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Cassava starch solid biopolymer electrolyte (SBPE) films were prepared by a thermochemical method with different concentrations of lithium triflate (LiTFT) as a dopant salt. The process began with dispersing cassava starch in water, followed by heating to facilitate gelatinization; subsequently, plasticizers and LiTFT were added at differing concentrations. The infrared spectroscopy analysis (FTIR-ATR) showed variations in the wavenumber of some characteristic bands of starch, thus evidencing the interaction between the LiTFT salt and biopolymeric matrix. The short-range crystallinity index, determined by the ratio of COH to COC bands, exhibited the highest crystallinity in the salt-free SBPEs and the lowest in the SBPEs with a concentration ratio (Xm) of 0.17. The thermogravimetric analysis demonstrated that the salt addition increased the dehydration process temperature by 5 °C. Additionally, the thermal decomposition processes were shown at lower temperatures after the addition of the LiTFT salt into the SBPEs. The differential scanning calorimetry showed that the addition of the salt affected the endothermic process related to the degradation of the packing of the starch molecules, which occurred at 70 °C in the salt-free SBPEs and at lower temperatures (2 or 3 °C less) in the films that contained the LiTFT salt at different concentrations. The cyclic voltammetry analysis of the SBPE films identified the redox processes of the glucose units in all the samples, with observed differences in peak potentials (Ep) and peak currents (Ip) across various salt concentrations. Electrochemical impedance spectroscopy was used to establish the equivalent circuit model Rf–(Cdl/(Rct–(CPE/Rre))) and determine the electrochemical parameters, revealing a higher conduction value of 2.72 × 10−3 S cm−1 for the SBPEs with Xm = 17 and a lower conduction of 5.80 × 10−4 S cm−1 in the salt-free SBPEs. It was concluded that the concentration of LiTFT salt in the cassava starch SBPE films influences their morphology and slightly reduces their thermal stability. Furthermore, the electrochemical behavior is affected in terms of variations in the redox potentials of the glucose units of the biopolymer and in their ionic conductivity. [ABSTRACT FROM AUTHOR]

This study evaluated this thermal reaction behavior of oxidized and pyrolyzed oils containing diverse clay minerals by means of differential scanning calorimetry (DSC) technology. The catalytic role of various clay minerals for thermal reaction processes involving oxidized oil and pyrolyzed oil during in situ combustion (ISC) was investigated in conjunction with kinetic calculation methods as well. The results demonstrated that all four clay minerals could shorten its temperature region of oxidized oil low-temperature oxidation (LTO) stage, with the peak temperature during the LTO stage of oxidized oil containing montmorillonite being dramatically reduced. The catalytic role of montmorillonite and illite on oxidized oil is more powerful in the high-temperature oxidation (HTO) stage with higher peak heat flow. The Lewis acid sites within clay minerals affect free radical reactions within the crude oil pyrolysis process, and in situ reforming performance of 400°C pyrolyzed oils containing clay minerals is less effective, along with low heat release in the LTO stage. Clay minerals can considerably minimize the activation energy during thermal reaction of oxidized oil, contributing to the coke generation and conversion in the fuel deposition (FD) stage and boosting the success rate of the ISC procedure. The catalytic role of clay minerals in the oxidation and pyrolysis reactions of crude oil contributes to the prediction of fuel deposition and the expansion of the combustion front during ISC under diverse types of rock conditions. [ABSTRACT FROM AUTHOR]

Pituitary adenylate cyclase-activating polypeptide (PACAP) is a bioactive peptide known for its diverse effects on the nervous system. While numerous studies have demonstrated the neuroprotective properties of PACAP, its role in tissue regeneration and potential as a therapeutic agent remain to be fully understood. Specifically, the understanding of PACAP's impact on cytoskeletal dynamics, particularly the organization and disorganization of actin filament networks, is limited due to the scarcity of in vitro studies in this area. Additionally, the interaction between PACAP and actin has been minimally explored, and the influence of PACAP on the thermal stability of actin is completely unknown. To address these gaps, the current study aimed to investigate the impact of different forms and fragments of PACAP on the thermal denaturation and renaturation of Ca2+-F-actin using a differential scanning calorimetry (DSC) approach. Our primary objective was to determine whether PACAP modulates the thermal stability of Ca2+-F-actin and establish a temperature-dependent pattern of any structural alterations that may occur as a result of PACAP interaction. Two PACAP forms exist in vivo: the 38 amino acid length PACAP38 and the PACAP27, the latter truncated at the C-terminal. Both in the PACAP38 + Ca2+-F-actin and in the PACAP6-38 + Ca2+-F-actin mixtures, the DSC scans exhibited a significant decrease of actin denaturation temperature compared to the control; however, the PACAP27 + Ca2+-F-actin and PACAP6-27 + Ca2+-F-actin revealed no remarkable differences compared to the actin control sample. The calorimetric enthalpy of the truncated PACAP27 and PACAP6-27 + actin mixture also followed the tendencies mentioned above. Thus, in PACAP27 and PACAP6-27 mixture, there was no change in the denaturation temperature of actin, and no significant ΔHcal was observed. Through this research, we sought to elucidate the underlying mechanisms of PACAP's effects on actin dynamics using thermal de- and renaturation cycles. [ABSTRACT FROM AUTHOR]

A low-temperature melt blending method was adopted to prepare ternary blends of poly(L-lactide) (PLLA), poly(butylene carbonate) (PBC), and poly(D-lactide) (PDLA), aiming to obtain fully biodegradable blends with well-balanced properties. The in situ formation of stereocomplex polylactide (SC-PLA) crystals was confirmed by torque changes, differential scanning calorimetry results, and wide-angle X-ray diffraction measurements. At a PDLA concentration of 5 mass%, SC-PLA crystals formed a percolating network structure, and the rheological behavior of the blend melts transformed from liquid-like to solid-like. The viscosity ratio between PLLA and PBC melts increased due to the presence of SC-PLA crystals, resulting in an enlargement of the PBC domain size. SC-PLA crystals exhibited an excellent nucleation effect, significantly accelerating the crystallization rate of PLLA. Compared to neat PLLA with elongation at break of 5.2%, PLLA/PBC/PDLA ternary blends containing 2 mass% PDLA with elongation at break of 247.2% presented excellent toughness. This work provided a facile method to prepare PLLA-based material with outstanding crystallization ability and tailored rheological behavior as well as mechanical properties, which had the potential to replace conventional plastic products. [ABSTRACT FROM AUTHOR]

Water pollution caused by dyes is a significant environmental issue, necessitating the development of effective, cost-efficient decolorization methods suitable for industrial use. In this study, a Chitosan-Fe polymeric gel was synthesized, characterized, and tested for removing the azo dye Direct Red 83:1 from water. The polymeric magnetic chitosan was analyzed using various techniques: Field Emission Scanning Electron Microscopy (FE-SEM) revealed a porous structure, Differential Scanning Calorimetry (DSC) and Thermal Gravimetric Analysis (TGA) demonstrated the thermal stability, Infrared Spectrophotometry (IR) indicated the successful coordination of iron at the C3 position, and X-ray Powder Diffraction (XRD) confirmed the crystalline nature of the polymeric structure. Optimal conditions for kinetic and isotherm models were found at 1 g and pH 7.0. Adsorption behavior of Direct Red 83:1 onto magnetic chitosan gel beads was studied through kinetic tests and isotherm curves. The maximum adsorption capacity was 17.46 mg/g (qmax). The adsorption process followed pseudo-second-order kinetics (R2 = 0.999) and fit the Temkin isotherm (R2 = 0.946), suggesting heterogeneous surface adsorption. The newly synthesized Chitosan-Fe polymeric gel demonstrated good adsorption properties and facilitated easy separation of purified water. [ABSTRACT FROM AUTHOR]

In this study, a series of poly(butylene succinate)-based copolymers containing various quantities of dimethyl 2,6-naphthalene dicarboxylate (NDC) were synthesized via melt polymerization. The thermal stabilities of the copolymers were maintained, while a slight increment in the stability was observed as the NDC content increased. The results of differential scanning calorimetry and wide-angle X-ray diffraction demonstrated a reduction in the crystallizability of the copolymers with increasing NDC concentration. Unexpectedly, the tensile tests showed significant enhancement of the elongation rate from 122.5 to 2645.0% as the NDC content increased from 0 to 32 mol%. Samples with 28, 30, and 32 mol% NDC showed remarkable abilities with recovery rates above 90% after three test cycles. Moreover, apparent cut mark repairing behaviors were observed under 70 °C heating in samples containing 25, 28, and 30 mol% NDC. These results indicate the potential of the copolymers for self-healing and highly stretchable shape memory wound dressing material applications. [ABSTRACT FROM AUTHOR]

