High Modulus Research Articles

An Enhanced Bioactive Glass Composition with Improved Thermal Stability and Sinterability

The development of new bioactive glasses (BGs) with enhanced bioactivity and improved resistance to crystallization is crucial for overcoming the main challenges faced by commercial BGs. Most shaping processes require thermal treatments, which can induce partial crystallization, negatively impacting the biological and mechanical properties of the final product. In this study, we present a novel bioactive glass composition, S53P4_MSK, produced by a melt–quench route. This novel composition includes magnesium and strontium, known for their therapeutic effects, and potassium, recognized for improving the thermal properties of bioactive glasses. The thermal properties were investigated through differential thermal analysis, heating microscopy and sintering tests from 600 °C to 900 °C. These characterizations, combined with X-ray diffraction analysis, demonstrated the high sinterability without crystallization of S53P4_MSK, effectively mitigating related issues. The mechanical properties—elastic modulus, hardness and fracture toughness—were evaluated on the sintered sample by micro-indentation, showing high elastic modulus and hardness. The bioactivity of the novel BG was assessed following Kokubo’s protocol and confirmed by scanning electron microscopy, X-ray energy dispersive spectroscopy, and Raman spectroscopy. The novel bioactive glass composition has shown high sinterability without crystallization at 700 °C, along with good mechanical properties and bioactivity.

Heat-Resistant Shape Memory Fully Biobased Epoxy Resins with High Storage Modulus and Recycle Performance

Heat-Resistant Shape Memory Fully Biobased Epoxy Resins with High Storage Modulus and Recycle Performance

Fenugreek gum improves the rheological properties of konjac glucomannan in dynamic simulated digestion system and delays its gastric emptying.

The physicochemical properties of konjac glucomannan (KGM) are impaired in the harsh gastrointestinal tract, which may reduce its effectiveness in physiological functions. In this paper, fenugreek gum (FG) with high water holding capacity and stability was used as a gastric protectant for KGM, and the effects of the KGM-FG complexes with different composite ratios on gastric emptying were researched by in vitro dynamic simulated gastric digestion system. The results showed that FG significantly enhanced the delayed gastric emptying properties of KGM. Adding FG reduced the apparent viscosity, flow behavior, and mechanical properties of KGM. The simulated gastric fluid (SGF) decreased the apparent viscosity of the KGM-FG complex and increased the microstructure network density of the KGM-FG complex compared with the water system. FG helped the structure of the KGM-FG complexes become more stable and trapped more water in the stomach. The KGM-FG complex with high viscosity, mechanical modulus, and frictional resistance in a dynamic simulated digestion system increased gastric retention. The KGM-FG complex with a composite ratio 5:5 showed the best performance and a potential satiety-enhancing property. The results provided a theoretical basis for designing satiety food formulations that help control energy intake and body weight.

Experimental and Numerical Simulation on the Generation and Development of Cumulative Plastic Strain of Cement Sheath in Salt Cavern Gas Storage Well

ABSTRACTSalt cavern gas storage is an important technical means to balance the demand for staggered energy supply. Due to the repeated injection and extraction of natural gas in gas storage facilities, sealing integrity failure in the wellbore of gas storage facilities frequently occurs. In response to this, considering the cyclic loading and unloading of the pressure load inside the casing, mechanical tests of set cement were carried out under alternating loads, quantifying the cumulative plastic strain change law of set cement and revealing the deterioration characteristics of its mechanical properties. A numerical model of cumulative plastic strain of casing cement sheath formation under alternating load was established based on the obtained experimental parameters. Comparative verification was conducted using experimental data, and the variation law of cumulative plastic strain of cement sheath was analyzed. The distribution of cumulative plastic strain on the cement sheath bonding surface of the entire wellbore was quantified. The research results indicate that the higher the internal pressure value of the casing, the earlier the plastic strain appears, and with the increase in the number of alternating loads, the cumulative plastic strain increases approximately linearly. After the internal pressure increased by 30 MPa, the cumulative plastic strain increased by a maximum of 46.75%. When the number of loading and unloading cycles under alternating loads is small, reducing the elastic modulus (6 GPa) of the cement sheath can effectively reduce its cumulative plastic strain. However, as the number of loading and unloading cycles under alternating loads exceeds a specific value, the cumulative plastic strain produced by high elastic modulus (15 GPa) cement sheaths decreases. Finally, the distribution pattern of cumulative plastic strain along the wellbore under different gas injection times and complex formation conditions was analyzed. Suggestions for establishing well barriers in salt cavern gas storage during cementing were proposed. The research results can provide theoretical and engineering references for evaluating the sealing integrity of gas storage wells.

