Differential Scanning Calorimetry Research Articles

Methodology for evaluation of lithium-ion black-mass battery recycling

Abstract In response to the growing demand for critical raw materials, the European Commission is actively pursuing strategies to recycle these materials from various sources, including disused batteries. One of the significant challenges in this endeavor is the heterogeneous nature of the materials arriving at recycling plants, necessitating effective process evaluation. In this study, crushed scooter batteries were utilized, and a range of analytical techniques were employed to initially characterize the composition of the raw material and subsequently evaluate previous physical separation processes efficiently, effectively, and economically. The analytical methods utilized included scanning electron microscopy with energy-dispersive X-rays spectroscopy (SEM–EDS), X-ray fluorescence spectroscopy (XRF), X-ray diffraction (XRD), atomic absorption spectroscopy (AAS), loss of ignition (LOI), and differential scan calorimetry (DSC). In addition, two separation techniques were conducted: froth flotation and sink-and-float tests. The cathode's oxide type was identified through XRD analysis, and statistical methods were applied to all XRF analyses. Furthermore, the other analytical methods facilitated the determination of flux compositions, enabling the assessment of process performance. Regarding the robustness of the presented method, as is well known, performing a complete characterization of a material, including XRD, AAS, XRF, DSC, and SEM, could comprise a relatively high time if it is to identify the efficiency of a process (we estimate in several days, and even weeks). However, by reducing the analytical methods to LOI, XRF, and stream sampling, it is possible to conduct process efficiency evaluation in a few hours. This methodology would give the opportunity to achieve effective verifications in a short time and reduce possible efficiency problems in a treatment plant of this type of material.

Crystallization Kinetics of Oleogels Prepared with Essential Oils from Thirteen Spices

In this study, corn oil and essential oils from thirteen spices were used as the oil phase, with glyceryl monostearate (GMS) serving as the gelling agent to prepare the oleogels. The effects of varying the concentrations of the gel additives (2%, 4%, 6%, and 8%) on the texture, oil retention, and rheological properties of the oleogels were investigated using differential scanning calorimetry (DSC) and X-ray diffraction (XRD). The results showed that GMS concentration markedly influenced the structure and properties of the gel. Positive correlations were observed between GMS concentration and the results of texture analysis, oil binding capacity, and microscopic morphology of the oleogels. Analyses via DSC and XRD demonstrated that gel formation was attributable to the crystalline network induced by GMS. Rheological assessments revealed that the oleogels exhibited pseudoplastic behavior and commendable thermal sensitivity.

FOIM: Thermal Foaming of Shape Memory Polyurethane Foil.

This work introduces the semi-finished product FOIM, a neologism from FOIl and foaM, a phase segregated polyester urethane urea (PEUU) foam, which is synthesized from poly(1,6-hexylene adipate) diol, 4,4'-methylene diphenyl diisocyanate, polyethylene glycol and water as blowing agent. The PEUU is obtained by following a one-shot synthesis and is characterized by a hard/soft segment ratio of 1.06 and an open pore content of 78%. Differential scanning calorimetry reveals a melting peak at 45°C and a crystallization signal at 14°C, both of which are associated with the phase transitions of the soft segment. The glass transition temperature, which is determined as a local maximum within the tanδ using dynamic mechanical analysis, is 1°C. During programming, the foam is heavily compressed at 60°C. Once unloaded at 23°C, a translucent foil, the FOIM, is obtained. When reheated to 60°C, the foil switches back to the foam due to its pronounced shape memory properties. Intriguingly, the structure remains largely unaffected by the drastic deformation as indicated by buoyancy and heat transmission measurements. The ease of manufacture and functionality makes the technology attractive for applications, in which both low transport volumes and drastic shape changes are desired.