Mesoporous silica particles (MSPs) have been investigated as potential carriers to increase the apparent solubility and dissolution rate of poorly water-soluble drugs by physically stabilising the amorphous nature of the loaded drug. In preparing such systems, it is recognized that the loading method has a critical impact on the physical state and performance of the drug. To date, there has been very limited investigation into the use of electrospraying for loading drugs into mesoporous silica. In this study, we further explore the use of this approach, in particular as a means of producing amorphous and high drug-loaded MSPs; the study includes an investigation of the effect of drug loading and MSP concentration on the formulation performance and process. A comparison with rotary evaporation, a more widely utilised loading technique, was conducted to assess the relative effectiveness of electrospraying. The physical state of the drug in the formulations was assessed using powder X-ray diffraction (PXRD) and differential scanning calorimetry (DSC). The drug release profiles were determined by a comparative in vitro drug release test. Electrospraying successfully produced formulations containing amorphous drug even at a high drug loading. In contrast, while itraconazole was present in amorphous form at the lower drug-loaded formulations produced by rotary evaporation, the drug was in the crystalline state at the higher loadings. The percentage of drug released was enhanced up to ten times compared to that of pure itraconazole for all the formulations apart from the highest loaded (crystalline) formulation prepared by rotary evaporation. Supersaturation for at least six hours was maintained by the formulations loaded with up to 30 mg/mL itraconazole produced by electrospraying. Overall, the results of this study demonstrate that electrospraying is capable of producing amorphous drug-loaded MSPs at high loadings, with associated favourable release characteristics. A comparison with the standard rotary evaporation approach indicates that electrospraying may be more effective for the production of higher loadings of amorphous material. [ABSTRACT FROM AUTHOR]

This research work dives into the complexity of hot-melt extrusion (HME) and its influence on drug stability, focusing on solid dispersions containing 30% of glibenclamide and three 50:50 polymer blends. The polymers used in the study are Ethocel Standard 10 Premium, Kollidon SR and Affinisol HPMC HME 4M. Glibenclamide solid dispersions are characterized using thermal analyses (thermogravimetric analysis (TGA) and differential scanning calorimetry), X-ray diffraction and scanning electron microscopy. This study reveals the transformation of glibenclamide into impurity A during the HME process using mass spectrometry and TGA. Thus, it enables the quantification of the extent of degradation. Furthermore, this work shows how polymer–polymer blend matrices exert an impact on process parameters, the active pharmaceutical ingredient's physical state, and drug release behavior. In vitro dissolution studies show that the polymeric matrices investigated provide extended drug release (over 24 h), mainly dictated by the polymer's chemical nature. This paper highlights how glibenclamide is degraded during HME and how polymer selection crucially affects the sustained release dynamics. [ABSTRACT FROM AUTHOR]

Ivermectin (IVM), a drug originally used for treating parasitic infections, is being explored for its potential applications in cancer therapy. Despite the promising anti-cancer effects of IVM, its low water solubility limits its bioavailability and, consequently, its biological efficacy as an oral formulation. To overcome this challenge, our research focused on developing IVM-loaded lipid polymer hybrid nanoparticles (LPHNPs) designed for potential pulmonary administration. IVM-loaded LPHNPs were developed using the emulsion solvent evaporation method and characterized in terms of particle size, morphology, entrapment efficiency, and release pattern. Solid phase characterization was investigated by Fourier transform infrared spectroscopy (FTIR), differential scanning calorimetry (DSC), and thermogravimetric analysis (TGA). Using a Twin stage impinger (TSI) attached to a device, aerosolization properties of the developed LPHNPs were studied at a flow rate of 60 L/min, and IVM was determined by a validated HPLC method. IVM-loaded LPHNPs demonstrated spherical-shaped particles between 302 and 350 nm. Developed formulations showed an entrapment efficiency between 68 and 80% and a sustained 50 to 60% IVM release pattern within 96 h. Carr's index (CI), Hausner ratio (HR), and angle of repose (θ) indicated proper flowability of the fabricated LPHNPs. The in vitro aerosolization analysis revealed fine particle fractions (FPFs) ranging from 18.53% to 24.77%. This in vitro study demonstrates the potential of IVM-loaded LPHNPs as a delivery vehicle through the pulmonary route. [ABSTRACT FROM AUTHOR]

This work aimed to evaluate the potential of the nanosystems constituted by dopamine (DA) and the antioxidant Citicoline (CIT) co-loaded in solid lipid nanoparticles (SLNs) for intranasal administration in the treatment of Parkinson disease (PD). Such nanosystems, denoted as DA-CIT-SLNs, were designed according to the concept of multifunctional nanomedicine where multiple biological roles are combined into a single nanocarrier and prepared by the melt emulsification method employing the self-emulsifying Gelucire® 50/13 as lipid matrix. The resulting DA-CIT-SLNs were characterized regarding particle size, surface charge, encapsulation efficiency, morphology, and physical stability. Differential scanning calorimetry, FT-IR, and X ray diffraction studies were carried out to gain information on solid-state features, and in vitro release tests in simulated nasal fluid (SNF) were performed. Monitoring the particle size at two temperatures (4 °C and 37 °C), the size enlargement observed over the time at 37 °C was lower than that observed at 4 °C, even though at higher temperature, color changes occurred, indicative of possible neurotransmitter decomposition. Solid-state studies indicated a reduction in the crystallinity when DA and CIT are co-encapsulated in DA-CIT-SLNs. Interestingly, in vitro release studies in SNF indicated a sustained release of DA. Furthermore, DA-CIT SLNs displayed high cytocompatibility with both human nasal RPMI 2650 and neuronal SH-SY5Y cells. Furthermore, OxyBlot assay demonstrated considerable potential to assess the protective effect of antioxidant agents against oxidative cellular damage. Thus, such protective effect was shown by DA-CIT-SLNs, which constitute a promising formulation for PD application. [ABSTRACT FROM AUTHOR]

The present study investigated the effect of different polymers and manufacturing methods (hot melt extrusion, HME, and spray drying, SD) on the solid state, stability and pharmaceutical performance of amorphous solid dispersions. In the present manuscript, a combination of different binary amorphous solid dispersions containing 20% and 30% of drug loadings were prepared using SD and HME. The developed solid-state properties of the dispersions were evaluated using small- and wide-angle X-ray scattering (WAXS) and modulated differential scanning calorimetry (mDSC). The molecular interaction between the active pharmaceutical ingredients (APIs) and polymers were investigated via infrared (IR) and Raman spectroscopy. The in vitro release profile of the solid dispersions was also evaluated to compare the rate and extend of drug dissolution as a function of method of preparation. Thereafter, the effect of accelerated stability conditions on the physicochemical properties of the solid dispersions were also evaluated. The results demonstrated higher stability of Soluplus® (SOL) polymer-based solid dispersions as compared to hydroxypropyl methylcellulose (HPMC)-based solid dispersions. Moreover, the stability of the solid dispersions was found to be higher in the case of API having high glass transition temperature (Tg) and demonstrated higher interaction with the polymeric groups. Interestingly, the stability of the melt-extruded dispersions was found to be slightly higher as compared to the SD formulations. However, the down-processing of melt-extruded strands plays critical role in inducing the API crystal nuclei formation. In summary, the findings strongly indicate that the particulate properties significantly influence the performance of the product. [ABSTRACT FROM AUTHOR]

Curcumin and piperine are plant compounds known for their health-promoting properties, but their use in the prevention or treatment of various diseases is limited by their poor solubility. To overcome this drawback, the curcumin–piperine amorphous polymer–phospholipid dispersions were prepared by hot melt extrusion technology. X-ray powder diffraction indicated the formation of amorphous systems. Differential scanning calorimetry confirmed amorphization and provided information on the good miscibility of the active compound–polymer–phospholipid dispersions. Owing to Fourier-transform infrared spectroscopy, the intermolecular interactions in systems were investigated. In the biopharmaceutical properties assessment, the improvement in solubility as well as the maintenance of the supersaturation state were confirmed. Moreover, PAMPA models simulating the gastrointestinal tract and blood-brain barrier showed enhanced permeability of active compounds presented in dispersions compared to the crystalline form of individual compounds. The presented paper suggests that polymer–phospholipid dispersions advantageously impact the bioaccessibility of poorly soluble active compounds. [ABSTRACT FROM AUTHOR]

