Ultrahigh Loading Research Articles

Interfacial Manipulation via In Situ Constructed Fast Ion Transport Channels toward an Ultrahigh Rate and Practical Li Metal Anode.

The successful substitution of Li metal for the conventional intercalation anode can promote a significant increase in the cell energy density. However, the practical application of the Li metal anode has long been fettered by the unstable solid electrolyte interface (SEI) layer on the Li metal surface and notorious dendritic Li growth. Herein, a stabilized SEI layer with in situ constructed fast ion transport channels has successfully been achieved by a robust In2S3-cemented poly(vinyl alcohol) coating. The modified Li metal demonstrates significantly enhanced Coulombic efficiency, high rate performance (10 mA cm-2), and ultralong life cycling stability (∼4900 cycles). The Li|LiCoO2 (LCO) cell presents an ultralong-term stable operation over 500 cycles at 1 C with an extremely low capacity decay rate (∼0.018% per cycle). And the Li|LCO full cell with the ultrahigh loading cathode (∼25 mg cm-2) and ultrathin Li foil (∼40 μm) also reveals a prolonged cycling performance under the low negative-to-positive capacity ratio of 2.2. Furthermore, the Li|LCO pouch cell with a commercial cathode and ultrathin Li foil still manifests excellent cycling performance even under the harsh conditions of limited Li metal and lean electrolyte. This work provides a cost-effective and scalable strategy toward high performance practical Li metal batteries.

Ultralong hydroxyapatite nanowires-based flow-through reactor with high loading of silver nanoparticles for fast continuous catalytic reduction of organic dyes and disinfection of wastewater

The noble metal nanoparticles (NPs) immobilized flow-through reactors have attracted significant attention for the continuous and efficient purification of wastewater contaminated with organic dyes and microorganisms without the need of subsequent recycling processes. However, achieving both high loading of noble metal NPs and high permeation flux concurrently has been a challenge for most reported flow-through reactors. In this study, inspired by the mussel bio-adhesion strategy, we have employed the tannic acid coating method and successfully synthesized Ag NPs-loaded ultralong hydroxyapatite (HAP) nanowires that exhibited an ultra-high loading amount (21.8 wt%). These nanowires were utilized as building blocks alongside chitosan (CS) to fabricate robust and highly porous flow-through reactors (Ag@HAP/CS) for continuous catalytic reduction of organic dyes and water disinfection. The Ag@HAP/CS reactor demonstrates excellent catalytic reduction efficiency (99.3 %) towards MEB at a high flux (2000 L m−2 h−1) with an extremely low concentration of NaBH4 (MEB:NaBH4 = 1:1). This result is attributed to the high loading of Ag NPs, great structural stability in flowing water, and sufficient length along the flowing direction. The reactor also shows remarkable recyclability through water flushing. Ag@HAP/CS exhibits remarkable water disinfection performance against Escherichia coli and diverse bacteria in natural river water, achieving nearly 100 % disinfecting efficiency. This study provides new insights into the strategy of using nanomaterials as intermediate carriers of noble metal nanoparticles to fabricate 3D flow-through reactors, which enable fast and continuous purification of wastewater with ultra-high catalytic efficiency and antimicrobial performance.

Interfacial engineered, hierarchically porous, and underwater superelastic nanofibrous aerogels with rime-mimetic structure for superior micropollutant extraction

Developing nanofibrous aerogels with high surface area, nanoscale porosity, and robust underwater stability has been considered as one of the most promising strategies for designing the next-generation of high-efficiency extraction media, yet still facing great challenges. Herein, we report a size rearrangement of porous organic polymers (POPs) into superelastic rime-mimetic structured aerogels based on bacterial cellulose nanofibers (BCNs)-assisted interfacial engineering strategy. This strategy facilitates micro-interlocking between POP and BCN, significantly enhancing the attaching strength of POP particles at the POP/BCN interface. Thus, the optimized aerogels (PNAs) exhibit excellent underwater elasticity and compression fatigue resistance (∼0% plastic deformation after 500 compression cycles), as well as high BET surface area (305.44 m2/g) and hierarchical porosity (containing micro/meso/macropores), mainly due to the ultrahigh loading of POP particles (83.33 wt%). Given the possession of the abovementioned features and the careful selection of elution solvents guided by Hansen solubility parameter theory, PNAs exhibit a superior micropollutant adsorption capability (∼250 mg/g) and elution efficiency (concentrate sample volume by 50 times). The successful preparation of such material could inspire the development of next-generation hierarchically porous nanofibrous aerogel-based extraction media for water treatment.

