Mechanical Rigidity Research Articles

Effect of reinforcement ratio and textile pre-impregnation on the mechanical properties of flax textile reinforced sulfoaluminate matrix

This study evaluates the effect of reinforcement ratio and textile pre-impregnation on the tensile behavior of flax textile, embedded in an inorganic CSA matrix (sulfoaluminate cementitious matrix), known as Fabric Reinforced Cementitious Matrix (FRCM). Two reinforcement ratios of (3 and 6%) and two impregnation techniques (polymeric and mineral) are applied. Direct tensile tests are conducted on FRCM specimens as well as on bare flax textiles featuring three configurations: NP (non-impregnated), PP (polymeric-impregnated), and PM (mineral-impregnated), between 1L (one layer) and 2L (two layers) of flax textile. The results show a direct correlation between the reinforcement ratio and the enhancement of mechanical properties, with a notable 44% increase in mechanical strength observed for NP FRCM specimens between 1L and 2L of flax textile. Mineral pre-impregnation enhances yarn-cement matrix bonding inside FRCM, while FRCM specimens with polymeric-impregnated textiles have limited influence on the mechanical properties due to premature failure. Polymeric impregnation has a pronounced effect when applied to bare flax textiles, with PP flax textiles demonstrating exceptional mechanical strength and rigidity, reaching up to 480 MPa and 37 GPa, respectively. In contrast, this effect was mitigated when employing PP textiles in FRCM specimens, where the lowest fabric efficiency reached 12% for the 2L.PP configuration suggests significant chemical incompatibility between epoxy resin and CSA matrix. Mineral-impregnated specimens display consistent efficiency regardless of reinforcement ratio, suggesting a novel and homogeneous distribution of cement matrix particles within the yarns of textiles. Two distinct failure modes of FRCM are observed in this study, a delamination for PP configurations and a fiber pullout for NP and PM configurations. No effect of reinforcement ratio is remarked on the failure mode. The cracking mode in PM FRCM configurations showcased improved aesthetics, durability, and elongation after rupture (6.28%). As a result, 2L.PM FRCM is the best configuration in terms of mechanical strength, rigidity, ductility, and durability.

Novel IR Laser Debonding for Heterogeneous and 3D Integration

Wafer carrier and thin wafer support during processing is key in 3D integration and advanced packaging processes. Today carrier technology can be divided based on the application and carrier wafer material. While for DRAM and other stacked memory applications silicon carriers are preferred, demanding special adhesive systems for mechanical debond, the adhesion is tuned to be high enough for processing but low enough for post process thin layer debonding. Which means the thin wafer thickness needs to be maintained typically thicker than 40µm in order to have a sufficient mechanical rigidity and support during debonding. On the other hand, UV based laser debonding decouples the adhesion during processing while the debonding is digitally triggered by UV laser irradiation and controlled destruction of engineered polymeric layer at the glass carrier surface. Despite this is the more universal debonding process, glass wafers are generally not suited for all process lines. To solve the above described difficulties, IR laser debonding has been developed enabling the combination of silicon as a carrier substrate as well as laser debonding through silicon. One solutions is in advanced packaging, where silicon can be seen as a replacement for glass wafers but still in combination with developed adhesive systems. The more impacting application, however, is the combination of IR laser release with fusion and hybrid bonding.

Enhancing vibration damping properties of MABS/VDT blends using SEBS-g-MAH as a compatibilizer

This investigation focuses on the enhancement of the damping properties of Methyl Methacrylate Acrylonitrile Butadiene Styrene (MABS) through the formulation of a specific blend with a styrene-based elastomer referred to as VDT, and with the incorporation of Ethylene Butylene Styrene grafted Maleic Anhydride (SEBS-g-MAH) as a compatibilizer. In contrast to traditional investigations that primarily focus on the mechanical rigidity, thermal conductivity, and electrical conductivity of materials, this research explores the enhancement of damping properties via the process of melt compounding. Using a twin-screw extruder in a precise melt-mixing process, a multiphase polymer blend is generated by including three different weight ratios (10, 20, and 30 wt.%) of VDT. Furthermore, in order to enhance the compatibility between MABS and VDT, three different weight percentages of SEBS-g-MAH (2, 4, and 6 wt.%) have been used in the blend. Tensile testing, laser confocal microscopy, dynamic mechanical analysis (DMA) and nuclear magnetic resonance (NMR), are used to thoroughly assess the compatibility and effectiveness of the blends. The results indicate that the damping performance of the blend increases in direct proportion to the amount of VDT. Conversely, the addition of SEBS-g-MAH has a non-monotonic effect: the inclusion of 4 wt.% SEBS-g-MAH leads to the most substantial improvements in both damping performance and tensile strength, exceeding the results obtained with 2 wt.% and 6 wt.% compatibilizer. The study highlights the need for carefully choosing the right wt.% of compatibilizers when aiming to formulate polymer blends with enhanced vibration dampening properties.