In this work, the phase equilibria of the binary Ag-In system were determined using electron probe microanalysis and differential scanning calorimetry on equilibrated alloys and diffusion couples. The compositions of the phase boundaries of solid phases that are highly scattered in the literature have been precisely determined. The temperatures of the invariant reaction ζ ⇄ γ + L and the polymorphic transformation ζ ⇄ γ are substantially lower than previously reported values. In addition, it was found that the In-rich ζ phase phase-separates after months of room-temperature aging. [ABSTRACT FROM AUTHOR]

Poly (butylene terephthalate) (PBT)/poly (ethylene glycol‐co‐cyclohexane‐1, 4‐dimethanolterephthalate) (PETG) blends were prepared by melt blending using a twin screw extruder. The non‐isothermal crystallization behaviors of PBT/PETG blends were investigated using differential scanning calorimetry (DSC). The results showed that the crystallization peaks of the PBT/PETG blends moved gradually toward lower temperature and the crystallinity decreased with the increase of PETG content. The PBT/PETG blends all show double melting peaks, which the low‐melting peak temperature Tm1 becomes lower as the cooling rate increases, but the high‐melting peak temperature Tm2 is not related to the cooling rate. The Jeziorny's method showed that the faster the cooling rate is, the shorter the crystallization time is required for the PBT/PETG blends. The Mo's method showed that the crystallization rate of the blends initially decreased and then increased with the addition of more PETG. The activation energy of non‐isothermal crystallization calculated by the Kissinger method is similar to that of the Takhor method. Highlights: The efficient blending of PBT and PETG was realized by twin screw extruder, which opened up a new way for the preparation of polymer materials.The crystallization behavior of PBT/PETG blends was successfully regulated, and the effect of PETG content on the crystallization peak temperature and crystallinity was revealed.The crystallization characteristics and kinetic behavior of the blends were comprehensively evaluated by DSC, Jeziorny method, Mo Zhishen method, and Kissinger method. [ABSTRACT FROM AUTHOR]

In the present study, a peroxide‐cured ethylene propylene diene monomer (EPDM) rubber composite with a non‐conductive path achieved through the use of a special‐grade carbon black, resistant to electrochemical degradation, for automotive applications, especially in the manufacturing of radiator coolant hoses, has been developed. The most significant aspect of this study is that the developed composite exhibits optimized physico‐mechanical properties such as hardness, tensile strength, elongation at break, and compression set, along with considerable thermal stability and cold flexibility. Both sulfur‐cured and peroxide‐vulcanized EPDM composites were prepared, and the final validation of the composite was obtained through a comprehensive comparison of these properties. The composite's stability was confirmed through heat aging measurements and glycol‐water coolant immersion tests. Furthermore, the thermal behavior of the composite was analyzed using thermo gravimetric analysis (TGA) and differential scanning calorimetry (DSC). The novel composite was characterized through Fourier Transform Infrared Spectroscopy (FTIR) studies, and its surface morphology was examined via Field Emission Scanning Electron Microscopy (FE‐SEM). The cold flexibility crack formation test was conducted in accordance with ASTM D 2137, and the electrochemical degradation (ECD) resistance test was carried out following SAE J 1684 method 2. The results indicate that the developed composite remained free from crack formation during these tests. Highlights: Novel EPDM composite resists ECD in radiator hoses.Optimized physico‐mechanical properties achieved.Thorough validation of sulfur versus peroxide curing.Successful prevention of crack formation.Comprehensive analysis: TGA, DSC, FE‐SEM, FTIR. [ABSTRACT FROM AUTHOR]

The primary objective of this research is to fabricate semi‐interpenetrating polymer networks (semi‐IPNs) via in‐situ polymerization of methyl methacrylate (MMA) within a polyurethane (PU) framework. To produce polymethyl methacrylate (PMMA) from MMA in the PU matrix, solution polymerization was utilized in the following weight ratios: 30/70, 50/50, 70/30, and 90/10. The effective formation of semi‐IPNs of PU/PMMA was confirmed by several techniques. Fourier transform infrared (FTIR) proves that no new chemical bonds formed between the semi‐IPNs, and only physical interactions were present, and X‐ray diffraction (XRD) techniques tell about the amorphous nature of these semi‐IPNs. The field emission scanning electron microscope (FESEM) and atomic force microscope (AFM) were utilized to examine the morphology of PU/PMMA semi‐IPNs. In contrast to alternative semi‐IPNs, 70/30 and 90/10 PU/PMMA exhibit a uniform morphology devoid of phase separation. Furthermore, the significant thermal stability and transitions of these semi‐IPNs were assessed using a thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC). Additionally, the mechanical analysis indicates that among the different percentages of PU/PMMA, 70/30 PU/PMMA exhibits the highest tensile strength of approximately 50.5 MPa. The observed enhancement in mechanical strength can be attributed to interpenetrating networks (IPNs) formed between the constituents. The synthesized PU/PMMA semi‐IPNs have potential in various fields, including medical devices, automotive components, sports, and other advanced applications. [ABSTRACT FROM AUTHOR]

A novel dicoumarol-based copolyester was synthesized via a one-step polycondensation reaction using titanium tetraisopropoxide (TTIP) as a catalyst. The copolyester was characterized using Fourier transform infrared spectroscopy (FT-IR), Nuclear Magnetic Resonance (NMR) spectroscopy (1H and 13C), and Differential Scanning Calorimetry (DSC). Scanning electron microscopy (SEM) was used to examine the surface morphology before and after degradation. The synthesized copolyester exhibited toxicity against MCF-7 breast cancer cells, with an IC50 value of 62.5 μg/mL, and demonstrated potential as a drug carrier with a consistent drug-release rate. The combination of dicoumarol, itaconic acid, and 1,12-dodecanediol in the copolyester enhances its biomedical capabilities, with dicoumarol providing anticancer properties, itaconic acid offering biocompatibility and mechanical stability, and 1,12-dodecanediol ensuring structural integrity and responsiveness. This study presents the first example of a dicoumarol-substituted copolyester, which was thoroughly characterized and shown to have promising biocompatibility for targeted anticancer therapy. The synthesis of this novel copolyester from renewable sources highlights the growing interest in sustainable materials for pharmaceutical and biomedical applications, particularly in drug delivery and tissue engineering for cancer treatment. [ABSTRACT FROM AUTHOR]

The Double Diaphragm Preforming (DDPF) process uses vacuum pressure and heat to pre-shape dry carbon fabric reinforcements between flexible diaphragms in liquid composite molding (LCM). Accurate modeling of heat transfer within DDPF requires knowledge of the thermophysical properties of the constituent materials under processing conditions. This study investigates the thermal conductivity of silicone diaphragms and carbon fabrics with embedded thermoplastic binder webs, utilizing transient plane source (TPS) and modified transient plane source (MTPS) methods, respectively. Additionally, the specific heat of silicone, carbon fibers (both chopped and powdered), and binder were measured using differential scanning calorimetry (DSC). Mixed samples comprising chopped fibers with 1.8 wt% binder and powdered fibers with 3.6 wt% binder was also analyzed with DSC. This study also examined the influence of reheating cycles on the specific heat of carbon fiber—3.6 wt% binder samples—and the effect of compaction and vacuum on the thermal conductivity of carbon fabrics with an embedded binder. While silicone exhibited linear-specific heat behavior, the thermoplastic binder showed non-linearity due to phase change. The combined carbon fiber-binder samples demonstrated slight non-linear specific heat variations depending on reheating cycles. The thermal conductivity of the fabric preforms decreased with the addition of thermoplastic binder and under vacuum-compaction conditions. The established temperature-dependent specific heat relationships and thermal conductivity provide valuable data for optimizing DDPF preforming parameters and enhancing energy efficiency in composite manufacturing. [ABSTRACT FROM AUTHOR]

