Mechanical strength

机械强度
  • 文章类型: Journal Article
    在这项工作中,合成了一种基于聚氧钒酸(NH4)7[MnV13O38](AMV)和1-乙基-3-甲基咪唑鎓双(三氟甲基磺酰基)酰亚胺(EMIMTFSI)的质子导电无机填料,用于与磺化聚(芳基醚酮砜)(SPEKS)杂化,以解决高质子电导率和机械强度之间的“权衡”。由于增强的离子相互作用,新型无机填料AMV-EMIMTFSI(AI)在聚合物基质中均匀分散且稳定。AI提供了额外的质子传输位点,导致提高离子交换容量(IEC)和改善质子电导率,即使在低溶胀率。优化的SPAEKS-50/AI-5(对于SPAEKS的磺化程度为50,对于AI填料的重量百分比为5)膜在80°C时表现出最高的质子电导率为0.188S·cm-1,IEC为2.38mmol·g-1。分子间力的增强使机械强度从35提高到55MPa,断裂伸长率从17提高到45%,表明优异的机械性能。由于氢键网络和阻塞效应,杂化膜还表现出增强的耐甲醇性,使其适用于直接甲醇燃料电池(DMFC)应用,在80°C时表现出15.1mW·cm-2的功率密度。进一步功能化这些杂化膜以针对特定应用定制其性能的可能性为研究和开发提供了令人兴奋的新途径。通过改变填料的类型和分布或加入额外的官能团,可以定制膜以满足各种能量存储和转换系统的独特需求,提高其性能,拓宽其应用范围。这项工作为通过无机填料杂化设计聚合物电解质膜提供了新的见解。
    In this work, a proton-conductive inorganic filler based on polyoxovanadate (NH4)7[MnV13O38] (AMV) and 1-ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl) imide (EMIM TFSI) was synthesized for hybridization with sulfonated poly(aryl ether ketone sulfone) (SPAEKS) to address the \"trade-off\" between high proton conductivity and mechanical strength. The novel inorganic filler AMV-EMIM TFSI (AI) was uniformly dispersed and stable within the polymer matrix due to the enhanced ionic interaction. AI provided additional proton transport sites, leading to an elevated ion exchange capacity (IEC) and improved proton conductivity, even at low swelling ratios. The optimized SPAEKS-50/AI-5 (50 for degree of sulfonation of SPAEKS and 5 for weight percentage of AI filler) membrane exhibited the highest proton conductivity of 0.188 S·cm-1 at 80 °C with an IEC of 2.38 mmol·g-1. The enhancement of intermolecular forces improved the mechanical strength from 35 to 55 MPa and improved the elongation at break from 17 to 45%, indicating excellent mechanical properties. The hybrid membrane also demonstrated reinforced methanol resistance due to the hydrogen bonding network and blocking effect, making it suitable for direct methanol fuel cell (DMFC) applications, which exhibited a power density of 15.1 mW·cm-2 at 80 °C. The possibility of further functionalizing these hybrid membranes to tailor their properties for specific applications presents exciting new avenues for research and development. By modification of the type and distribution of fillers or incorporation of additional functional groups, the membranes could be customized to meet the unique demands of various energy storage and conversion systems, enhancing their performance and broadening their application scope. This work provides new insights into the design of polymer electrolyte membranes through inorganic filler hybridization.