Ultra-light Mg-Li alloy with high modulus prepared by cold metal transfer-based directed energy deposition

Ultra-light Mg-Li alloy with high modulus prepared by cold metal transfer-based directed energy deposition

Compositing effects for high thermoelectric properties of n-type Bi2S3 via doping C60 nanoparticles

Bi2S3 is one of the most inexpensive and eco-friendly thermoelectric materials in the medium temperature region. In this work, functionalized fullerene (C60) was successfully doped into Bi2S3 to optimize its thermoelectric properties by a simple hydrothermal method. Guided by first-principles calculations for compositional design, electron band structure of Bi2S3/C60 nanocomposites is reduced. Additionally, the high modulus elasticity of C60 further increases phonon scattering in Bi2S3. Due to composite effects synergistically optimized the transports of electron and phonon by C60 nanoparticles in Bi2S3-based materials, the electrical and thermal conductivity of Bi2S3-based nanocomposites are optimized and decreased to varying degrees, respectively. The highest power factor (PF) of Bi2S3/C60 nanocomposites is up to 181μW·m-1·K-2, and the lowest thermal conductivity is 0.17W m-1·K-2. Ultimately, the ZT value of Bi2S3/C60 (10ml) nanocomposites reached 0.38, nearly a threefold improvement over the pure Bi2S3, which further expands the application range of Bi2S3-based thermoelectric materials.

Designing high modulus Mg-Li alloy by forming heterostructures resistant to age softening due to Ag diffusion drags

Designing high modulus Mg-Li alloy by forming heterostructures resistant to age softening due to Ag diffusion drags

Hydroxyapatite (HAp) Extracted from Cockle Shells with Polylactic Acid (PLA) for Bone Implant Application

Cockle shell waste has been utilized to produce HAp powders for biomedical applications. This research involves creating HAp powder through a precipitation method and analyzing the properties of CaCO₃, CaO, and HAp. A composite PLA/HAp material was produced with varying ratios of 10%, 20%, and 30% HAp for tensile test samples. The results show that HAp derived from cockle shells contains calcium and phosphorus, similar to commercial HAp. Samples with different weight percentage of HAp provides Young's modulus values comparable to cortical bone (7-30 GPa), with the sample containing 30% HAp achieving the highest value (8.17 GPa), where High Young's modulus values indicate increased stiffness. In summary, cockle shell-derived HAp is a promising material for biomedical applications.

Research on the Performance of Carbon Fiber Composite Railings for Ships

With the development of the shipbuilding industry, the requirements for the safety and corrosion resistance of ship structural components are becoming increasingly high. Most of the components used in traditional ships are made of steel, which cannot meet the requirements of corrosion resistance and safety for existing ships. In order to improve the structural safety and corrosion resistance of ship railings, as well as their lightweight requirements, this article proposes a lightweight design for ship railing structures based on the advantages of carbon fiber composite materials, such as light weight, high strength, and high modulus, on the basis of the existing traditional metal railing structures for ships. Based on the anisotropy of carbon fiber composite fibers, the characteristics of overlapping/weaving structures, and the influence of the interface between carbon fiber composite materials and metal materials on the strength of ship railing structures, a finite element simulation model of carbon fiber composite materials is established. By setting constraints such as volume fraction, stress, strain, displacement,etc.in the given simulation model, the layout of materials in the optimization results is used to guide the design of the structure, and the size parameters of the ship railing barrel are optimized for structural optimization. Thus achieving lightweight design of ship railings and meeting the requirements for lightweight, safety, service life, and corrosion resistance of ship structural components.

