoplastic polyimide foams (TPIFs) were fabricated via a novel two-step foaming approach using supercritical carbon dioxide (scCO2) as a blowing agent. The poly(amic acid) (PAA) and polyester ammonium salt (PEAS) precursor solutions were synthesized with pyromellitic dianhydride (PMDA) as dianhydride reagents and polyether amine Jeffamine D230 as aliphatic diamine reagent via blending and solution polymerization, respectively. The solution polymerization process demonstrated a higher molecular weight and superior formability than the blending process. The optimum thermal imidization temperature of 200 °C was optimized via the thermal and rheological property analysis. The cell morphology and mechanical properties of the TPIFs could be turned by varying the saturation time, foaming pressure, and imidization temperature. At a thermal imidization temperature of 200 °C, the TPIFs exhibited a branched structure with a small mean cell diameter (123.78 μm), and a high compressive strength (0.4 MPa) under 10 % strain at high temperature and pressure, which was more than ten times that of the TPIFs with thermal imidization temperature of 130 °C. This research provides a feasible method for producing high volume expansion ratio TPIFs with adjustable microcellular structures and outstanding mechanical properties.

Pembuatan Poliuretan Sebagai Bahan Pelapis Besi Dengan Pengisi Cangkang Kulit Telur

Research on the manufacture of polyurethane as an iron coating material with an eggshell filler has been done. The purpose of this study was to determine the effect of eggshell weight as an additive on the preparation of polyurethane as an iron coating material and to determine the weight effect of Methylene Diphenyl Diisocyanate (MDI) on the manufacture of polyurethane as an iron coating material with an eggshell filler. By mixing Jatropha oil polyols, Methylene Diphenylene Diisocyianate (MDI), and eggshell, then applied to an iron plate. Polyurethane coatings formed in the analysis of thermal adhesion properties of coatings, Thermal (TGA), functional groups (FT-IR), crystal structures (XRD), and coating morphology (SEM). The results obtained which in addition to the ratio of polyol: isocyanate: eggshell shell of 7: 3: 5% obtained the best results that have the strongest adhesion and has a good mixing structure, and has a heat resistance of 300 0C

Thermal behaviour of Paraffin-MWCNT stabilized by Sodium dodecylbenzene sulphonate nano-enhanced phase change material for energy storage applications

The Phase change materials (PCMs) possess the great potential to store renewable and sustainable thermal energy that can mitigate the issue of energy to a great extent. However, the low thermal conductivity hinders the extensive use of PCM in various applications. To alleviate this deficiency, the PCMs are often incorporated with highly conductive nanoparticles. The carbon-based nanoparticles are highly regarded to be a promising option because of their elevated thermal conductivity like Multiwall carbon-nanotube (MWCNT). However, these highly conductive nanoparticles sometimes exhibit the issue of non-uniform dispersion with PCM. In this paper, we report the use of surface-modified MWCNT by using stabilized Sodium dodecylbenzene sulphonate surfactant (SDBS) with Paraffin wax (PW) RT47 at wt% 0.1 and 0.3 of MWCNT. The sample is created by using two-step method. Further, for characterization; chemical composition by Fourier transform infrared spectroscopy (FTIR), thermal conductivity by thermal property analyzer (TEMPOs) and for thermal stability, thermal gravimetric analyzer (TGA) is used. The results showed a significant enhancement in the thermal conductivity of composite PCM, the inclusion of 0.1 and 0.3 wt% of surface-modified MWCNT increased the thermal conductivity up to 51.29% and 76.5% respectively. The FT-IR confirms that the components are physically mixed in NePCM composite, no chemical reaction appeared as no displacement of characteristic peaks or a new peaks appeared. TGA results showed the prepared nano-enhanced phase change material (NePCM) is stable. Thus, surface modification of MWCNT by using SDBS for PW can be the effective method to boost the overall performance of NePCM without losing its basic characteristics. Therefore, based on results, it can be concluded that the surface modified Paraffin/MWCNT NePCM is well suited for applications like energy storage, photovoltaic thermal system, and battery thermal management. PCM showed enhanced thermo-physical properties. Therefore, it might be the candidate for energy storage and other thermal practical applications in future.

Investigating the optical absorption and thermal conductivity of nano-enhanced lauric acid phase change material for energy storage application

The issue of energy storage can be significantly reduced owing to phase change materials’ (PCMs) tremendous capacity for storing latent heat in a reliable and sustainable method. The limited thermal conductivity, however, prevents PCM from being widely used in a variety of uses. Highly conductive nanoparticles (NPs) are frequently integrated into PCMs to address this shortcoming. Due to their high thermal conductivity, such as Graphene (GR), carbon-based NPs are considered potential NPs to be implemented in PCMs. Herein, we report the Lauric acid (LA) PCM, and nano-enhanced LA with 0.3% and 0.7% additions of GR NPs. The composites were prepared by using two-step method. The samples were examined thermo-physically; thermal conductivity was obtained using a thermal property analyzer (TEMPOs), chemical composition was identified using Fourier transform infrared spectroscopy (FTIR), photo-transmittance by Ultra-Violet Visible spectra (UV-Vis) and thermal stability was assessed by employing thermal gravimetric analyzer (TGA). As per results, thermal conductivity of LA was enhanced by 13.5% and 18.4% by inclusion of 0.3 and 0.7 weight percentages of GR NPs. The 0.7 weight percentage addition of GR NPs to base PCM exhibited 60% transmittance reduction in comparison to base LA. Further all prepared samples were thermally stable with no weight degradation until 140°C. The FTIR confirmed the samples were chemically stable as no any new peak observed in composites. Therefore, based on results, GR enhanced LA PCM can be considered as future potential composite to be implemented in energy storage applications.

