Langmuir最新文献

{"title":"Evaluating the Effect of Oxygen Vacancies on the Oxygen Evolution Reaction (OER) Activity of LaNiO3","authors":"Chuanmu Tian, Danni Wang, Kelvin H. L. Zhang, Jan P. Hofmann","doi":"10.1021/acs.langmuir.4c04833","DOIUrl":"https://doi.org/10.1021/acs.langmuir.4c04833","url":null,"abstract":"In this work, we have investigated the effect of oxygen vacancies on the surface composition, electronic structure, and oxygen evolution reaction (OER) performance of LaNiO₃. The results show that the OER performance of LaNiO₃ can be improved both by decreasing the oxygen partial pressure during film growth and annealing the thin film in a H₂ atmosphere. X-ray photoemission spectroscopy (XPS) shows a significant increase in the Ni:La ratio on the LaNiO₃ surface after the introduction of oxygen defects, especially after H₂ treatment, where the Ni:La ratio reaches 3.5:1. The presence of oxygen vacancies leads to the aggregation of Ni on the surface of LaNiO₃, which plays a crucial role in enhancing the OER performance of LaNiO₃. In addition, the OER activity of both LaNiO₃ and oxygen vacancy rich LaNiO₃ decreases upon cyclic voltammetry (CV) between 1.0 and 1.5 V versus the RHE with an increase in the cycle number. XPS results reveal that the CV treatments lead to a decrease in the Ni concentration at the LaNiO₃ surface, which is an important factor for the decrease in the OER performance of LaNiO₃ as well as oxygen vacancy rich LaNiO₃.","PeriodicalId":50,"journal":{"name":"Langmuir","volume":"57 1","pages":""},"PeriodicalIF":3.9,"publicationDate":"2025-03-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143713556","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A Sprayable Polyelectrolyte Coating to Mitigate the Foreign Body Response of Implants","authors":"Yu Yan, Xianchi Zhou, Zuolong Liu, Zihao Zhu, Wenzhong Cao, Kexin Chen, Jian Ji, Peng Zhang","doi":"10.1021/acs.langmuir.5c00868","DOIUrl":"https://doi.org/10.1021/acs.langmuir.5c00868","url":null,"abstract":"The foreign body response (FBR) presents a significant challenge to biomedical implants, leading to fibrotic capsule formation that compromises implant functionality. In this study, we report a straightforward method for fabricating stable anti-fibrotic polyelectrolyte coatings on implant surfaces using industrialized ultrasonic spraying technology. The coating thickness and surface charge can be adjusted through variations in spraying time and polyelectrolyte ratio, respectively. We investigate the fibrotic response of polyelectrolyte-coated implants with varying surface charges and thicknesses. Our findings reveal that surface charge significantly influences the fibrotic response, while electronegative polyelectrolyte coatings most effectively inhibit FBR compared to electrically neutral, positively charged, and uncoated surfaces. Meanwhile, coating thickness beyond 10 μm resulted in thinner capsules than coatings at a 1 μm or nanometer scale. The simple and versatile polyelectrolyte coating method reported here holds great potential to enhance and extend the functionality of implants in a mass-produced manner by mitigating host responses to implantable biomaterials.","PeriodicalId":50,"journal":{"name":"Langmuir","volume":"30 1","pages":""},"PeriodicalIF":3.9,"publicationDate":"2025-03-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143713613","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Synthesis and Characterization of a Series of Biofriendly Fluoroether Betaines","authors":"Sheng Zhou, Libo Qian, Zhaoben Su, Meiwei Huang, Tao Lv, Chengying Wu, Yong Guo, Ji-Chang Xiao","doi":"10.1021/acs.langmuir.5c00254","DOIUrl":"https://doi.org/10.1021/acs.langmuir.5c00254","url":null,"abstract":"Fluoroether approach has been extensively employed as an alternative to conventional fluorinated surfactants; however, it faces challenges such as inadequate performance of short fluoroether chains and environmental contamination from long fluoroether chains. This study aims to address the conflict between environmental compatibility and the performance of fluoroether surfactants. The design of the surfactants is centered around the OC chain (CF₃(OCF₂)_<i>n</i>–), utilizing reduced fluorine content to achieve superior surface activity. A series of surfactant molecules featuring elongated hydrophobic chains and dual-chain structures have been synthesized and characterized. All of the molecules have good surface activity at low concentrations. Among them, CF₃(OCF₂)₄CH₂O(CH₂)₃SO₂NH(CH₂)₃N⁺(CH₃)₂CH₂COO^– (OC4F-B), which employs a strategy of extending the hydrophobic chain by insertion of –CH₂O(CH₂)₃–, shows the best performance. This surfactant can achieve a surface tension of 20 mN/m at a concentration of 0.005 