surface energy

表面能
  • 文章类型: Journal Article
    膜蒸馏(MD)是传统脱盐系统的有希望的替代方案,特别是对高盐废水的处理。然而,MD的大规模应用受到膜润湿等挑战的阻碍,膜污染,和低渗透通量。在这里,我们提出了一种气/液界面沉积方法来制造Janus膜,称为PVDF-PDA/PEI-Si膜。该膜具有纳米筛分功能,超亲水聚多巴胺/聚乙烯亚胺(PDA/PEI)层装饰有二氧化硅纳米颗粒,再加上微孔,疏水聚偏氟乙烯(PVDF)层。具有高表面能的致密PDA/PEI-Si层的引入显着增强了膜的润湿性和抗污染性,对渗透通量影响较小。当使用含有十二烷基硫酸钠(SDS)和油性污染物的高咸水作为进料时,性能增强尤其明显。使用XDLVO理论和分子动力学模拟计算了膜与污染物之间的相互作用,以阐明增强的抗润湿和防污特性的潜在机制。分别。根据XDLVO理论,必须克服大的能量势垒以使SDS附着到PDA/PEI-Si表面上。同时,分子动力学模拟证实了油性污垢和PVDF-PDA/PEI-Si膜之间的弱相互作用能,由于其高表面能。这项研究为高性能MD膜的制造提供了一种有前途的方法,并为增强的抗润湿和防污性能的机理提供了新的见解。
    Membrane distillation (MD) presents a promising alternative to conventional desalination systems, particularly for the treatment of hypersaline wastewater. However, the large-scale application of MD is hindered by challenges such as membrane wetting, membrane fouling, and low permeate flux. Herein, we proposed an air/liquid interface deposition method to fabricate a Janus membrane, termed the PVDF-PDA/PEI-Si membrane. The membrane featured a nanosieving, superhydrophilic polydopamine/polyethylenimine (PDA/PEI) layer decorated with silica nanoparticles, coupled with a microporous, hydrophobic polyvinylidene fluoride (PVDF) layer. The introduction of a dense PDA/PEI-Si layer featuring high surface energy significantly enhanced the wetting and fouling resistance of the membrane, with a minor effect on the permeate flux. The performance enhancement was particularly evident when hypersaline water containing sodium dodecyl sulfate (SDS) and oily contaminants was used as the feed. The interactions between the membrane and contaminants were calculated using the XDLVO theory and molecular dynamics simulations to elucidate the mechanisms underlying the enhanced anti-wetting and anti-fouling properties, respectively. According to the XDLVO theory, a large energy barrier must be overcome for the SDS to attach onto the PDA/PEI-Si surface. Meanwhile, molecular dynamics simulations confirmed the weak interaction energy between the oily foulants and the PVDF-PDA/PEI-Si membrane due to its high surface energy. This study presents a promising approach for the fabrication of high-performance MD membranes and provides new insights into the mechanisms underlying the enhanced anti-wetting and anti-fouling properties.
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  • 文章类型: Journal Article
    目的:软材料,特别是弹性体,被广泛研究,但研究纯软凝胶接触系统是有限的,由于其复杂的两相组成的聚合物和自由液体。虽然双波长反射干涉共聚焦显微镜(DW-RICM)对于从仰视图实现界面的非侵入性可视化是有效的,由于聚合物网络和自由液体的折射率接近,它在凝胶研究中面临挑战。我们假设使用纳米粒子(NPs)调节软凝胶的折射率可以增强自由表面下接触区的可视化,提供对凝胶上凝胶接触系统中相分离游离油的配置的见解。
    方法:使用不混溶的有机凝胶和水凝胶制备凝胶上凝胶接触体系。将二氧化钛(TiO2)NP引入有机凝胶中以调节折射率。鉴于缺乏对凝胶之间的隐藏接触区的先前研究,各种技术,包括DW-RICM,侧视成像,和倒置光学显微镜,被用来观察和验证我们的发现。使用弹性体对刚性材料进行了比较分析,凝胶弹性体,和凝胶刚性接触系统。
    结果:我们的研究表明,最少量的TiO2NP有效地描绘了有机凝胶聚合物网络和水凝胶表面之间的直接接触半径。比较实验表明,添加TiO2不会改变凝胶的机械和表面性能,但会显着增强凝胶接触变形的信息。这种增强的可视化技术有可能促进我们对凝胶中粘合剂接触的理解,为涉及生物软组织和细胞的界面现象提供有价值的见解。
    OBJECTIVE: Soft materials, particularly elastomers, are extensively studied, but investigations into purely soft gel contact systems are limited due to their complex dual phases consisting of polymer and free liquids. While Dual Wavelength-Reflection Interference Confocal Microscopy (DW-RICM) is effective for noninvasively visualizing interfaces from a bottom view, it faces challenges in gel studies due to close refractive indices of polymeric networks and free liquids. We hypothesize that modulating the refractive index of soft gels using nanoparticles (NPs) enhances the visualization of contact zone beneath the free surface, providing insights into the configuration of phase-separated free oil within gel-on-gel contact systems.
