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Background/Objectives: This study compared two pilot scale continuous manufacturing methods of solid self-emulsifying drug delivery systems (SEDDSs) via hot melt extrusion (HME). Methods: A model poorly water-soluble drug carvedilol in low dose (0.5–1.0% w/w) was processed in HME either in a conventional powder form or pre-dissolved in the liquid SEDDS. Results: HME yielded a processable final product with up to 20% w/w SEDDS. Addition of carvedilol powder resulted in a non-homogeneous drug distribution in the extrudates, whereas a homogeneous drug distribution was observed in pre-dissolved carvedilol. SEDDSs were shown to have a plasticizing effect, reducing the HME process torque up to 50%. Compatibility between excipients and carvedilol in the studied ratios after HME was confirmed via DSC and WAXS, demonstrating their amorphous form. Solid SEDDSs with Kollidon® VA64 self-emulsified in aqueous medium within 15 min with mean droplet sizes 150–200 nm and were independent of the medium temperature, whereas reconstitution of Soluplus® took over 60 min and mean droplet size increased 2-fold from 70 nm to 150 nm after temperature increased from 25 °C to 37 °C, indicating emulsion phase inversion at cloud point. Conclusions: In conclusion, using Kollidon® VA64 and pre-dissolved carvedilol in SEDDS has shown to yield a stabile HME process with a homogenous carvedilol content in the extrudate. [ABSTRACT FROM AUTHOR]

Nd-Fe-C alloys have been reported as hard magnetic materials with a potential higher coercivity than Nd-Fe-B alloys. However, it has been seldom studied since its intrinsic properties were investigated in the last century. Here, we revisited the structure, phase precipitation and magnetic properties of rapidly quenched ternary Nd-Fe-C alloys for further understanding their composition-microstructure-property relationships. The Nd10+xFe84−xC6 (x = −2, 0, 2, 3, 4, 5) alloys with various compositions were prepared by melt spinning. The results show that the hard magnetic Nd2Fe14C phase can be hardly formed in the as-spun alloys. Instead, the alloys are composed of soft magnetic α-Fe phase and planar anisotropic Nd2Fe17Cx phase. After annealing above 650 °C, the Nd2Fe14C phase is precipitated by the peritectoid reaction. All optimally annealed alloys contain Nd2Fe14C and Nd2Fe17Cx phases, while the presence and content of α-Fe phase are determined by the alloy composition. The crystallization degree of the as-spun alloys has an effect on their magnetic properties after annealing. After the annealing treatment, partly crystallized as-spun alloys exhibit better magnetic properties than the amorphous alloys. The intrinsic coercivity Hcj = 847 kA/m, remanence Jr = 0.69 T, and maximum energy product (BH)max = 64.3 kJ/m3 were obtained in the Nd14Fe80C6 alloy annealed at 725 °C. The formation of the Nd2Fe14C and Nd2Fe17Cx phases with the Nd2O3 phase precipitated at the triangular grain boundaries is responsible for its relatively good properties. Although the magnetic properties of Nd-Fe-C alloys obtained in this work are inferior to those of Nd-Fe-B, the present results help us to further understand the magnetic behavior of Nd-Fe-C alloys. [ABSTRACT FROM AUTHOR]

Nanofibers, with their high surface area-to-volume ratio and unique physical properties, hold significant promise for a wide range of applications, including medical devices, filtration systems, packaging, electronics, and advanced textiles. However, their development and commercialization are hindered by several key challenges and hazards. The main issues are production cost and yield, high voltage, clogging, and toxic materials driven by complex production techniques, which limit their adoption. Additionally, there are environmental and health concerns associated with nanofiber production and disposal, necessitating the development of safer and more sustainable processes and materials. Addressing these challenges requires continued innovation in materials science and industrial practices, as well as a concerted effort to balance production, material, and surrounding condition parameters. This study emphasizes the challenges and hazards associated with nanofiber materials and their production techniques, including electrospinning, centrifugal spinning, solution blow spinning, electro-blown spinning, wet spinning, and melt spinning. It also emphasizes biopolymers and recycling as sustainable and eco-friendly practices to avoid harming the environment and human beings. [ABSTRACT FROM AUTHOR]

Additive manufacturing of pharmaceutical formulations offers advanced micro-structure control of oral solid dose (OSD) forms targeting not only customised dosing of an active pharmaceutical ingredient (API) but also custom-made drug release profiles. Traditionally, material extrusion 3D printing manufacturing was performed in a two-step manufacturing process via an intermediate feedstock filament. This process was often limited in the material space due to unsuitable (brittle) material properties, which required additional time to develop complex formulations to overcome. The objective of this study was to develop an additive manufacturing MicroFactory process to produce an immediate release (IR) OSD form containing 250 mg of mefenamic acid (MFA) with consistent drug release. In this study, we present a single-step additive manufacturing process employing a novel, filament-free melt extrusion 3D printer, the MicroFactory, to successfully print a previously 'non-printable' brittle Soluplus®-based formulation of MFA, resulting in targeted IR dissolution profiles. The physico-chemical properties of 3D printed MFA-Soluplus®-D-sorbitol formulation was characterised by thermal analysis, Fourier Transform Infrared spectroscopy (FTIR), and X-ray Diffraction Powder (XRPD) analysis, confirming the crystalline state of mefenamic acid as polymorphic form I. Oscillatory temperature and frequency rheology sweeps were related to the processability of the formulation in the MicroFactory. 3D printed, micro-structure controlled, OSDs showed good uniformity of mass and content and exhibited an IR profile with good consistency. Fitting a mathematical model to the dissolution data correlated rate parameters and release exponents with tablet porosity. This study illustrates how additive manufacturing via melt extrusion using this MicroFactory not only streamlines the manufacturing process (one-step vs. two-step) but also enables the processing of (brittle) pharmaceutical immediate-release polymers/polymer formulations, improving and facilitating targeted in vitro drug dissolution profiles. [ABSTRACT FROM AUTHOR]

Black ginseng (BG), a traditional medicinal herb produced through a nine-stage steaming and drying process, exhibits stronger pharmacological efficacy, including antioxidant, anti-inflammatory, and anti-cancer properties, when compared to white and red ginseng. The ginsenosides in BG are classified as major and minor types, with minor ginsenosides demonstrating superior pharmacological properties. However, their low concentrations limit their availability for research and clinical applications. In this study, hot melt extrusion (HME) was utilized as an additional processing technique to enhance the content of minor ginsenoside in BG, and the physicochemical properties of the formulation were analyzed. Ginsenoside content in BG and HME-treated BG (HME-BG) was analyzed using high-performance liquid chromatography (HPLC), while their physicochemical properties were evaluated through dynamic light scattering (DLS), electrophoretic light scattering (ELS), X-ray diffraction (XRD), thermogravimetric analysis (TGA), and Fourier-transform infrared spectroscopy (FT-IR). HME treatment resulted in a significant increase in minor ginsenosides Rg3 and compound K (CK) by 330% and 450%, respectively, while major ginsenosides Rg1 and Rb1 decreased or were not detected. Additionally, HME-BG demonstrated reduced particle size, improved PDI, and decreased crystallinity. HME treatment effectively converts major ginsenosides in BG into minor ginsenosides, enhancing its pharmacological efficacy and showing great potential for research and development applications. [ABSTRACT FROM AUTHOR]