Miltefosine (MLT) is a broad-spectrum drug included in the alkylphospholipids (APL) used against leishmania and various types of cancer. The most crucial feature of APLs is that they are thought to only kill cancerous cells without harming normal cells. However, the molecular mechanism of action of APLs is not completely understood. The increase in the phosphatidylserine (PS) ratio is a marker showing the stage of cancer and even metastasis. The goal of this research was to investigate the molecular effects of miltefosine at the molecular level in different PS ratios. The effects of MLT on membrane phase transition, membrane orders, and dynamics were studied using DPPC/DPPS (3:1) and DPPC/DPPS (1:1) multilayer (MLV) vesicles mimicking DPPS ratio variation, Differential Scanning Calorimetry (DSC), and Fourier Transform Infrared spectroscopy (FTIR). Our findings indicate that miltefosine is evidence at the molecular level that it is directed towards the tumor cell and that the drug's effect increases with the increase of anionic lipids in the membrane depending on the stage of cancer. [ABSTRACT FROM AUTHOR]

Co-melting paracetamol with different cellulose derivatives leads to full or partial amorphization of active substance. The aim of this study was to determine whether the amorphization of paracetamol after co-melting with cellulose derivatives is stable and whether it depends on the type of cellulose derivative added and the ratio of components. Mixtures of paracetamol with cellulose derivatives containing different proportions of components were prepared. Using differential scanning calorimetry (DSC), the samples were melted and the amorphization of paracetamol was confirmed. After 2 and 4 months, the samples were reanalyzed to determine the amorphization stability during storage and the difference in the effect of different polymers on the amorphization stability. The physical mixtures were additionally tested using Fourier transform infrared (FTIR) and Raman spectroscopic methods to confirm that no solid-phase interactions were noticed. Samples were also analyzed using ultrahigh-performance liquid chromatography (UHPLC) to assess the effect of co-melting and storage on the chemical stability of paracetamol. The results show that paracetamol amorphizes after co-melting with cellulose derivatives. The crystallization of paracetamol after co-melting depends on the polymer used and the proportions of the components. No interactions between the components and the chemical stability of paracetamol in the tested samples were confirmed. [ABSTRACT FROM AUTHOR]

Urea–formaldehyde (UF) and phenol–formaldehyde (PF) resins are the most widely used adhesives in the production of wood composites, and are cured through hot-pressing to provide adhesion strength with the composites. This study investigates the relationship between thermal curing behavior monitored by differential scanning calorimetry (DSC) and adhesive bond strength development measured by an automated bonding evaluation system (ABES) for UF and PF resins with different molecular weights (Mw). DSC results demonstrated that UF resins cured faster than PF resins, as indicated by a lower apparent activation energy (Ea). In addition, UF and PF resins with lower Mw cured faster in the early stages of curing and slower in the latter stages of curing as compared to higher-Mw resins. Furthermore, according to the ABES results, when increasing the molecular weight, both UF and PF resins exhibited greater adhesive bond strength, irrespective of pressing parameters (temperature and time). The isothermal DSC and ABES results demonstrated that the adhesive bond strength increased with an increase in the degree of cure of the resins, indicating a correlation between them. It also showed that UF resins attained optimal adhesive bond strength at low temperature (110–130 °C) in roughly 180 s while PF resins attained it at high temperature (120–130 °C) in about 300 s. However, the degree of cure under isothermal scans was inconsistent with temperatures. These results indicate that the degree of cure is closely related to the adhesion strength development of UF and PF resins which are curing at low and high temperatures to obtain the optimum adhesion strength. [ABSTRACT FROM AUTHOR]

Electrospinning technology is widely used for preparing biological tissue engineering scaffolds because of its advantages of simple preparation, accurate process parameters, and easy control. Poly(L-lactide) (PLLA) is regarded as a promising biomass-based polymer for use in electrospinning. The incorporation of Fe3O4 nanoparticles (NPs) could improve the osteogenic differentiation and proliferation of cells in the presence or absence of a static magnetic field (SMF). In this work, these two materials were blended together to obtain electrospun samples with better dispersibility and improved magnetic properties. First, composite PLLA and Fe3O4 NP fibers were prepared by means of electrospinning. The influence of electrospinning conditions on the morphology of the composite fibers was then discussed. Changes in magnetic properties and thermal stability resulting from the use of different PLLA/Fe3O4 mass ratios were also considered. Next, the morphology, crystal state, thermodynamic properties, and magnetic properties of the electrospun samples were determined using scanning electron microscopy (SEM), thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FTIR), and vibration sample magnetization (VSM). The results showed that the fibers prepared using PLLA with Mn = 170,000 exhibited good morphology when electrospun at 12 KV. The magnetic properties of PLLA/Fe3O4 composite electrospun fibers increased with the NP content, with the exception of thermal stability. The results of the present study may help to promote the further development of PLLA/Fe3O4 composite materials in the biomedical field. [ABSTRACT FROM AUTHOR]

In this paper, enhancing the tribological characteristics of novel cast metallic materials—hybrid multi-component cast irons—by applying a strengthening heat treatment is described. The experimental materials were the cast alloys of a nominal composition (5 wt.% W, 5 wt.% Mo, 5 wt.% V, 10 wt.% Cr, 2.5 wt.% Ti, Fe is a balance) supplemented with 0.3–1.1 wt.% C and 1.5–2.5 wt.% B (total of nine alloys). The heat treatment was oil-quenching followed by 200 °C tempering. The quench temperature (QT) varied in the range of 900–1200 °C, with a step of 50 °C (with a 2-h holding at QT). The correlation of the QT with microstructure and properties was estimated using microstructure/worn surface characterization, differential scanning calorimetry, hardness measurement, and three-body-abrasive wear testing (using Al2O3 particles). The as-cast alloys had a multi-phase structure consisting of primary and/or eutectic borocarbide M2(B,C)5, carboborides M(C,B), M7(C,B)3, M3(C,B), and the matrix (ferrite, martensite, pearlite/bainite) in different combinations and volume fractions. Generally, the increase in the quenching temperature resulted in a gradual increase in hardness (maximally to 66–67 HRC) and a decrease in the wear rate in most alloys. This was due to the change in the phase-structure state of the alloys under quenching, namely, the secondary carboboride precipitation, and replacing ferrite and pearlite/bainite with martensite. The wear rate was found to be inversely proportional to bulk hardness. The maximum wear resistance was attributed to QT = 1150–1200 °C, when the wear rate of the alloys was lowered by three to six times as compared to the as-cast state. With the QT increase, the difference in the wear rate of the alloys decreased by three times. The highest abrasive resistance was attributed to the alloys with 1.1 wt.% C, which had a 2.36–3.20 times lower wear rate as compared with that of the reference alloy (13 wt.% Cr cast iron, hardness of 66 HRC). The effects of carbon and boron on hardness and wear behavior are analyzed using the regression models developed according to the factorial design procedure. The wear mechanisms are discussed based on worn surface characterization. [ABSTRACT FROM AUTHOR]

Thermochromic phase change materials (TPCMs) are gaining increasing interest among scientists. These multifunctional materials can store thermal energy but also, at the same time, during the phase transition, they can change colour. Thermal conductivity is also extremely important for this type of material, which is why various additives are used for this purpose. This work aimed to study the properties of thermochromic phase change materials with an inorganic modifier. Stearic acid, behenyl alcohol, and bromocresol purple were used as thermochromic system components, while boron nitride particles were used as an additive. The key tests for such systems are thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC), which allow determining the thermal stability of the materials (at around 170 °C) and phase transition parameters (thermal energy storage of 300 J/g in the range of 40–75 °C). The thermochromic properties were tested, and satisfactory results were obtained. In the end, laser flash analysis (LFA) tests indicated that boron nitride improves the thermal conductivity of the organic thermochromic phase change material by almost 30%. The results showed that the tested materials have great potential as thermochromic phase change materials for thermal energy storage. [ABSTRACT FROM AUTHOR]

Recently, double network (DN) gels with dynamic non‐covalent interaction such as hydrogen bonds has drawn much attention as an innovative material having both high water content and high mechanical strength. Research efforts have identified DN gels as a promising class of materials due to their unique network architecture. These gels comprise two interpenetrating networks formed by different types of polymer. Herein, we report a tough DN hydrogel with high mechanical strength and high swelling ability. The DN gel is synthesized via a two‐step network formation. The first network gel was synthesized via frontal polymerization. Then, the first gel is immersed in an aqueous solution of a second monomer and carrying out a second polymerization in the presence of first network. The spectroscopic analysis and thermal behavior with differential scanning calorimeter measurements corroborated the existence of hydrogen bonds. The mechanical test and microscopic morphology were further explored to explain the strength and high imbibing characteristics. We expect that this facile strategy may explore a dynamic and tunable hydrogel to expand its potential applications in biomedical field. [ABSTRACT FROM AUTHOR]

