Differential Scanning Calorimetric Analysis Research Articles

Synergistic Effect of PBz/Epoxy/PCLA Composite Films with Improved Thermal Properties

Polybenzoxazines (PBzs) are advanced forms of phenolic resins that possess many attractive properties, including thermally induced self-curing polymerization, which produces void-free polymer products without any by-product formation. They also possess a high Tg (glass transition temperature) and thermal stability, but the produced materials are brittle in nature, due to which the final form of their application is very difficult. Hence, in this paper, an attempt has been made to overcome the brittleness of PBz by blending it with epoxy and ε-caprolactam (CPLA) to produce free-standing PBz/Epoxy/PCLA (polycaprolactam) films. The curing process between the three components (i.e., Bzo, epoxy, and caprolactam) was monitored using differential scanning calorimetric (DSC) analysis. The results show that there is no appreciable shift in curing the exotherm observed, except a slight shift in the curing process. However, the heat liberated during the exotherm (ΔH) decreases drastically from 121 to 84 J/g, indicating that the content of benzoxazine is very important as it is involved in the polymerization process through oxazine ring-opening. The morphological studies analyzed using SEM and AFM analyses indicate that there was no observable phase separation up to 30 wt.% of CPLA loading, whereas a higher CPLA content of 50 wt.% causes agglomeration and leads to distinctive phase separation. Moreover, the thermal stability of the composite film, PBz/Epoxy/PCLA30, is also increased with a 10% degradation temperature, T10, of 438 °C, when compared with an PBz/Epoxy film. From the obtained results, it is evident that the formation of a composite film through the melt blending process could produce a tough and thermally stable film without sacrificing individual properties.

Exploring the rheological and thermal behavior of cowpea protein concentrate: Impact of pH and concentration

This study confronts challenges from global population growth, focusing on protein supply strains and the environmental impact of traditional animal sources. Delving into unexplored territory, this study investigates the combined effects of pH, concentration, and temperature on the rheological and thermal properties of cowpea protein concentrate (CPC). Steady-state and oscillatory rheological tests, along with differential scanning calorimetric analysis, were conducted to unveil the behavior of CPC solutions. The results revealed sensitivity to protein concentration and shear rate, especially at higher concentrations (>10%), and pH emerged as a critical factor, significantly influencing shear stress and viscosity. The elastic and viscous components of alkaline CPC solutions exhibit weak gel behavior, influenced by both pH and frequency. Temperature-induced changes in viscosity and gelation highlight the interaction between thermal conditions and protein structures. The thermal cycle helps explain changes in molecular interactions induced by temperature, with pH playing a role in influencing gelatinization and denaturation. The denaturation temperature (Td) in the thermograms corresponds to vicilin fractions and emphasizes the prominence of denaturation and gelation at neutral pH, where Td was pH 7 > pH 9 > pH 11. Alkaline pH induced significant structural changes, resulting in a gelation onset temperature below the denaturation onset temperature. This study provides a deeper understanding into the rheological and thermal properties of CPC solutions, emphasizing the roles of concentration, pH, and temperature, useful for various steps of industrial processing, before and after thermal gelation. These findings are important for promoting the use of cowpea proteins in the food industry in response to the evolving needs of a growing global population.

Two easy methods to increase SO2-resistance ability of Mn-based catalyst

Manganese-based catalysts show high activities in selective catalytic reduction of nitrogen oxide (NO), but easily deactivated by sulfur dioxide. In this work, operation sequence and rare-earth-element doping were investigated to increase the anti-SO2 ability of Fe-doped manganese oxide (FM300). On one hand, when the catalyst pre-adsorbed NH3, SO2 only decreased the NO conversion from 100 % to 75 % at 200 °C. Otherwise, the conversion was decreased to 30 %. In-situ Diffuse Reflection Fourier Transform Infrared Spectroscopy proved that NH3 competed with SO2 and protected part of the Brønsted acidic sites. On the other hand, rare-earth-element doping increased the long-time anti-SO2 performance of FM300 from 150 min to 300 min (Sm-FM300) and > 700 min (Ho-FM300). Differential Scanning Calorimeter analysis indicated that Ho optimized ferromagnetism of FM300, which was in favor of NH3 adsorption. The main result of this work will help to increase applicability of the manganese-based catalyst.