As a promising innovative energy storage material, phase change fibers (PCFs) have been widely studied. PCFs are equipped with the ability of temperature regulation by introducing phase change materials (PCMs) and have been successfully prepared by melt spinning, wet spinning and electrospinning. With the rapid development of PCM and fibrous preparation technology, the combination of different processes of PCF preparation has been explored and developed. In this paper, the research progress of the preparation methods of PCFs is reviewed. Firstly, the preparation methods are classified according to the different loading forms of PCMs, and the fibrous maceration method, composite method and microcapsule method are introduced. Then, the special preparation methods and characteristics of PCF are elaborated. Finally, the research hot spots and development of PCFs are summarized for providing guidance for fabricating PCFs with desired comprehensive properties; among them, with the continuous innovation of smart fibers, the single function of PCFs will cause limited use, so the multi-functionality of PCFs is also discussed in detail for various applications. [ABSTRACT FROM AUTHOR]

Ti-V-based alloys are proved of huge potential in storing hydrogen, but the incomplete reversible hydrogen storage capacity caused by overstability of V hydride has limited the large-scale application. In this study, Ti32V40+xFe23-xMn5 (x=0, 4, 8, 12, at.%) alloys were designed, and the effects of V/Fe ratio on phase constitution and hydrogen storage properties were investigated. The main phase of the alloys is body-centered cubic (BCC) phase, and the lattice constants of the BCC phase decrease with the decrease of V/Fe ratio. Moreover, C14 Laves phase exists in alloys with a Fe content of 19at.% to 23at.%. For hydrogenation, the C14 Laves phase can accelerate the hydrogen absorption rate, but the hydrogen absorption capacity is reduced. With the decrease of V/Fe ratio, the hydride gradually destabilizes. Owing to its large lattice constant and high hydrogen absorption phase content, the Ti32V52Fe11Mn5 alloy shows the most enhanced hydrogen storage properties with hydrogenation and dehydrogenation capacities of 3.588wt.% at 298 K and 1.688wt.% at 343 K, respectively. The hydrogen absorption capacity of this alloy can be reserved to 3.574wt.% after 20 cycles of hydrogen absorption and desorption. [ABSTRACT FROM AUTHOR]

This study examines the impact of Pineapple Leaf Fiber (PALF) loading on the properties of High-Density Polyethylene (HDPE)/PALF composites successfully produced through a melt extrusion process. The melt-extruded HDPE/PALF composites were characterized by their thermal and mechanical properties and their morphologies. Subsequently, adding 5% maleic anhydride (MA) to the HDPE/PALF composite formulation led to significant improvements in the mechanical strength properties. Moreover, adding 10 wt.% PALF and 5% MA to the composites improves the crystallinity (10.38%) and Young's modulus (17.30%) properties and affects the thermal stability. The optimal formulation is achieved with 10 wt.% PALF filler incorporated into the HDPE composite. This study highlights the promising potential of HDPE/PALF composites for plastic product applications. [ABSTRACT FROM AUTHOR]

Polymer fibers are considered ideal transmission media for all-optical networks, but their high intrinsic loss significantly limits their practical use. Quantum dot-doped polymer fiber amplifiers are emerging as a promising solution to this issue and are becoming a significant focus of research in both academia and industry. Based on the properties of CdSe/ZnS quantum dots and PMMA material, this study experimentally explores three fabrication methods for CdSe/ZnS quantum dots-doped PMMA fibers: hollow fiber filling, melt-drawing, and melt extrusion. The advantages and disadvantages of each method and key issues in fiber fabrication are analyzed. Utilizing the CdSe/ZnS quantum dots-doped PMMA fibers that were fabricated, we theoretically analyzed the key factors affecting gain performance, including fiber length, quantum dots doping concentration, and signal light intensity. Under the conditions of 1.5 W power and 445 nm laser pumping, a maximum on-off gain of 16.2 dB was experimentally achieved at 635 nm. Additionally, using a white light LED as the signal source, a broadband on-off gain with a bandwidth exceeding 70 nm and a maximum gain of 12.4 dB was observed in the 580–650 nm range. This research will contribute to the development of quantum dots-doped fiber devices and broadband optical communication technology, providing more efficient solutions for future optical communication networks. [ABSTRACT FROM AUTHOR]

In response to an investigation on the paths of changes in the crystallization and radial differences during the forming process of nascent fibers, in this study, we conducted numerical simulation and analyzed the changes in crystallization mechanical parameters and tensile properties through a fluid dynamics two-phase model. The model was based on the melt-spinning method focusing on melt spinning, the environment of POLYFLOW, and the method of joint simulation, coupled with Nakamura crystallization kinetics, including the development of process collaborative parameters, stretch-induced crystallization, viscoelasticity, filament cooling, gravity term, inertia, and air resistance. Finally, for nylon 6 BHS and CN9987 resin spinning, the model successfully predicted the distribution changes in temperature, velocity, strain rate tensor, birefringence, and stress tensor along the axial and radial fibers and obtained the variation pattern of fibers' crystallinity along the entire spinning process under different stretching rates. Furthermore, we also explored the effects of spinning conditions, including inlet flow rate, winding speeds, and the extrusion temperature, on the fibers' crystallization process and obtained the influence rules of different spinning conditions on fiber crystallization. Knowing the paths of changes in mechanical performance can provide important guidance and optimization strategies for the future industrial preparation of high-performance fibers. [ABSTRACT FROM AUTHOR]

A high-Zn Al–27Zn-1.5Mg-1.2Cu-0.08Zr alloy was prepared by traditional casting and melt spinning. The as-casted alloy consists of well-developed α-Al dendrites with many coarse η-phase and low solute concentration, coarse network precipitates at grain boundaries and the α-Al/η-phase eutectic structures at triple junctions. Due to these featured structures, the as-cast alloy exhibits a low tensile strength of 101 MPa with room temperature and high temperature (300 °C) damping capacity of 0.0058 and 0.027 respectively. Comparatively, the as-spun alloy reveals gradient cross-sectional microstructures after solidification: an ultrafine grained region near the wheel surface, a transition region and an equiaxed-grained region near the ribbon free surface, with changes of precipitate morphologies from granular shape to network shape via vermicular. High-density nano-sized η′-phase/GP-zones within α-Al grains result in a higher tensile strength (121 MPa) of as-spun alloy with room temperature and high temperature (300 °C) damping capacity of 0.0049 and 0.048 respectively. Fracture analysis shows that the as-casted alloy fails in a mixed-mode fracture, comprised predominantly of transgranular fracture, quasi-cleavage fracture, cleavage fracture and dimple fracture, whereas the as-spun alloy failed in cleavage fracture and dimple fracture.