Structural flexibility of apolipoprotein E-derived arginine-rich peptides improves their cell penetration capability

Amphipathic arginine-rich peptide, A2-17, exhibits moderate perturbation of lipid membranes and the highest cell penetration among its structural isomers. We investigated the direct cell-membrane penetration mechanism of the A2-17 peptide while focusing on structural flexibility. We designed conformationally constrained versions of A2-17, stapled (StpA2-17) and stitched (StchA2-17), whose α-helical conformations were stabilized by chemical crosslinking. Circular dichroism confirmed that StpA2-17 and StchA2-17 had higher α-helix content than A2-17 in aqueous solution. Upon liposome binding, only A2-17 exhibited a coil-to-helix transition. Confocal microscopy revealed that A2-17 had higher cell penetration efficiency than StpA2-17, whereas StchA2-17 remained on the cell membrane without cell penetration. Although the tryptophan fluorescence analysis suggested that A2-17 and its analogs had similar membrane-insertion positions between the interface and hydrophobic core, StchA2-17 exhibited a higher membrane affinity than A2-17 or StpA2-17. Atomic force microscopy demonstrated that A2-17 reduced the mechanical rigidity of liposomes to a greater extent than StpA2-17 and StchA2-17. Finally, electrophysiological analysis showed that A2-17 induced a higher charge influx through transient pores in a planer lipid bilayer than StpA2-17 and StchA2-17. These findings indicate that structural flexibility, which enables diverse conformations of A2-17, leads to a membrane perturbation mode that contributes to cell membrane penetration.

Utilizing Nanostructured Materials for Hydrogen Generation, Storage, and Diverse Applications.

The rapid advancement of refined nanostructures and nanotechnologies offers significant potential to boost research activities in hydrogen storage. Recent innovations in hydrogen storage have centered on nanostructured materials, highlighting their effectiveness in molecular hydrogen storage, chemical storage, and as nanoconfined hydride supports. Emphasizing the importance of exploring ultra-high-surface-area nanoporous materials and metals, we advocate for their mechanical stability, rigidity, and high hydride loading capacities to enhance hydrogen storage efficiency. Despite the evident benefits of nanostructured materials in hydrogen storage, we also address the existing challenges and future research directions in this domain. Recent progress in creating intricate nanostructures has had a notable positive impact on the field of hydrogen storage, particularly in the realm of storing molecular hydrogen, where these nanostructured materials are primarily utilized.

Poly-adenine-mediated tetrahedral DNA nanostructure with multiple target-recognition sites for ultrasensitive and rapid electrochemical detection of Aflatoxin B1

Tetrahedral DNA nanostructures (TDNs) are widely used in the development of electrochemical biosensors due to their structural stability, programmability, and strong interfacial orderliness. However, the complex modifications on the electrode and the single vertex target recognition of the TDNs limit their applications in electrochemical biosensing. Herein, we developed a universal detection system based on a novel polyadenine-based tetrahedral DNA nanostructure (ATDN) using Aflatoxin B1 (AFB1) as the model target for analysis. In the absence of target AFB1, the signal probes (SP) modified with ferrocene would be anchored by five aptamers on ATDN. The target capture by aptamers led to a release of SP from the electrode surface, resulting in a significant reduction of the electrochemical signal. This new nanostructure was not only dispensed with multi-step electrode modifications and strong mechanical rigidity but also had five modification sites which enhanced the detection sensitivity for the target. As a result, this biosensor shows good analytical performance in the linear range of 1 fg mL−1 to 1 ng mL−1, exhibiting a low detection limit of 0.33 fg mL−1. Satisfactory accuracy has also been demonstrated through good recoveries (95.2%–98.9%). The proposed new tetrahedral DNA nanostructure can provide a more rapid and sensitive alternative to previous electrochemical sensors based on the conventional TDN. Since DNA sequences can be designed flexibly, the sensing platform in this strategy can be extended to detect various targets in different fields.