Fabrication of a robust zwitterionic coating on glass with anti-fogging, anti-frosting, self-cleaning and antibacterial properties via UV-induced grafting polymerization

In this work, glass slides were separately silanized by silane coupling agents, 3-(trimethoxysilyl) propyl methacrylate (TPM) and 3-(mercaptopropyl) trimethoxysilane (MPS). Then, in presence of a photoinitiator, multifunctional hydrophilic coatings were fabricated facilely on these silanized glasses via UV-induced grafting polymerization of zwitterionic acrylic monomer methacryloxyethyl sulfobetaine (SBMA). The results showed that both TPM and MPS silanized glasses could participate in the UV-induced grafting polymerization of SBMA, while more SBMA could be grafted to the former glass to gain a little bit higher hydrophilicity. The structure, morphology and properties of the multifunctional glasses were investigated fully. As the hydrophilic polymer brushes poly(SBMA) (pSBMA) covalently attached to the glass surface, the glasses could render a series of excellent performances, including underwater superoleophobicity, anti-fogging, anti-frosting, abrasion resistance, self-cleaning and antibacterial adhesion, and especially high stability even after being immersed in water for 20 days. The strong interaction of pSBMA and water was confirmed via differential scanning calorimeter (DSC) and Raman spectrum analysis, to explicit the anti-fogging mechanism. Therefore, it is promising that the scalable multifunctional glass fabricated via UV-induced grafting polymerization could be potentially applied in the fields of automobile, bathroom, medical, etc.

Physicochemical properties of amorphous granular starch (AGS) prepared by non-thermal gelatinization by high hydrostatic pressure (HHP) and spray drying

Corn starch was gelatinized by high hydrostatic pressure (HHP) and spray drying to make amorphous granular starch (AGS), and their physicochemical properties were compared with the conventionally prepared (heat-gelatinized and spray dried) AGS to devise a novel AGS preparation methodology. Pressure-induced (PAGS) and heat-induced AGS (HAGS) maintained their granular shape but lost their birefringence indicating that both methods could prepare AGS. DSC (differential scanning calorimeter) and XRD (X-ray diffraction) analysis confirmed the complete loss of amylopectin double helices and crystallinity of both PAGS and HAGS. However, their swelling power, solubility, RVA pasting properties, acid/shear stability, gel forming ability and textural properties were completely different. PAGS exhibited constrained swelling, suppressed amylose leaching, and reduced viscosity. Notably, HAGS formed a gel without heating, whereas PAGS yielded a viscous paste with water-soluble attributes. Even after reheating, PAGS maintained its granular structure with comparably less swelling and weaker gel strength than HAGS. Consequently, newly developed PAGS exhibited distinctive characteristics compared to the conventional HAGS, such as lower solubility and swelling power, viscosity, textural properties, and high acid and shear stabilities, rendering it a viable option for various applications within the food industry.

Improving water resistance and mechanical properties of starch-based films by incorporating microcrystalline cellulose in a dynamic network structure

The widespread use of starch-based films is hindered by inadequate tensile strength and high water sensitivity. To address these limitations, a novel starch film with a dynamic network structure was produced via the dehydration-condensation reaction of N, N′-methylene diacrylamide (MBA) and microcrystalline cellulose (MCC). The improvement in mechanical properties was enhanced by the incorporation of MCC, which was achieved through intermolecular hydrogen bonding and chemical crosslinking. To verify the interactions among MCC, MBA, and starch, x-ray photoelectron spectroscopy (XPS), fourier transform infrared spectroscopy (FTIR), and x-ray diffraction (XRD) were conducted. The results established the predicted interactions. The dynamic network structure of the film reduced the water absorption capacity (WAC) of starch and MCC hydroxyl groups, as confirmed by differential scanning calorimeter (DSC) and dynamic mechanical thermal analysis (DMTA). These analyses showed a restriction in the mobility of starch chains, resulting in a higher glass transition temperature (Tg) of 69.26 °C. The modified starch films exhibited excellent potential for packaging applications, demonstrating a higher contact angle (CA) of 89.63°, the lowest WAC of 4.73 g/g, and the lowest water vapor transmission rate (WVTR) of 13.13 g/m2/d, along with improved mechanical properties and identical light transmittance compared to pure starch films.