In this paper, linear low-density polyethylene (LLDPE) fibers were stabilized by ultraviolet ray (UV) irradiation, which provided a new treatment method for fabricating carbon fiber precursors. LLDPE chips were blended with a photo-initiator 4-chlorobenzophenone (4-CBP) and a crosslinker 1,2-polybutadiene (1,2-PB) to obtain spun particles, and then they were melt spun into the fibers. Then, UV irradiation of the as-spun fibers was performed to obtain precursors. An orthogonal experimental design investigated the effects of the ingredient ratio LLDPE:1,2-PB and UV irradiation time on the fiber gelation. The results show that the factor's order of influence was: ingredient ratio > UV irradiation time. The fiber gelation reaches a maximum of 67.51% at a dosage ratio of LLDPE:1, 2-PB of 97:2, and a UV irradiation time of 30 min. The UV irradiation introduced the crosslinking structure of LLDPE fibers, and the melting temperature of UV-XLPE fibers shifts toward lower temperatures, and the crystal size of the fibers decreased with increasing UV irradiation time. However, longer irradiation time does not beneficially affect the gelation degree. The low cost and feasible crosslinking method in this study offer the possibility of wide application of low-cost polyethylene-based carbon fibers. [ABSTRACT FROM AUTHOR]

Fiber-based technologies are widely used in various industries, but their use in pharmaceuticals remains limited. While melt extrusion is a standard method for producing medical fibers such as sutures, it is rarely used for pharmaceutical fiber-based dosage forms. The EsoCap system is a notable exception, using a melt-extruded water-soluble filament as the drug release trigger mechanism. The challenge of producing drug-loaded fibers, particularly due to the use of spinning oils, and the processing of the fibers are addressed in this work using other approaches. The aim of this study was to develop processes for the production and processing of pharmaceutical fibers for targeted drug delivery. Fibers loaded with polyvinyl alcohol and fluorescein sodium as a model drug were successfully prepared by a continuous melt extrusion process and directly spun. These fibers exhibited uniform surface smoothness and consistent tensile strength. In addition, the fibers were further processed into tubular dosage forms using a modified knitting machine and demonstrated rapid drug release in a flow cell. [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]

There is a growing need to address waste generated from Fused Filament Fabrication (FFF) 3D printing activities. This study explores the mechanical recycling of waste polylactic acid (PLA) accumulated from failed 3D printing operations and PLA biocomposite filaments containing nanocellulose fibres. FFF 3D printable filaments were produced via melt mixing and extrusion of virgin PLA containing varying amounts of waste PLA. The chemical, thermal and thermomechanical characterisation of each specimen was evaluated using Fourier‐transform infrared spectroscopy (FTIR), simultaneous thermal analysis (SDT), dynamic mechanical analysis (DMA), and uniaxial tensile analysis (UTA). A desktop FFF 3D printer was used to fabricate UTA and DMA test specimens. The thermal stability of the filament specimens containing waste derived from the failed 3D prints were comparable with that of the commercial filaments. However, a 11% decrease in the onset of thermal degradation is observed for the filament containing waste biocomposites. The specimens containing waste PLA exhibited higher crystallinity and storage modulus. UTA results revealed similar tensile strength and % elongation, except for the specimen containing 50% waste PLA which exhibited a 29% decrease in tensile strength. This work successfully demonstrates mechanical recycling as a viable waste management strategy for waste materials generated during FFF 3D printing. [ABSTRACT FROM AUTHOR]

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The extremely low melt flowability of ultra‐high molecular weight polyethylene (UHMWPE) is the primary obstacle to its melt processing. Particularly in melt spinning processes, the extremely high molecular weight of UHMWPE and the density of entangled molecular chains severely limit its production efficiency and monofilament performance. This study investigates the effect of flow modifiers on the melt spinning process of UHMWPE/HDPE blends, focusing on CaSt2, PEG, and CaSt2/silicone powder composite additives, and their impact on the standard tensile samples and monofilament tensile properties of UHMWPE/HDPE. The mechanism of additive influence on the tensile properties of UHMWPE/HDPE blends is analyzed through tensile strength testing, thermal analysis, and microscopic morphology observation. The results show that in standard tensile samples, CaSt2 or CaSt2/silicone powder composite additives can enhance the crystallinity of the blend, thereby improving its tensile strength. Conversely, adding PEG significantly reduces the crystallinity and tensile strength of the blend. The maximum tensile strength of CaSt2‐modified UHMWPE/HDPE monofilament is 1236.61 MPa. This enhancement is attributed to the lubricating effect of CaSt2, which simultaneously assists the molecular chains in the amorphous region, and the reorientation of the stress‐induced molten lamellar structure under tension, greatly promoting the formation of straight‐chain crystals in the monofilament. During hot drawing, PEG inhibits the formation of straight‐chain crystals in the monofilament, resulting in a 3.06% decrease in maximum crystallinity compared with standard tensile samples. When CaSt2 is combined with silicone powder, the additives tend to aggregate during hot drawing, and these larger aggregate particles hinder the orientation of molecular chains along the drawing direction, resulting in a 30.75% decrease in maximum tensile strength of the monofilament compared with the standard tensile samples. Highlights: The tensile property of UHMWPE/HDPE blends modified with additives was discussed.Analytical techniques including DSC, SEM, and tensile strength tests were used.The maximum tensile strength of the monofilament can reach up to 1236.61 MPa.UHMWPE/HDPE/CaSt2 = 60/40/0.5 exhibits the best tensile property. [ABSTRACT FROM AUTHOR]

We applied computing-as-a-service to the unattended system-agnostic miscibility prediction of the pharmaceutical surfactants, Vitamin E TPGS and Tween 80, with Copovidone VA64 polymer at temperature relevant for the pharmaceutical hot melt extrusion process. The computations were performed in lieu of running exhaustive hot melt extrusion experiments to identify surfactant-polymer miscibility limits. The computing scheme involved a massively parallelized architecture for molecular dynamics and free energy perturbation from which binodal, spinodal, and mechanical mixture critical points were detected on molar Gibbs free energy profiles at 180 °C. We established tight agreement between the computed stability (miscibility) limits of 9.0 and 10.0 wt% vs. the experimental 7 and 9 wt% for the Vitamin E TPGS and Tween 80 systems, respectively, and identified different destabilizing mechanisms applicable to each system. This paradigm supports that computational stability prediction may serve as a physically meaningful, resource-efficient, and operationally sensible digital twin to experimental screening tests of pharmaceutical systems. This approach is also relevant to amorphous solid dispersion drug delivery systems, as it can identify critical stability points of active pharmaceutical ingredient/excipient mixtures. [ABSTRACT FROM AUTHOR]

Parallel micropillars of quasicrystal approximants are fabricated in Al20Si20Mn20Fe20Ga20 high-entropy alloy via melt spinning, and their micromorphology is observed by scanning electron microscopy. Unlike the traditional quasicrystal system where the crystal structure of the decagonal prism is decagonal quasicrystal, the crystal structure of micropillars reported here is identified as the orthorhombic (1/0, 2/1) quasicrystal approximant (a = 0.73 nm, b = 1.23 nm, c = 2.24 nm) through transmission electron microscopy. The cross-section structure of the micropillars consists of multiple twinned (1/0, 2/1) approximant domains or alternating splicing of (1/0, 2/1) and defective (1/0, 2/1) quasicrystal approximants. The thermal stability and the microstructure evolutions of micropillars after being heat treated are also investigated. Meanwhile, the nanomechanical properties of micropillars are characterized. [ABSTRACT FROM AUTHOR]