wt %, which is 20 times lower than that required for CF₃(OCF₂)₄CONH(CH₂)₃N⁺(CH₃)₂CH₂COO^– (OC4-betaine) to attain the same surface tension. In contrast, (CF₃(OCF₂)₃CH₂O(CH₂)₃SO₂NHCH₂CH₂)₂N⁺(CH₃)CH₂COO^– (DOC3F-B), utilizing both dual-chain and extended carbon chain strategies, exhibits a critical micelle concentration that is diminished by 2 orders of magnitude relative to OC3-betaine, reaching to 0.047 g/L. Merely adjusting the length of the fluorocarbon chain is insufficient to reconcile the conflict between the performance and environmental impact of fluorinated surfactants. This study introduces an innovative approach by incorporating hydrocarbon hydrophobic chains and adopting a dual-chain design, thereby addressing this challenge effectively.","PeriodicalId":50,"journal":{"name":"Langmuir","volume":"34 1","pages":""},"PeriodicalIF":3.9,"publicationDate":"2025-03-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143723693","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"First-Principles Investigation of Monolayer Sc2Se2X2 (X = Cl, Br) as a High-Performance Photocatalyst for Efficient Water Splitting","authors":"Dandan Mao, Rundong Wan, Zhengfu Zhang, Mengnie Li, Guocai Tian, Song Chen","doi":"10.1021/acs.langmuir.5c00155","DOIUrl":"https://doi.org/10.1021/acs.langmuir.5c00155","url":null,"abstract":"Two-dimensional materials hold substantial promise for photocatalytic water splitting, primarily due to their unique structural properties and high-efficiency light absorption. However, finding such applicable materials poses a huge challenge because there are many strict requirements to meet. In this study, we employ first-principles calculations to design and evaluate two monolayers, Sc₂Se₂X₂ (X = Cl, Br), highlighting their potential as high-performance photocatalysts. these materials exhibit low activation energy barriers for water-splitting redox reactions, which facilitate high catalytic performance. The photogenerated electric field promotes oxygen adsorption, accelerating the overall reaction. The structural, mechanical, dynamical, and thermodynamic stabilities of these materials are confirmed through comprehensive analyses. With band gaps of 2.65 and 2.40 eV, respectively, these materials meet the band gap requirements for photocatalytic water splitting. Furthermore, a prominent characteristic of these materials is their significantly high electron mobility along the <i>y</i>-axis, reaching 26,560.74 and 17,634.01 cm² V^–1 s^–1, which far surpasses the hole mobility. This characteristic effectively reduces electron–hole recombination and enhances photocatalytic performance. With solar-to-hydrogen efficiencies of 13.60% and 20.58%, respectively, these materials surpass the 10% threshold required for commercial photocatalytic applications. These findings indicate that monolayer Sc₂Se₂X₂ (X = Cl, Br) has great theoretical potential for photocatalytic water splitting.","PeriodicalId":50,"journal":{"name":"Langmuir","volume":"15 1","pages":""},"PeriodicalIF":3.9,"publicationDate":"2025-03-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143713562","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Droplet Fast Gyrating on the Anisotropic Surface","authors":"Fei Zhan, Yongping Hou, Wei Sun, Yingchao Yue, Yihao Wang, Jiaming Mao, Daheng Wu, Jianjun Cheng, Lei Wang","doi":"10.1021/acs.langmuir.5c00620","DOIUrl":"https://doi.org/10.1021/acs.langmuir.5c00620","url":null,"abstract":"It is fundamental and practical to understand the basic hydrodynamic principles of bouncing droplets on superhydrophobic surfaces and to develop control strategies. Although recent research has focused on adjusting the contact time of the bouncing droplet, little attention has been paid to manipulating the rebound of the droplet from the perspective of energy optimization, which determines the development of long-term continuous dynamics. Here, we study the impact of water droplets on an anisotropic superhydrophobic surface at a low Weber number of 3.85, where the droplets bounce vertically after impacting the surface and gyrotron tangentially at a speed of 7200 rpm. The initial kinetic energy required can be reduced by more than double relative to the traditional bounce behavior at the same bounce distance in the horizontal direction. This study proposes a low-energy long-distance transport method for droplets, providing valuable insights for enabling energy-efficient applications, including self-cleaning surfaces, liquid transfer, and spray cooling in industrial settings.","PeriodicalId":50,"journal":{"name":"Langmuir","volume":"59 1","pages":""},"PeriodicalIF":3.9,"publicationDate":"2025-03-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143724007","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Sensing