Preparation and mechanical properties of epoxy resin filled with shaped hybrid nanobrushes

Nanostructure formed through self-assembly of block copolymer has been used to modify epoxy resins and the shape of the nanobrushes has a significant effect on its properties. Through RAFT polymerization and bulk self-assembly of PMMA-b-PTEPM block copolymers, SiO2@PMMA hybrid nanobrushes was prepared with three different shapes, i.e., nanospheres, nanowires and nanosheets. According to the transmission electron microscope results, all three kinds of nanobrushes were well dispersed in the epoxy resins. The differential scanning calorimeter and thermogravimetric analysis tests showed that the addition of these nanobrushes has no significate effect on the curing behaviour and the glass transition temperature of epoxy resins. Their modification effects have been investigated through tensile, bending and impact tests. Compared with the neat epoxy resin, the bending and tensile strengths of 0.5 wt% nanosphere-filled epoxy resins were increased by 11.7% and 27.0%, and the impact strength of 0.5 wt% nanowire-modified epoxy resins was increased by 93.0%. And the nanosphere-modified epoxy resins showed a better comprehensive performance.

Plastik mobilya atıkları ve odun unu ile üretilen kompozit malzemenin seçili bazı özellikleri

In this study, composite boards were produced using waste plastic furniture parts and wood flour. Wood flour was used at rates of 0%, 15%, 30% and 45% in the preparation of composite boards. Thus, 1 control and 3 composite groups were created. The boards are produced in dimensions of 3.5x175x175 mm (thickness, width, length). Density, flexural strength, flexural modulus, deformation at break, tensile strength, tensile modulus, elongation at break, hardness tests and thermal gravimetric analysis (TGA) and differential scanning calorimeter (DSC) analysis were performed on the produced composite boards. According to the obtained data, it was determined that as the percentage of wood flour in the composite groups increased compared to the control group, the values of flexural strength, deformation at break, tensile strength and elongation at break decreased whereas the values of density, hardness, flexural modulus and tensile modulus increased. According to the TGA and DSC analysis results, it was understood that the waste plastic furniture parts were composed of linear low density polyethylene (LLDPE) and polypropylene (PP) polymer materials, also the decomposition temperature of the composite materials partially increased with the increase in the percentage of wood flour.

Formulation, Optimization, and Evaluation of Gliclazide loaded Nanosuspension for Dissolution Rate Enhancement

Diabetes mellitus is a prolonged metabolic condition categorized through elevated blood glucose levels. To treat this condition, oral antihyperglycemic medications like gliclazide, a second-generation sulfonylurea insulin secretagogue, are commonly used. Gliclazide comes into the biopharmaceutical classification system (BCS) class-II types, known for its lower solubility. To enhance its solubility, gliclazide was integrated into nanosuspensions. This study focused on formulating these gliclazide nanosuspensions using Kollicoat IR and Soluplus through the anti-solvent-precipitation method, through optimization achieved using the Box Behnken Design. Key parameters assessed included particle size (224 ± 1.23 nm) and entrapment efficiency (95.65 ± 0.12%). The drug release studies conducted on pH 7.4 indicated that over 95% of the drug was released within 30 minutes for the nanosuspension, whereas the pure drug solution released less than 70% in the same time frame, indicating immediate release with the nanosuspension. The morphology was examined using scanning electron microscopy (SEM), while fourier transform infrared (FTIR), X-Ray diffractometers (XRD), and differential scanning calorimeter (DSC) analyses confirmed the presence of the drug within the nanosuspension. In summary, the incorporation of gliclazide into nanosuspensions proved successful, resulting in enhanced release characteristics and ameliorated solubility.