Development of biodegradable tableware from novel combination of paddy straw and pine needles: A potential alternative against plastic cutlery

Plastic cutlery for food packaging and serving has long been in trend due to its versatile properties but accumulation of the single use plastic cutlery creates disposal problem due to its non-biodegradability. The two biomasses paddy straw and pine needles are known to cause serious problems of stubble burning and forest fires respectively. However, these two biomasses hold tremendous potential to be used as raw material in pulp industry due to their high holocellulose and cellulose content which can be further enhanced after pre-treatments. This study aims to use a combination of two biomasses in a ratio of 1:1 and further process it to derive pulp by employing enzymes such as laccase, manganese peroxidase, and lignin peroxidase for lignin removal by fermentation mechanism. After sufficient lignin removal, the processed beaten pulp was casted into cups and bowls. Binding agents such as carboxymethyl cellulose, gum acacia and potato starch along with cross-linking polymer were blended with pulp in binding matrix to cast durable and non-brittle biodegradable cups. PLA (bio-plastic) polymer was applied in the form of a thin film over the developed tableware. The developed tableware was further verified for anti-microbial properties by testing it with common food-poisoning pathogens. Mechanical stiffness and rigidity were estimated along with thermal stability examined over a wide temperature range by dynamic scanning colorimetric (DSC). Lattice structure and morphology was studied by SEM and XRD analyses. Based on the analytical analyses, the developed biodegradable tableware can be a suitable alternative to combat plastic cutlery menace.

Rheological properties of high‐pressure treated xanthan gum and guar gum blend solutions: A response surface approach

AbstractIn this research, the impact of pressurization (300–600 MPa) on the oscillatory rheology of a blend of xanthan gum (XG) and guar gum (GG) in solution (XG/GG) was examined at a selected gum concentration using a response surface methodology. Three independent variables pressure (0.101–600 MPa) concentration (0.75%–1.25%), and temperature (40–70°C)—were employed to maximize the dynamic moduli (G′, G″, and η*) of the blend solutions. The developed model suggested that all the linear, two quadratics (concentration and temperature), and two interactions (concentration‐pressure and concentration‐temperature) terms were significant (p < 0.05) for the dynamic moduli (R2 = 0.99) with insignificant lack‐of‐fit. The pressure‐induced mechanical rigidity was found to be higher when compared with the heat‐treated solutions, which requires further comprehensive structural assessment to endorse the order–disorder transition produced by high pressure. The superposition principles correlating time–temperature and time–pressure adequately fit the pressurized blend solutions.Practical applicationsThe influence of high‐pressure on a blend of gum containing xanthan and guar has industrial significance by improving the structure/texture, and consistency of food products. The synergic action of gums enables them to act as a fat replacer and texture modifier in HP‐treated foods for special needs, in particular dysphagia diets.

Scale-up fabrication of a biodegradable PBAT/PLA composite film compatibilized with a chain extender for industrial agricultural mulch film application

Low-density polyethylene (LDPE) mulch films have become a prevalent practice in agriculture to increase crop yield. However, because of their high environmental impact after use, biodegradable plastic films are considered desirable alternatives in agroecosystems. Herein, a polybutylene adipate-co-terephthalate (PBAT) and polylactic acid (PLA) composite film compatibilized with a chain extender (CE) was prepared via a two-step extrusion process. First, PBAT and PLA were blended at different ratios in a laboratory-scale twin-screw extruder, and the PBAT/PLA blends (80/20 wt.%) compatibilized with 1 phr of CE exhibited the most comparable physicochemical properties. The CE integration into the PBAT/PLA binary blend significantly increased mechanical rigidity and strength (p ≤ 0.05). The enhanced compatibility between the immiscible polymers was verified through thermal and phase morphological analyses. The optimum composite was then produced using a pilot-scale extrusion system. The pilot-scale extruded optimal biodegradable mulch composite exhibited excellent water barrier properties, as evidenced by a water vapor permeability of 0.83 g mm/m2·day·kPa and a water contact angle of 93.77° These values surpassed those of commercially available biodegradable mulch films. Furthermore, it demonstrated a weight reduction of 2.9% during a 3-month period of soil burial, exhibiting durability compared to commercial biodegradable mulch films. These results suggest that the developed film has great potential for practical food and agricultural applications.