Casting speed, casting temperature and secondary cooling water flow rate are the main process parameters affecting the DC casting process. These parameters significantly influence the flow and temperature fields during casting, which are crucial for the quality of the ingot and can determine the success or failure of the casting operation. Numerical simulation, with the advantages of low cost, rapid execution, and visualized results, is an important method to study and optimize the DC casting process. In the present work, a simulation model of DC casting 2024 aluminum alloy was established, and the reliability of the model was verified. Then, the influence of casting parameters on flow field and temperature field was studied in detail by numerical simulation method. Results show that with the increase of casting speed, the melt flow becomes faster, the depths of slurry zone and mushy zone increase, and the variation of slurry zone depth is greater than that of mushy zone. With an increase in casting temperature, the melt flow rate increases, the depth of the slurry zone becomes shallower, and the depth of the mushy zone experiences only minor changes. The simulation results further indicate that the increase of the flow rate of the secondary cooling water slightly reduces the depths of both slurry and mushy zone. [ABSTRACT FROM AUTHOR]

Plastic recycling facilities deal with single‐ and mixed‐stream plastic waste. Clean single‐stream waste is sold as clean flake, or the flake is converted to pellets for material handling. The flake conversion process uses a conventional melt‐phase extruder to convert extruded filaments that are cooled and then pelletized. Friction extrusion (FE), a solid phase processing technique that has successfully extruded metal and metal matrix composites with desired properties, has never been utilized to address its ability to process plastic wastes. In this study, FE was performed on single‐stream low‐density polyethylene (LDPE) and single‐stream polypropylene (PP). Consolidated filaments of 2.5 mm diameter were extruded from different polymers. The energy efficiency of FE was estimated based on extrusion rates. A potentially 50%–80% reduction in energy cost was calculated for FE compared to the conventional melt extrusion process. Thermal properties of pellets and extruded filaments were measured to evaluate the effects of FE process on the molecular and morphological structures of LDPE and PP. The thermal properties of PP before and after FE were not significantly changed. For LDPE, the melting and crystallization temperatures increased by 3 and 7°C while the degree of crystallinity decreased by 3%, probably associated with side chain realignment under shearing. Highlights: Direct extruded polyolefin into filaments without melting via friction extrusion.Estimated over 50% energy reduction compared melt extrusion process.This novel mechanical process does not degrade polyolefin material. [ABSTRACT FROM AUTHOR]

Enhancing food preservation and safety using environmentally friendly techniques is urgently needed. The aim of this study was to develop food packaging films using biodegradable poly-L-lactic acid (PLA) as biopolymer and carvacrol (CV) essential oil as an antioxidant/antibacterial agent for the replacement of chemical additives. CV was adsorbed onto natural zeolite (NZ) via a new vacuum adsorption method. The novel nanohybrid CV@NZ with a high CV content contained 61.7%wt. CV. Pure NZ and the CV@NZ nanohybrid were successfully dispersed in a PLA/triethyl citrate (TEC) matrix via a melt extrusion process to obtain PLA/TEC/xCV@NZ and PLA/TEC/xNZ nanocomposite films with 5, 10, and 15%wt CV@NZ or pure NZ content. The optimum resulting film PLA/TEC/10CV@NZ contained 10%wt. CV@NZ and exhibited self-healable properties, 22% higher tensile strength, 40% higher elongation at break, 45% higher water barrier, and 40% higher oxygen barrier than the pure PLA/TEC matrix. This film also had a high CV release content, high CV control release rate as well as 2.15 mg/L half maximal effective concentration (EC50) and 0.27 mm and 0.16 mm inhibition zones against Staphylococcus aureus and Salmonella enterica ssp. enterica serovar Typhimurium, respectively. This film not only succeeded in extending the shelf life of fresh minced pork, as shown by the total viable count measurements in four days but also prevented the lipid oxidation of fresh minced pork and provided higher nutritional values of the minced meat, as revealed by the heme iron content determination. It also had much better and acceptable sensory characteristics than the commercial packaging paper. [ABSTRACT FROM AUTHOR]

Al–Mg alloys offer a compelling combination of high tensile strength and low density, yet conventional high-Mg alloying often yields dense Al3Mg2 precipitates that compromise processability and ductility. To address this challenge, this work combined melt spinning and hot extrusion to achieve a supersaturated matrix and fine-grain structure in Al–Mg alloys with high-Mg content. The produced Al–9 Mg alloy exhibited exceptional tensile strength (~ 388 MPa) and elongation (~ 31%), surpassing Al–6 Mg and Al–12 Mg alloys. It is revealed that the high-Mg solute concentration contributes significantly to solid solution strengthening, reduces stacking fault energy to facilitate recrystallization and grain refinement, and, most crucially, augments strain-hardening ability. This augmentation delays localized deformation, alleviates stress concentration and enhances strength and ductility concurrently. The novel process holds the potential to overcome challenges associated with conventional alloying and paves the way for developing high-performance alloys with exceptional strength-ductility synergy. [ABSTRACT FROM AUTHOR]

Biodegradable biopolymers such as polylactic acid and polybutylene succinate are sustainable alternatives to traditional petroleum-based plastics. However, the factors affecting their degradation must be characterized in detail to enable successful utilization. Here we compared the extruder dwell time at three different melt-spinning scales and its influence on the degradation of both polymers. The melt temperature was the same for all three processes, but the shear stress and dwell time were key differences, with the latter being the easiest to measure. Accelerated degradation tests, including quick weathering and disintegration, were used to evaluate the influence of dwell time on the structural, mechanical, and thermal properties of the resulting fibers. We found that longer dwell times accelerated degradation. Quick weathering by UV pre-exposure before the disintegration trial, however, had a more significant effect than dwell time, indicating that degradation studies with virgin material in a laboratory-scale setting only show the theoretical behavior of a product in the laboratory. A weathered fiber from an industrial-scale spinning line more accurately predicts the behavior of a product placed on the market before ending up in the environment. This highlights the importance of optimizing process parameters such as the dwell time to adapt the degradability of biopolymers for specific applications and environmental requirements. By gaining a deeper insight into the relationship between manufacturing processes and fiber degradability, products can be adapted to meet suitable performance criteria for different applications. [ABSTRACT FROM AUTHOR]