    METHODS: Gel-on-gel contact systems were fabricated using immiscible organogels and hydrogels. Titanium dioxide (TiO2) NPs were introduced into the organogel to modulate refractive indices. Given the lack of prior studies on the hidden contact zone between gels, various techniques, including DW-RICM, side-view imaging, and inverted optical microscopy, were employed to observe and validate our findings. Comparative analyses were conducted with elastomer-on-rigid, elastomer-on-gel, and gel-on-rigid contact systems.
    RESULTS: Our investigation demonstrated that a minimal amount of TiO2 NPs effectively delineates the direct contact radius between organogel polymeric networks and hydrogel surfaces. Comparative experiments showed that TiO2 addition did not alter the gels\' mechanical and surface properties but significantly enhanced information on gel contact deformation. This enhanced visualization technique has the potential to advance our understanding of adhesive contacts in gels, providing valuable insights into interface phenomena involving biological soft tissues and cells.
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  • 文章类型: Journal Article
    金属纳米晶体的电化学生长是材料合成的关键,processing,和资源回收。了解电解质和电极之间的异质界面对于纳米晶体成核至关重要,但是这种相互作用的影响仍然知之甚少。这项研究采用先进的原位测量来研究金属在固体表面上的异质成核。通过观察铜纳米晶体的电沉积,揭示了高度依赖于衬底表面能的相间相互作用诱导的成核机制。它表明高能(HE)电极倾向于形成多晶结构,而低能(LE)电极诱导单晶结构。拉曼和电化学表征证实,HE界面增强了相间相互作用,减少坚固纳米结构的成核障碍。这导致晶体层厚度减少30.92-52.21%,电荷转移能力增加19.18-31.78%,促进形成均匀致密的薄膜。早期成核晶体的结构致密性增强了长时间电沉积的沉积稳定性。这项研究不仅激发了人们对与异质成核相关的物理化学过程的理解,同时也为金属纳米材料的高质量合成和高效回收开辟了新的途径。
    Electrochemical growth of metal nanocrystals is pivotal for material synthesis, processing, and resource recovery. Understanding the heterogeneous interface between electrolyte and electrode is crucial for nanocrystal nucleation, but the influence of this interaction is still poorly understood. This study employs advanced in situ measurements to investigate the heterogeneous nucleation of metals on solid surfaces. By observing the copper nanocrystal electrodeposition, an interphase interaction-induced nucleation mechanism highly dependent on substrate surface energy is uncovered. It shows that a high-energy (HE) electrode tended to form a polycrystalline structure, while a low-energy (LE) electrode induced a monocrystalline structure. Raman and electrochemical characterizations confirmed that HE interface enhances the interphase interaction, reducing the nucleation barrier for the sturdy nanostructures. This leads to a 30.92-52.21% reduction in the crystal layer thickness and a 19.18-31.78% increase in the charge transfer capability, promoting the formation of a uniform and compact film. The structural compactness of the early nucleated crystals enhances the deposit stability for long-duration electrodeposition. This research not only inspires comprehension of physicochemical processes correlated with heterogeneous nucleation, but also paves a new avenue for high-quality synthesis and efficient recovery of metallic nanomaterials.