UV‐Curable Polyester Oligomers Containing Triptycene Segments

ABSTRACTA series of UV‐curable polyesters containing triptycene segments were synthesized via the melt polycondensation of 1,4‐cyclohexanedicarboxylic acid, triptycene‐1,4‐hydroquinone‐bis(2‐hydroxyethyl) ether, and various comonomer diols including 1,6‐hexanediol, neopentyl glycol, and 1,4‐cyclohexanedimethanol. The polyesters were characterized by 1H nuclear magnetic resonance spectroscopy, Fourier‐transform infrared spectroscopy, gel‐permeation chromatography, and differential scanning calorimetry. Thin films were prepared by solvent casting and were cured via exposure to UV‐light at elevated temperature. The crosslinked films were subsequently analyzed by differential scanning calorimetry, dynamic mechanical analysis, Soxhlet extractions, and tensile tests. Most of the samples that contained a high concentration of the triptycene monomer resulted in brittle materials with relatively high moduli and tensile strengths, but poor extensibilities. However, the 1,6‐hexanediol/1,4‐cyclohexanedicarboxylic acid polyester with 30 mol% of triptycene‐1,4‐hydroquinone‐bis(2‐hydroxyethyl) ether exhibited a Tg above room temperature, a relatively high modulus (~1.1 GPa) and tensile strength (~25 MPa), and ductility (144% elongation‐at‐break). These unique properties were attributed to the triptycene monomer, which is capable of threading polymer chains through its V‐shaped cavities to reinforce the polymer network. When these polyesters were formulated into UV‐curable coatings, the coatings displayed excellent impact resistance and substrate adhesion.

Enhancing the tensile strength and morphology of Sansevieria trifasciata Laurentii fibers using liquid smoke and microwave treatments: an RSM approach

Liquid smoke (LS), an eco-friendly substance, is effective in modifying natural fibers to enhance their mechanical properties, surface morphology, and thermal stability. This study investigates the effects of LS immersion followed by microwave treatment on the tensile strength, surface morphology, and thermal characteristics of Sansevieria trifasciata Laurentii (STL) fibers. Response surface methodology (RSM) with central composite design (CCD) was used to optimize treatment parameters, including LS immersion time, microwave heating temperature, and duration. Mechanical, morphological, structural, and thermal properties were analyzed using scanning electron microscopy (SEM), Fourier-transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), thermogravimetric analysis (TGA), and differential scanning calorimetry (DSC). Optimal treatment conditions: 120 min LS immersion and microwave heating at 40 °C for 30 min. They resulted in a tensile strength of 370.23 MPa, a 37.21% improvement compared to untreated fibers. Treated fibers exhibited enhanced thermal stability, increased crystallinity, and improved surface morphology. These findings demonstrate that LS and microwave treatments effectively enhance STL fibers’ mechanical properties, surface morphology, and thermal stability, positioning them as promising reinforcement materials for sustainable composite applications.

Isolation and Characterisation of Acid Soluble Collagens and Pepsin Soluble Collagens from Eel (Anguilla japonica Temminck et Schlegel) Skin and Bone

Eel (Anguilla japonica) is an important and valuable food fish in East Asia and its by-products have been reported to include bioactive and profitable components. This study aimed to extract, characterise, and compare the structure and properties of acid-soluble collagens (ASCs) and pepsin-soluble collagens (PSCs) from the skin and bone of eel (Anguilla japonica), providing insights into their composition, structure, and properties for various applications. The yields of ASC-S (from skin), PSC-S (from skin), ASC-B (from bone), and PSC-B (from bone) were 12.16%, 15.54%, 0.79%, and 1.34% on a dry weight basis, respectively. Glycine, the dominant amino acid, accounted for 16.66% to 22.67% of total amino acids in all samples. SDS-PAGE and FTIR analyses showed the typical triple-helical structure of type I collagen with slight variations in molecular order in extract and intermolecular cross-linking between skin and bone collagens. The denaturation temperature (Tmax1) measured by differential scanning calorimetry (DSC) is 81.39 °C and 74.34 °C, respectively, for ASC-B and ASC-S. Bone collagen has higher thermal resistance than skin collagen. Surface morphology imaged using a scanning electron microscope (SEM) showed that the bone collagen had a denser network structure, whilst the skin collagen was more fibrous and porous. The findings suggest that eel-derived collagens from skin and bone can serve as potential alternatives in the food, cosmetic, and healthcare industries.