One of the most effective strategies for modifying the surface properties of nano-fillers and enhancing their composite characteristics is through polymer grafting. In this study, a coprecipitation method was employed to modify hydroxyapatite (HAP) with epoxidized soybean oleic acid (ESOA), resulting in ESOA-HAP. Subsequently, oligomeric poly(lactic acid) (OPLA) was grafted onto the surface of ESOA-HAP, yielding OPLA-ESOA-HAP. HAP, ESOA-HAP, and OPLA-ESOA-HAP were comprehensively characterized. The results demonstrate the progressive grafting of ESOA and OPLA onto the surface of HAP, resulting in enhanced hydrophobicity and improved dispersity in organic solvent for OPLA-ESOA-HAP compared to HAP. The vitality and adhesion of Wistar rat mesenchymal stem cells (MSCs) were assessed using HAP and modified HAP materials. Following culture with MSCs for 72 h, the OPLA-ESOA-HAP showed an inhibition rate lower than 23.0% at a relatively high concentration (1.0 mg/mL), which is three times lower compared to HAP under similar condition. The cell number for OPLA-ESOA-HAP was 4.5 times higher compared to HAP, indicating its superior biocompatibility. Furthermore, the mechanical properties of the OPLA-ESOA-HAP/PLLA composite almost remained unaltered ever after undergoing two stages of thermal processing involving melt extrusion and inject molding. The increase in the biocompatibility and relatively high mechanical properties render OPLA-ESOA-HAP/PLLA a potential material for the biodegradable fixation system. [ABSTRACT FROM AUTHOR]

The aim of this study was to fabricate mini-tablets of polyhedrons containing theophylline using a fused deposition modeling (FDM) 3D printer, and to evaluate the correlation between release kinetics models and their geometric shapes. The filaments containing theophylline, hydroxypropyl cellulose (HPC), and EUDRAGIT RS PO (EU) could be obtained with a consistent thickness through pre-drying before hot melt extrusion (HME). Mini-tablets of polyhedrons ranging from tetrahedron to icosahedron were 3D-printed using the same formulation of the filament, ensuring equal volumes. The release kinetics models derived from dissolution tests of the polyhedrons, along with calculations for various physical parameters (edge, SA: surface area, SA/W: surface area/weight, SA/V: surface area/volume), revealed that the correlation between the Higuchi model and the SA/V was the highest (R2 = 0.995). It was confirmed that using 3D- printing for the development of personalized or pediatric drug products allows for the adjustment of drug dosage by modifying the size or shape of the drug while maintaining or controlling the same release profile. [ABSTRACT FROM AUTHOR]

A novel ratio colorimetric sensor based on magnetic nanoparticles (Fe3O4@Au) and silver nanoparticles (Ag NPs) was constructed for the detection of Ochratoxin A (OTA) by complementary DNA base pairing. The OTA aptamer coupled Fe3O4@Au was served as reference signal, and complementary DNA (cDNA) coupled Ag NPs was served as the response signal. A ratio nanoprobe (Fe3O4@Au-Ag) with two UV absorption peaks was prepared by regulating the ratio and DNA base complementarity. In absence of OTA, the absorbance peak ratio (A400/A580) of the ratio colorimetric sensor could maintain a constant value. The detection conditions (time, pH, and temperature) were optimized, and under optimized conditions, the sensor showed a good linear relationship to OTA detection, with a linear range of 0.01 ng⋅mL-1 to 1000 ng⋅mL-1 and a detection limit of 0.033 ng⋅mL-1. The sensor had good selectivity, reproducibility and high sensitivity, which was successfully applied to the detection of OTA in pea powder with a recovery rate of 93.9%~96.0%. [ABSTRACT FROM AUTHOR]

This article explores the challenges of recycling thermosetting polymers, specifically epoxy resins, which are widely used but difficult to recycle. Scientists have made progress in developing chemical processes to break the crosslinks in these materials, making them more recyclable. Examples include the development of a recyclable epoxy resin called Pecan, derived from a plant-based sugar, and a scalable method to recycle epoxy resin from wind turbine blades. Researchers at Washington State University have received a grant to develop a recycling technique for wind turbine materials, while scientists at Case Western Reserve University have made thermoset elastomers recyclable by converting them into vitrimers. These advancements have the potential to improve the sustainability and recyclability of thermosetting polymers, benefiting industries such as aerospace and adhesives. [Extracted from the article]

All-solid-state battery (ASSB) technology is a new energy system that reduces the safety concerns and improves the battery performance of conventional lithium-ion batteries (LIB). The increasing demand for such new energy systems makes the transition from laboratory scale production of ASSB components to larger scale essential. Therefore, this study investigates the dry extrusion of poly(ethylene oxide):lithium bis (trifluoromethylsulfonyl)imide (PEO:LiTFSI) all-solid-state electrolytes at a ratio of 20:1 (EO:Li). We investigated the influence of different extruder setups on the product quality. For this purpose, different screw designs consisting of conveying, kneading and mixing elements are evaluated. To do so, a completely dry and solvent-free production of PEO:LiTFSI electrolytes using a co-rotating, intermeshing, twin-screw extruder under an inert condition was successfully carried out. The experiments showed that the screw design consisting of kneading elements gives the best results in terms of process stability and homogeneous mixing of the electrolyte components. Electrochemical impedance spectroscopy was used to determine the lithium-ion conductivity. All electrolytes produced had an ionic conductivity (σionic) of (1.1–1.8) × 10−4 S cm−1 at 80 °C. [ABSTRACT FROM AUTHOR]

This research highlights the importance of addressing bioplastic contamination in recycling processes to ensure the quality of recycled material and move towards a more sustainable circular economy. Polyethylene (PE) is a conventional plastic commonly used in packaging for which large amounts of waste are produced; therefore, PE is generally recycled and has an established recycling process. However, the contamination of biodegradable polymers in the PE waste stream could impact recycling. This study, therefore, focuses on polyethylene (PE) that has been polluted with a commercial thermoplastic starch polymer (TPS), as both materials are used to produce plastic films and bags, so cross-contamination is very likely to occur in waste separation. To achieve this, recycled PE was blended with small quantities of the commercial TPS and processed through melt extrusion and injection molding, and it was further characterized. The results indicate that the PE-TPS blend lacks miscibility, evidenced by deteriorated microstructure and mechanical properties. In addition, the presence of the commercial TPS affects the thermal stability, oxidation, and color of the recycled PE. [ABSTRACT FROM AUTHOR]

In the present report, we have studied the structural, microstructural, magnetic, exchange blas (EB) properties and magnetoresistance (MR) in Mn rich (Mn at. -50%) Mn50Ni50-xSnx (x = 10) shape memory Heusler alloy ribbons, prepared using the melt spinning method. These ribbons were found to exhibit a first order structural (i.e., martensitic) transition at around 205 K from the high temperature austenite to the low temperature martensite phase. The martensitic transition occurs at comparatively lower temperatures in these ribbons than in the same bulk alloy. Curie temperature of the austenite phase (TCA) is found to be larger i.e., around room temperature than that of bulk alloy. A significant EB field (HEB) of around 960 Oe has been observed at 2 K for these ribbons, which is found to be comparable to that reported for other Heusler systems. The presence of the EB effect in these ribbons is attributed to the coexistence of FM/AFM exchange interactions in the martensite phase. They are also found to show a maximum negative MR of around 12% near the martensitic transition, for 50 kOe field change. Investigation of DC magnetization, AC susceptibility measurements and the observation of training effect (i.e., characteristic feature of EB) strongly corroborates with the coexistence of FM/AFM exchange interactions in the martensite phase of these ribbons, which results in the large EB. The effects of temperature and magnetic field on the EB properties and MR have also been studied here. [ABSTRACT FROM AUTHOR]