Low carbon footprint lightweight GPM production: Optimization of carbon fiber and hydrogen peroxide

This study examines the effects of using Carbon Fiber (CF) and Hydrogen Peroxide (H2O2) on the mechanical and thermal properties of ground Raw Perlite (RP) based Geopolymer Mortar (GPM). It focuses on determining the optimal dosages of CF and H2O2. This study aims to make perlite-based GPMs that form strong bonds with alkali activators lightweight, while also improving their compressive, tensile, flexural, and thermal properties. Sodium Silicate (Na2SiO3) and Sodium Hydroxide (NaOH) were used as alkali activators, while H2O2 served as the foaming agent. The NaOH solution was 13 M, and Na2SiO3 was used with a 2-module specification. In this context, a reference GPM was prepared using RP and Crushed Sand (CS). CF was chosen for its advantages, such as low density, high Young's modulus and tensile strength. Various amounts of CF and H2O2 were used to determine the optimal dosage to achieve a durable and lightweight mortar. The results showed that the best performance was achieved with 1 % CF and 1 % H2O2. Compressive strength increased to around 3.5 MPa with the addition of 2 % H2O2 and 2 % CF. It was found that the use of CF provided significant protection in compressive and flexural strength, but increasing the fiber weight or volume ratio beyond a certain dosage could decrease strength efficiency. These findings support the use of 6 mm CF as a reinforcing material in GPMs within the construction industry while emphasizing the need to avoid exceeding a 2 % H2O2 ratio. The results of this research can be considered an important step toward developing environmentally friendly and durable building materials.

Gastric fold-inspired microwrinkled carbon nanotube sheets for harvesting mechanical energy of organ motion

Biomechanical energy from daily activities and organ motion is an attractive energy source because of its sustainability. Mechanical energy harvesters, including triboelectric, piezoelectric, and chemo-mechanical harvesters, are gaining significant attention for converting energy into electrical power for self-powered devices. Chemo-mechanical energy harvesters that utilize the piezoionic effect are particularly suited for harnessing the movements of organs, such as the heart, stomach, and lungs, in the electrolyte-rich environment of the human body. However, existing harvesters are inefficient because of their unidirectional response and high modulus, which hinder organ motion. In this paper, we propose a microwrinkled carbon nanotube (CNT) sheets harvester (MCSH), inspired by the gastric wrinkle morphology and featuring a low modulus (43.9 kPa), capable of multidirectional energy harvesting. The MCSH generates energy through the relaxoionic effect during unfolding and folding cycles, achieving an open-circuit voltage change of 11.6 mV and a peak current of 112.5 A kg−1 in 0.1 M HCl. Finally, the MCSH demonstrated stable energy generation in a human stomach model using simulated body fluids.

Propped fracture conductivity in shale oil reservoirs: Prediction model and influencing factors