The antifungal activity and mechanism of Perillaldehyde and its stabilized encapsulation technology for fruit preservation

Perillaldehyde (PAE), an essential oil extracted from perilla (Perilla frutescens (L.) Britt.), exhibits excellent antioxidant and antimicrobial activity. In this study, we found that the antifungal mechanism of PAE was attributed to the stimulation of ROS levels, destruction of mitochondrial function, and induction of spore apoptosis. Transcriptomic analysis showed that the gene expression pattern of Botrytis cinerea significantly changed after PAE treatment, and the differentially expressed genes (DEGs) were mainly involved in the MAPK signaling pathway and cell wall integrity pathway. For the better utilization of PAE for fruit preservation, the inclusion complex (IC) of PAE and hydroxypropyl-β-cyclodextrin was successfully synthesized by ultrasonic-assisted method, as proved by UV–vis spectroscopy, fourier transform infrared spectroscopy, thermal properties analysis, scanning electron microscopy, and 1H NMR. It was demonstrated that water solubility and thermal stability of PAE/HPβCD-IC were significantly improved compared to pure PAE. Furthermore, both in vitro and in vivo antifungal assessment showed that PAE/HPβCD-IC was effective for inhibiting B. cinerea. Overall, our results indicated that PAE/HPβCD-IC had promising antifungal activity, water solubility and thermal stability, which provided a theoretical basis for the utilization of PAE/HPβCD-IC for fruit preservation.

Extraction and characterization of natural cellulosic fiber from Mariscus ligularis plant as potential reinforcement in composites

In this paper, fiber from the Mariscus ligularis (ML) plant was extracted and investigated as a naturally derived fiber for its potential as a reinforcement material for composite applications. Physical, morphological, chemical, thermal, and mechanical property analyses of the Mariscus ligularis fiber (MLF) were performed to evaluate its suitability as a reinforcement material while also generating useful data to serve as the basis for its selection in the development of new composite materials. Physical and morphological analysis results showed MLF as a lightweight fiber of diameter 243.6 μm and density 768.59 kg/m3 with a very rough surface that provides excellent interfacial bonding performance. Chemical and thermal results show MLF has mainly cellulose as its crystallized phase, with cellulose and wax contents of 58.32 % and 0.73 %, respectively, and possesses a 72.23 % crystallinity index and a 3.15 nm crystallite size with thermal stability up to 258 °C. The mechanical results show that the tensile strength, elastic modulus, strain to failure, and microfibril angle were in the ranges of 109–134 MPa, 3.27–5.06 GPa, 3.32–9.13 %, and 13.35–20.33°, respectively. These findings show MLF as a potential reinforcement material.

Multifunctional hydrogels simultaneously featuring ultrahigh stretchability, remarkable tearing resistance, and reusable fluorescence for information encoding–decoding and smart anticounterfeiting

Fluorescent hydrogels with fluorescent dyes are widely used for anti-counterfeiting encryption. However, developing highly stretchable and remarkable tear-resistant hydrogels with reusable fluorescence for anti-counterfeiting purposes remains challenging. In this study, we fabricated and characterized double network (DN) hydrogels comprising polyvinyl alcohol-borax (PVA-borax) as the first network and poly(methacrylamide-co-polyethylene glycol-co-pyrenylmethyl acrylate) (P(MAM-co-PEGMA-co-PyMA)) as the second network with varying MAM to PEGMA ratios. SEM images showed the hydrogels had 3D porous structures. FT-IR and thermal properties analysis (DSC and TGA) indicated the presence of hydrogen bonds between PVA-borax and P(MAM-co-PEGMA-co-PyMA) without any chemical bonds. The red shift in characteristic absorption bands at 841 and 710 cm−1 further confirmed the presence of π-π* interactions between pyrene moieties. XRD analysis revealed no significant changes in crystalline phase of the hydrogels, which facilitated the formation of a 3D network due to abundant hydrogen bond presence. When the MAM to PEGMA ratio was adjusted to 9:2, the resulting hydrogels exhibited remarkable properties such as ultra-high stretchability (strain over 3300 %), excellent notch-insensitivity, and exceptional tear resistance (tearing energy over 3.25 × 105 J/m2). Importantly, the hydrogel's fluorescence intensity could be reversibly changed by alternatively adding Fe3+ and EDTA-2Na. It could be reused more than 10 times while maintaining a fluorescence intensity of around 80 %, demonstrating its reliability as a versatile hydrogel probe for Fe3+ detection with “ON-OFF-ON” fluorescence behavior. Furthermore, the hydrogels demonstrated exceptional 2D encryption and decryption capabilities, highlighting their potential applications in information storage and data security. To improve the level of anti-counterfeiting, multiple encryption approaches such as QR codes and ASCII binary codes were rationally designed. Overall, this study successfully developed a universal DN hydrogel platform with ultra-high stretchability and remarkable tear resistance, capable of rapid encoding and decoding of complex information for smart anti-counterfeiting.