Amphiphilic Poly(ethylene glycol)-Cholesterol Conjugate: Stable Micellar Formulation for Efficient Loading and Effective Intracellular Delivery of Curcumin.

A biodegradable and biocompatible micellar-based drug delivery system was developed using amphiphilic methoxy-poly(ethylene glycol)-cholesterol (C1) and poly(ethylene glycol)-S-S-cholesterol (C2) conjugates and applied to the tumoral release of the water-insoluble drug curcumin. These synthesized surfactants C1 and C2 were found to form stable micelles (CMC ∼ 6 μM) and an average hydrodynamic size of around 20-25 nm. The curcumin-encapsulated C1 micelle was formulated by a solvent evaporation method. A very high drug encapsulation efficiency (EE) of ∼88% and a drug loading (DL) capacity of ∼9% were determined for both the micelles. From the reduced rate of curcumin degradation and differential scanning calorimetry (DSC) analysis, the stability of the curcumin-loaded C1 micelle was found to be higher than that of the unloaded micelle, which confirmed a more compact structural arrangement in the presence of hydrophobic curcumin. A pH-sensitive release of curcumin (faster release with decrease in pH) was observed for the curcumin-loaded C1 micelle, attributed to the diffusion and relaxation/erosion of micellar aggregates. To achieve reduction environment-sensitive drug release, a disulfide (S-S) chemical linkage-incorporated mPEG-cholesterol conjugate (C2) was synthesized, which was found to show glutathione-responsive faster release of curcumin. The in vitro experiments carried out in SCC9 oral cancer cell lines showed that the blank C1 and C2 micelles were noncytotoxic at lower concentrations (<50 μM), while curcumin-loaded C1 and C2 micelles inhibited the proliferation and promoted the apoptosis. An increased in vitro cytotoxicity was observed for curcumin-loaded micelles compared to that of curcumin itself, demonstrating a better cell penetration efficacy of the micelle. These results were further supplemented by the in vivo anticancer analysis of the curcumin-loaded C1 and C2 micellar formulations using the mice xenograft model. Notably, curcumin-loaded C2 micelles showed a significantly stronger apoptotic effect in xenograft mice compared to curcumin-loaded C1 micelles, indicating the GSH environment-sensitive drug release and improved bioavailability. In conclusion, the mPEG-cholesterol C1 and C2 micellar system with the advantages of small size, high encapsulation efficiency, high drug loading, simple preparing technique, biocompatibility, and good in vitro and in vivo performance may have the potential to be used as a drug carrier for sustained and stimuli-responsive release of the hydrophobic drug curcumin.

Enhanced Biological, Thermal and Dielectric Properties of Polyvinyl Alcohol by a Methacrylate Polymer and Green Synthesized Silver Nanoparticles

Abstract Due to the increasing adverse environmental effects of synthetic polymers, the need for environmentally friendly alternative biomaterials is increasing daily. In this context, the synthesis of novel Poly(vinyl alcohol) (PVA) -based composite materials was aimed. In this study, methacrylate-based poly(2-oxo-2-[4-(trifluoromethyl)anilino]ethyl-2-methylprop-2-enoate) (PTFMAM) polymer synthesized for the first time was blended with PVA by hydrothermal method. Biosynthesized silver nanoparticles (Ag NPs) were added to the PTFMAM-PVA blend using the hydrothermal method. Nanocomposites were characterized by XRD, SEM, TEM, and FTIR. The thermal stability of nanocomposites was determined by thermogravimetric analysis (TGA), and glass transition temperatures (Tg) were determined by differential scanning calorimetry (DSC) techniques. According to TGA data, the thermal stability of PVA was improved by blending with PTFMAM and loading with Ag NPs. While the Tg of PVA and PTFMAM-PVA were 78 °C and 103 °C, this value increased to 116 °C with 7% Ag NP loading. The dielectric properties of the nanocomposites also increased with the loading of Ag NPs. Ag NPs loading also decreased the solubility of PVA in water. Combining PVA with PTFMAM and Ag NP increased the oxidant/antioxidant activity. At the same time, increases in the antimicrobial activities of the nanocomposites were observed. The inhibition zones of the nanocomposites against E. coli, S. aureus, and C. albicans strains were between 8.56 and 15.08 mm. The results showed that PVA equipped with synthetic PTFMAM and biosynthesized Ag NPs caused improvements in thermal, dielectric, and biological properties. The produced PTFMAM-PVA/Ag nanocomposites showed that they could be alternative materials in areas where PVA is frequently used with their improved properties.