Hydraulic fracturing is the main measure for stimulation of shale oil reservoirs, but the high content of clay minerals, well-developed bedding, and low mechanical strength of shale rock often result in a strong stress sensitivity of propped fractures associated with shale hydration expansion and proppant embedment in fracture wall. Especially under conditions of low sand laying concentration, the fracture conductivity can be greatly reduced. In this paper, a comprehensive prediction model of propped fracture conductivity in shale oil reservoirs was established, which considers the damage mechanisms of proppant compression, embedment, crushing, and shale hydration and expansion. The sensitivity analysis of factors affecting the fracture conductivity indicates that the proppant particle size, involved damage mechanisms, Kozeny-Carman coefficient, proppant layer number, and proppant density are the main factors to determine the fracture width and permeability and further affect the fracture conductivity. Most of the rest factors are related to the specific fracture damage mechanisms. The influence of shale hydration expansion is larger than that of proppant particle compression which is further larger than that of proppant crushing. In a real hydraulic fracture, the fracture width decreases from fracture heel to toe, caused by the non-uniform laying concentration of proppant. For the fracture near the wellbore usually with a large sand laying concentration, the influences of different factors are ranked as follows: proppant particle size > elastic modulus of proppant > fluid pressure > hydration expansion coefficient > filtration depth. For the front of the fracture with a low sand laying concentration, it is easy to close, which is sensitive to all the above factors. To achieve a high and stable fracture conductivity, the anti-swelling agent should be used to prevent shale hydration expansion. Large-size proppants with high elastic modulus should be selected to prop up the front of the fracture, and the decline of bottom-hole flow pressure should be controlled during the depressurized production process. The obtained results have a certain guiding significance for understanding the factors of shale fracture conductivity and the optimization of fracture parameters.

Modeling abscission of cacti branches

During evolution, various functional principles have evolved that allow plants to create predetermined breaking points for the spatially defined abscission of organs. In the plant family of cacti, some species, such as Cylindropuntia bigelovii, have fragile branch–branch junctions that serve vegetative reproduction, while in other species, such as Opuntia ficus-indica, they are very stable. The fracture behavior of these junctions has been thoroughly characterized anatomically and mechanically, the data being the prerequisite for the performance of cactus-inspired phase field simulations. We have found that models composed of homogeneous materials or material systems with low elastic modulus contrast (analogous to Cylindropuntia bigelovii) exhibit a fracture mode where cracks initiation occurs at the epidermis of the junction notch. In comparison, heterogeneous material systems with high elastic modulus contrast (similar to Opuntia ficus-indica) show fracture nucleation along the inner vascular bundles, with an increase in the maximum fracture energy by a factor of 2.2. In the high contrast heterogeneous models, the V-notch and stiffening of the dermal tissue (“periderm”) have a negligible effect on their fracture behavior. In addition, the fracture morphologies of these models resemble the rough junction fracture sites found experimentally. The knowledge gained about the geometric influences and the importance of the contrasts in the mechanical properties of the individual materials in the overall system can be transferred as functional principles to bioinspired engineering composites in order to program their fracture behavior.

Toward Sustainable Poly(lactic acid)/Poly(propylene carbonate) Blend Films with Balanced Mechanical Properties, High Optical Transmittance, and Gas Barrier Performance via Reactive Compatibilization and Biaxial Stretching.

Sustainable poly(lactic acid) (PLA)/poly(propylene carbonate) (PPC) blends were compatibilized by the environmentally friendly epoxidized soybean oil (ESO) through the chemical reaction of epoxy functional groups on ESO with the terminated carboxyl and hydroxyl groups of PLA/PPC. The compatibilization effect of ESO was confirmed by Fourier transform infrared spectroscopy, rheological property testing, differential scanning calorimetry, and morphological observations. It was revealed that the molecular chain entanglement between PLA and PPC was significantly enhanced and the dispersed PPC phase size was decreased, which endowed the blend with high viscosity modulus, low tan δ, and great stretchability, especially for the blend containing 1.0 wt % ESO. The compatibilization effect dramatically reinforced the toughening modification of PPC on PLA, resulting in a great ductility with a fracture strain up to 187.3%, more than 20 times that of the pristine PLA, while maintaining a high strength of 44.5 MPa. Compared to the neat PLA and the PLA/PPC blend, the compatibilized blend showed a much larger draw ratio of up to 6.5 × 6.5 during biaxial stretching, producing a uniform film with balanced mechanical properties, high optical transparency, and good oxygen barrier performance. This work will be of vital importance for guiding the preparation of PLA-based films with superior comprehensive properties.

Extreme Toughening of Conductive Hydrogels Through Synergistic Effects of Mineralization, Salting-Out, and Ion Coordination Induced by Multivalent Anions.