This study evaluated cryogels from albumin (ALB) and albumin–pectin (ALB:PEC) as carriers for pink pepper (Schinus terebinthifolius Raddi) essential oil. Cryogels were evaluated through infrared spectrophotometry, X-ray diffraction, scanning electron microscopy, thermogravimetric analysis, and differential scanning calorimetry. The bioactivity of the cryogels was analyzed by measuring their encapsulation efficiency (EE%), the antimicrobial activity of the encapsulated oil against S. aureus, E. coli, and B. cereus using the agar diffusion method; total phenolic content and antioxidant activity were analyzed by UV-vis spectrophotometry. The EE% varied between 59.61% and 77.41%. The cryogel with only ALB had the highest total phenolic content with 2.802 mg GAE/g, while the cryogel with the 30:70 ratio (ALB:PEC) presented a value of 0.822 mg GAE/g. A higher proportion of PEC resulted in a more significant inhibitory activity against S. aureus, reaching an inhibition zone of 18.67 mm. The cryogels with ALB and 70:30 ratio (ALB:PEC) presented fusion endotherms at 137.16 °C and 134.15 °C, respectively, and semicrystalline structures. The interaction between ALB and PEC increased with their concentration, as evidenced by the decreased intensity of the O-H stretching peak, leading to lower encapsulation efficiency. The cryogels obtained can be considered a suitable matrix for encapsulating pink pepper oil. [ABSTRACT FROM AUTHOR]

This study aimed to investigate the potential of antimony-doped tin oxide (ATO) as a reinforcing agent for polyamide 12 (PA12) in 3D printing by examining four mixtures with varying ATO concentrations (2.0 to 8.0 wt.%, with a 2.0 wt.% interval). These mixtures were used to fabricate filaments for the manufacturing of specimens through the material extrusion method. The mechanical properties of the resulting PA12/ATO composites and PA12 pure samples were evaluated through tensile, Charpy impact, flexural, and microhardness tests. Additionally, rheology, structure, morphology, thermal properties, pore size, and consistency in the dimensions of the samples were evaluated. Thermogravimetric analysis, along with differential scanning calorimetry, scanning electron microscopy, energy-dispersive and Raman spectroscopy, and micro-computed tomography, were conducted. The results were correlated and interpreted. The greatest reinforcement was achieved with the PA12/ATO 4.0 wt.% mixture, which exhibited a 19.3% increase in tensile strength and an 18.6% increase in flexural strength compared with pure PA12 (the control samples). The Charpy impact strength and microhardness were also improved by more than 10%. These findings indicate the merit of composites with ATO in additive manufacturing, particularly in the production of components with improved mechanical performance. [ABSTRACT FROM AUTHOR]

Polymer-based materials, such as polyethylene glycol and its derivatives, are popular as biomaterials, including for clinical purposes. The hydrogels used in drug-carrying systems have become beneficial in cancer therapy. Due to their unique biocompatibility, durability, enhanced drug loading capacity, and low cytotoxicity, poly(ethylene glycol) dimethacrylate (PEGDMA) hydrogels are widely used in drug delivery systems. In this work, we illustrated the photopolymerization of four PEGDMA/methyl cellulose (MC) hydrogels at four concentrations. Irgacure 2959 (2-hydroxy-4′-(2-hydroxyethoxy)-2-methylpropiophenone) was used as a UV photoinitiator. Various aspects of the properties of hydrogels were studied. Fourier-transform infrared spectroscopy (FTIR) was used for the chemical bonds, scanning electron microscopy (SEM) for the surface morphology, and differential scanning calorimetry (DSC) to identify the thermal behavior, and swelling, contact angle, and degradation tests were executed to understand the hydrogels' behavior against moisture. Cancer cells' ability to grow and proliferate on PEGDMA hydrogels was examined to assess the hydrogels' viability as a drug carrier system for tissue engineering applications. The results suggest that the F4 hydrogels present a novel all-round means of cell culture and drug delivery as they permit target drug delivery and exhibit nontoxic behavior due to their high swelling ratio, good degradation profile, and biocompatibility, confirming that these hydrogels are suitable for further applications in cell culture analysis. [ABSTRACT FROM AUTHOR]

In the present study, the capacity of two commercial NiTi and NiTiCu shape memory alloy (SMA) wires to develop work-generating (WG) and constrained-recovery (CR) shape memory effects (SMEs), as well as the capacity of a commercial NiTiFe super-elastic wire to act as cold-shape restoring element, have been investigated. Using differential scanning calorimetry (DSC), the reversible martensitic transformation to austenite of the three NiTi-based wires under study was emphasized by means of an endothermic minimum of the heat flow variation with temperature. NiTi and NiTiCu wire fragments were further tested for both WG-SME and CR-SME developed during the heating, from room temperature (RT) to different maximum temperatures selected from the DSC thermograms. The former tests revealed the capacity to repetitively lift various loads during repetitive heating, while the latter tests disclosed the repetitive development of shrinkage stresses during the repetitive heating of elongated wires. The tensile behavior of the three NiTi-based SMA wires was analyzed by failure and loading–unloading tests. The study disclosed the actuation capacity of NiTi and NiTiCu shape memory wires, which were able to develop work while being heated, as well as the resetting capacity of NiTiFe super-elastic wires, which can restore the initial undeformed shape of shape memory wires which soften while being cooled down. These features enable the design of a robotic gripper based on the development of NiTi-based actuators with repetitive action. [ABSTRACT FROM AUTHOR]

Wind turbine generator output cables are subjected to alternating torsional loads during long-term operation, combined with electrothermal stress, which may lead to insulation failure and other serious issues. Currently, the electrothermal aging mechanism under torsional stress is not fully understood. This study explores the synergistic degradation mechanism of electrothermal aging and nonlinear torsion by constructing a multi-stress aging test platform in the laboratory environment. This study involved accelerated aging tests with thermal, electrothermal, and electrothermal–torsional alternating stresses. The aged cable samples were analyzed for their physical and chemical properties using differential scanning calorimetry and Fourier transform infrared spectroscopy, while dielectric spectroscopy and mechanical tests were employed to evaluate their dielectric and mechanical performance. The results indicate that torsional stress induces physical changes at the molecular level in the ethylene–propylene rubber (EPR), leading to reduced strength, hardening, and increased brittleness, resulting in decreased mechanical strength. In addition, torsional stress promotes oxidation reactions and chain scission processes in the insulation layer, reducing crystallinity and causing a decline in mechanical performance. Increased oxidation and chain scission reactions result in an increase in polar groups, leading to an increase in the dielectric loss factor of the EPR. The findings of this study provide valuable insights for the design, manufacturing, and operational monitoring of wind turbine generator output cables. [ABSTRACT FROM AUTHOR]

In this investigation, composite poly(lactic acid) (PLA) systems of hollow glass microspheres (MS) and carbonyl iron particles (CIP) were processed and characterized to investigate the effects of using conductive and insulating particles as additives in a polymer system. PLA-MS and PLA-CIP were set at the two levels of 3.94 and 7.77 vol.% for each particle type to study the effects of the particle material type and loading on neat PLA's thermal properties. It was observed during the twin-screw extrusion that the addition of CIP greatly decreased the viscosity of the PLA melt during processing. Correlations determined using thermogravimetric analysis, differential scanning calorimetry, thermal conductivity, and shear rheology provided insights into how thermal stability was affected. The incorporation of MS and CIP altered thermal properties such as the glass transition temperature (Tg), melting temperature (Tm), and cold crystallization temperature (Tcc). The metal CIP-filled systems had large increases in their thermal conductivity values and viscoelastic transitions compared to those with PLA that were correlated with the observed overheating during extrusion. [ABSTRACT FROM AUTHOR]