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  • 文章类型: Journal Article
    基于水凝胶的储库通常倾向于在注射的地方保留并且具有优异的生物相容性,但在控制药物释放方面相对较差。纳米颗粒(NP)通常具有相反的性质。NP越小,他们离开注射部位的可能性就越大。它们的生物相容性根据材料而变化,但可能较差。然而,NPs可以很好地控制药物释放。在这些和其他属性中,结合NP和水凝胶可以利用它们的优点并消除它们的缺点。这篇综述强调了混合NP-水凝胶系统在药物递送中的基本原理,生产它们的基本方法,以及将两个系统结合起来解决特定问题的示例。
    Hydrogel-based depots typically tend to remain where injected and have excellent biocompatibility but are relatively poor at controlling drug release. Nanoparticles (NPs) typically have the opposite properties. The smaller the NPs are, the more likely they are to leave the site of injection. Their biocompatibility is variable depending on the material but can be poor. However, NPs can be good at controlling drug release. In these and other properties, combining NPs and hydrogels can leverage their advantages and negate their disadvantages. This review highlights the rationale for hybrid NP-hydrogel systems in drug delivery, the basic methods of producing them, and examples where combining the two systems addressed specific problems.
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  • 文章类型: Journal Article
    在本文中,提出了一种涉及耐磨和可重复使用的模板的新方法,用于基于电火花线切割加工(WEDM)制备高机械强度的超疏水聚合物膜。建立了固液接触角模拟模型,以获得可以实现超疏水性的表面纹理类型和尺寸。模板制备的实验结果表明,接触角的模拟结果与实验结果具有良好的一致性。在适当的三角形表面纹理和电火花线切割粗加工的情况下,模板上的最大接触角可以达到155.3°。此外,制备的超疏水模板具有良好的耐磨性和可重复使用性。采用模板法制备了PDMS超疏水聚合物薄膜,并对其性能进行了测试。制备超疏水聚合物薄膜的实验结果表明,聚合物薄膜的最大接触角可达154.8°,并且这些薄膜具有良好的自清洁和防冰性能,耐磨性,耐弯曲性,和延展性。
    In this paper, a new method involving a wear-resistant and reusable template is proposed for the preparation of high-mechanical-strength superhydrophobic polymer film based on wire electrical discharge machining (WEDM). A solid-liquid-contact-angle simulation model was established to obtain surface-texture types and sizes that may achieve superhydrophobicity. The experimental results from template preparation show that there is good agreement between the simulation and experimental results for the contact angle. The maximum contact angle on the template can reach 155.3° given the appropriate triangular surface texture and WEDM rough machining. Besides, the prepared superhydrophobic template exhibits good wear resistance and reusability. PDMS superhydrophobic polymer films were prepared by the template method, and their properties were tested. The experimental results from the preparation of superhydrophobic polymer films show that the maximum contact angle of the polymer films can be up to 154.8° and that these films have good self-cleaning and anti-icing properties, wear resistance, bending resistance, and ductility.
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  • 文章类型: Journal Article
    废水的复杂组成阻碍了农业和工业废水的回收利用。本研究旨在探讨剑麻叶废水(SLW)的潜力,水处理(WTSLW)和碱处理(ATSLW),在生产矿渣-粉末-和粉煤灰基复合材料中作为碱活化剂(NaOH溶液)的替代品,重点研究了WTSLW替代率和剑麻叶浸泡时间的影响。最初,评估新鲜特性,包括电导率和流动性。对WTSLW和ATSLW对干燥收缩的影响进行了进一步分析,密度,和机械强度,包括弯曲和压缩措施。使用SEM和CT成像表征微观结构特征,同时采用XRD图谱和FTIR光谱来剖析WTSLW替代对复合材料产品的影响。结果表明,在复合材料中加入14wt%的WTSLW可将90天的抗弯和抗压强度提高34.8%和13.2%,分别,而WTSLW减少干燥收缩。相反,ATSLW增加孔隙率并降低密度。封装在碱性基质中的WTSLW和ATSLW中的有机成分均无法改变复合材料的化学组成。这些结果强调了通过综合回收工厂废水和固体副产品实现可持续建筑材料的潜力。
    The intricate composition of wastewater impedes the recycling of agricultural and industrial effluents. This study aims to investigate the potential of sisal leaf wastewater (SLW), both water-treated (WTSLW) and alkali-treated (ATSLW), as a substitute for the alkali activator (NaOH solution) in the production of slag-powder- and fly-ash-based composites, with a focus on the effects of WTSLW substitution ratios and sisal leaf soaking durations. Initially, the fresh properties were assessed including electrical conductivity and fluidity. A further analysis was conducted on the influence of both WTSLW and ATSLW on drying shrinkage, density, and mechanical strength, including flexural and compressive measures. Microstructural features were characterized using SEM and CT imaging, while XRD patterns and FTIR spectra were employed to dissect the influence of WTSLW substitution on the composite\'s products. The results show that incorporating 14 wt% WTSLW into the composite enhances 90-day flexural and compressive strengths by 34.8% and 13.2%, respectively, while WTSLW curtails drying shrinkage. Conversely, ATSLW increases porosity and decreases density. Organic constituents in both WTSLW and ATSLW encapsulated in the alkaline matrix fail to modify the composites\' chemical composition. These outcomes underscore the potential for sustainable construction materials through the integrated recycling of plant wastewater and solid by-products.