Performance of Crn (n = 1–3) Clusters Doped WSe2 and WTe2 for Gases in Power Transformer Winding Deformation Fault by DFT Calculation","authors":"Haonan Xie, Guozhi Lin, Hao Wu, Zhonghe Tong, Yang He, Lin Chen, Chenmeng Liu, Tianyan Jiang","doi":"10.1021/acs.langmuir.5c00004","DOIUrl":"https://doi.org/10.1021/acs.langmuir.5c00004","url":null,"abstract":"In order to verify the adsorption effect of WTe₂ on the fault gas of power transformer winding deformation, this paper uses density functional theory (DFT) to study and compare the adsorption mechanism and sensing characteristics of three fault gases (CO, CO₂, C₂H₂) on the surface of WSe₂ and WTe₂ substrates after cluster doping with Cr_<i>n</i> (<i>n</i> = 1–3). By analyzing the binding energy, band structure, adsorption distance, adsorption energy, DCD and DOS of the two substrate systems, the adsorption effect of Cr cluster doped WSe₂ and WTe₂ on fault gas is compared. Higher stability and conductivity indicate that Cr cluster doping is beneficial for WSe₂ and WTe₂ substrates. CO and CO₂ have the best adsorption characteristics and sensing performance among the three doping systems on Cr₂–WSe₂, while C₂H₂ can be best captured by Cr₃–WTe₂. This study also analyzes the work function, band gap and energy gap, further verifying the conductivity changes described in the previous article. In addition, the recovery time and sensitivity are used to discuss the practical application prospects of the two substrates after Cr cluster doping, and corresponding conclusions are obtained. This study provides a theoretical basis for evaluating and preventing winding deformation failures in power transformers, and also provides new insights into whether WTe₂ can be used as a mainstream gas-sensitive material in engineering fields.","PeriodicalId":50,"journal":{"name":"Langmuir","volume":"47 1","pages":""},"PeriodicalIF":3.9,"publicationDate":"2025-03-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143713560","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Anodic Potential Driven Electrochemiluminescence of Luminol/O2 System with the Immobilized TEMPO Mediator","authors":"Yuxin Yang, Haidong Li, Danli Zhong, Guangyue Zhao, Xianjing Huang, Zhenxing Yang, Chengyin Wang","doi":"10.1021/acs.langmuir.5c00094","DOIUrl":"https://doi.org/10.1021/acs.langmuir.5c00094","url":null,"abstract":"The oxygen reduction reaction (ORR) has been recognized well as an essential step to trigger the electrochemiluminescence (ECL) of the luminol/O₂ system but suffers from sluggish reaction kinetics. Herein, ECL of the luminol/O₂ system without involving ORR is reported by using a 4-amino-2,2,6,6-tetramethylpiperidine-1-oxyl (4-amino-TEMPO) grafted glassy carbon electrode (4-amino-TEMPO/GCE). This electrode exhibits high catalytic activity toward the oxidation of luminol, though it is covered with an organic film. Such promoted luminol oxidation on the electrode results in a 5.0-fold ECL enhancement at an anodic potential, ensuring the ECL detection as more sensitive. The mechanism studies indicate that the catalysis of 4-amino-TEMPO/GCE can provide additional luminol anion radical (L^–•) for enhancing the ECL of the luminol/O₂ system. Hence, this work introduces a different approach to modulate luminol oxidation for enhancing ECL emission based on an immobilized organic oxidation catalyst.","PeriodicalId":50,"journal":{"name":"Langmuir","volume":"37 1","pages":""},"PeriodicalIF":3.9,"publicationDate":"2025-03-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143713561","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Molecular Dynamics Simulation of Polymer Concrete Enhanced by Carbon Nanoparticles: Effect of Surface Functional Groups","authors":"Kaixuan Zhang, Dongshuai Hou, Shaochun Li, Muhan Wang","doi":"10.1021/acs.langmuir.5c00346","DOIUrl":"https://doi.org/10.1021/acs.langmuir.5c00346","url":null,"abstract":"Polymer concrete (PC) has attracted considerable interest for its excellent deformation resistance and durability. However, the mechanical drawbacks of polymers, particularly their limited compressive strength, constrain the wider application and design flexibility of PC. While experimental techniques such as X-ray diffraction and scanning electron microscopy provide insights into nanoparticle interactions within the polymer matrix, they lack the resolution to fully elucidate nanoscale mechanisms. To bridge this gap, this study utilizes molecular dynamics (MD) simulations to analyze the shearing behavior of carbon nanoparticle (CNP)-reinforced PC composites. MD simulations allow for atomic-level insights into the interactions between CNPs and the polymer matrix, providing a more detailed understanding of how