Indomethacin (IND) as a non-selective cyclooxygenase 1 and 2 inhibitor administered orally causes numerous adverse effects, mostly related to the gastrointestinal tract. Moreover, when applied exogenously in topical preparations, there are obstacles to its permeation through the stratum corneum due to its low water solubility and susceptibility to photodegradation. In this work, solid dispersions (SDs) of IND with low-substituted hydroxypropyl cellulose (LHPC) were developed. The IND—SDs were incorporated into a hydroxypropyl guar (HPG) hydrogel to enhance drug solubility on the skin. The hydrogels were characterized by scanning electron microscopy (SEM), differential scanning calorimetry (DSC), powder X-ray diffraction (XRPD), Fourier-transform infrared spectroscopy (FTIR), viscosity, drug release, and unspecific cytotoxicity in mammalian cells. SEM showed a highly porous structure for SD hydrogels. DSC and XRPD studies showed that amorphous IND species were formed; therefore, these hydrogels exhibited superior drug release in comparison with IND raw material hydrogels. FTIR evidenced the presence of the hydrogen bond in the SD hydrogel. The rheology parameter viscosity increased across gels formulated with SDs in comparison with hydrogels with pure IND. In addition, IND—SD hydrogels combine the advantages of a suitable viscosity for dermal use and no potentially hazardous skin irritation. This study suggests that the formulated IND—SD hydrogels represent a suitable candidate for topical administration. [ABSTRACT FROM AUTHOR]

This study investigates the crosslinking dynamics and swelling properties of pH-responsive poly(ethylene glycol) (PEG)/poly(acrylic acid) (PAA) interpenetrating polymer network (IPN) hydrogels. These hydrogels feature denser crosslinked networks compared to PEG single network (SN) hydrogels. Fabrication involved a two-step UV curing process: First, forming PEG-SN hydrogels using poly(ethylene glycol) diacrylate (PEGDA) through UV-induced free radical polymerization and crosslinking reactions, then immersing them in PAA solutions with two different molar ratios of acrylic acid (AA) monomer and poly(ethylene glycol) dimethacrylate (PEGDMA) crosslinker. A subsequent UV curing step created PAA networks within the pre-fabricated PEG hydrogels. The incorporation of AA with ionizable functional groups imparted pH sensitivity to the hydrogels, allowing the swelling ratio to respond to environmental pH changes. Rheological analysis showed that PEG/PAA IPN hydrogels had a higher storage modulus (G′) than PEG-SN hydrogels, with PEG/PAA-IPN5 exhibiting the highest modulus. Thermal analysis via thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC) indicated increased thermal stability for PEG/PAA-IPN5 compared to PEG/PAA-IPN1, due to higher crosslinking density from increased PEGDMA content. Consistent with the storage modulus trend, PEG/PAA-IPN hydrogels demonstrated superior mechanical properties compared to PEG-SN hydrogels. The tighter network structure led to reduced water uptake and a higher gel modulus in swollen IPN hydrogels, attributed to the increased density of active network strands. Below the pKa (4.3) of acrylic acid, hydrogen bonds between PEG and PAA chains caused the IPN hydrogels to contract. Above the pKa, ionization of PAA chains induced electrostatic repulsion and osmotic forces, increasing water absorption. Adjusting the crosslinking density of the PAA network enabled fine-tuning of the IPN hydrogels' properties, allowing comprehensive comparison of single network and IPN characteristics. [ABSTRACT FROM AUTHOR]

The formation of polylactide stereocomplex (sc-PLA), involving the blending of poly(L-lactide) (PLLA) and poly(D-lactide) (PDLA), enhances PLA materials by making them stronger and more heat-resistant. This study investigated the competitive crystallization behavior of homocrystals (HCs) and stereocomplex crystals (SCs) in a 50/50 PLLA/PDLA blend with added polyethylene glycol (PEG). PEG, with molecular weights of 400 g/mol and 35,000 g/mol, was incorporated at concentrations ranging from 5% to 20% by weight. Differential scanning calorimetry (DSC) analysis revealed that PEG increased the crystallization temperature, promoted SC formation, and inhibited HC formation. PEG also acted as a plasticizer, lowering both melting and crystallization temperatures. The second heating DSC curve showed that the pure PLLA/PDLA blend had a 57.1% fraction of SC while adding 5% PEG with a molecular weight of 400 g/mol resulted in complete SC formation. In contrast, PEG with a molecular weight of 35,000 g/mol was less effective, allowing some HC formation. Additionally, PEG consistently promoted SC formation across various cooling rates (2, 5, 10, or 20 °C/min), demonstrating a robust influence under different conditions. [ABSTRACT FROM AUTHOR]

The development of more recyclable materials is a key requirement for a transition towards a more circular economy. Thanks to exchange reactions, vitrimer, an attractive alternative for recyclable materials, is an innovative class of polymers that is able to change its topology without decreasing its connectivity. In this work, a bisphenol compound (VP) was prepared from saturated cardanol, i.e., 3−pentadecylphenol and vanillyl alcohol. Then, VP was epoxidized to obtain epoxide (VPGE). Finally, VPGE and citric acid (CA) were polymerized in the presence of catalyst TBD to prepare a fully bio−based vitrimer based on transesterification. The results from differential scanning calorimetry (DSC) showed that the VPGE/CA system could be crosslinked at around 163 °C. The cardanol−derived vitrimers had good network rearrangement properties. Meanwhile, because of the dynamic structural elements in the network, the material was endowed with excellent self−healing, welding, and recyclability. [ABSTRACT FROM AUTHOR]

Aqueous solutions of a thermoresponsive diblock copolymer poly(di-[ethylene glycol] methyl ether methacrylate)-b-poly(2-[diisopropylamino] ethyl methacrylate) (PDEGMA-b-PDIPAEMA) were studied by static, dynamic and electrophoretic light scattering, small-angle X-ray scattering and differential scanning calorimetry. Thermoresponsive behavior of PDEGMA-b-PDIPAEMA was investigated at two pH values, pH = 2, at which the terminal carboxylic group of the PDEGMA chain and the PDIPAEMA block are protonated, and pH = 7, where the carboxyl terminal group is ionized while the PDIPAEMA block is partially deprotonated and more hydrophobic. Both at pH = 2 and 7, PDEGMA-b-PDIPAEMA copolymer underwent extensive association (the size of the aggregates was between 100 and 300 nm), indicating strong interchain interactions. While the measurements confirmed thermoresponsive behavior of PDEGMA-b-PDIPAEMA at pH = 7, no changes in the association with temperature were observed at pH 2 as the thermoresponsivity of PDEGMA was suppressed by hydrogen bonding between carboxylic groups and PDEGMA segments, as well as due to the increased hydrophilicity of the PDIPAEMA block. Fluorescence measurements with pyrene as a fluorescent probe showed that both at pH = 2 and pH = 7 the associates were able to solubilize hydrophobic substances. [ABSTRACT FROM AUTHOR]

Biodegradable poly(butylene succinate‐co‐adipate)/Poly(3‐hydroxybutyrate‐co‐3‐hydoxyvalerate) (PBSA/PHBV) filled with lignocellulosic sidestream/fibers from cowpea, a neglected and underutilized African crop are produced by injection molding and extrusion film casting. Differential scanning calorimetry (DSC) and dynamic mechanical analysis (DMA) suggests that the fibers have more affinity and interfacial interaction with PBSA than PHBV. This is shown by a decrease in dampening of PBSA and an increase in dampening of PHBV with fiber addition. In addition, fiber addition results in more homogeneous crystal morphology of PBSA, while resulting in more heterogeneous crystal morphology of PHBV. The tensile strength of injection molded bio‐composites increases with fiber addition due to good interfacial adhesion between the matrix and fibers revealed by scanning electron microscope. In contrast, the tensile strength of bio‐composite films decreases with fiber addition due to the high‐volume fraction of pores in bio‐composite films that act as stress raisers. The stiffness of both injection molded, and bio‐composite films increase with fiber addition, as revealed by an increase in Young's modulus and storage modulus, while the tensile strain decreases. In conclusion, low‐value cowpea sidestream can be used as a filler to produce injection molded bio‐composites and bio‐composite films for potential application as rigid and flexible packaging. [ABSTRACT FROM AUTHOR]

Waxes find use as processing aids in filled compounds and polyethylene‐based masterbatches. In such applications, the thermal and physical property changes they impart to the polymer matrix are important. Therefore, this study details results obtained for blends prepared by mixing a Fischer–Tropsch (F–T) wax with a high‐flow linear low‐density polyethylene (LLDPE). The melting and crystallization behavior are studied using hot‐stage polarized optical microscopy (POM) and differential scanning calorimetry (DSC). The calorimetry results are consistent with partial cocrystallization of the two components. The melting and crystallization exo‐ and endotherms for the wax‐ and LLDPE‐rich phases remained separate. However, they change in shape and shift toward higher‐ and lower temperature ranges, respectively. It is found that increasing the wax content delays the crystallization, decreases the overall crystallinity, and reduces the size of the crystallites of the polyethylene‐rich phase. Rotational viscosity is measured at 170 °C in the Newtonian shear‐rate range. The variation of the zero‐shear viscosity with blend composition is consistent with the assumption of a homogeneous melt in which the chains are in an entangled state. Therefore, it is concluded that the wax and LLDPE are, in effect, miscible in the melt and partially compatible in the solid state. [ABSTRACT FROM AUTHOR]