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  • 文章类型: Journal Article
    作为碱式硫酸镁水泥(BMSC)的原料之一,光烧氧化镁(MgO)的活性对水化速率有重要影响,水化产物,BMSC的力学性能。为了揭示包装方法的影响,存储环境,和储存时间对MgO活性和BMSC力学性能的影响,使用普通编织袋进行了一项实验,腹膜编织袋,和塑料和纸复合袋,以存储成品BMSC和原材料(轻烧MgO,MgSO4·7H2O,粉煤灰,和化学添加剂)在自然环境条件下,密封环境,潮湿的环境,分别。包装方法效果的对比分析,储存条件,通过砂浆试件的力学强度测试,研究了储存时间对MgO活性和BMSC力学性能的影响。结果表明,在密封的环境中,将轻烧MgO中a-MgO含量的损失降至最低,更有利于保持BMSC的力学性能稳定。在潮湿的环境中,BMSC的机械强度在早期(1天)显着降低,由于MgO的活性显着降低,并且成品BMSC和制备的BMSC在储存120天后的机械强度仍然丧失,无论包装方法如何。然而,储存环境和包装方式对BMSC的后期机械强度(28天)影响相对较小。建议在自然和密封环境中使用普通编织袋进行包装,因为这对于工程应用更经济。塑料和纸复合袋在潮湿环境中优于普通编织袋和腹膜编织袋。
    As one of the raw materials of basic magnesium sulfate cement (BMSC), the activity of light-burned magnesium oxide (MgO) has an important effect on the hydration rate, hydration products, and mechanical properties of BMSC. To reveal the influence of packaging method, storage environment, and storage time on the activity of MgO and the mechanical properties of BMSC, an experiment was conducted by using ordinary woven bags, peritoneal woven bags, and plastic and paper compound bags to store the finished BMSC and the raw materials (light-burned MgO, MgSO4·7H2O, fly ash, and a chemical additive) under the conditions of natural environment, sealed environment, and wet environment, respectively. Comparative analysis of the effects of packaging method, storage conditions, and storage time on the activity of MgO and the mechanical properties of BMSC was performed through the mechanical strength test of mortar specimens. The results showed that in a sealed environment, the loss of a-MgO content in light-burned MgO was minimized, which was more conducive to keeping the mechanical properties of BMSC stable. In the wet environment, the mechanical strength of BMSC was significantly reduced in the early stage (1 day) due to the significant reduction in the activity of MgO, and the mechanical strength of the finished BMSC and prepared BMSC after 120 days of storage was still lost, regardless of the packaging method. However, the storage environment and packaging method had relatively little effect on the late mechanical strength (28 days) of BMSC. It is advisable to use ordinary woven bags for packaging in natural and sealed environments as this is more economical for engineering applications. Plastic and paper compound bags are superior to ordinary woven bags and peritoneal woven bags in wet environments.