Differential Thermal Analysis of a Wood-gypsum Composite

Statement of the problem. An increase in the range of production of products and structures based on gypsum binders with the addition of various fillers that improve some of the technological properties of the resulting composites is a promising direction in building materials science. The paper proposes the development of a technology for creating decorative slabs for interior decoration, reinforced with sawdust. Taking into account the increased requirements for thermal protection of buildings (SNiP 23-02-03), the issue of reducing the average density and increasing the thermal resistance of heat-shielding (heat-insulating and wall) for interior decoration is relevant. A decrease in density can be achieved, for example, by porousizing a gypsum product, but this requires carbonates and solutions of acids or salts with the formation of a porous agent in the form of CO2, which is not economically and environmentally friendly enough, so it was decided to introduce pine sawdust into the gypsum composite for decorative boards. In this case, it is necessary to conduct an experiment to identify the effect of adding sawdust on the fire safety of the composite as a whole. Results. In the course of the work, the results of a differential thermal analysis of a gypsum matrix with the addition of sawdust were obtained. It has been established that at an increase above 490 °C, sawdust filler is completely subject to destruction with the formation of coke residue and slight pore formation due to weight loss (judging by the thermogravimetric curve) due to the release of volatile substances, and only CaSO4 inversion occurs near the gypsum part. Conclusions. Thus, when studying the effect of thermal action on the structure and properties of materials by differential scanning calorimetry, it was revealed that exo- and endothermic processes, characteristic of both wood materials and gypsum, are superimposed during kinetic changes. Therefore, a fire hazard does not occur.

Thermodynamic and Structural Characterization of a Mechanochemically Synthesized Pyrazinamide–Acetylsalicylic–Acid Eutectic Mixture

Background/Objectives: This study aims to develop a sustainable and environmentally friendly drug delivery system by synthesizing a novel drug–drug eutectic mixture (DDEM) of acetylsalicylic acid (ASA) and pyrazinamide (PZA) using a green and efficient mechanochemical approach. Methods: The DDEM was characterized using various techniques, including differential scanning calorimetry (DSC), thermogravimetry and differential thermal analysis (TG-DTA), powder X-ray diffraction (PXRD), Fourier transform infrared spectroscopy (FT-IR), and Raman spectroscopy. Binary phase diagrams and Tammann’s triangle analysis determined the eutectic point. Density functional theory (DFT) calculations were performed on the starting compounds. The new system was evaluated for aqueous solubility, dissolution, and hygroscopicity. Results: A V-shaped binary phase diagram indicated the formation of a DDEM with a 2:1 molar ratio of ASA to PZA. A positive mixing enthalpy suggested a quasi-eutectic structure. The solubility of ASA and PZA increased by 61.5% and 85.8%, respectively, in the DDEM compared to the pure drugs. Conclusions: These findings highlight the potential of DDEMs to enhance drug properties and delivery. The synergistic interaction between ASA and PZA in the eutectic mixture may further improve therapeutic efficacy, warranting further investigation.