The flammability properties of polymers and polymeric composites play an important role in ensuring the safety of humans and the environment; moreover, flame-retardant materials ensure a greater number of applications. In the present study, we report the obtaining of polypropylene (PP) composites contain a mixture of two green flame retardants, lignin and clinoptilolite, by melt extrusion. These additives are abundantly found in nature. Fourier transform infrared (FT-IR), thermogravimetric analysis (TGA), mechanical properties, scanning electron microscopy–energy dispersive X-ray spectroscopy (SEM-EDS), cone calorimetry, UL-94, and carbonized residues analysis were carried out. TGA analysis shows that PPGFR-10 and PPGFR-20 compounds presented better thermal stability with respect to PP without flame retardants. The conical calorimetric evaluation of the composites showed that PPGFR-10 and PPGFR-20 presented decreases in peak heat release rates (HRRs) of 9.75% and 11.88%, respectively. The flammability of the composites was evaluated with the UL-94 standard, and only the PPGFR-20 composite presented the V-0 and 5VB classification, which indicates good flame-retardant properties. Additives in the polymer matrix showed good dispersion with few agglomerates. The PPGFR-20 composite showed an FRI value of 1.15, higher percentage of carbonized residues, and UL-94 V-0 and 5VB rating, suggesting some kind of synergy between lignin and clinoptilolite, but only at high flame-retardant concentrations. [ABSTRACT FROM AUTHOR]

The experimental investigations focus on the thermoelectric and structural properties of newly synthesized Hf1.75Ti0.25FeNiSb2-xInx (x = 0.05 and 0.1) alloys, which are double half-Heusler alloys. The objective is to determine the impact of altering the production method from ball milling to melt spinning. Two of the samples were synthesized utilizing distinct techniques: melt spinning, arc melting, and spark plasma sintering. In contrast, the other two samples were created by ball milling instead of melt spinning. The X-ray diffraction technique was used to determine the crystal structures of all the samples. The face-centered cubic structure was identified as the primary crystallization phase for all the samples. The manufactured samples were determined to be uniform. Thermoelectric properties were investigated across a wide temperature range of 300 to 870 K. The thermal properties of the ball-milled samples were superior to those of the melt-spun samples due to the presence of larger pores, which enhanced phonon scattering. The Hf1.75Ti0.25FeNiSb1.9In0.1 alloy, which was subjected to ball milling, achieved the greatest thermoelectric figure of merit value of 0.38 at a temperature of 870 K. [ABSTRACT FROM AUTHOR]

Simulation models are used to design extruders in the polymer processing industry. This eliminates the need for prototypes and reduces development time for extruders and, in particular, extrusion screws. These programs simulate, among other process parameters, the temperature and pressure curves in the extruder. At present, it is not possible to predict the resulting melt quality from these results. This paper presents a simulation model for predicting the melt quality in the extrusion process. Previous work has shown correlations between material and thermal homogeneity and the screw performance index. As a result, the screw performance index can be used as a target value for the model to be developed. The results of the simulations were used as input variables, and with the help of artificial intelligence—more precisely, machine learning—a linear regression model was built. Finally, the correlation between the process parameters and the melt quality was determined, and the quality of the model was evaluated. [ABSTRACT FROM AUTHOR]

The as-cast amorphous Ti48Zr27Cu6Nb5Be14 composites, comprising in situ formed β-Ti ductile crystalline precipitates, were prepared by water cooled copper mold suction casting. Then, the semi-solid composites were obtained after the as-cast composites were treated by semi-solid isothermal treatment. The microstructure evolution and kinetics of the composites were examined. Results show that the microstructures of both the as-cast and semi-solid composites comprise of β-Ti crystal phases and amorphous matrix phases. Before and after treatment, the crystals evolve from fine granular or fine dendritic crystals to coarse crystals. As the treatment temperature increasing or the time prolonging, the average crystal size gradually increases and the surface morphology of the crystals gradually becomes regular. By studying the microstructural evolution and dynamics during the isothermal treatment process, it is found that the final morphology of β-Ti crystals is influenced by the isothermal treatment temperature and time (t), and the β-Ti evolution rate increases with an increase in treatment temperature. In addition, a linear relationship was observed between the size of cubic β-Ti crystals (D³) and t; the growth kinetics factor K is 3.8 μm³·s-1. As the K value closes to 4 μm³·s-1, it is inferred the morphology evolution of β-Ti crystals is a coarsening behavior controlled by the diffusion of solute elements. [ABSTRACT FROM AUTHOR]

Utilizing lightweight Al alloys in various industrial applications requires achieving precise pressure tightness and leak requirements. Vacuum pressure impregnation (VPI) with thermosetting polymers is commonly used to address leakage defects in die-cast Al alloys. In this study, the efficacy of the VPI technique in sealing alloy parts was investigated using a combination of nondestructive micro X-ray computed tomography (micro XCT) and a standard leak test. The results demonstrate that the commonly used water leak test is insufficient for determining the sealing performance. Instead, micro XCT shows distinct advantages by enabling more comprehensive analysis. It reveals the presence of a low atomic number impregnates sealant within casting defects, which has low grey contrast and allows for visualizing primary leakage paths in 3D. The effective atomic number of impregnated resin is 6.75 and that of Al alloy is 13.69 by dual-energy X-ray CT. This research findings will contribute to enhancing the standard VPI process parameters and the properties of impregnating sealants to improve quality assurance for impregnation in industrial metals. [ABSTRACT FROM AUTHOR]

The influences of cooling rate on the phase constitution, microstructural length scale, and microhardness of directionally solidified Galvalume (Zn-55Al-1.6Si) alloy were investigated by directional solidification experiments at different withdrawal speeds (5, 10, 20, 50, 100, 200, and 400 µm·s-1). The results show that the microstructure of directionally solidified Galvalume alloys is composed of primary Al dendrites, Si-rich phase and (Zn-Al-Si) ternary eutectics at the withdrawal speed ranging from 5 to 400 µm·s-1. As the withdrawal speed increases, the segregation of Si element intensifies, resulting in an increase in the area fraction of the Si-rich phase. In addition, the primary Al dendrites show significant refinement with an increase in the withdrawal speed. The relationship between the primary dendrite arm spacing (λ1) and the thermal parameters of solidification is obtained: λ1=127.3V-0.31. Moreover, as the withdrawal speed increases from 5 to 400 µm·s-1, the microhardness of the alloy increases from 90 HV to 151 HV. This is a combined effect of grain refinement and second-phase strengthening. [ABSTRACT FROM AUTHOR]

The article offers news briefs related to advancements in chemistry and materials science. Researchers have developed an effective treatment for chronic wounds using plasma-activated poly(vinyl alcohol) (PVA) hydrogel dressings. A compact, wirelessly powered light-source comprising magnetoelectric transducers and custom-designed organic light-emitting diodes has been developed for biomedical applications. Organic chemists exploration of curved structures in nanoscale graphene sheets.