Investigation on growth, spectral, hardness, piezoelectric, contact angle, optical stress and nonlinear optical properties of acid blue 22 dye on ADP single crystals

Reclusive single crystals of ammonium dihydrogen phosphate (ADP) and 0.1[Formula: see text]mol.% Acid Blue 22 dye-incorporated ADP were harvested by using a standard slow cooling mechanism. The skeletal framework of the anisotropic materials was analyzed by using single crystal X-ray diffraction cram. The powder X-ray diffraction examines the phase growth and incorporation of substituents in the crystalline matrices. The incorporation of additives in the system was examined by employing Fourier Transform Infrared Spectroscopy. The analysis of vibrational bands gives insights into the incorporation of additives in ADP crystal system. The transmission window of the specimen and optical bandgap of the given material were analyzed by using UV–Vis spectroscopic analysis. The incorporation of additives to parent crystals was examined by using Scanning Electron Microscope. The quantification of elements in the grown specimen was investigated by using Energy Dispersive X-ray spectroscopy. The mechanical rigidity of the material was inspected by using Vickers microhardness analysis. The piezoelectric charge coefficient of dye-incorporated ADP is higher than pristine ADP. The wettability of the material was identified by contact angle measurements. The optical stress was identified by employing photoelastic measurements. The second- and third-order nonlinear optical properties of pristine and dye-incorporated ADP crystals were investigated by using Kurtz–Perry powder technique and Z-scan technique.

Oscillatory rheology of chitosan and calcium chloride crosslinked pectin blend filmogenic solutions and atomic force microscopy of film surface topography

This work examines the synergistic interaction between chitosan (CS) and calcium crosslinked pectin (CP) in aqueous solution by small-amplitude oscillatory shear measurements at selected CS/CP blend ratios (1:1, 1:2, 1:3, and 1:4) and compares the surface morphology of cast films of those blends using atomic force microscopy (AFM). A 2% (w/v) pectin solution concentration could not produce a film, which was improved with the addition of 0.18 M calcium chloride solution, and the corresponding dynamic moduli increased by 3 log cycles. The mechanical rigidity of the blends increased with increasing CP contents. The complex viscosity (η*) decreased with increasing temperature due to molecular mobility at higher temperatures and the breaking of the junction between CS and CP. The applicability of the Cole-Cole plot to selected blend ratios demonstrated that only the CS/CP ratio of 1:3 best fitted and established the well-miscibility between the polymers. AFM phase imaging further illustrates the distribution of CS and CP particles in the blended films and provides complementary information to the topography image, revealing the variations in the surface properties of the films. AFM proves to be a powerful tool for investigating microstructural changes in polymer blends and complementing rheological measurements.

Compressible sponge electrodes by oxidative molecular layer deposition (oMLD) of polyethylenedioxythiophene (PEDOT) onto open-cell polyurethane sponges

The formation of compressible porous sponge electrodes is appealing to overcome diffusion limitations in porous electrodes for applications including electrochemical energy storage, electrochemical water desalination, and electrocatalysis. Previous work has employed wet chemical synthesis to deliver conductive materials into porous polymer sponge supports, but these approaches struggle to produce functional electrodes due to (1) poor electrical connectivity of the conductive network and (2) mechanical rigidity of the foam after coating. In this work we employ oxidative molecular layer deposition (oMLD) via sequential gas-phase exposures of 3,4 ethylenedioxythiophene (EDOT) and molybdenum pentachloride (MoCl5) oxidant to imbibe polyurethane (PU) sponges with electrically-conductive and redox-active poly(3,4 ethylenedioxythiophene) (PEDOT) coatings. We analyze the oMLD deposition on compressive PU sponges and modify the reaction conditions to obtain mechanically compressible and electrically conductive sponge electrodes. We specifically identify the importance MoCl5 dose time to enhance the conductivity of the sponges and the importance of EDOT purge time to preserve the mechanical properties of the sponges. Controlling these variables produces an electrically conductive PEDOT network within the sponge support with reduced impact on the sponge’s mechanical properties, offering advantages over wet-chemical synthesis approaches. The compressible, conductive sponges we generate have the potential to be used as compressible electrodes for water desalination, energy storage, and electrocatalysis.