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  • 文章类型: Journal Article
    胞外聚合物(EPS)被认为在形成颗粒的物理性质中起关键作用。在这一贡献中,我们从9个全规模工业厌氧反应器的颗粒中表征了EPS的粘弹性特性;并定量研究了这些特性是否与颗粒的抗压缩性(Ecandile)和剪切强度(Scandile)相关。大多数颗粒具有较高的剪切强度,还表现出较强的抗压缩性(r=0.96,p=0.002),除了那些在EPS中含有相对更多蛋白质的颗粒。有趣的是,这些颗粒对剪切应力的抵抗力也最强(颗粒≥110±40h)。此外,这些颗粒的EPS水凝胶的软化速率(κ<0.9)比其他的(κ范围在0.95和1.20之间)更慢,表明形成了更强的凝胶。这些发现表明,EPS水凝胶软化速率可能是解释颗粒剪切强度的关键参数。
    Extracellular polymeric substances (EPS) are considered to play a pivotal role in shaping granules\' physical properties. In this contribution, we characterized the viscoelastic properties of EPS from granules of 9 full-scale industrial anaerobic reactors; and quantitatively investigate whether these properties correlate with granules\' resistance to compression (Egranule) and shear strength (Sgranule). Most granules with a higher shear strength, also exhibited a stronger resistance to compression (r = 0.96, p = 0.002), except those granules that contained relatively more proteins in their EPS. Interestingly, these granules were also the most resistant to shear stress (Sgranule ≥ 110 ± 40 h). Furthermore, the EPS hydrogels of these granules had slower softening rates (κ < 0.9) compared to the others (κ ranged between 0.95 and 1.20), indicating stronger gels were formed. These findings suggest that the EPS hydrogel softening rate could be a key parameter to explain granule\'s shear strength.
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  • 文章类型: Journal Article
    聚(甲基丙烯酸甲酯)(PMMA)骨水泥已广泛应用于骨科;由于其优异的机械性能,生物相容性,和化学稳定性。硫酸钡和氧化锆通常被添加到PMMA骨水泥中,以增强X射线射线不透性,而机械强度,射线不透性,和生物相容性没有得到很好的改善。在这项研究中,不溶性和耐腐蚀的陶瓷,碳化钽(TaC),作为不透射线剂添加到PMMA骨水泥中,显著提高了机械,不透射线,生物相容性,骨水泥的成骨性能。具有不同TaC含量的TaC-PMMA骨水泥表现出超过100MPa的抗压强度,高于商业的30%BaSO4-PMMA骨水泥。有趣的是,当TaC含量达到20%时,射线不透性相当于在PMMA中含有30%BaSO4的商业骨水泥。细胞毒性和成骨性能表明,TaC的掺入不仅增强了PMMA的成骨特性,而且不会降低细胞活力。这项研究表明,TaC可能是PMMA骨水泥的优质多功能放射性安抚奶嘴,为改善骨科应用中的患者预后提供了有希望的途径。
    Poly(methyl methacrylate) (PMMA) bone cements have been widely used in orthopedics; thanks to their excellent mechanical properties, biocompatibility, and chemical stability. Barium sulfate and zirconia are usually added into PMMA bone cement to enhance the X-ray radiopacity, while the mechanical strength, radiopacity, and biocompatibility are not well improved. In this study, an insoluble and corrosion-resistant ceramic, tantalum carbide (TaC), was added into the PMMA bone cement as radiopacifies, significantly improving the mechanical, radiopaque, biocompatibility, and osteogenic performance of bone cement. The TaC-PMMA bone cement with varied TaC contents exhibits compressive strength over 100 MPa, higher than that of the commercial 30% BaSO4-PMMA bone cement. Intriguingly, when the TaC content reaches 20%, the radiopacity is equivalent to the commercial bone cement with 30% of BaSO4 in PMMA. The cytotoxicity and osteogenic performance indicate that the incorporation of TaC not only enhances the osteogenic properties of PMMA but also does not reduce cell viability. This study suggests that TaC could be a superior and multifunctional radio-pacifier for PMMA bone cement, offering a promising avenue for improving patient outcomes in orthopedic applications.