Thermal decomposition and non‐isothermal kinetics of microcrystalline magnesite

AbstractThe thermal decomposition (TD) of magnesite is crucial for its high‐value applications, and understanding its reaction mechanisms requires establishing accurate kinetic models. This research investigates the TD kinetics of microcrystalline magnesite under varying heating rates (HRs) using thermogravimetry and differential scanning calorimetry (TG–DSC) analysis. Kinetic parameters were derived using the Coats–Redfern (CR), Kissinger–Akahira–Sunose (KAS), and Flynn–Wall–Ozawa (FWO) methods. The influence of HRs on the decomposition process and the resulting MgO morphology was analyzed. The results demonstrated that as HRs increased, the decomposition and reaction rate curves shifted to higher temperatures, necessitating elevated temperatures for similar levels of decomposition. The mean activation energy () was calculated to be 162.45 kJ/mol, with a strong linear correlation between the and pre‐exponential factor, suggesting robust kinetic compensation. The TD followed a two‐dimensional phase boundary mechanism with cylindrical symmetry. “Original shape pseudomorphs” were found to significantly affect the microstructure, particle size variation, and kinetic behavior of the decomposition products. These findings provide important insights for the industrial processing of microcrystalline magnesite.

The impact of Ta2O5 in multinucleating agents on chemically strengthened MgO–Al2O3–SiO2 transparent glass‐ceramics

AbstractMgO–Al2O3–SiO2 (MAS) glass‐ceramics are significant due to their excellent mechanical properties. However, most of these glass‐ceramics are opaque and lack chemically strengthened capabilities. In this study, chemically strengthened transparent MAS glass‐ceramics were successfully synthesized by employing SnO2 + ZrO2 + Ta2O5 as a multinucleating agent. Systematic investigation was conducted using differential scanning calorimetry (DSC), X‐ray diffraction (XRD), transmission electron microscope (TEM), field emission scanning electron microscope (FE‐SEM), Scattered Light Photoelastic Stress Meter (SLP), and Vickers hardness measurements. The results show that Ta2O5 exhibits a good nucleation effect. With the increase of Ta2O5 content from 0 mol% to 0.5 mol%, the exothermic peak temperature of the precipitated crystals decreased from 976.3°C to 937.6°C. The primary crystalline phases precipitated in the MAS system were MgAl₂O₄ (PDF#21‐1152) and ZnAl₂O₄ (PDF#05‐0669), with secondary phases including SnO2 (PDF#46‐1088), ZrO2 (PDF#50‐1089), and Ta2O5 (PDF#21‐1198). TEM‐tested interplanar spacing data and electron diffraction ring data further confirmed the presence of these crystalline phases. At 0.5 mol% Ta2O5 content, after crystallization at 920°C, the average grain size was approximately 40.34 nm, with 86.57% transmittance at 550 nm. The Vickers hardness of the parent glass increased from 6.68 GPa to 7.17 GPa after heat treatment at 920°C. Following 5 h of ion exchange, Vickers hardness increased to 7.97 GPa, with surface compressive stress (CS) of 150.29 MPa and depth of layer (DOLzero) of 80.96 µm. After 24 h of ion exchange, Vickers hardness reached 8.16 GPa, with CS of 239.86 MPa and DOLzero of 93.28 µm. The conclusions provide new insights for further study of the MAS system and broaden its application field such as in cover materials.

Sustainable Geopolymer Tuff Composites Utilizing Iron Powder Waste: Rheological and Mechanical Performance Evaluation