Three‐dimensional (3D) printing is an innovative manufacturing method for preparing designer materials with complex geometries. However, there are very few studies on the fabrication of antimicrobial polymer materials suitable for use in everyday clinical objects, via 3D printing. In this work, an antibacterial polymer material is prepared by blending polyamide 11 (matrix), a high‐performance engineering thermoplastic, and a styrene maleimide copolymer with pendant quaternary amine moieties, and the blend 3D printed via selective laser sintering. The quaternary amine functionalities confer permanent antimicrobial properties. Blend properties are studied prior to printing via differential scanning calorimetry, powder X‐ray diffraction, and FTIR spectroscopy. Additionally, the mechanical and antimicrobial properties of the polymer blends and printed material are also assessed. The microstructure of the 3D printed polymer materials is further characterized via DOSY NMR spectroscopy. This study indicates that this is a promising approach for preparing nonleaching antimicrobial 3D printable materials. [ABSTRACT FROM AUTHOR]

In the present study, a resin is synthesized from resorcinol and formaldehyde in the presence of phenylboronic acid. Properties of resins such as free formaldehyde content, total solid content, density, gelation time, viscosity are determined. The chemical structure of the resorcinol‐formaldehyde resin and the resorcinol‐formaldehyde resin containing phenylboronic acid is confirmed by Fourier transform infrared spectroscopy (FTIR), nuclear magnetic resonance spectroscopy, X‐ray photoelectron spectroscopy (XPS), X‐ray diffraction (XRD), and scanning electron microscopy (SEM). The thermal stability and curing behaviors of the polymers are investigated by thermogravimetric analysis (TGA) and differential scanning calorimetry, respectively. Modification of the resorcinol‐formaldehyde resin with a boron source, phenylboronic acid results in a certain increase in thermal stability with a higher residual weight. The 6% PBA loaded polymer has the highest thermal efficiency, so the thermal behavior of it is investigated by curing at different temperatures. The 80 °C/4 h curing method is the most reasonable for energy savings. In differential scanning calorimetry (DSC) analysis, a 6 wt% PBA loading ratio was determined as the optimum value according to the energy requirements. [ABSTRACT FROM AUTHOR]

Aging of polymers is a natural process that occurs during their usage and storage. Predicting the lifetime of polymers is a crucial aspect that should be considered at the design stage. In this paper, a series of bio-based thermoplastic poly(ether-urethane) elastomers (bio-TPUs) with modified hard segments were synthesized and investigated to understand the structural and property changes triggered by accelerated aging. The bio-TPUs were synthesized at an equimolar ratio of reagents using the prepolymer method with the use of bio-based poly(trimethylene ether) glycol, bio-based 1,3-propanediol, and hexamethylene diisocyanate or hexamethylene diisocyanate/partially bio-based diisocyanate mixtures. The polymerization reaction was catalyzed by dibutyltin dilaurate (DBTDL). The structural and property changes after accelerated aging under thermal and hydrothermal conditions were determined using Fourier transform infrared spectroscopy (FTIR), differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), and dynamic mechanical thermal analysis (DMTA). Among other findings, it was observed that both the reference and aged bio-TPUs decomposed in two main stages and exhibited thermal stability up to approximately 300 °C. Based on the research conducted, it was found that accelerated aging impacts the supramolecular structure of TPUs. [ABSTRACT FROM AUTHOR]

Albendazole (ABZ) is a highly effective yet poorly water-soluble antiparasitic drug known to form salts (ABZ-FMA, ABZ-DTA, and ABZ-HCl) with fumaric acid (FMA), D-tartaric acid (DTA), and hydrochloric acid (HCl). This research utilized a range of analytical techniques, including Fourier transform infrared spectroscopy (FT-IR), nuclear magnetic resonance hydrogen spectroscopy (1H NMR), powder X-ray diffraction (PXRD), dynamic vapor sorption (DVS), thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), and scanning electron microscopy (SEM), to validate and characterize the solid-state properties of these drug salts. This study also assessed the solubility and intrinsic dissolution rate (IDR) of these salts under different pH conditions compared to the active pharmaceutical ingredient (API) and conducted stability studies. Moreover, the in vivo pharmacokinetic performance of ABZ salt was evaluated. The results of this study reveal that the new solid form of ABZ is primarily associated with amino acid esters and benzimidazole groups, forming intermolecular interactions. All three ABZ salts significantly improved the solubility and dissolution rate of ABZ, with ABZ-HCl demonstrating the optimal performance. Importantly, the drug salt exhibited robust physical stability when exposed to adverse conditions, including strong light irradiation (4500 ± 500 lux), high humidity (92.5 ± 5% relative humidity), elevated temperatures (50 ± 2 °C), and accelerated test conditions (40 °C/75 ± 5% relative humidity). Lastly, the in vivo pharmacokinetic analysis demonstrated that ABZ salt led to a substantial increase in AUC(0–24) and Cmax compared to ABZ. This elevation in solubility in aqueous solvents signifies that ABZ salt exhibits characteristics that can enhance oral bioavailability and pharmacokinetics. These findings provide potential solutions for the development of more effective and innovative drug formulations. [ABSTRACT FROM AUTHOR]

A phospholipid bilayer is a typical structure that serves crucial functions in various cells and organelles. However, it is not unusual for it to take part in pathological processes. The cell membrane may be a binding target for amyloid-forming proteins, becoming a factor modulating the oligomerization process leading to amyloid deposition—a hallmark of amyloidogenic diseases—e.g., Alzheimer's disease. The information on the mechanisms governing the oligomerization influenced by the protein–membrane interactions is scarce. Therefore, our study aims to describe the interactions between DPPA, a cell membrane mimetic, and amyloidogenic protein human cystatin C. Circular dichroism spectroscopy and differential scanning calorimetry were used to monitor (i) the secondary structure of the human cystatin C and (ii) the phase transition temperature of the DPPA, during the protein–membrane interactions. NMR techniques were used to determine the protein fragments responsible for the interactions, and molecular dynamics simulations were applied to provide a molecular structure representing the interaction. The obtained data indicate that the protein interacts with DPPA, submerging itself into the bilayer via the AS region. Additionally, the interaction increases the content of α-helix within the protein's secondary structure and stabilizes the whole molecule against denaturation. [ABSTRACT FROM AUTHOR]

BACKGROUND: In this work, a process development study for the crystallization step of dexlansoprazole API has been demonstrated under the Quality‐by‐Design (QbD) paradigm. Dexlansoprazole (crystalline) samples prepared under different crystallization conditions of reactor temperature and addition time of anti‐solvent were subjected to solid‐state characterization with variety of analytical techniques, including X‐ray powder diffraction (XRPD), differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), dynamic vapour sorption (DVS), scanning electron microscopy (SEM), particle size distribution (PSD) by laser diffraction and intrinsic dissolution rate (IDR). RESULTS: The crystalline samples were observed to have identical polymorphic phase integrity but differed in their physical characteristics. The particle size distribution and microscopy data collectively elucidated the particle growth kinetics and the extent of agglomeration could be correlated to crystallization conditions, namely reactor temperature and addition time of anti‐solvent. The intrinsic dissolution rate of samples was in good agreement with the morphological properties. CONCLUSION: An empirical model has been proposed for intrinsic dissolution rate correlating with crystallization process parameters. In conclusion, it was possible to elucidate the impact of crystallization parameters on the solid‐state behaviour of dexlansoprazole for development of appropriate pharmaceutical dosage forms. © 2024 Society of Chemical Industry (SCI). [ABSTRACT FROM AUTHOR]