3D-Printed river-type thick carbon electrodes for docking possible practical application-level capacitive deionization

The low carbon mass loading along with serious imbalance between the carbon mass loading and the electrode performance greatly hinders practical applications of capacitive deionization (CDI). Traditional thick bulk-type (BT) carbon electrodes often suffer from extremely limited active sites, thereby being vital to explore a basic strategy to unlock the performance. Herein, 3D-printed thick carbon electrodes were utilized for CDI desalination for the first time. The experimental outcomes revealed that BT electrodes existed a serious salt adsorption capacity (SAC) drop under variable mass loading of 3–30 mg/cm2. In contrary, 3D-printed river-type (RT) electrodes acquired a superior SAC of 10.67 mg/g and achieved 54.1 % SAC rise compared with that of BT electrodes (500 mg/L; 1.0 V; 30 mg/cm2). Meanwhile, RT electrodes took only 12 min to reach the equilibrium SAC of BT electrodes, being 44 min faster. Further, RT electrodes with diverse mass loading of 30–45 mg/cm2 were investigated, and it still kept 7.13 mg/g SAC under ultrahigh mass loading of 45 mg/cm2. This strategy has been successfully extended and carbons with proper micro-meso pore distribution, high specific capacitances and low resistance may be a better selection. Besides, the impact of electrode channel structure on the desalting performance was investigated, and the influence mechanism was revealed via COMSOL simulation. Overall, this work demonstrates the splendid feasibility of utilizing 3D-printed thick carbon electrodes for possible practical application-level CDI desalination.

Chemical reactions of Ni/Al multilayers upon ultrahigh compressive load at ambient temperature

Energetic multilayers are peculiarized by their self-propagation reactions when giving them a thermal pulse. This work reports the chemical reactions of Ni/Al energetic multilayers can be triggered upon ultrahigh compressive load (stress >1 GPa) at ambient temperature, which is realized by micro-compressions of Ni/Al micropillars with equal molar ratio. Detailed microscopic characterizations evidence monolayer reactions of Ni20Al30 and Ni110Al140 (NixAly: x and y are average thickness of individual layers in nanometer) are triggered, forming a stoichiometric NiAl phase after micropillar compression. The as-observed reactions must be triggered by ultrahigh compressive loads, which aid for nucleation of NiAl grains at atomic intermixing zones of Ni-Al interfaces. Once occurrence, the grain growth is self-sustained by the released heat during NiAl formation. The grain textures depend strongly on the deformation extent. The self-sustained process is terminated until the whole micropillar is reacted. Analogous chemical reactions are not observed in the thickest Ni450Al620 micropillar where atomic intermixing is absent. The comparison highlights the critical role of ultrahigh compressive load to trigger monolayer reactions of Ni/Al multilayers, and could forward the advance of Ni/Al energetic multilayers for diffusion welding purpose.

Carrier-Free Nanovaccine: An Innovative Strategy for Ultrahigh Melanoma Neoantigen Loading.

In personalized cancer immunotherapy, developing an effective neoantigen nanovaccine with high immunogenicity is a significant challenge. Traditional nanovaccine delivery systems often require nanocarriers, which can hinder the delivery of the neoantigen and cause significant toxicity. In this study, we present an innovative strategy of carrier-free nanovaccine achieved through direct self-assembly of 2'-fluorinated CpG (2'F-CpG) with melanoma neoantigen peptide (Obsl1). Molecular dynamics simulations demonstrated that the introduction of a fluorine atom into CpG increases the noncovalent interaction between 2'F-CpG and Obsl1, which enhanced the loading of Obsl1 on 2'F-CpG, resulting in the spontaneous formation of a hybrid 2'F-CpG/Obsl1 nanovaccine. This nanovaccine without extra nanocarriers showed ultrahigh Obsl1 loading up to 83.19 wt %, increasing the neoantigen peptide uptake by antigen-presenting cells (APCs). In C57BL/6 mice models, we demonstrated the long-term preventive and therapeutic effects of the prepared 2'F-CpG/Obsl1 nanovaccine against B16F10 melanoma. Immunocellular analysis revealed that the nanovaccine activated innate and adaptive immune responses to cancer cells. Hence, this study established a simple, safe, and effective preparation strategy for a carrier-free neoantigen nanovaccine, which could be adapted for the future design of personalized cancer vaccines in clinical settings.