Bioinspired fine-tuning of the mechanical rigidity of SNEDDS for the efficient crossing of multiple gastrointestinal barriers

Nanoproperties, such as size, charge, and rigidity, have been demonstrated to be crucial for nanovehicles to overcome numerous gastrointestinal obstacles. However, the facile approach of modifying the rigidity of nanovehicles remains scarce, limiting understanding of how rigidity impacts their oral delivery. Inspired by the fact that cellular phospholipid content regulates plasma membrane rigidity, the rigidity of self-nanoemulsifiying drug delivery system (SNEDDS) could be fine-tuned via phosphocholine content while their size and zeta potential remain unchanged, using insulin as a model drug. Notably, soft SNEDDS exerted longer gastrointestinal transit time, higher drug release rate, stronger gastrointestinal stability and relatively lower mucus permeation but superior epithelial transcytosis than their hard counterparts in a macropinocytosis-dependent manner. The rigidity-related enhanced transcytosis was attributed to improved endocytosis, lysosome escape capability and exocytosis. Rats with type 1 diabetes exhibited greater oral insulin absorption and blood glucose lowering effect with soft SNEDDS. This study demonstrated the regulatory role of phospholipids in nanovehicle rigidity, which could help develop mechanically optimized nanomedicines in the future.

High-Performance K Metal Batteries Enabled by Regulating an Electrolyte Solvation Structure

Batteries using a potassium metal (K-metal) anode are attention to a new type of low-cost and high-energy storage devices. However, the thermodynamic instability of the K-metal anode in organic electrolyte solutions causes uncontrolled growth of dendrites and parasitic reactions, which leads rapid capacity loss and low Coulombic efficiency.[1-4] In this presentation, I will introduce the advanced electrolyte using dual-salt for regulated solvation chemistry showing an improved the K-metal anode stability. Experimental and theoretical studies supported the details of solvation chemistry and results. Incorporating dual-salt into the electrolyte solution decreased the number of free solvent molecules surrounding the K+ leading to facile K+ desolvation as well as lowering the exchange current density improving the uniform K electrodeposition. Moreover, the modified electrolyte mitigates decomposition of the solvent molecules and leads to form enhanced mechanical rigidity of the SEI layer on the surface of the K–metal electrode with larger fraction of KF compound. Compared to previous studies, the K-metal anode using modified electrolyte shows long cycling stability at fast charge-discharge capability in symmetrical K | K cells. Even under high current density, the modified electrolyte ensures high areal capacity and an unprecedented lifespan with stable Coulombic efficiency for the K-metal full battery employing a sulfurized polyacrylonitrile cathode. M. Park, Y. Jeong, M. H. Alfaruqi, Y. Liu, X. Xu, S. Xiong, M.–G. Jung, H.–G. Jung, J. Kim, J.–Y. Hwang, Y.–K. Sun. Stable Solid Electrolyte Interphase for Long–Life Potassium Metal Batteries, ACS Energy Lett. 7 (2022) 401–409.Kim, W. Song, D.–Y. Son, L. K. One, Y. Qi. Lithium–Ion Batteries: Outlook on Present, Future, and Hybridized Technologies. J. Mater. Chem. A 7 (2019) 2942–2964.–H. Kim, G.–T. Park, B.–K. Son, G. W. Nam, J. Liu, L.–Y. Kuo, P. Kaghazchi, C. S. Yoon, Y.–K. Sun. Heuristic Solution for Achieving Long–Term Cycle Stability for Ni–Rich Layered Cathodes at Full Depth of Discharge, Nat. Energy 5 (2020) 860.–Y. Hwang, S.–T. Myung, Y.–K. Sun. Recent Progress in Rechargeable Potassim Batteries, Adv. Funct. Mater. 28 (2018) 1802938.