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  • 文章类型: Journal Article
    光活性甲酰胺三碘化铅(α-FAPbI3)钙钛矿主导了盛行的高性能钙钛矿太阳能电池(PSC),通常对于那些旋涂的,传统的n-i-p结构器件。不幸的是,由于不可控的结晶动力学和FAPbI3钙钛矿的复杂相演化,α-FAPbI3尚未在通过刮涂技术制造的反向p-i-n结构PSC中充分利用其优势。在这里,通过将0.5mol%的N-氨基乙基哌嗪氢碘化物(NAPI)添加剂掺入α-FAPbI3晶体衍生的钙钛矿墨水中,创新性地开发了定制的晶体表面能调节策略,这使得相纯的形成,高取向α-FAPbI3薄膜。通过结合一系列原位表征,我们破译了刀片涂覆的α-FAPbI3钙钛矿薄膜的相变机理和结晶动力学。有趣的是,NAPI和无机Pb-I骨架之间的强化学相互作用有助于将(100)晶面的表面能降低42%,延缓α-FAPbI3的结晶速率并降低其形成能。基于(100)取向的α-FAPbI3钙钛矿薄膜的刀片涂覆的倒置PSC实现了高达24.16%的有希望的效率(比随机取向的同行高〜26.5%),同时提高了运行稳定性。该结果代表了迄今为止报道的通过可扩展沉积方法制造的基于FAPbI3的反向PSC的最佳性能之一。
    Photoactive black-phase formamidinium lead triiodide (α-FAPbI3) perovskite has dominated the prevailing high-performance perovskite solar cells (PSCs), normally for those spin-coated, conventional n-i-p structured devices. Unfortunately, α-FAPbI3 has not been made full use of its advantages in inverted p-i-n structured PSCs fabricated via blade-coating techniques owing to uncontrollable crystallization kinetics and complicated phase evolution of FAPbI3 perovskites during film formation. Herein, a customized crystal surface energy regulation strategy has been innovatively developed by incorporating 0.5 mol % of N-aminoethylpiperazine hydroiodide (NAPI) additive into α-FAPbI3 crystal-derived perovskite ink, which enabled the formation of highly-oriented α-FAPbI3 films. We deciphered the phase transformation mechanisms and crystallization kinetics of blade-coated α-FAPbI3 perovskite films via combining a series of in-situ characterizations and theoretical calculations. Interestingly, the strong chemical interactions between the NAPI and inorganic Pb-I framework help to reduce the surface energy of (100) crystal plane by 42 %, retard the crystallization rate and lower the formation energy of α-FAPbI3. Benefited from multifaceted advantages of promoted charge extraction and suppressed non-radiative recombination, the resultant blade-coated inverted PSCs based on (100)-oriented α-FAPbI3 perovskite films realized promising efficiencies up to 24.16 % (~26.5 % higher than that of the randomly-oriented counterparts), accompanied by improved operational stability. This result represented one of the best performances reported to date for FAPbI3-based inverted PSCs fabricated via scalable deposition methods.
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  • 文章类型: Journal Article
    目的:本研究的目的是评估经过不同预处理的不同计算机辅助设计/计算机辅助制造(CAD/CAM)混合陶瓷材料的粘结强度。
    方法:共制造了306个CAD/CAM混合材料试样,每种材料的n=102(通过3D打印的VarseoSmileCrownplus[VSCP];通过铣削的VitaEnamic[VE]和Grandio块[GB])。每种材料被随机分为六组关于不同的预处理策略:对照,硅烷,喷砂(50μm氧化铝颗粒),喷砂+硅烷,蚀刻(9%氢氟酸),蚀刻+硅烷。随后,表面粗糙度(Ra)值,测量表面自由能(SFE)。每个样品用双重固化的粘合剂复合材料粘合。一半的样品进行了热循环(5000次循环,5-55°C)。进行剪切粘结强度(SBS)测试。数据采用双向方差分析,独立t检验,和Mann-Whitney-U检验(α=0.05)。
    结果:材料类型(p=0.001),预处理策略(p<0.001),交互作用(p<0.001)对Ra值均有显著影响。然而,仅在VSCP和VE表面上进行蚀刻显着增加了SFE值。关于SBS值,三种材料之间没有发现显着差异(p=0.937),而预处理策略对SBS有显著影响(p<0.05)。对VSCP标本的蚀刻显示所有组的平均值最低,而喷砂和硅烷导致所有测试材料的SBS较高。
    结论:用于铣削和3D打印的CAD/CAM混合陶瓷材料的粘结强度相当。喷砂和硅烷偶联适用于可磨和可印刷材料,而对于CAD/CAM混合陶瓷材料,不建议使用氢氟酸刻蚀。
    结论:由于可3D打印和可铣削CAD/CAM牙科混合材料之间的可比证据很少,本研究为不同材料的预处理计划提供了明确的指导。
    OBJECTIVE: The purpose of this study is to evaluate the bond strength of different computer-aided design / computer-aided manufacturing (CAD/CAM) hybrid ceramic materials following different pretreatments.