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  • 文章类型: Journal Article
    适应植入材料与脑组织之间的机械强度对于胶质母细胞瘤的术后治疗至关重要。然而,没有相关研究的报道。在这里,我们报告了一种可注射的硫辛酸-铁(LA-Fe)水凝胶(LFH),可以适应各种脑组织的机械强度,包括人类的脑组织,通过将Fe3+配位到LA及其钠盐(LANa)的混合水凝胶中。当LFH,与小鼠脑组织的机械性能(337±8.06Pa)相匹配,被注射到大脑切除腔中,脑组织含水量维持在正常水平(77%)。同样,LFH不诱导神经胶质细胞的活化或肥大,有效预防脑水肿和瘢痕增生。值得注意的是,LFH在间质液中自发降解,将LA和Fe3+释放到肿瘤细胞中。氧化还原对LA/DHLA(二氢硫辛酸,细胞中LA的还原形式)和Fe3/Fe2会彼此再生以连续提供ROS以诱导铁凋亡并激活免疫原性细胞死亡。随着抗PDL1的负载,抗PDL1@LFH进一步增强了肿瘤免疫疗法的功效并促进了肿瘤的铁凋亡。适应组织机械强度的可注射水凝胶为肿瘤术后治疗提供了新的思路。
    Adapting the mechanical strength between the implant materials and the brain tissue is crucial for the postoperative treatment of glioblastoma. However, no related study has been reported. Herein, we report an injectable lipoic acid‑iron (LA-Fe) hydrogel (LFH) that can adapt to the mechanical strength of various brain tissues, including human brain tissue, by coordinating Fe3+ into a hybrid hydrogel of LA and its sodium salt (LANa). When LFH, which matches the mechanical properties of mouse brain tissue (337 ± 8.06 Pa), was injected into the brain resection cavity, the water content of the brain tissue was maintained at a normal level (77%). Similarly, LFH did not induce the activation or hypertrophy of glial astrocytes, effectively preventing brain edema and scar hyperplasia. Notably, LFH spontaneously degrades in the interstitial fluid, releasing LA and Fe3+ into tumor cells. The redox couples LA/DHLA (dihydrolipoic acid, reduction form of LA in cells) and Fe3+/Fe2+ would regenerate each other to continuously provide ROS to induce ferroptosis and activate immunogenic cell death. As loaded the anti-PDL1, anti-PDL1@LFH further enhanced the efficacy of tumor-immunotherapy and promoted tumor ferroptosis. The injectable hydrogel that adapted the mechanical strength of tissues shed a new light for the tumor postoperative treatment.
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  • 文章类型: Journal Article
    下颌骨重建手术对于较大的骨缺损是必要的。尽管临床上已经进行了各种重建方法,下颌骨重建方法既满足足够的强度标准,也满足患者的特定形态。在这项研究中,研究了使用钛合金粉末通过电子束熔化增材制造形成的圆柱晶格结构的材料强度,以进行下颌骨重建。使用有限元软件进行数值材料测试,比较了28个晶格结构的虚拟强度。随后,从初步测试中比较选定结构的材料特性,压缩试验,进行了静态弯曲试验和疲劳试验。结果表明,当比较内应力与变形时,各种结构之间存在相对密度的相关性和显着差异。尽管基于晶格结构特征存在局部应力集中和不均匀应力分布的可能性。这些结果表明,具有节点和细胞大小为3.0mm的身体对角线的晶格结构是下颌骨重建手术中金属人造下颌骨的潜在候选者。
    Mandibular reconstructive surgery is necessary for large bone defects. Although various reconstruction methods have been performed clinically, there is no mandibular reconstruction method that meets both sufficient strength criteria and the patient\'s specific morphology. In this study, the material strength of the cylindrical lattice structures formed by electron-beam melting additive manufacturing using titanium alloy powder was investigated for mandibular reconstruction. The virtual strengths of 28 lattice structures were compared using numerical material tests with finite element method software. Subsequently, to compare the material properties of the selected structures from the preliminary tests, compression test, static bending test and fatigue test were conducted. The results showed that there were correlations with relative density and significant differences among the various structures when comparing internal stress with deformation, although there was a possibility of localized stress concentration and non-uniform stress distribution based on the lattice structure characteristics. These results suggest that the lattice structure of body diagonals with nodes and a cell size of 3.0 mm is a potential candidate for metallic artificial mandibles in mandibular reconstruction surgery.