Geopolymers are a sustainable alternative to Portland cement, with the potential to significantly reduce the carbon footprint of conventional cement production. This study investigates the valorization of industrial waste iron powder (IP) as a fine filler in geopolymers synthesized from volcanic tuff (VTF). Composites were prepared with IP substitutions of 5%, 10%, and 20% by weight, using sodium hydroxide and sodium silicate as alkaline activators. Microstructural and phase analyses were conducted using scanning electron microscope coupled with energy dispersive X-ray spectroscopy (SEM-EDS), X-ray fluorescence (XRF), X-ray diffraction (XRD), and differential scanning calorimetry (DSC), while rheological properties, compressive strength, and flexural strength were assessed. The impact of curing temperatures (25 °C and 80 °C) on mechanical performance was evaluated. Results revealed that air content increased to 3.5% with 20% IP substitution, accompanied by a slight rise in flow time (0.8–2 s). Compressive and flexural strengths at 25 °C decreased by up to 22.48% and 28.39%, respectively. Elevated curing at 80 °C further reduced compressive and flexural strengths by an average of 45.30% and 64.68%, highlighting the adverse effects of higher temperatures. Although these formulations are not suitable for load-bearing applications, the findings suggest potential for non-structural uses, such as pavement base layers, aligning with sustainable construction principles by repurposing industrial waste and reducing reliance on energy-intensive cement production.

Enhanced thermal stability and mechanical properties of polypropylene matrices reinforced with SiO2 nanoparticles

Abstract The current study focuses on incorporating SiO2 nano-fillers into a polypropylene matrix to enhance and regulate the coefficient of thermal expansion (CTE), while simultaneously improving its physical, mechanical, and thermal properties. Our approach involves the addition of small quantities of SiO2 filler to occupy the vacant spaces between polymer chains, resulting in a reduction in the CTE of the polymer without affecting its structure. Hence, silicon dioxide nanoparticles (SiO2-NPs) were added to a polypropylene (PP) matrix at various concentrations (1%wt, 2%wt, 3%wt, 4%wt, 5%wt, 6%wt). The prepared samples underwent characterization through techniques including X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FT-IR), and differential scanning calorimetry (DSC), along with analysis of the coefficient of thermal expansion, Young's modulus, and tensile strength. Observations revealed that the inclusion of small quantities of filler significantly enhances the mechanical and thermal properties of PP, particularly at 3%wt of SiO2, which exhibited the lowest CTE value. This methodology can be regarded as an effective approach for controlling the CTE value of polymers, potentially opening avenues for various industrial applications of these materials.&amp;#xD;

Enhancing structural, thermal, and electrical properties of plasticized lithium-based PVdF-HFP polymer electrolytes for flexible energy storage applications

Lithium ion-conducting plasticized polymer electrolyte membranes were prepared using poly (vinylidene fluoride-co-hexafluoropropylene) (PVdF-HFP) as the host polymer, lithium triflate (LiTf) as the dopant salt, and ethylene carbonate (EC) as the plasticizer, with varying compositions accomplished using the solution casting technique. X-ray diffraction (XRD), Fourier transform infrared (FTIR) spectroscopy, scanning electron microscopy (SEM), and differential scanning calorimetry (DSC) analyses validate the presence of substantial structural alterations and the formation of a complex in the plasticized polymer electrolytes. The electrochemical impedance spectroscopy (EIS) analysis demonstrates an increase in ionic conductivity by about two orders of magnitude after the addition of EC. Estimates of ionic transference numbers derived from the direct current (DC) polarization approach indicate that charge transport in plasticized polymer electrolytes is mostly ionic. We examined the discharge characteristics of our flexible electrochemical storage device (FESD) over 25 h. The mean discharge current is 1.4 mA with a 0.04 C rating.

Interaction of Squalamine with Lipid Membranes.