    METHODS: A total of 306 CAD/CAM hybrid material specimens were manufactured, n = 102 for each material (VarseoSmile Crownplus [VSCP] by 3D-printing; Vita Enamic [VE] and Grandio Blocs [GB] by milling). Each material was randomly divided into six groups regarding different pretreatment strategies: control, silane, sandblasting (50 μm aluminum oxide particles), sandblasting + silane, etching (9% hydrofluorics acid), etching + silane. Subsequently, surface roughness (Ra) values, surface free energy (SFE) were measured. Each specimen was bonded with a dual-cured adhesive composite. Half of the specimens were subjected to thermocycling (5000 cycles, 5-55 °C). The shear bond strength (SBS) test was performed. Data were analyzed by using a two-way analysis of variance, independent t-test, and Mann-Whitney-U-test (α = 0.05).
    RESULTS: Material type (p = 0.001), pretreatment strategy (p < 0.001), and the interaction (p < 0.001) all had significant effects on Ra value. However, only etching on VSCP and VE surface increased SFE value significantly. Regarding SBS value, no significant difference was found among the three materials (p = 0.937), while the pretreatment strategy significantly influenced SBS (p < 0.05). Etching on VSCP specimens showed the lowest mean value among all groups, while sandblasting and silane result in higher SBS for all test materials.
    CONCLUSIONS: The bond strength of CAD/CAM hybrid ceramic materials for milling and 3D-printing was comparable. Sandblasting and silane coupling were suitable for both millable and printable materials, while hydrofluoric etching should not be recommended for CAD/CAM hybrid ceramic materials.
    CONCLUSIONS: Since comparable evidence between 3D-printable and millable CAD/CAM dental hybrid materials is scarce, the present study gives clear guidance for pretreatment planning on different materials.
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  • 文章类型: Journal Article
    直接海水电解中的一个重大挑战是由于Mg(OH)2的大规模结垢导致的阴极的快速失活。在这里,我们合成了一种Pt涂层高度无序的NiCu合金(Pt-NiCu合金)电极,能够在富含Mg2+和Ca2+的电解质中稳定地产生氢气(100mAcm-2,>1000h耐久性)和同时产生Mg(OH)2(>99.0%纯度)。非常规的疏固性能主要源于NiCu合金基材的高表面能,这促进了地表水的吸附,从而迫使Mg(OH)2通过均匀成核形成。这种疏固体电极的发现将革命性地简化用于海水电解的现有技术并增加用于海水电解的经济可行性。
    A significant challenge in direct seawater electrolysis is the rapid deactivation of the cathode due to the large scaling of Mg(OH)2. Herein, we synthesized a Pt-coated highly disordered NiCu alloy (Pt-NiCu alloy) electrode with superior solidophobic behavior, enabling stable hydrogen generation (100 mA cm-2, >1000 h durability) and simultaneous production of Mg(OH)2 (>99.0% purity) in electrolyte enriched with Mg2+ and Ca2+. The unconventional solidophobic property primarily stems from the high surface energy of the NiCu alloy substrate, which facilitates the adsorption of surface water and thereby compels the bulk formation of Mg(OH)2 via homogeneous nucleation. The discovery of this solidophobic electrode will revolutionarily simplify the existing techniques for seawater electrolysis and increase the economic viability for seawater electrolysis.