Solvent electrospinning amorphous solid dispersions with high itraconazole, celecoxib, mebendazole and fenofibrate drug loading and release potential

In this work, the feasibility of ultra-high drug loaded amorphous solid dispersions (ASDs) for the poorly soluble itraconazole, mebendazole and celecoxib via solvent electrospinning in combination with poly(2-ethyl-2-oxazoline) and fenofibrate in combination with polyvinylpyrrolidone is demonstrated. By lowering the polymer concentration in the electrospinning solution below its individual spinnable limit, ASDs with a drug content of up to 80 wt% are obtained. This is attributed to drug-polymer interactions not being limited by default to hydrogen bonds, as also Van der Waals interactions can result in high drug loadings. The theoretically predicted miscibility by the Flory-Huggins theory is corroborated by the experimental findings based on (modulated) differential scanning calorimetry and x-ray diffraction. Globally, the maximally obtained amorphous drug loadings are higher compared to the loadings found in literature. Additionally, non-sink dissolution tests demonstrate an increase in solubility of up to 50 times compared to their crystalline counterparts. Moreover, due to the lack of precipitation biocompatible PEtOx succeeds in stabilizing the dissolved drug and inhibiting its instant precipitation. The current work thus demonstrates the broader applicability of the electrospinning technique for the production of physically stable ASDs with ultra-high drug loadings, a result which has been validated for several Biopharmaceutics Classification System class II drugs.

Electrochemically Finely Regulated NiCo‐LDH/NiCoOOH Nanostructured Films for Supercapacitors with Record High Mass Loading, Areal Capacity, and Energy Density

AbstractThe design of supercapacitor materials with both high mass loading and high areal capacity is a major strategy to overcome relatively low energy density of supercapacitors. Herein, NiCo‐layered double hydroxide (NiCo‐LDH)/NiCoOOH composite films with both ultrahigh mass loading and high areal capacity are prepared by a two‐step cyclic voltammetry method. The films consist of NiCo‐LDH/NiCoOOH microspheres assembled with ultrafine nanosheets with highly ordered pore distribution from macropores to micropores and abundant defect active sites, which are conducive to the transport of electrolyte ions, increasing the reaction kinetics, and greatly improving the utilization of active material. The optimal film with hierarchical microstructure featuring an ultrahigh mass loading of 80 mg cm−2 not only exhibits a state‐of‐the‐art high areal capacity of 14.7 mAh cm−2, but also shows a record‐high energy density of 10.7 mWh cm−2 , as well as presents remarkable mechanical stabilityand superior capacity retention of 99% after 20000 galvanostatic charge‐discharge cycles. Moreover, by combining the experimental analysis and theoretical calculations, the mechanism of preferential conversion of the NiCo‐LDH in the subtle defect region to NiCoOOH by electrochemistry and the synergistic effect in electrochemical energy storage of the NiCo‐LDH and NiCoOOH phases is proposed.

Nonviral In Vivo Delivery of CRISPR-Cas9 Using Protein-Agnostic, High-Loading Porous Silicon and Polymer Nanoparticles.

The complexity of CRISPR machinery is a challenge to its application for nonviral in vivo therapeutic gene editing. Here, we demonstrate that proteins, regardless of size or charge, efficiently load into porous silicon nanoparticles (PSiNPs). Optimizing the loading strategy yields formulations that are ultrahigh loading─>40% cargo by volume─and highly active. Further tuning of a polymeric coating on the loaded PSiNPs yields nanocomposites that achieve colloidal stability under cryopreservation, endosome escape, and gene editing efficiencies twice that of the commercial standard Lipofectamine CRISPRMAX. In a mouse model of arthritis, PSiNPs edit cells in both the cartilage and synovium of knee joints, and achieve 60% reduction in expression of the therapeutically relevant MMP13 gene. Administered intramuscularly, they are active over a broad dose range, with the highest tested dose yielding nearly 100% muscle fiber editing at the injection site. The nanocomposite PSiNPs are also amenable to systemic delivery. Administered intravenously in a model that mimics muscular dystrophy, they edit sites of inflamed muscle. Collectively, the results demonstrate that the PSiNP nanocomposites are a versatile system that can achieve high loading of diverse cargoes and can be applied for gene editing in both local and systemic delivery applications.