Squalamine is an aminosterol from dogfish shark which has drawn attention, besides its antimicrobial activity, as a drug candidate in the treatment of Parkinson's disease due to its ability to prevent binding of α-synuclein to lipid membranes. To get insight into the mode of action of this steroid, we studied the influence of squalamine on lipid bilayers and whether it could inhibit the binding of a model peptide. Solid-state 19F NMR of labeled [KIGAKI]3 indicated that, indeed, this peptide no longer binds as a flexible chain to the bilayer in the presence of squalamine. When the cationic squalamine was added to lipid vesicles containing phosphatidylglycerol lipids, the aminosterol was found in differential scanning calorimetry and solid-state 31P NMR experiments to lower the gel-to-fluid phase transition and cause the phase separation of domains enriched in anionic lipids. Squalamine had only a little influence on 2H NMR relaxation and on the order parameters of the chains. These findings indicate that the aminosterol does not affect the molecular mobility of the hydrophobic core of the bilayer; hence, it does not insert into the membrane, nor causes thinning as found for molecules inserting in the headgroup region. On the other hand, squalamine was found to interact with lipid headgroups through electrostatic interactions, as seen by solid-state 2H NMR on headgroup-labeled lipids. Furthermore, 31P NMR showed that squalamine shifted the lamellar-to-hexagonal phase transition of phosphatidylethanolamine lipids to higher temperatures, indicating a preference for positively curved membranes. Altogether, our experiments indicate a strong interaction of the cationic squalamine with lipid headgroups, in particular with anionic lipids. This affinity for membranes is strong enough to efficiently displace cationic polypeptides, confirming the proposed action mechanism in Parkinson treatment. Notably, supported by 1H-1H NOESY experiments, it was found that squalamine does not insert into the bilayer, but rather acts as facial amphiphile binding to the membrane surface. The binding to membranes may be envisaged in the form of oligomeric or micellar assemblies, which can disrupt the membrane at high concentrations, thereby explaining the antimicrobial and antifungal activities of squalamine.

The THE EFFECT OF ZIRCONIUM ADDITIVES ON PROPERTIES OF (Cu22%Zn4%Al) SHAPE MEMORY ALLOY

Shape memory alloys (SMAs) are one of the most important types of smart materials. It define as the materials that can undergo large pseudo elastic deformations while having the ability to recover to their original shape once subjected to a memory stimuli such as a specific temperature ,stress ,or strain. This study examines the effects of varying Zirconium (Zr) additive amounts on the microstructure, mechanical, and shape memory effect for all specimens of Cu-Zn-Al SMAs. Powder metallurgy was used to create Cu–22%Zn–4%Al SMAs, both base and with the inclusion of 0.2 and 0.4 weight percent Zr. 650MPa compact pressure was used to create the alloys after the particles had been mixed for five hours. The alloys underwent a three-step sintering procedure in a vacuum tube furnace for one hour at 350 ˚C, then for one hour at 550 ˚C, and for two hours at 850 ˚C. To characterise the microstructural and phase characteristics of alloys, both with and without Zr additions, XRD diffraction analyses, optical microscopy (OM), and scanning electron microscopy (SEM) were performed. With differential scanning calorimetry, the transition temperatures of all alloys were determined (DSC).As well as the shape memory effect test (SME) was measured. Results confirmed that all alloys compositions were found to include the predominant (Cu5Zn8) phase, as proven by XRD and microstructural investigation. The Zr addition dramatically lowered the transition temperatures, according to the transformation temperature data. Hardness experiments reveal that alloys' hardness and volume losses were enhanced by adding up to 0.4% weight percent of Zr reached to (64.8%) and (0.3909)mm3 respectively compared to base alloy.

The Release of Bound Phenolics to Enhance the Antioxidant Activity of Cornmeal by Liquid Fermentation with Bacillus subtilis

This study investigated the influence of Bacillus subtilis fermentation on the composition of phenolic substances and antioxidant activity in cornmeal. The results indicate that the fermentation process significantly increased both the total phenolic content (TPC) and total flavonoid content (TFC). After 5 days of fermentation, the TPC rose from 31.68 ± 1.72 mg/g to 39.46 ± 2.95 mg/g, representing a 24.56% increase, while the TFC increased from 2.13 ± 0.11 mg/g to 7.56 ± 0.29 mg/g, marking a 254.93% increase. Additionally, the proportion of free phenolic compounds in cornmeal increased from 20.24% to 83.98%, while the proportion of bound phenolic compounds decreased from 79.76% to 16.02%. Furthermore, the hydrolytic enzyme activities of cellulase, β-glucosidase, and xylanase were significantly correlated with the free phenolic content (FPC) (r &gt; 0.85, p &lt; 0.05), indicating their crucial role in releasing free phenolic compounds from cornmeal. Employing scanning electron microscopy, differential scanning calorimetry, X-ray diffraction, and Fourier-transform infrared spectroscopy analyses, we inferred that the carbohydrase enzymes produced by the microorganisms disrupted the cellular structure of cornmeal and weakened the interactions between bound phenolics and the food matrix, thereby facilitating the release of phenolic compounds. This release resulted in an overall increase in the antioxidant activity of the cornmeal. The study provided a novel approach to enhancing the bioavailability of phenolic acids in cornmeal, indicating the potential benefits of fermentation in food processing.