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  • 文章类型: Journal Article
    为了解释Al和Mn取代对La-Ni-Al-Mn合金活化性能的影响,测量了初始激活曲线,结果表明,随着合金中Al含量的增加,活化的孵育时间延长,而将二重奏缩短为锰替代。Further,采用第一原理计算。我们发现(1)LaNi5的(100)/(010)表面最稳定,其稳定性可以通过Al代替Ni而降低;(2)优先氢吸附位点是空穴和Ni(或Mn)-顶部位点;(3)Al和Mn取代可以增加氢吸附稳定性,但是铝掺杂减少了可用位点的数量,因此延迟激活,虽然锰掺杂保证了可用位点的数量,使活化更容易;(4)H与邻居Ni(或Mn)共价结合,与La离子结合,一起确定氢吸附的稳定性。
    To interpret the effect of Al and Mn substitutions on activation performances of La-Ni-Al-Mn alloy, the initial activation curve has been measured, which shows that the incubation time of activation is prolonged with the increase of Al content in alloy, while shortened duo to Mn substitution. Further, the first-principles calculations are employed. We find that (1) (100)/(010) surface of LaNi5 is the most stable and its stability can be improved by Al substitution for Ni while decreased by Mn substitution; (2) the preferential hydrogen adsorption sites are the hole and Ni (or Mn)-top sites; (3) Al and Mn substitutions can increase the hydrogen adsorption stability, but Al doping decreases the number of available sites, therefore retarding activation, while Mn doping guarantees the number of available sites, making activation easier; (4) H bonds covalently with neighbor Ni (or Mn) and ionically with La, together determining the stability of hydrogen adsorption.
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  • 文章类型: Journal Article
    用于制造全无机钙钛矿薄膜阵列的基于溶液的方法通常受到对成核和结晶的有限控制的影响。导致均匀性和覆盖率差。为了提高胶片质量,先进的气相沉积技术用于连续薄膜。这里,全无机钙钛矿薄膜阵列的气相沉积策略,通过衬底调制使钙钛矿的区域选择性沉积得以扩展。它可以产生具有不同像素形状的高质量钙钛矿薄膜阵列,各种钙钛矿成分,和423dpi的高分辨率。最终的光电探测器阵列具有显着的光电性能,开/关比为13887,响应度为47.5AW-1。该装置还显示在潮湿条件下长达12小时的长期稳定性。基于钙钛矿薄膜阵列的脉搏监测传感器在佩戴12h和0.055mWcm-2的低照度下显示出对脉搏信号的稳定监测,突出了在可穿戴光电设备中的潜在应用。
    Solution-based methods for fabricating all-inorganic perovskite film arrays often suffer from limited control over nucleation and crystallization, resulting in poor homogeneity and coverage. To improve film quality, advanced vapor deposition techniques are employed for continuous film. Here, the vapor deposition strategy to the all-inorganic perovskite films array, enabling area-selective deposition of perovskite through substrate modulation is expanded. It can yield a high-quality perovskite film array with different pixel shapes, various perovskite compositions, and a high resolution of 423 dpi. The resulting photodetector arrays exhibit remarkable optoelectronic performance with an on/off ratio of 13 887 and responsivity of 47.5 A W-1. The device also displays long-term stability in a damp condition for up to 12 h. Moreover, a pulse monitoring sensor based on the perovskite films array demonstrates stable monitoring for pulse signals after being worn for 12 h and with a low illumination of 0.055 mW cm-2, highlighting the potential application in wearable optoelectronic devices.
