Langmuir最新文献

{"title":"Revealing Mechanisms of an Eco-Friendly GaN Electrochemical Mechanical Removal Process Modified with Green Fenton Reaction","authors":"Yang Peng, Zirui Wang, Qingyu Yao, Feng Cheng, Tianyu Zhang, Yuguang Zhu, Yongguang Wang, Chuanyang Wang","doi":"10.1021/acs.langmuir.4c05003","DOIUrl":"https://doi.org/10.1021/acs.langmuir.4c05003","url":null,"abstract":"Gallium Nitride (GaN), a leading third-generation semiconductor material, offers exceptional properties and broad application potential. However, its high hardness and chemical inertness make GaN wafers difficult to process, posing significant challenges in improving the polishing efficiency. During the electrochemical mechanical polishing (ECMP) process, the oxidation effect on the GaN surface critically affects the material removal rate (MRR). While various methods have been developed to enhance the concentration of hydroxyl radicals (OH*) to improve the process, their instability and rapid decomposition present further obstacles to maintaining concentration and stability. The present study proposed a novel approach using sodium tripolyphosphate (STPP) as an electrolyte additive for ECMP under a green Fenton reaction. Furthermore, the MRR and surface roughness (<i>R</i>_a) of GaN-ECMP were comprehensively evaluated. Atomic force microscopy (AFM) was used to observe the surface morphologies of GaN wafers after ECMP. Energy-dispersive spectrometry (EDS) and X-ray Photoelectron Spectroscopy (XPS) were used to characterize the generated oxide layers. The nanoscratch tests were conducted to reveal the material removal mechanisms of GaN under the synergistic effect of STPP and Fe²⁺. The results indicated that an efficient GaN-ECMP process (MRR &gt; 800 nm/h) with good surface quality (<i>R</i>_a &lt; 0.33 nm) can be realized by employing STPP as electrolyte additives. This study breaks the limitation of iron precipitate formation in the ECMP slurries during the Fenton reaction. It extends the lifetime of the hydroxyl radicals (OH*) produced by the Fenton reaction, which presents a beneficial exploration of seeking an eco-friendly polishing slurry for GaN-ECMP.","PeriodicalId":50,"journal":{"name":"Langmuir","volume":"61 1","pages":""},"PeriodicalIF":3.9,"publicationDate":"2025-02-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143083790","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":"Photoswitchable Molecular Motor Phospholipid: Synthesis, Characterization, and Integration into Lipid Vesicles","authors":"Ainoa Guinart, Daniel Doellerer, Yusuf Qutbuddin, Henry Zivkovic, Cristina Branca, Dominik Hrebik, Petra Schwille, Ben L. Feringa","doi":"10.1021/acs.langmuir.4c04173","DOIUrl":"https://doi.org/10.1021/acs.langmuir.4c04173","url":null,"abstract":"Lipid membranes are essential for cellular function, acting as barriers and platforms for major cellular and biochemical activities. The integration of photoisomerizable units into lipid structures allows for tunable membrane properties, offering insights into major membrane-related processes. In this study, we present the first molecular-motor-conjugated phospholipid system. The synthesis of two phosphatidylcholine derivatives is reported, where one acyl chain is replaced with a light-responsive molecular rotary motor moiety. We explore the photochemical and thermodynamic behaviors of these compounds in solution and as self-assembled systems, demonstrating their rotation cycles under illumination and their dynamic properties in combination with lipid molecules. Additionally, giant unilamellar vesicles with these compounds are formed to investigate the mechanisms of the photoinduced responses in synthetic lipid membranes. Our findings show that molecular motor-based lipids can operate in aqueous solution and with natural phospholipids, maintaining photoisomerization properties and enabling oxidation-driven release within giant lipid vesicles.","PeriodicalId":50,"journal":{"name":"Langmuir","volume":"123 1","pages":""},"PeriodicalIF":3.9,"publicationDate":"2025-02-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143084012","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":"Multifunctional Thick Films Obtained by Electrodeposition of 1,8-Dihydroxynaphtalene, an Allomelanin Precursor","authors":"Kévin Ziegler, Marcel Boecker, Vincent Ball, Ann-Kathrin Kissmann, Julia Moser, Clément Sanchez, Cédric Boissière, Ovidiu Ersen, Dris Ihiawakrim, Tommaso Marchesi D’Alvise, Frank Rosenau, Tanja Weil, Christopher V. Synatschke","doi":"10.1021/acs.langmuir.4c04184","DOIUrl":"https://doi.org/10.1021/acs.langmuir.4c04184","url":null,"abstract":"The deposition of conformal films from redox-active biological molecules, such as catechols, catecholamines, and other polyphenols, has demonstrated great versatility in terms of the substrate used. Precursors of allomelanins, mainly found in plants and fungi, have been largely overlooked as precursors for the design of conformal and robust coatings. Moreover, their potential application for the electrodeposition of films on conductive substrates has not yet been investigated. Here, the electrodeposition by cyclic voltammetry and chronoamperometry of 1,8-dihydroxynaphthalene (1,8-DHN), a precursor of allomelanin, onto gold electrodes and onto Co–Cr alloys from aqueous solution–ethanol mixtures yields films with potential sweep rate tunable thickness and swelling. The resulting films are antioxidants, and the reservoir of antioxidant moieties is not limited to their surface but also extends into the bulk of the film. In addition, the films produced