The quaternary glass system 60TeO2-(25−x)Bi2O3-15B2O3-xKCl has been prepared by the melt-quenching process with x ranging from 0 to 20 mol%. X-ray diffraction patterns confirmed the amorphous nature of the synthesized glasses, showing no sharp crystalline peaks. The techniques field emission scanning electron microscopy and energy dispersive X-ray spectroscopy provide information about the surface morphology and elemental composition of the synthesized glass system, respectively. Physical parameters such as density, molar volume, ion concentration, interionic distance, polaron radius, and cation field strength were calculated to determine structural stability. Density and molar volume both decrease with an increase in KCl content. Oxygen packing density decreases with increasing KCl concentration, indicating a rise in non-bridging oxygen atoms. Using differential scanning calorimetry, the glass transition temperature (Tg) was calculated. Its value is found to decrease as the KCl content increases. FTIR and Raman spectra indicate the transformation of TeO4 units into TeO3 units and BO4 units into BO3 units with an increase in KCl content. The diffuse reflectance spectra method is used to study optical parameters such as optical band gap, cut-off wavelength, Urbach energy, refractive index, and metallization criteria. The optical indirect band gap energies (Eopt) range from 2.78 to 3.31 eV and are calculated by applying Tauc's relation. On the other hand, the values of the urbach energy (EU) vary from 0.289 to 0.183 eV, indicating disorderliness or defects in the glass samples decrease with increasing KCl content. The synthesized glasses can be considered for non-linear optical applications since their metallization criterion (M) values ranged from 0.373 to 0.407. The dielectric parameters of the glasses were calculated on a frequency scale of 10–1 to 106 Hz by varying the temperature from 453 to 553 K. Dielectric analysis of the as-prepared glasses shows the non-Debye type behavior. [ABSTRACT FROM AUTHOR]

The present work investigates the physicochemical stability of spray paints when irradiated with artificial solar light (at spectral range 300–800 nm). This research highlights the importance of understanding the materials used in street art and public murals, recognising them as a significant component of contemporary cultural heritage. By examining the stability and degradation of spray paints toward solar light exposure, the study aims to contribute to the preservation of contemporary murals, which reflect current social and cultural narratives. A physicochemical approach was employed for the study of spray paints' physical and thermal properties, as well as the effect of specific photochemical ageing reactions/processes. The photochemical ageing results were compared with reference (unaged) samples. Specifically, a multi-technique approach was applied using stereo microscopy, scanning electron microscopy (SEM), atomic force microscopy (AFM), contact angle measurement, colorimetry, glossimetry, differential scanning calorimetry (DSC), UV-Vis spectroscopy, attenuated total reflectance-Fourier transform infrared spectroscopy (ATR-FTIR), and pyrolysis-GC/MS (Py-GC/MS). The photodegradation of the spray paints occurred from the first 144 h of solar light irradiation, resulting in changes in morphology, colour, gloss, roughness, and wettability. Regarding photochemical stability, ageing seems to affect the binders more than the synthetic organic pigments and the inorganic fillers. In particular, acrylic binders showed small chemical changes, whereas the alkyd, nitrocellulose, and styrene binders underwent severe chemical modification. The results suggest that simulated daylight irradiation prompts the migration of additives toward the surface of the spray paint films. In addition, the results of the analyses on the white spray paints in comparison with the coloured paints (from the same manufacturer) showed that there seems to be an active distinct photoageing mechanism involving titanium dioxide, but the whole issue needs further investigation. [ABSTRACT FROM AUTHOR]

Lithium‐ion batteries are widely used in various industrial and consumer applications. One key point is the thermal stability of these batteries regarding safety. Thermogravimetric analysis and differential scanning calorimetry (DSC) are ideal methods to study the thermal properties of differently charged electrode materials without safety issues associated with thermal runaway tests of the complete cell. This study shows a significant relationship between state of charge (SOC) and power released by the electrode material during the heating process. For the utilized cathode material LixCoO2, a linear relationship is apparent between the decomposition temperature and the decomposition energy, enabling estimation of the SOC. The decomposition temperature of differently charged anode material strongly correlates with the selected heating rate. This study reveals substantial dependencies of the measured power on the utilized crucibles, providing a systematic approach to benchmark the impact of crucible type on observed DSC signals during battery component analysis. [ABSTRACT FROM AUTHOR]

The utility of polymers in the fabrication of nanofibres via electrospinning is well established. Paramount to their application is understanding of their thermal properties, as these dictate not only their processability but also their mechanical robustness, stability under elevated temperatures, and suitability for intended applications. The electrospinning process, which involves heating polymers and subjecting them to high voltage, inherently modifies their thermal characteristics. This study attempts to elucidate these alterations, particularly by focusing on polyacrylonitrile (PAN) nanofibres. Employing techniques such as thermogravimetric analysis (TGA) and Differential Scanning Calorimetry (DSC), the study compares the thermal properties of electrospun PAN nanofibre mats with those of their virgin counterparts. The PAN nanofibres were synthesised by electrospinning the PAN polymer solution and collecting the resultant mat on a flat plate collector. For a comparative analysis, virgin PAN, from which nanofibres were derived, underwent identical thermal testing. The findings reveal a reduction in the glass transition temperature of PAN nanofibres by approximately 3–5 % compared to virgin PAN. In addition, a significant reduction in heat capacity of about 42 % was observed in the nanofibres. Additionally, the TGA results indicated solvent evaporation at approximately 110 °C. Therefore, this investigation sheds light on the nuanced alterations in the thermal characteristics of PAN nanofibre mats as a result of the electrospinning process, providing vital insights for their application in various thermal management scenarios. [ABSTRACT FROM AUTHOR]

Purpose: A cataract is a cloudy area in the crystalline lens. Cataracts are the leading cause of blindness and the second cause of severe vision impairment worldwide. During cataract surgery, the clouded lens is extracted and replaced with an artificial intraocular lens, which restores the optical power. The fabrication of intraocular lenses using existing molding and lathing techniques is a complex and time-consuming process that limits the development of novel materials and designs. To overcome these limitations, we have developed a stereolithography-based process for producing models of clear lens designs without refractive function, serving as a proof of concept. This process has the potential to contribute toward new lens development, allowing for unlimited design iterations and an expanded range of materials for scientists to explore. Methods: Lens-like 3D objects without refractive function were fabricated by using stereolithography. A photopolymerizable resin containing 2-phenoxyethyl acrylate, poly (ethylene glycol) dimethacrylate, and a suitable photoinitiator was developed for the production of lens-like 3D object prototypes. The morphology of the printed devices was characterized by scanning electron microscopy. The transparency and thermal properties were analyzed using spectrophotometry and differential scanning calorimetry, respectively. The biocompatibility of the devices was investigated in a cultured human lens cell line (FHL-124), using a standard lactate dehydrogenase assay, and the lenses were folded and implanted in the human capsular bag model. Results: One-piece lens-like 3D objects without refractive function and with loop-haptic design were successfully fabricated using Stereolithography (SLA) technique. The resulting 3D objects were transparent, as determined by UV spectroscopy. The lactate dehydrogenase test demonstrated the tolerance of lens cells to the prototyping material, and apparent foldability and shape recovery was observed during direct injection into a human capsular bag model in vitro. Conclusions: This proof-of-principle study demonstrated the potential and significance of the rapid prototyping process for research and development of lens-like 3D object prototypes, such as intraocular lenses. [ABSTRACT FROM AUTHOR]

YVO4, YPO4 and YV1-xPxO4 phosphors with various Tb3+ doping concentrations were prepared by high-temperature solid-state method. Differential scanning calorimetry (DSC) measurements were conducted to evaluate the chemical reactions during synthesis process, determining 1 350 °C as the optimal synthesis temperature. X-ray diffraction (XRD) analysis of the synthesized materials confirmed a tetragonal crystal structure for all samples. The luminescent properties of the mentioned phosphors at room temperature were investigated. Under ultraviolet excitation, luminescence in YVO4 : Tb3+ predominantly arises from the 5D3→7FJ(J = 6, 5, 4, 2) transitions, resulting in blue emission. The introduction of P element modified the crystal field environment in YV1 - xPxO4 :Tb3+, enhancing multi-phonon relaxation (MPR) and cross-relaxation (CR) between 5D3 and 5D4 energy levels. With increasing P element content, the emission gradually shifted towards 5D4→7FJ' (J' = 6, 5, 4, 3), displaying blue, cyan, and green emissions. In YPO4 : Tb3+, higher doping concentrations enhanced cross relaxation between 5D3 and 5D4 energy levels of Tb3+, leading to weakened 5D3 luminescence and intensified 5D4 luminescence. Fine- tuning the doping concentration enabled the control of luminescence from blue to green. In conclusion, by adjusting the matrix composition and doping concentration, the blue-green luminescence modulation of Tb3+ -doped vanadium phosphate system can be achieved. [ABSTRACT FROM AUTHOR]