With the megatrend of digitalization, the demand for sensors in previously difficult-to-access scenarios is increasing. Filament-shaped sensors (FSS) are ideal for this demand, especially in applications in which the monitoring of textile structures is the focus. Electrically conductive bicomponent filaments based on thermoplastic polyurethane (TPU) and doped with carbon nanotubes (CNTs) offer great potential due to their flexible mechanical properties. Through the core-conducting, bicomponent structure, the sensing material is protected from environmental factors such as surrounding conductive materials and external moisture. The insulating material, however, simultaneously complicates the contacting method in order to measure sensing changes in the conductive core. In this work, laser cutting is employed as a technology in order to expose the conductive core of the filaments. The filament is then coated with silver and mechanically crimped, providing both a conductive interface for the data acquisition device as well as a protective layer. Laser parameters (power 20–100 W and speed 5–50 mm/s) are investigated to identify the parameters with the best cutting properties for which the filaments are analyzed visually and electrically. This work provides a robust and reproducible method for contacting core-conducting TPU filaments for strain-sensing applications. This study shows that while the choice of laser parameter influences the morphology of the cut surface, its impact on the resulting linear resistivity is negligible. [ABSTRACT FROM AUTHOR]

Several materials were prepared by melt extrusion, based on an L-rich polylactide (PLA), as polymeric matrix, acetyl tri-n-butyl citrate (ATBC) or trioctyl trimellitate (TOTM), as plasticizer, and mesoporous MCM-41 particles, playing a nucleant role. Influence of the addition of these nucleating particles, together with the comparative effect of the two plasticizers, has been thoroughly evaluated on the features of the several phase transitions existing in the PLA polymeric matrix (glass transition, cold crystallization, α′ to α transition, melting processes and melt crystallization) as well as on the rate of PLA crystallization. The window where this ordering process can take place is shifted down to lower temperatures for these binary and ternary systems and the range of temperatures at which the α′ and α polymorphs crystallize under isothermal crystallization from the glassy state significantly changes in the materials containing ATBC as plasticizer, either the binary or ternary ones. Type of the major crystalline lattice developed at 85 and 110 °C has been confirmed, additionally to the DSC experiments, by FTIR spectroscopy. [ABSTRACT FROM AUTHOR]

The increased use of plastics in industrial and agricultural applications has led to high levels of pollution worldwide and is a significant challenge. To address this plastic pollution, conventional methods such as landfills and incineration are used, leading to further challenges such as the generation of greenhouse gas emissions. Therefore, increasing interest has been directed to identifying alternative methods to dispose of plastic waste from agriculture. The novelty of the current research arose from the lack of critical reviews on how 3-Dimensional (3D) printing was adopted for recycling plastics, its application in the production of agricultural plastics, and its specific benefits, disadvantages, and limitations in recycling plastics. The review paper offers novel insights regarding the application of 3D printing methods including Fused Particle Fabrication (FPF), Hot Melt Extrusion (HME), and Fused Deposition Modelling (FDM) to make filaments from plastics. However, the methods were adopted in local recycling setups where only small quantities of the raw materials were considered. Data was collected using a systematic review involving 39 studies. Findings showed that the application of the 3D printing methods led to the generation of agricultural plastics such as Polylactic Acid (PLA), Acrylonitrile Butadiene Styrene (ABS), Polyethylene Terephthalate (PET), and High-Density Polyethylene (HDPE), which were found to have properties comparable to those of virgin plastic, suggesting the viability of 3D printing in managing plastic pollution. However, limitations were also associated with the 3D printing methods; 3D-printed plastics deteriorated rapidly under Ultraviolet (UV) light and are non-biodegradable, posing further risks of plastic pollution. However, UV stabilization helps reduce plastic deterioration, thus increasing longevity and reducing disposal. Future directions emphasize identifying methods to reduce the deterioration of 3D-printed agricultural plastics and increasing their longevity in addition to UV stability. [ABSTRACT FROM AUTHOR]

Due to the increasing amounts of textile waste, textile to textile recycling is of prime concern. Polyethylene terephthalate (PET) represents the most extensively used type of chemical fiber. Its spinnability suffers from impurities and degradation in the processing, which limits its recycling to new fibers. Here, recycled polyester is blended with a small amount of recycled nylon, and the regenerated fibers, which demonstrated good mechanical properties, were obtained via a melt spinning machine. The mechanical properties, thermal properties, rheological properties, and chemical structure of the modified recycled fibers were investigated. It was found that when compared with rPET-T fibers, the elongation at break of rPET-Ax fibers increased to 17.48%, and the strength at break decreased to 3.79 cN/dtex. The compatibility of PET and PA6 copolymer were enhanced by copolymers produced by in-situ reaction in the processing. Meanwhile, the existence of PA6 increases the crystallization temperature and improves the hydrophilicity of the fibers. This study realized the high-value recycling of waste PET fabric to new fibers, which opens a door for the large utilization of waste textiles. [ABSTRACT FROM AUTHOR]

The fine regulation of catalysts by the atomic-level removal of inactive atoms can promote the active site exposure for performance enhancement, whereas suffering from the difficulty in controllably removing atoms using current micro/nano-scale material fabrication technologies. Here, we developed a surface atom knockout method to promote the active site exposure in an alloy catalyst. Taking Cu3Pd alloy as an example, it refers to assemble a battery using Cu3Pd and Zn as cathode and anode, the charge process of which proceeds at about 1.1 V, equal to the theoretical potential difference between Cu2+/Cu and Zn2+/Zn, suggesting the electricity-driven dissolution of Cu atoms. The precise knockout of Cu atoms is confirmed by the linear relationship between the amount of the removed Cu atoms and the battery cumulative specific capacity, which is attributed to the inherent atom-electron-capacity correspondence. We observed the surface atom knockout process at different stages and studied the evolution of the chemical environment. The alloy catalyst achieves a higher current density for oxygen reduction reaction compared to the original alloy and Pt/C. This work provides an atomic fabrication method for material synthesis and regulation toward the wide applications in catalysis, energy, and others. [ABSTRACT FROM AUTHOR]

The inherently low signal-to-noise ratio of NMR and MRI is now being addressed by hyperpolarization methods. For example, iridium-based catalysts that reversibly bind both parahydrogen and ligands in solution can hyperpolarize protons (SABRE) or heteronuclei (X-SABRE) on a wide variety of ligands, using a complex interplay of spin dynamics and chemical exchange processes, with common signal enhancements between 103 and 104 . This does not approach obvious theoretical limits, and further enhancement would be valuable in many applications (such as imaging mM concentration species in vivo). Most SABRE/X-SABRE implementations require far lower fields (μT-mT) than standard magnetic resonance (>1T), and this gives an additional degree of freedom: the ability to fully modulate fields in three dimensions. However, this has been underexplored because the standard simplifying theoretical assumptions in magnetic resonance need to be revisited. Here, we take a different approach, an evolutionary strategy algorithm for numerical optimization, multi-axis computer-aided heteronuclear transfer enhancement for SABRE (MACHETE-SABRE). We find nonintuitive but highly efficient multiaxial pulse sequences which experimentally can produce a sevenfold improvement in polarization over continuous excitation. This approach optimizes polarization differently than traditional methods, thus gaining extra efficiency. [ABSTRACT FROM AUTHOR]