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  • 文章类型: Journal Article
    为了降低全球腐蚀成本,了解复杂的腐蚀机理和提高材料的耐腐蚀性是至关重要的。然而,在极端环境中,铝硅酸钙镁(CMAS)熔盐腐蚀的主要机理的模糊性阻碍了关键稀土元素的混合匹配,以增加单硅酸盐对CMAS腐蚀的抵抗力。在这里,提出了一种基于相关电子显微镜技术与密度泛函理论计算相结合的方法,以阐明控制单硅酸盐CMAS腐蚀的竞争机制的复杂相互作用。这些发现揭示了热力学和动力学之间的竞争,依赖于温度和腐蚀过程。开发了创新的中熵单硅酸盐,即使在1500°C下也具有出色的耐腐蚀性。这是通过精确调节单硅酸盐中稀土离子的半径以在热力学和动力学竞争之间达成微妙的平衡来实现的。经过50和100小时的腐蚀,测得最薄的反应层只有28.8和35.4µm,分别。
    For decreasing the global cost of corrosion, it is essential to understand the intricate mechanisms of corrosion and enhance the corrosion resistance of materials. However, the ambiguity surrounding the dominant mechanism of calcium-magnesium aluminosilicate (CMAS) molten salt corrosion in extreme environments hinders the mix-and-matching of the key rare earth elements for increasing the resistance of monosilicates against corrosion of CMAS. Herein, an approach based on correlated electron microscopy techniques combined with density functional theory calculations is presented to elucidate the complex interplay of competing mechanisms that control the corrosion of CMAS of monosilicates. These findings reveal a competition between thermodynamics and kinetics that relies on the temperatures and corrosion processes. Innovative medium-entropy monosilicates with exceptional corrosion resistance even at 1500 °C are developed. This is achieved by precisely modulating the radii of rare earth ions in monosilicates to strike a delicate balance between the competition in thermodynamics and kinetics. After 50 and 100 h of corrosion, the thinnest reactive layers are measured to be only 28.8 and 35.4 µm, respectively.
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  • 文章类型: Journal Article
    随着低温电子显微镜(cryoEM)在结构生物群落中获得牵引力,作为确定生物复合物原子结构的首选方法,它已经越来越认识到,许多配合物,表现良好,在传统的负染色电子显微镜倾向于具有优先取向,聚集或只是神秘地“消失”在CryoEM网格上。然而,这种不当行为的原因还没有得到很好的理解,这限制了解决问题的系统方法。这里,我们已经开发了一个理论公式来解释这些观察结果。我们的公式预测,所有颗粒都迁移到空气-水界面(AWI)以降低总的潜在表面能-合理化使用表面活性剂,是降低水溶液表面张力的直接溶液。通过对广泛测试的样品进行低温电子层析成像(cryoET),GroEL,我们证明,在标准缓冲溶液中,几乎所有的粒子迁移到AWI。通过引入表面活性剂逐渐降低表面张力降低了暴露于表面的颗粒的百分比。通过进行单粒子冷冻EM,我们确认合适的表面活性剂不会破坏生物复合物,因此暗示他们可能会提供一个实用的,简单,和高分辨率冷冻EM问题的通用解决方案。将此解决方案应用于涉及更具挑战性的膜蛋白的现实世界AWI吸附问题,即,ClC-1通道,已使用cryoEM确定其近原子结构。
    As cryogenic electron microscopy (cryoEM) gains traction in the structural biology community as a method of choice for determining atomic structures of biological complexes, it has been increasingly recognized that many complexes that behave well under conventional negative-stain electron microscopy tend to have preferential orientation, aggregate or simply mysteriously \"disappear\" on cryoEM grids. However, the reasons for such misbehavior are not well understood, which limits systematic approaches to solving the problem. Here, we have developed a theoretical formulation that explains these observations. Our formulation predicts that all particles migrate to the air-water interface (AWI) to lower the total potential surface energy-rationalizing the use of surfactant, which is a direct solution to reduce the surface tension of the aqueous solution. By performing cryogenic electron tomography (cryoET) on the widely-tested sample, GroEL, we demonstrate that, in a standard buffer solution, nearly all particles migrate to the AWI. Gradually reducing the surface tension by introducing surfactants decreased the percentage of particles exposed to the surface. By conducting single-particle cryoEM, we confirm that suitable surfactants do not damage the biological complex, thus suggesting that they might provide a practical, simple, and general solution to the problem for high-resolution cryoEM. Applying this solution to a real-world AWI adsorption problem involving a more challenging membrane protein, namely, the ClC-1 channel, has resulted in its near-atomic structure determination using cryoEM.
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