Toward soft, stretchable and resilient high filled composite gels for potential application as thermal interface materials

Due to the different coefficients of thermal expansion between the heat generation and heat dissipation units, the applications of soft high filled composite gels as thermal interface materials require both high stretchability and excellent resilience. However, high stretchable composite gels reported far usually contain sacrificial species to dissipate energy, thus compromising their resilience. Herein, a soft (0.13 MPa), stretchable (172%), and resilient (>70%) composite gel with ultrahigh filler loading (90 wt%) is developed. The stretchability and resilience are realized by lengthening free polymer strands to form appropriate entanglements, in which the loose entanglements transfer the applied force into a large area and the stiff crosslinks prevent the entanglements from disentangling. In additional, the reversible elasticity of the filler network also dictates the resilience, so delaying its deconstruction allows for excellent resilience. The ultrahigh filler loading also endows the composite gel with high thermal conductivity (4.04 W·m−1·k−1), and the potential of the as-prepared composite gel for a TIM is discovered.

Tight Binding and Dual Encapsulation Enabled Stable Thick Silicon/Carbon Anode with Ultrahigh Volumetric Capacity for Lithium Storage.

Silicon (Si) is regarded as one of the most promising anode materials for high-performance lithium-ion batteries (LIBs). However, how to mitigate its poor intrinsic conductivity and the lithiation/delithiation-induced large volume change and thus structural degradation of Si electrodes without compromising their energy density is critical for the practical application of Si in LIBs. Herein, an integration strategy is proposed for preparing a compact micron-sized Si@G/CNF@NC composite with a tight binding and dual-encapsulated architecture that can endow it with superior electrical conductivity and deformation resistance, contributing to excellent cycling stability and good rate performance in thick electrode. At an ultrahigh mass loading of 10.8mg cm-2 , the Si@G/CNF@NC electrode also presents a large initial areal capacity of 16.7mA h cm-2 (volumetric capacity of 2197.7mA h cm-3 ). When paired with LiNi0.95 Co0.02 Mn0.03 O2 , the pouch-type full battery displays a highly competitive gravimetric (volumetric) energy density of ≈459.1Wh kg-1 (≈1235.4Wh L-1 ).

H-bond-type thermo-responsive schizophrenic copolymers: The phase transition correlation with their parent polymers and the improved protein co-assembly ability

Schizophrenic copolymers are one type of the popular smart polymers that show invertible colloidal structures in response to temperature stimulus. However, the lack of principles to predict the phase transition temperature of a schizophrenic copolymer from its corresponding parent thermo-responsive polymers limits their development. Additionally, studies on their applications remain scarce. Herein, a series of schizophrenic copolymers were synthesized by polymerization of a RAFT-made polymer precursor poly(acrylamide-co-N-acryloxysuccinimide-co-acrylic acid) (P(AAm-co-NAS-co-AAc)) with the mixture of N-isopropylmethacrylamide (NIPAm) and acrylamide (AAm) in varying molar ratios. In aqueous solution, the block P(AAm-co-NAS-co-AAc) and the block poly(NIPAm-co-AAm) exhibited upper and lower critical solution temperature (UCST and LCST) behavior, respectively. The schizophrenic copolymers featured either UCST-LCST, LCST-UCST, or only LCST thermo-responsive transition. A preliminary correlation of phase transition between the schizophrenic copolymers and their parent polymers was summarized. Furthermore, the co-assembly of the schizophrenic copolymers and proteins were conducted and the kinetics of protein loading and protein activity were investigated, which showed that the schizophrenic copolymers were efficient platforms for protein co-assembly with ultra-high protein loading while preserving the protein bioactivities. Additionally, all the materials were non-toxic towards NIH 3T3 and MCF-7 cells. This work offers the prospects of the schizophrenic polymers in soft colloidal and assembly systems, particularly in guiding the design of new materials and their use in biomedical applications.