Electrodeposition of Microfabricated Rhenium-Filaments

Metallic filaments comprised of refractory materials are a necessary part of mass spectrometers used to measure isotopes. The current state-of-the-art material, rhenium, is formed into filaments using a mechanical crimper, limiting the accuracy, speed, and quantity of filaments that can be fabricated. The current work describes the development of wafer-scale, microfabricated Re filaments using silicon molds followed by electrodeposition of Re. The goal is to develop filaments with tight dimensional tolerances, high purity, and mechanical rigidity for the desired application and offer the ability to create 100’s-1000’s of filaments on a single silicon wafer.Electrodeposition of Re is notoriously difficult as the reduction potential of rhenium is close to the hydrogen evolution reaction in aqueous solutions.1 While rhenium has been successfully deposited from alkaline, acid, and concentrated lithium chemistries,2 the films are often thin, porous, and contain many impurities such as hydrogen and oxygen. Rhenium oxide is susceptible to reaction with moisture in the air, resulting in poor quality films with short functional lifetimes. To electroform precise, pure rhenium structures, hardier chemistries must be developed.The current work seeks to address this challenge using a water-in-salt chemistry (WISE) comprised of up to 4M lithium salts, complexing agents, reducing agents, and oxygen scavengers. Numerous physical agitation techniques were utilized to improve the quality of the film. Solutions were analyzed using various electrochemical techniques, UV-VIS, and Raman spectroscopy. The optimized chemistry was used to electrodeposit bulk batches of microfabricated 2mm x 300 um x 300 um filaments. The filaments were analyzed using microscopy, XRF, XRD, SEM, and EDS with a goal of use in high temperature mass spectrometry experiments. References (1) Naor, A.; Eliaz, N.; Burstein, L.; Gileadi, E. Direct Experimental Support for the Catalytic Effect of Iron-Group Metals on Electrodeposition of Rhenium. Electrochemical and Solid-State Letters 2010, 13 (12), D91. DOI: 10.1149/1.3489532.(2) Pappas, D. P.; David, D. E.; Lake, R. E.; Bal, M.; Goldfarb, R. B.; Hite, D. A.; Kim, E.; Ku, H.-S.; Long, J.; McRae, C. Enhanced superconducting transition temperature in electroplated rhenium. Applied Physics Letters 2018, 112 (18), 182601. Sandia National Laboratories is a multimission laboratory managed and operated by National Technology & Engineering Solutions of Sandia, LLC, a wholly owned subsidiary of Honeywell International Inc., for the U.S. Department of Energy’s National Nuclear Security Administration under contract DE-NA0003525. SAND2022-*****

Unexpected self-assembly of carbon dots during digital light processing 3D printing of vanillin Schiff-base resin

Bio-based and recyclable composite thermosets were obtained through digital light processing (DLP) 3D printing by dispersing cellulose-derived carbon dots (CDs) in a photocurable vanillin Schiff-base resin. The exposure of CDs to DLP induced a partial reduction of the oxygen functionalities and a self-assembly of CDs into micrometric fibers embedded in the thermoset matrix. A comparison with the vanillin Schiff-base thermoset, illustrated lower transition temperature from the glassy to the rubbery state and inferior shape memory properties for the CD containing thermoset. This is ascribed to a lower crosslinking density due to the replacement of the covalent interactions of the thermosets with supramolecular interactions generated inside the microfibers and between the microfibers and the surrounding matrix. This can also explain the inferior mechanical rigidity of the composites with respect to the single component thermosets. However, the supramolecular interactions endow the composites with better mechanical and chemical recyclability with an almost complete preservation of the original mechanical properties.

Hybrid steel–composite cross-arm for distribution power lines

This paper describes the development of electrically insulating hybrid steel–composite cross-arm for medium-voltage overhead distribution power lines with three conductors. The main goal was to achieve substantial weight savings compared to a common steel cross-arm with three ceramic insulators widely used in the Czech Republic. The structure has been designed as a combination of two main composite components – a pultruded horizontal profile and a braided vertical conical tube. These components are connected by a steel locking component which also serves for attaching the whole cross-arm to common concrete utility poles. The hybrid cross-arm is conceived to insulate electrical current in the default configuration thanks to the properties of the glass fiber reinforced composite materials, yet additional insulating elements can be used to further increase the electrical insulation distance. The materials and components used for the construction are chosen by combining finite element simulations of mechanical and electrical behavior with experimental testing and verification of important characteristics on selected substructures. The final design of the cross-arm is then manufactured and subjected to long-term testing in real-life environmental conditions. The achieved reduction of weight exceeds 50% while maintaining the mechanical rigidity and strength of the steel solution as well as the required insulation properties. The future trend of the cross-arm development is aiming at the weight reduction and increase of manipulation capabilities resulting in lowering many additional costs. In this work the designed cross-arm has half the weight of the original one.

Ethanol Enhances Endothelial Rigidity by Targeting VE-Cadherin-Implications for Acute Aortic Dissection.