Quantifying the Thermochemistry of Kinetic Transitions in a Solid-State Charged Li/Llzo/LCO Cell Using Differential Scanning Calorimetry

It is a general understanding that removal of combustible organic solvent with the introduction of solid-state electrolytes would make a battery safer. However, safety in solid state batteries is multifaceted and involves analysis of self-heating rates, total generated energy, thermal runaway onset temperature, maximum temperature, and thermal runaway prevention mechanisms1,2. The use of reactive lithium metal as the anode, and cathode material such as LiCoO2 that releases O2 when heated in its delithiated state, results in conditions in which the exothermic reaction 4Li+O2→2Li2O may occur if these reactants come into contact. We measure heat flow data using a differential scanning calorimeter (DSC) and hermetically sealed DSC pans to establish a reaction thermochemistry responsible for self-heating of LixCoO2|LLZO|Li metal cell, with x=0.43 (which corresponds to 4.3V vs. Li). While the main exothermic reaction is 4Li+O2→2Li2O when only Li0.43CoO2 is present in the cathode3, a practical solid-state cathode will almost certainly contain conductive carbon and a fluorinated binder. We carry out careful DSC analysis with a range of components and ratios of components to quantify the expected reaction pathway, and amount of heat released, for a cathode that contains Li0.43CoO2, carbon additive, and PVDF binder. We find that the carbon and PVDF strongly influence the reaction pathway upon heating to 500°C in our DSC experiments. Hence, the presence of even small weight fraction components in a solid-state cathode should be considered when evaluating their thermochemistry upon heating.

Superhydrophobic polyether sulfone (PES) dialysis membrane with enhanced hemocompatibility and reduced human serum protein interactions: Ex vivo, in situ synchrotron imaging, experimental, and computational studies

This study aimed to enhance the hemocompatibility of polyethersulfone (PES) membranes by increasing their hydrophobicity. Two methods were used: chemical modification with a hydrophobic substance and creating a micropatterned structure using modified silica nanoparticles (SiO2 NP) in a mixed matrix membrane (MMM). Fibrinogen adsorption was assessed using synchrotron radiation micro-computed tomography (SR-µCT), and surface roughness was analyzed with atomic force microscopy (AFM). Hemocompatibility was evaluated by studying interactions with patients' serum and measuring the release of inflammatory biomarkers (C5a, IL-1α, IL-1β, IL-6, vWF, C5b-9 and PF-4). Differential Scanning Calorimeter (DSC) analysis determined the stability of the membrane hydration layer, and water contact angle (WCA) measurements assessed hydrophobic properties. Fourier-transform infrared spectroscopy (FTIR) and surface charge analysis examined surface stability. Molecular docking analysis showed reduced interaction between hydrophobized PES membranes and fibrinogen and albumin in human serum. SR-µCT analysis revealed 20% less fibrinogen adsorption on hydrophobized PES membrane surfaces. MMM PES membranes exhibited minimal fibrinogen adsorption due to the micropatterned structure. Both hydrophobized PES membranes demonstrated reduced vWF biomarker release (25–28%) compared to unmodified PES, with MMM PES membranes performing best. However, both hydrophobized PES membranes led to a significant increase (150%) in IL-6 upon blood contact, attributed to the reduced hydration layer. MMM PES membranes contained the least strongly bound water (0.2%) and exhibited the highest hydrophobicity (98°). This study highlights the potential of hydrophobized PES membranes and MMM structures for enhancing hemocompatibility, with opportunities for optimizing surface modifications to reduce inflammation responses while maintaining desirable properties.