High-loading of organosilane-grafted carbon dots in high-performance luminescent solar concentrators with ultrahigh transparency

Carbon dots (CDs) generally suffer from aggregation-induced fluorescence quenching effect in solid-state, which significantly limits their application in photoelectric devices. Due to this effect, it is a great challenge to achieve high-transparency and high-performance luminescent solar concentrators (LSCs) based on CDs. Here, the synthesis of organosilane-grafted carbon dots (Si-CDs) is rationally designed by hydrothermal method using anhydrous citric acid, ethanolamine and KH-792 as the reaction precursors. The obtained Si-CDs can be uniformly dispersed in the polyvinyl alcohol (PVA) matrix through the dehydration condensation reaction and hydrogen bonding between the silicon hydroxyl group of Si-CDs and the hydroxyl group of PVA. Based on this property, Si-CDs/PVA thin-film LSCs (5 ×5 ×0.2 cm3) with ultrahigh CD loading (25 wt%) and high transparency can be fabricated, exhibiting excellent absorption in the UV spectral region and about 90 % transmission in the visible range. Furthermore, the power conversion efficiency (PCE) of the LSCs can reach 2.09 % under a standard solar light and shows excellent stability even over 12 weeks. This synthetic design is expected to be beneficial for future development of CD synthesis and paves the way for the development of CDs-based photoelectric devices.

Ultrahigh-Loading Manganese-Based Electrodes for Aqueous Batteries via Polymorph Tuning.

Manganese-based aqueous batteries utilizing Mn2+ /MnO2 redox reactions are promising choices for grid-scale energy storage due to their high theoretical specific capacity, high power capability, low-cost, and intrinsic safety with water-based electrolytes. However, the application of such systems is hindered by the insulating nature of deposited MnO2 , resulting in low normalized areal loading (0.005-0.05mAhcm-2 ) during the charge/discharge cycle. In this work, the electrochemical performance of various MnO2 polymorphs in Mn2+ /MnO2 redox reactions is investigated, and ɛ-MnO2 with low conductivity is determined to be the primary electrochemically deposited phase in normal acidic aqueous electrolyte. It is found that increasing the temperature can change the deposited phase from ɛ-MnO2 with low conductivity to γ-MnO2 with two order of magnitude increase in conductivity. It is demonstrated that the highly conductive γ-MnO2 can be effectively exploited for ultrahigh areal loading electrode, and a normalized areal loading of 33mAhcm-2 is achieved. At a mild temperature of 50°C, cells are cycled with an ultrahigh areal loading of 20mAhcm-2 (1-2 orders of magnitude higher than previous studies) for over 200 cycles with only 13% capacity loss.

Design and construction of low resistance copper doped polyaniline electrode with ultrahigh loading density for high performance supercapacitor applications

Polyaniline is a promising material for the development of high performance flexible supercapacitor devices. However, the loose structure of polyaniline materials and the high intermolecular transport impedance between molecular chains remain significant technical barriers, particularly at high loading density. In this study, we developed a copper ion doped polyaniline electrode (Cu-PANI@CC) on carbon cloth using a simple one-step in-situ electrochemical deposition method. The structure and electrochemical properties of this electrode were investigated via different testing techniques. Benefiting from the catalysis and regulation of copper ions between PANI molecular chains, the electrode demonstrated a relatively low internal resistance at high loading densities (> 10 mg cm−2). Moreover, this electrode exhibited specific capacitance of 3.49 F cm−2 at 5 mA cm−2 and capacitance retention of 83.31% at 50 mA cm−2. Two Cu-PANI@CC electrodes were used to fabricate a symmetrical capacitor, which exhibited remarkable cycling stability and wide operating temperature range. The excellent electrochemical performance of the Cu-PANI@CC electrode highlights the potential for use in high-performance supercapacitor devices.

One-Step Synthesis of Structurally Stable CO2-Philic Membranes with Ultra-High PEO Loading for Enhanced Carbon Capture

Membrane technology has been considered a promising strategy for carbon capture to mitigate the effects of increasing atmospheric CO 2 levels because CO 2 -philic membranes have demonstrated significant application potential, especially, for CO 2 /light gas separation. In this regard, poly(ethylene oxide) (PEO), which is a representative CO 2 -philic material, has attracted extensive research attention owing to its specific dipole–quadrupole interaction with CO 2 . Herein, we report a facile one-step synthesis protocol via the in situ polymerization of highly flexible polyethylene glycol to overcome the limitations of PEO, including high crystallinity and poor mechanical strength. The robust structure derived from intricate entanglements between short PEO chains and the polymer matrix enables an extremely high loading of linear polyethylene glycol (up to 90 wt%). Consequently, the separation performance easily surpasses the upper-bound limit. Moreover, the high structural stability allows for the concurrent increase of CO 2 permeability and CO 2 /light gas selectivity at high feed pressure (up to 20 bar). This study provides a promising strategy to simultaneously improve the toughness and gas separation properties of all-polymeric membranes, demonstrating significant potential for industrial carbon capture and gas purification.