Hot melt extrusion (HME) is a common manufacturing process used in the pharmaceutical industry to improve the solubility of poorly soluble active pharmaceutical ingredients (API). The goal is to create an amorphous solid dispersion (ASD) where the amorphous form of the API is stabilized within a polymer matrix. Traditionally, the development of pharmaceutically approved polymers has focused on requirements such as thermal properties, solubility, drug–polymer interactions, and biocompatibility. The mechanical properties of the material have often been neglected in the design of new polymers. However, new downstream methods require more flexible polymers or suitable plasticizer polymer combinations. In this study, two grades of the polymer polyvinyl alcohol (PVA), which is already established for HME, are investigated in terms of their mechanical, rheological, and thermal properties. The mechanical properties of the extruded filaments were tested by the three-point bending test. The rheological behavior was analyzed by oscillating plate measurements. Thermal analysis was performed by differential scanning calorimetry (DSC). In addition, the solid and liquid plasticizers mannitol, sorbitol, triacetin, triethyl citrate, polyethylene glycol, and glycerol were evaluated for use with PVA and their impact on the polymer properties was elaborated. Finally, the effects of the plasticizers are compared to each other, and the correlations are analyzed statistically using principal component analysis (PCA). Thereby, a clear ranking of the plasticizer effects was established, and a deeper understanding of the polymer–plasticizer interactions was created. [ABSTRACT FROM AUTHOR]

The widespread use of disposable facemasks during the COVID‐19 pandemic has led to environmental concern due to microplastic pollution. Biodegradable disposable facemasks are a first step to reducing the environmental impact of pandemics. Here, high‐performance facemask components based on novel poly(ester amide)s (PEA) grades synthesized from biosourced materials and processed into nonwoven facemask components are presented. PEA‐based polymers present an excellent compromise between mechanical performance and biodegradability. Importantly, the properties of the PEA can easily be tuned by changing the ratio of ester and amide, or by varying diol and diacid parts. Seven polymers are synthesized which are optimized for biodegradability and processability. Among them, two grades combines 1) electrospinning process compatibility with 2) full degradation within 35 days, using a normalized biodegradation test. The ultra‐thin filters thus developed are evaluated for performance on a custom‐made characterization bench. The filters achieve microparticle capture efficiency and air permeability comparable to commercial filters. Another PEA grade is optimized to reach optimal viscothermal properties that made it compatible with solvent‐free melt‐spinning process as demonstrated with continuous fiber production. Overall, this environmentally friendly solution paves the way for the fabrication of high‐performance fibers with excellent biodegradability for the next‐generation facemasks. [ABSTRACT FROM AUTHOR]

Nitrogen doped lutetium hydride has drawn global attention in the pursuit of room-temperature superconductivity near ambient pressure and temperature. However, variable synthesis techniques and uncertainty surrounding nitrogen concentration have contributed to extensive debate within the scientific community about this material and its properties. We used a solid-state approach to synthesize nitrogen doped lutetium hydride at high pressure and temperature (HPT) and analyzed the residual starting materials to determine its nitrogen content. High temperature oxide melt solution calorimetry determined the formation enthalpy of LuH1.96N0.02 (LHN) from LuH2 and LuN to be -28.4 ± 11.4 kJ/mol. Magnetic measurements indicated diamagnetism which increased with nitrogen content. Ambient pressure conductivity measurements observed metallic behavior from 5 to 350 K, and the constant and parabolic magnetoresistance changed with increasing temperature. High pressure conductivity measurements revealed that LHN does not exhibit superconductivity up to 26.6 GPa. We compressed LHN in a diamond anvil cell to 13.7 GPa and measured the Raman signal at each step, with no evidence of any phase transition. Despite the absence of superconductivity, a color change from blue to purple to red was observed with increasing pressure. Thus, our findings confirm the thermodynamic stability of LHN, do not support superconductivity, and provide insights into the origins of its diamagnetism. [ABSTRACT FROM AUTHOR]

Magmatism in the Quaternary Clear Lake volcanic field (CLVF), with its youngest eruption having only occurred c. 10 ka ago, is commonly invoked as the heat source for the world's largest commercial geothermal reservoir, The Geysers, in northern California. A shallow silicic magma reservoir in the upper-middle crust has been discovered for some time, but the location and mechanism of a potential deep mafic magma reservoir have remained elusive. Here, we present a seismic tomographic model that images the entire crustal column, clearly revealing a multilevel transcrustal magmatic system beneath the Geysers-Clear Lake area. Upwelling melts from the mantle traverse across the crust-mantle boundary and accumulate in the lower crust underneath the southeastern part of Clear Lake, resulting in a hot Moho in between. Mafic melts primarily ascend westward due to the extensional regime in the west and physical barrier effect from the overlying rigid ophiolite fragment, ultimately forming a shallow silicic magma reservoir underlying and heating The Geysers geothermal field. In addition, this study also links compositionally diverse volcanism in a continental setting to differentiation in a multilevel transcrustal magmatic system. [ABSTRACT FROM AUTHOR]

Poly(lactic acid) has great potential in sectors where degradability is an important advantage due to its polymer nature. The medical, pharmaceutical, and packaging industries have shown interest in using PLA. To overcome the limitations of stiffness and brittleness in the polymer, researchers have conducted numerous modifications to develop fibers with improved properties. One such modification involves using plasticizing modifiers that can provide additional and desired properties. The scientific reports indicate that low-molecular-weight esters (LME) (triethyl citrate and bis (2-ethylhexyl) adipate) affect the plasticization of PLA. However, the research is limited to flat structures, such as films, casts, and extruded shapes. A study was conducted to investigate the impact of esters on the process of forming, the properties, and the morphology of fibers formed through the melt-spinning method. It was found that the modified PLA required different spinning and drawing conditions compared to the unmodified polymer. DSC, FTIR, WAXD, and GPC/SEC analyses were performed for the modified fibers. Mechanical tests and morphology evaluations using SEM microscopy were also conducted. The applied plasticizers lowered the temperature of the spinning process by 40 °C, and allowed us to obtain a higher degree of crystallinity and a better tenacity at a lower draw ratio. GPC/SEC analysis confirmed that the polymer–plasticizer interaction is physical because the booth plasticizer peaks were separated in the chromatographic columns. The use of LME in fibers significantly reduces the temperature of the spinning process, which reduces production costs. Additives significantly change the production process and the structure of the fiber depending on their rate, which may affect the properties, e.g., the rate of degradation. We can master the degree of crystallinity through the variable amount of LME. The degree of crystallization of the polymers has a significant influence on polymer application. [ABSTRACT FROM AUTHOR]