Fabrication and in vitro characterization of delafloxacin-laden electrosprayed hydroxypropyl cellulose nanoparticulated solid dispersions for enhanced aqueous solubility and release rate of the drug

With the aim of fabricating and characterizing an optimized drug delivery system (DDS) for an effective administration of poorly water-soluble delafloxacin (DFX) via the oral route, several formulations of delafloxacin-laden solid dispersions (SD) were prepared employing the solvent-evaporation and electrospraying techniques concomitantly. Solubility and release rate of the drug in the SD were assessed. Solid-state characterization was performed via the X-ray diffraction (PXRD) and differential scanning calorimetric (DSC) analyses, scanning electron microscopy (SEM) and Fourier transform infrared spectroscopic (FTIR) analysis. Amongst the prepared SD, an optimized formulation consisting of DFX, HPC, and SLS at the weight ratio of (1/8/0.2) showed about 9-fold higher solubility and 13-fold faster release rate of delafloxacin as compared to delafloxacin plain drug powder (DPDP). The drug existed in the amorphous form in the spherical particles and had no covalent interaction with any of the excipients. Thus, this optimized formulation might be a useful DDS for an effective administration of DFX.

Microstructural and thermal properties of coal measure sandstone subjected to high temperatures

To study the microscopic structure, thermal and mechanical properties of sandstones under the influence of temperature, coal measure sandstones from Southwest China are adopted as the research object to carry out high-temperature tests at 25 °C–1000 °C. The microscopic images of sandstone after thermal treatment are obtained by means of polarizing microscopy and scanning electron microscopy (SEM). Based on thermogravimetric (TG) analysis and differential scanning calorimetric (DSC) analysis, the model function of coal measure sandstone is explored through thermal analysis kinetics (TAK) theory, and the kinetic parameters of thermal decomposition and the thermal decomposition reaction rate of rock are studied. Through the uniaxial compression experiments, the stress‒strain curves and strength characteristics of sandstone under the influence of temperature are obtained. The results show that the temperature has a significant effect on the microstructure, mineral composition and mechanical properties of sandstone. In particular, when the temperature exceeds 400 °C, the thermal fracture phenomenon of rock is obvious, the activity of activated molecules is significantly enhanced, and the kinetic phenomenon of the thermal decomposition reaction of rock appears rapidly. The mechanical properties of rock are weakened under the influence of rock thermal fracture and mineral thermal decomposition. These research results can provide a reference for the analysis of surrounding rock stability and the control of disasters caused by thermal damage in areas such as underground coal gasification (UCG) channels and rock masses subjected to mine fires.

Carboxymethyl Cellulose-Amuniacum Gum Based Edible Films Enriched with Clove Essential Oil: Optimization Formulation Using Response Surface Methodology (RSM)

Backgraound: Polysaccharides, particularly Carboxymethyl Cellulose (CMC) and Ammoniacum Gum (AMG), are considered valuable due to their thermal stability and non-toxicity. CMC has good film-forming ability but weak mechanical properties, while AMG shows promise with its unique chemical composition. Additionally, essential oils, such as Clove Essential Oil (CEO), are being used to enhance the antimicrobial properties of edible films, offering a natural way to extend the shelf life of food products.
 Methods: This study investigated the combined effect of CMC: 0.5-1.5 wt %, AMG: 1-5 wt %, as well as CEO: 0-30 v/v % on the physical characteristics of the CMC-AMG films by Response Surface Methodology. The optimization was performed with the aim of maximizing Whiteness Index, Ultimate Tensile Strength (UTS), and Strain at Break (SB) and minimizing total color difference (ΔE) values. Fourier-Transform Infrared Spectroscopy, film microstructure, Differential Scanning Calorimeter analysis, and antibacterial activity were investigated. The analysis was conducted using Design Expert software version 10.00 (STAT-EASE Inc., Minneapolis, USA).
 Result: The films with the highest UTS have been obtained through a composition of 5 g CMC, 1.5 g AMG, and 15% CEO. On the contrary, using a composition of 5 g CMC, 1 g AMG, and 30% CEO revealed the highest SB (115.41%). The highest UTS value of 13.17 MPa was obtained with a formulation consisting of 5% AMG, 1.5% CMC, and 15% CEO. Nevertheless, the maximum SB value of 115.41% was achieved with a formulation containing 5% AMG, 1% CMC, and 30% CEO. Moreover, heterogeneous microstructure and more opaque films were obtained as identified by the higher ΔE. The Differential Scanning Calorimeter results demonstrated that incorporating a CEO did not impinge on thermal stability. Furthermore, the addition of CEO led to a rise in antimicrobial activity against Salmonella enterica, Pseudomonas fluorescens, Escherichia coli, and Listeria monocytogenes.
 Conclusion: In conclusion, combination of CMC and AMG in optimum levels, led to the production of a film with acceptable mechanical properties. Also, these films showed significant antimicrobial activity.