Membrane adsorbers with ultrahigh metal–organic framework loading for high flux selective separations to isomer

Membrane-based separation processes have received significant attention as promising schemes realizing energy-efficiency micro-molecule separation. However, traditional Mixed Matrix Membranes (MMMs) inevitably faced the restriction that of low-level substrate-polymer interfacial consistency, functional loaders agglomeration, instability under long-term reaction and so on, causing it extremely challengeable to construct high-performance membrane-based separation system. Here, incorporating ideas of mussel biomimetic chemistry, a 3D nano-hybrid seeding strategy was designed for in situ assembling nanosized zeolitic imidazolate frameworks (ZIFs) to polydopamine-adhesive nanofibers, followed by the construction of specific imprinting sites within nanofiber membranes driven by boron-affinity sol–gel strategy, which achieved high-efficiency selective separation to shikimic acid (SA) with great medicinal value. This strategy simultaneously improved permeability and selectivity of separation membrane to nanoscale molecules. And superior SA affinity stability was maintained with the ultrahigh ZIF-8 loadings (73 %) even during long-term cyclic tests, where only less than 10.09 % of rebinding selective capacity loss and 6.50% of perm-selectivity damage existed. In addition, the antifouling durability as well as antibacterial persistence were obtained due to ZIF-8-functionalized polydopamine (PDA)-connected nanofibers construction. This symbiosis-inspired de novo strategy could promisingly draw bright blueprint for burgeoning MMMs to realize specifical separation of molecules with medical value against isomer mixture.

DNA-Guided Li2S Nanostructure Deposition for High-Sulfur-Loaded Li–S Batteries

The low areal capacity caused by low sulfur loading (<2.0 mg cm–2) and the poor sulfur utilization due to the insulating Li2S layer covering the cathode always limit the practical applications of lithium–sulfur batteries (Li–S batteries). Deoxyribonucleic acid (DNA)-controlled nucleation and growth of Li2S in the Li–S system were first studied in this work. The negatively charged sugar-phosphate backbone of DNA could attract Li+ ions and allow crystalline Li2S to grow along the DNA chains. The electrodeposition of Li2S with a unique three-dimensional nanostructure during the polysulfide conversion and deposition process was realized, which can not only boost electron and ion transport but also expose and retain more active sites in the cathode. A Li–S battery with ultrahigh sulfur loading of 10 mg cm–2 and a low electrolyte/sulfur ratio of 6.08 delivered a high areal capacity of 8.1 mA h cm–2, which is more than 2 times that of commercial Li-ion batteries, demonstrating a great enhancement of the Li–S battery compared to other studies. Therefore, this study provides an effective strategy of DNA-guided 3D Li2S deposition for achieving high-sulfur-loading Li–S batteries.

Embedding of metal components into the structure of titanium carbonitride under ultrahigh loads of plasma-spark and explosive sintering

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Mechanical response of HTPB propellant grain under ultra-high overload

In this study, the mechanical response of HTPB propellant grain under ultra-high loads is investigated. The low, intermediate and high strain rate of uniaxial compression tastings (1.7×10−4~3×103s−1) of the hydroxyl terminated polybutadiene (HTPB) propellant at room temperature were carried out by using the universal testing machine and the split Hopkinson pressure bar (SHPB) system, respectively. The uniaxial compression tests of the cellular rubber, the EPDM rubber and felted wool were carried out. A linear viscoelastic constitutive model of the HTPB propellant was developed by using the test data. The mechanical property of the cellular rubber, the EPDM rubber and the felted wool were studied by the test data. The dynamic mechanical response of the propellant grain under high overloads was simulated with the developed constitutive model by using the finite element method. The deformation of the grain under high overload was studied. The result shows when the overload value is maximum, the stress value of the grain is maximum. The location where the stress value of the grain is maximum is the center of the inner hole of the cushion. The maximum stress value is 20.17MPa.