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  • 文章类型: Journal Article
    具有高机械-电性能的还原氧化石墨烯(rGO)膜的可扩展生产是可穿戴电子设备和能量存储应用的理想候选。去除由组装过程产生的石墨烯膜中的结构不完整性(例如褶皱或空隙)将极大地优化其机械性能。然而,薄膜中密集堆叠的石墨烯片降低了它们的离子动力学,从而限制了它们的发展。这里,水平-纵向结构调节策略被证明可以产生增强的机械,导电和电容石墨烯薄膜。通常,二维(2D)大石墨烯片(LGS)在组装过程中诱导GO的规则堆叠,以减少皱纹,而一维(1D)单壁碳纳米管(SWCNT)与石墨烯片桥接,以加强多向插层并减少GO层的重新堆叠。LGS和SWCNT的同时结合协同地形成精细的微观结构,改善石墨烯片的排列,增加连续导电路径以促进电子传输,并扩大层间间距以促进电解质离子扩散。因此,获得的石墨烯薄膜是平坦的,并表现出显著增强的机械性能,电导率(38727Sm-1),以及比电容(232Fg-1)作为超级电容器电极,而不是原始的rGO薄膜。此外,由于综合性能的改善,由石墨烯膜基电极组装的柔性凝胶超级电容器显示出高能量密度,良好的灵活性和优异的循环稳定性(93.8%的电容保留后10000次循环)。这项工作提供了一种通用策略,可以为柔性和可穿戴电子设备中的储能应用制造坚固的石墨烯结构材料。
    Scalable production of reduced graphene oxide (rGO) films with high mechanical-electrical properties are desirable candidates for wearable electronics devices and energy storage applications. Removing structural incompleteness such as wrinkles or voids in the graphene films generated from the assemble process would greatly optimize their mechanical properties. However, the densely stacked graphene sheets in the films degrades their ionic kinetics and thus limits their development. Here, a horizontal-longitudinal-structure modulating strategy is demonstrated to produce enhanced mechanical, conductive and capacitive graphene films. Typically, two-dimensional (2D) large graphene sheets (LGS) induce regular stacking of GO during assembling process to reduce wrinkles, while one-dimensional (1D) single-walled carbon nanotubes (SWCNT) bridge with graphene sheets to strengthen the multidirectional intercalation and reduce GO layer restacking. The simultaneous incorporation of LGS and SWCNT synergistically makes fine microstructure with improving the alignment of graphene sheets, increasing continuous conductive pathways to facilitate electron transport, and enlarging interlayer spacing to promote the electrolyte ion diffusion. As a result, the obtained graphene films are flat and exhibit signally reinforced mechanical properties, electrical conductivity (38727 S m-1), as well as specific capacitance (232 F g-1) as supercapacitor electrodes than those of original rGO films. Moreover, owing to the comprehensive improved properties, the flexible gel supercapacitor assembled by the graphene film-based electrodes shows high energy density, good flexibility and excellent cycling stability (93.8% capacitance retention after 10000 cycles). This work provides a general strategy to manufacture robust graphene structural materials for energy storage applications in flexible and wearable electronics.
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