surface-modified CNPs enhance mechanical properties. Our results show that surface-modified CNPs influence the distribution and conformation of epoxy within the PC system. Amino-functionalized CNPs strengthen the epoxy and calcium silicate hydrate (C–S–H) interface by facilitating calcium–oxygen bond formation. These interactions play a crucial role in improving the mechanical properties of PC. This study provides a fundamental understanding of how surface-modified CNPs reinforce PC and offers valuable insights for optimizing the performance of CNP-reinforced cementitious composites.","PeriodicalId":50,"journal":{"name":"Langmuir","volume":"30 1","pages":""},"PeriodicalIF":3.9,"publicationDate":"2025-03-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143723785","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Coarse-Grained Molecular Dynamics Simulation of Nucleation and Stability of Electrochemically Generated Nanobubbles","authors":"Bin Li, Wei Xiang, Xiaohui Dou, Yan Wu, Wei Zhang, Zhentao Wang, Junfeng Wang","doi":"10.1021/acs.langmuir.4c04049","DOIUrl":"https://doi.org/10.1021/acs.langmuir.4c04049","url":null,"abstract":"With growing concerns over environmental pollution associated with fossil fuels, hydrogen (H₂) energy has emerged as a promising alternative. Water electrolysis, a key hydrogen production method, is fundamentally governed by the nucleation and stability of electrochemically generated nanobubbles. This study employs coarse-grained molecular dynamics (MD) simulations incorporating a self-programming gas generation algorithm to investigate the nucleation and growth dynamics of nanobubbles on hydrophilic and hydrophobic electrodes. Key parameters, such as contact angle, electric current, and nanobubble number density, were computed to validate the MD model. The findings reveal a three-stage nucleation process: (i) <i>induction</i>─gas molecules accumulate to form a nucleus, (ii) <i>nucleation and growth</i>─gas nuclei expand into nanobubbles, and (iii) <i>stationary state</i>─nanobubble growth ceases. Increased electrode hydrophilicity resulted in larger nanobubble contact angles, aligning well with classical nucleation theory (<i>CNT</i>) at the nanoscale. Three distinct nanobubble types─surface, solution, and pancake nanobubbles─were identified, each exhibiting unique interfacial behaviors based on electrode properties. Solution nanobubbles primarily formed on hydrophilic electrodes, pancake nanobubbles adhered to hydrophobic electrodes, and surface nanobubbles appeared as spherical caps. Energy analysis and phase mapping further delineated the critical parameter ranges for these nanobubble modes, providing valuable insights for optimizing electrode materials to enhance hydrogen production efficiency.","PeriodicalId":50,"journal":{"name":"Langmuir","volume":"15 1","pages":""},"PeriodicalIF":3.9,"publicationDate":"2025-03-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143713555","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Directional Droplet Coalescence-Induced Jumping Regulated by Laplace Pressure","authors":"Zijin Zhang, Jin Wang, Yongqing He, Feng Jiao","doi":"10.1021/acs.langmuir.5c00279","DOIUrl":"https://doi.org/10.1021/acs.langmuir.5c00279","url":null,"abstract":"Coalescence-induced droplet jumping, a spontaneous droplet transport phenomenon, holds significant potential in anti-icing, anti-fogging, self-cleaning, and enhancing condensation heat transfer. However, droplet jumping has a low energy efficiency and an uncontrolled jumping orientation, severely restricting its practical use. We demonstrate experimentally that a pillar superhydrophobic surface may achieve dimensionless jumping velocity <i>v</i>_j^* = 0.72 and outstanding energy efficiency <i>η</i> = 56%. Compared to a flat superhydrophobic surface, the energy efficiency is raised by about 860%. The improvement in jumping efficiency is due to the pillar limitations and regularization of the internal droplet flow by restricting droplet deformation. For the first time, we have accomplished controlled droplet directional jumping within the 45–130° range by adjusting the magnitude and direction of the Laplace pressure. In addition, we thoroughly investigate how directional droplet jumping is affected by pillar geometric dimensions, droplet radius, and droplet size mismatch. This work introduces a new avenue for increasing the jumping velocity while managing the direction, resulting in better droplet jumping performance in applications.","PeriodicalId":50,"journal":{"name":"Langmuir","volume":"22 1","pages":""},"PeriodicalIF":3.9,"publicationDate":"2025-03-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143713609","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}