Analysis of fabrics obtained during the archeological excavation sites in Israel

AbstractThe aim of this work is to determine the type of material in the given unknown fabric which was excavated from the various archeological sites in Israel using advanced material technology. The four fabrics that were obtained appeared as fragmentary and very degraded textiles. Therefore, we established the treatment method for these fabrics that would be most suitable to deal with the analysis and identification of the material they are made. Fourier transform infrared spectrometry (FTIR), nuclear magnetic resonance (NMR), energy dispersive x‐ray analysis (EDX), scanning electron microscope (SEM) and differential scanning calorimeter (DSC) analysis were used to confirm the material in the fabric samples. Upon detailed analysis it was concluded that all the fabrics are composed either of the synthetic materials such as nylon 6, polyester, and polyacrylonitrile (PAN). The developed method and analysis present herein has the advantages of being rapid and effective for identification of the fabrics and can be applied to varieties of archeological fabrics.

Green synthesis and characterization of an orally bioactive artemisinin-zinc nanoparticle with enhanced bactericidal activity

The occurrence of multidrug-resistant bacteria necessitates the development of new antibacterial agents. This study synthesized artemisinin-zinc nanoparticles (AZ NPs) using a simple green method and investigated their physicochemical properties, antibacterial activity, and oral biological activity. A spherical shape morphology of AZ NPs was observed by scanning and transmission electron microscopy, with a particle size of 73 ± 2.604 nm. Energy dispersive spectrometry analysis showed that the AZ NPs consisted mainly of Zn, C, N, and O elements. According to differential scanning calorimeter analysis, the AZ NPs were stable up to 450 °C. Fourier-transform infrared spectroscopy revealed that artemisinin successfully bound to zinc acetate. The AZ NPs showed antibacterial activity against Salmonella and Escherichia coli, with a minimum inhibitory concentration of 0.056 mg/mL for both and minimum bactericidal concentrations of 0.21 and 0.11 mg/mL, respectively. The mechanisms by which AZ NPs mediate membrane damage were revealed by the downregulation of gene expression, and potassium ion and protein leakage. In vivo safety trials of these drugs revealed low toxicity. After AZ NPs were administered to infected mice, the intestinal bacteria decreased significantly, liver and kidney function were restored, histopathological damage to the liver and spleen were reduced, and the expression of inflammatory cytokines decreased. Therefore, AZ NPs have the potential as an oral antibacterial agent and can be used in antibiotic development and in the pharmaceutical industry.

Waste-Energy Nexus: Cellulose Wood Chips Conjugated Metal Nanoparticles Based Phase Transformation for Improving Thermal Energy Storage Performance.

Highlighting waste as a wealth is the future sustainability of the world. Also, using solar energy stored during off-sun periods will overcome the energy crisis. The introduction of wood chip waste for thermal energy storage systems is a sustainable opportunity. Cellulose derived from wood chips was mixed with the environmentally benign magnetite to form a composite (WCM) and mixed with paraffin-based PCM. The composite was characterized through transmission electron microscopy, TEM analysis, scanning electron microscopy, SEM (augmented with dispersive X-ray analysis, EDX). Micrographs, Fourier transform infrared (FTIR), and X-ray diffraction (XRD), which confirmed that the composite material was prepared. Various system proportions of the composite (0.5, 1.0, 2.0, and 4.0%) are embedded in paraffin, and then the thermal system performance is compared. The experimental data revealed that the addition of 2.0 weight percent of composite material showed superior system performance. Also, differential scanning calorimeter (DSC) and TEM analyses of the paraffin-based WCM-composite materials are conducted. The system achieved a heat gain of 87 kJ/min in comparison to 7 kJ/min for 2.0% WCM-PCM and pristine PCM, respectively. Hence, WCM-PCM embedded with waste stream nanoparticles could be suggested as a potential candidate for heating applications.