(1) Background: Acute aortic dissection (AAD) is caused by an endothelial entry tear followed by intimomedial delamination of the outer layers of the vessel wall. The established risk factors include hypertension and smoking. Another rising candidate risk factor is excessive alcohol consumption. This experimental study explores the effects of nicotine (Nic), angiotensin II (Ang II), and ethanol (EtOH) on human aortic endothelial cells (hAoEC). (2) Methods: HAoECs were exposed to Nic, Ang II, and EtOH at different dose levels. Cell migration was studied using the scratch assay and live-cell imaging. The metabolic viability and permeability capacity was investigated using the water-soluble tetrazolium (WST)-1 assay and an in vitro vascular permeability assay. Cell adherence was studied by utilizing the hanging drop assay. The transcriptional and protein level changes were analyzed by RT-qPCR, Western blotting and immunohistochemistry for major junctional complexing proteins. (3) Results: We observed reduced metabolic viability following Ang II and EtOH exposure vs. control. Further, cell adherence was enhanced by EtOH exposure prior to trituration and by all risk factors after trituration, which correlated with the increased gene and protein expression of VE-cadherin upon EtOH exposure. The cell migration capacity was reduced upon EtOH exposure vs. controls. (4) Conclusion: Marked functional changes were observed upon exposure to established and potential risk factors for AAD development in hAoECs. Our findings advocate for an enhanced mechanical rigidity in hAoECs in response to the three substances studied, which in turn might increase endothelial rigidity, suggesting a novel mechanism for developing an endothelial entry tear due to reduced deformability in response to increased shear and pulsatile stress.

Employing sulfolane as a green solvent in the fabrication of nanofiltration membranes with excellent dye/salt separation performances for textile wastewater treatment

This study explores the potential use of sulfolane, a green and sustainable solvent, as an alternative to toxic solvents in the fabrication of high-performance nanofiltration membranes. A comparison of Hansen solubility parameter (HSP) with N-methyl-2-pyrrolidone (NMP) indicates that sulfolane is a “poor” solvent for the sulfonated polyphenylenesulfone (sPPSU) polymer, which results in a lower critical polymer concentration (CPC) required to produce a macrovoid-free membrane structure. Moreover, the addition of a low molecular weight hyperbranched polyethyleneimine (HPEI) of MW = 800 g/mol as a crosslinker enhances the mechanical rigidity of the membranes without affecting the pore structure required for retaining salts from dye/salt mixtures, enabling practical applications in wastewater treatment. Notably, the membranes demonstrate exceptional dye/salt separation performance with a separation factor SDye/Salt of up to 69.32, even for low molecular weight dyes as low as 268 g/mol (i.e., a Disperse blue 1 and Na2SO4 mixture). To the best of our knowledge, this is the lowest MW dye ever tested for dye/salt separation. The membranes also show good antifouling capability over an extended period of use. Literature comparison shows that the sPPSU/sulfolane membrane crosslinked with HPEI800 for 60 min, referred to as sPSlf-c60, exhibits superior dye/salt separation performance, indicating their potential for the treatment of textile wastewater effluents.

Nanostructured Electrospun Fibers with Self-Assembled Cyclo-L-Tryptophan-L-Tyrosine Dipeptide as Piezoelectric Materials and Optical Second Harmonic Generators.

The potential use of nanostructured dipeptide self-assemblies in materials science for energy harvesting devices is a highly sought-after area of research. Specifically, aromatic cyclo-dipeptides containing tryptophan have garnered attention due to their wide-bandgap semiconductor properties, high mechanical rigidity, photoluminescence, and nonlinear optical behavior. In this study, we present the development of a hybrid system comprising biopolymer electrospun fibers incorporated with the chiral cyclo-dipeptide L-Tryptophan-L-Tyrosine. The resulting nanofibers are wide-bandgap semiconductors (bandgap energy 4.0 eV) consisting of self-assembled nanotubes embedded within a polymer matrix, exhibiting intense blue photoluminescence. Moreover, the cyclo-dipeptide L-Tryptophan-L-Tyrosine incorporated into polycaprolactone nanofibers displays a strong effective second harmonic generation signal of 0.36 pm/V and shows notable piezoelectric properties with a high effective coefficient of 22 pCN-1, a piezoelectric voltage coefficient of geff=1.2 VmN-1 and a peak power density delivered by the nanofiber mat of 0.16μWcm-2. These hybrid systems hold great promise for applications in the field of nanoenergy harvesting and nanophotonics.