Characterization of Interpolyelectrolyte Complexes Based on Eudragit® RL and Oppositely Charged Eudragit® Polyanions as a Novel Matrix System for Colon-specific Drug Delivery.

The design of new interpolyelectrolyte complexes (IPEC) between Eudragit® polycation (type RL) and oppositely charged Eudragit® polyanions (types L100-55, L100, S100, FS) was investigated. The formation and chemical composition of novel IPECs between countercharged Eudragit® copolymers was established by gravimetric and elemental analysis. The structure and solid state properties of the synthesized IPEC were investigated comparatively to correspondent physical mixtures pairs of copolymers in similar molar ratio, using Fourier transform infrared (FTIR) spectroscopy and modulated temperature differential scanning calorimetry (mDSC). The binding ratio of a unit molecule of RL with polyanions was found to range between 1.73:1 and 4.19:1 while increasing the percentages of carboxylic groups in their structures from 10% (FS) to 50% (L100-55). As a result of electrostatic interaction between the copolymer chains, the glass transition temperature of the IPEC changed significantly. Considerable pH-sensitive swelling in acidic and neutral media was observed for different type of IPECs. Through evaluation of diffusion-transportation properties of the IPECs, basic mechanisms controlling the delivery of indomethacin were obtained. The results of swelling and release of the model drug from the polycomplex matrices confirm that they have potential to be used in colon-specific drug delivery.

Dynamic Behavior of the Glassy and Supercooled Liquid States of Aceclofenac Assessed by Dielectric and Calorimetric Techniques

Aceclofenac (ACF), a non-steroidal anti-inflammatory drug, was obtained in its amorphous state by cooling from melt. The glass transition was investigated using dielectric and calorimetric techniques, namely, dielectric relaxation spectroscopy (DRS), thermally stimulated depolarization currents (TSDC), and conventional and temperature-modulated differential scanning calorimetry (DSC and TM-DSC). The dynamic behavior in both the glassy and supercooled liquid states revealed multiple relaxation processes. Well below the glass transition, DRS was able to resolve two secondary relaxations, γ and β, the latter of which was also detectable by TSDC. The kinetic parameters indicated that both processes are associated with localized motions within the molecule. The main (α) relaxation was clearly observed by DRS and TSDC, and results from both techniques confirmed a non-Arrhenian temperature dependence of the relaxation times. However, the glass transition temperature (Tg) extrapolated from DRS data significantly differed from that obtained via TSDC, which in turn showed reasonable agreement with the calorimetric Tg (Tg-DSC = 9.2 °C). The values of the fragility index calculated by the three experimental techniques converged in attributing the character of a moderately fragile glass former to ACF. Above the α relaxation, TSDC showed a well-defined peak. In DRS, after “removing” the high-conductivity contribution using ε’ derivative analysis, a peak with shape parameters αHN = βHN = 1 was also detected. The origin of these peaks, found in the full supercooled liquid state, has been discussed in the context of structural and dynamic heterogeneity. This is supported by significant differences observed between the FTIR spectra of the amorphous and crystalline samples, which are likely related to aggregation differences resulting from variations in the hydrogen bonds between the two phases. Additionally, the pronounced decoupling between translational and relaxational motions, as deduced from the low value of the fractional exponent x = 0.72, derived from the fractional Debye–Stokes–Einstein (FDSE) relationship, further supports this interpretation.