Developing conductive hydrogels with both high strength and fracture toughness for diverse applications remains a significant challenge. In this work, an efficient toughening strategy is presented that exploits the multiple enhancement effects of anions through a synergistic combination of mineralization, salting-out, and ion coordination. The approach centers on a hydrogel system comprising two polymers and a cation that is highly responsive to anions. Specifically, polyvinyl alcohol (PVA) and chitosan quaternary ammonium (HACC) are used, as PVA benefits from salting-out effects and HACC undergoes ion coordination with multivalent anions. After just 1 h of immersion in an anionic solution, the hydrogel undergoes a dramatic improvement in mechanical properties, increasing by more than three orders of magnitude. The optimized hydrogel achieves high strength (26 MPa), a high Young's modulus (45 MPa), and remarkable fracture toughness (67.3 kJ m-2), representing enhancements of 860, 3200, and 1200 times, respectively, compared to its initial state. This breakthrough overcomes the typical trade-off between stiffness and toughness. Additionally, the ionic conductivity of the hydrogel enables reliable strain sensing and supports the development of durable supercapacitors. This work presents a simple and effective pathway for developing hydrogels with exceptional strength, toughness, and conductivity.

Mechanical shutdown of battery separators: Silicon anode failure

The pulverization of silicon (Si) anode materials is recognized as a major cause of their poor cycling performance, yet a mechanistic understanding of this degradation from a full cell perspective remains elusive. Here, we identify an overlooked contributor to Si anode failure: mechanical shutdown of separators. Through mechano-structural characterization of Si full cells, combined with digital-twin simulation, we demonstrate that the volume expansion of Si exerts localized compressive stress on commercial polyethylene separators, leading to pore collapse. This structural disruption impairs ion transport across the separator, exacerbating redox nonuniformity and Si pulverization. Compression simulation reveals that a Young’s modulus greater than 1 GPa is required for separators to withstand the volume expansion of Si. To fulfill this requirement, we design a high modulus separator, enabling a high-areal-capacity pouch-type Si full cell to retain 88% capacity after 400 cycles at a fast charge rate of 4.5 mA cm−2.

Investigating temperature effects on the shear behavior of clays: Molecular dynamics simulations

The shear behavior of clays is critically important for the stability and safety of nuclear waste repositories and clay gouges. These contexts expose clayey geomaterials to high pressures and temperatures. Under such varying conditions, the shear behavior of these materials becomes complex, necessitating thorough investigations. This study aims to elucidate the effect of temperature on the shear behavior of three clayey materials: kaolinite, illite, and montmorillonite—through Molecular Dynamics. The research replicates a geotechnical shear setup at the molecular scale, varying the temperature (including sub-freezing temperatures below 300 K and elevated temperatures 400-500 K and hydrostatic pressures. The results reveal stick-slip behavior, enabling the calculation of nanoscale cohesion, friction angle, and shear modulus across different temperatures. Thermal effects are notably significant for illite and kaolinite, both exhibiting a marked decrease in shear properties with increasing temperature. Kaolinite demonstrates a high shear modulus of up to 40 GPa, indicating substantial shear strength. Illite displays the highest friction angle among the studied materials. For montmorillonite, thermal effects on shear behaviour is comparatively less pronounced. This study provides critical insights into the mechanical behaviour of clays under varying thermal conditions, contributing to the broader understanding of geomaterial stability in high-stake environments.

A self-healing plastic ceramic electrolyte by an aprotic dynamic polymer network for lithium metal batteries.