A comprehensive overview of the performance of polyamide 6 in the consolidation of vegetable-tanned leathers

Sometimes, vegetable-tanned leathers in museums, excavations, libraries, and storehouses deteriorate due to unsuitable environmental conditions that affect their properties. Accordingly, leather becomes weak. This study evaluates some mechanical, chemical, and physical characteristics of vegetable-tanned leather treated with polyamide 6 (PA6). The authors prepared new vegetable-tanned leather samples. PA6 at different concentrations was applied to the aged leather samples. The accelerated heat aging was applied on the new sample (reference before aging) and treated samples (aged untreated sample after treatment with PA6). Analytical techniques used were: test of the mechanical properties (tensile strength and elongation), attenuated total reflectance/Fourier Transform Infrared (ATR/FTIR), differential scanning calorimeter (DSC) measurement, contact angle, and pH measurement. The results proved that the accelerated heat aging affected the properties studied, as it reduced in the mechanical properties, pH value, and contact angle. Treating aged leather samples with PA6 improved all the properties studied. The mechanical properties, pH value, and contact angle of the treated and aged treated samples increased compared to the aged- untreated- sample. FTIR and DSC analysis proved the stability of the treated and aged treated samples compared to the aged untreated sample. The concentration of 2 % of PA6 gave the best concentrations used, and it is recommended to treat fragile vegetable-tanned leather.

Comprehensive analysis of 3D printed PA6.6 and fiber‐reinforced variants: Revealing mechanical properties and adhesive wear behavior

AbstractWhile 3‐dimensional (3D) printing technology is advancing rapidly, commonly used filament materials are struggling to meet growing expectations. Polyamide (PA) is a material with high potential to replace commonly used low‐performance filament materials, thanks to its cost‐effectiveness and optimal material properties compared to advanced engineering materials. To explore this potential, the thermal, thermomechanical, and mechanical properties (at different temperatures), as well as the wear characteristics, of PA, short carbon fiber reinforced‐PA (SCFR‐PA), and short glass fiber reinforced‐PA (SGFR‐PA) filaments were comparatively examined in this study. Differential scanning calorimeter analysis (DSC), Dynamic Mechanical Thermal Analysis (DMA), uniaxial tensile tests, and Shore D hardness tests were conducted on the 3D printed specimens. The yield strength decreased by 48% and 73%, respectively, for neat PA as compared to room temperature when tested at 40 °C and 60 °C, while for SCFR‐PA, it decreased by 40% and 60%, and for SGFR‐PA, it decreased by 33% and 48%, respectively. The findings obtained from wear tests conducted on both bottom and top surfaces have demonstrated that glass reinforcement yields better results than carbon reinforcement. The experimental findings have been compared with SEM images, revealing their consistency.Highlights This study focuses on the performance evaluation of 3D printed PA and its composites. The mechanical properties of the materials at different temperatures were compared. Adhesive wear behavior is not directly related to fiber type, wear surface or hardness. Morphological analysis was conducted to elucidate the influence of fiber type on mechanical properties and wear behavior.

A novel super high latent heat ternary eutectic salt for high temperature thermal energy storage

This work is concerned with a novel ternary eutectic salt based phase change material (PCM) for high temperature thermal energy storage applications. We designed the PCM formulation in a FactSage environment and demonstrated that the formulation had a very high latent heat. The microstructure, thermal physical properties, thermal stability and cycling service life of the eutectic salt were measured experimentally with various analytical methods including scanning electron microscopy (SEM), X-ray diffractometer analysis (XRD), simultaneous thermogravimetric analyzer (STA) technique, differential scanning calorimeter (DSC) and thermogravimetric analysis (TGA). The results indicated that the eutectic salt had a melting point of 552.23 °C with a superhigh fusion enthalpy of 661.33 J/g. The change of melting point and latent heat of salt after 1500 cycles is 0.48% and 7.84%, respectively, showing excellent cycle stability.