Oxide ceramic electrolytes (OCEs) have great potential for solid-state lithium metal (Li0) battery applications because, in theory, their high elastic modulus provides better resistance to Li0 dendrite growth. However, in practice, OCEs can hardly survive critical current densities higher than 1 mA/cm2. Key issues that contribute to the breakdown of OCEs include Li0 penetration promoted by grain boundaries (GBs), uncontrolled side reactions at electrode-OCE interfaces, and, equally importantly, defects evolution (e.g., void growth and crack propagation) that leads to local current concentration and mechanical failure inside and on OCEs. Here, taking advantage of a dynamically crosslinked aprotic polymer with non-covalent -CH3⋯CF3 bonds, we developed a plastic ceramic electrolyte (PCE) by hybridizing the polymer framework with ionically conductive ceramics. Using in-situ synchrotron X-ray technique and Cryogenic transmission electron microscopy (Cryo-TEM), we uncover that the PCE exhibits self-healing/repairing capability through a two-step dynamic defects removal mechanism. This significantly suppresses the generation of hotspots for Li0 penetration and chemomechanical degradations, resulting in durability beyond 2000 hours in Li0-Li0 cells at 1 mA/cm2. Furthermore, by introducing a polyacrylate buffer layer between PCE and Li0-anode, long cycle life >3600 cycles was achieved when paired with a 4.2 V zero-strain cathode, all under near-zero stack pressure.

Preparation of high internal phase emulsions based on high-temperature glycation-modified egg white protein: Structural characteristics, stability, and β-carotene bioavailability under multi-parameter regulation

In recent years, freeze-thaw stability of high internal phase emulsions (HIPEs) has gained increasing attention. High-temperature glycosylation-modified proteins have shown to produce stable HIPEs. This study examines the effects of high-temperature glycosylation on egg white protein (EWP) and fructo-oligosaccharides (FO), focusing on how pH and EWP/FO ratios affect the structure of glycosylated EWPs (GEWPs) and HIPEs stability. Specifically, strong alkaline conditions promoted the glycosylation reaction, with the highest DG value at pH 11.0. At pH 5.0, close to the isoelectric point of EWP, GEWPs could not successfully stabilize HIPEs. However, they stabilized HIPEs under other pH conditions, with the best freeze-thaw stability and flocculation resistance when EWP ≥ FO. At pH 3.0, HIPEs had high viscosity and storage modulus, but phase transitions occurred after freeze-thaw when EWP ≤ FO. GEWPs-stabilized HIPEs formed gel structures with elastic properties upon thermal induction. Encapsulation experiments with β-carotene demonstrated that HIPEs prepared from GEWPs showed potential in DPPH and ABTS+ radical scavenging, improving β-carotene stability and bioavailability. Our findings show that GEWPs-stabilized HIPEs offer excellent stability, rheological properties, and carrier performance, with enhanced applications through optimized emulsifiers and preparation processes.

A4Ta2O9 (A=Ca, Mg) tantalate as novel thermal barrier coatings materials with superior calcium-magnesium-alumino-silicate corrosion resistance

The CaO-MgO-AlO1.5-SiO2 (CMAS) corrosion leads to premature failure of thermal barrier coatings (TBCs), which has beset scholars for decades. Previous study has shown that A4Ta2O9 (A=Ca, Mg) tantalates are promising TBCs attributed to the excellent thermo-mechanical properties, and this work elucidates the robust CMAS corrosion resistance of A4Ta2O9 from CMAS contact angle, reaction products, corrosion depth, thermal stress, and reaction activity. It is found out that the main reaction products between CMAS and A4Ta2O9 are Ca2Ta2O7, and the abundant Ca2+ ions in Ca4Ta2O9 can promote formations of a dense Ca2Ta2O7 reaction layer, which can prevent further penetrations of CMAS melts. Additionally, a small CMAS contact angle and higher optical basicity differences between Ca4Ta2O9 and CMAS prove that their reactions are more intense than those between Mg4Ta2O9 and CMAS, which are beneficial for accelerating the formations of a dense Ca2Ta2O7 reaction layer. The interface thermal stress between A4Ta2O9 and Ca2Ta2O7 reaction layer is estimated based on nano Young’s modulus, and Mg4Ta2O9 has higher thermal stress than Ca4Ta2O9 because it has a higher modulus. The lower of interface thermal stress, the better of high-temperature stability. Accordingly, Ca4Ta2O9 is proposed as a novel CMAS-resistant TBC material.