after a limited energy supply (in the potential window −1 to +1 V vs Ag/AgCl) are strongly antimicrobial against two strains of <i>Pseudomonas aeruginosa</i> without further post-deposition treatment. In addition, their mechanical properties allow them to be detached from their substrates as free-standing films, opening avenues for diverse applications in biomedicine, energy storage, catalysis, sensing, and optoelectronics.","PeriodicalId":50,"journal":{"name":"Langmuir","volume":"62 1","pages":""},"PeriodicalIF":3.9,"publicationDate":"2025-02-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143083735","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":"Biomimetic Approaches for Detecting Lead in Water Contaminated by Perovskite Solar Cells","authors":"Jinu Joji, T. S. Sunil Kumar Naik, Praveen C. Ramamurthy","doi":"10.1021/acs.langmuir.4c04017","DOIUrl":"https://doi.org/10.1021/acs.langmuir.4c04017","url":null,"abstract":"Perovskite-based solar cells (PSCs) have emerged as highly promising in photovoltaics. New techniques are being developed for enhancing the device’s lifetime and performance. However, damaged or end-of-life lead-perovskite solar modules pose significant health and environmental risks due to the release of Pb²⁺ ions into the environment. This work developed an electrochemical detection of lead ions leached from degraded PSCs to address this issue. The biomimicking architecture of the sensing moiety was designed to replicate the interaction between lead ions and amino acids in various proteins, enabling more specific detection. Here, aminopropyl trimethoxysilane-functionalized metal–organic framework/ZIF-67 (ZIF-<i>N</i>) was used to detect lead, specifically in water leaked from lead-based PSCs. The ZIF-67-based sensing element, combined with a carbon paste electrode, exhibited a selective interaction with lead ions, allowing for the detection of lead in water as low as 60 ppb. This detection strategy relies on measuring changes in electronic properties using an electrochemical approach. Real-time lead detection in perovskite-contaminated water was successfully demonstrated using the differential pulse voltammetry technique, with ZIF-<i>N</i> as the sensing element.","PeriodicalId":50,"journal":{"name":"Langmuir","volume":"10 1","pages":""},"PeriodicalIF":3.9,"publicationDate":"2025-02-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143077041","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":"Heterogeneous Nickel Molybdenum Oxide Nanorods Conjugated Graphitic Carbon Nitride: A Bifunctional Electrocatalyst for Overall Water Splitting","authors":"Shubham Mishra, Vartika Sharma, Vaibhav Kulshrestha","doi":"10.1021/acs.langmuir.4c04651","DOIUrl":"https://doi.org/10.1021/acs.langmuir.4c04651","url":null,"abstract":"The pursuit of sustainable energy solutions has driven extensive research into efficient and cost-effective water-splitting techniques. This study introduces a straightforward method employing nickel molybdenum oxide NiMoO₄ (NMO) nanorods integrated with graphitic carbon nitride (g-CN) sheets as promising catalysts for water splitting. The integrated coupling between NMO nanorods and g-CN leverages the distinctive properties of both materials to boost robustness as well as effectiveness in catalysis for the oxygen evolution reaction (OER) and hydrogen evolution reaction (HER). We systematically optimized the nanostructure by adjusting the reduction annealing temperature during calcination to improve HER and OER activities. The NMO@g-CN-600 nanostructured catalyst demonstrates exceptional electrochemical HER activity in acidic media, with an overpotential of 148 mV at 10 mA cm^–2 current density, which is approximately 2.72 times lower than that of bare NMO and 2.97 times lower than pristine g-CN catalysts. Under alkaline conditions, the NMO@g-CN-600 nanostructured catalyst exhibited superior OER activity with an overpotential of 252 mV to reach a current density of 10 mA cm^–2, outperforming bare NMO and pristine g-CN catalysts. Additionally, the nanostructured catalyst demonstrated excellent long-term electrochemical stability with chronoamperometric testing over 50 h in both basic and acidic environments, showing low Tafel slopes for the OER and HER of 97 and 98 mV dec^–1, respectively. Various analytical methods confirmed the successful synthesis and structural stability of prepared catalysts. The outstanding electrocatalytic properties of the NMO@g-CN-600 nanostructured catalyst position it as a feasible choice to platinum-group-based catalysts for overall water electrolysis.","PeriodicalId":50,"journal":{"name":"Langmuir","volume":"47 1","pages":""},"PeriodicalIF":3.9,"publicationDate":"2025-02-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143077042","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":"Soft Wetting Ridge Rotation in Sessile Droplets and Capillary Bridges","authors":"Bo Xue Zheng, Tak Shing Chan","doi":"10.1021/acs.langmuir.4c04667","DOIUrl":"https://doi.org/10.1021/acs.langmuir.4c04667","url":null,"abstract":"We investigate the deformation of soft solid layers in the presence of sessile droplets or capillary bridges. Unlike models that assume Young’s law governs the contact angle, we incorporate the surface tension balance at the contact line to analyze the rotation of the wetting ridge and the corresponding change in the contact angle. Our findings reveal that the rotation direction of the wetting ridge aligns with the sign of the Laplace pressure. Interestingly, although a softer solid layer typically decreases the contact angle for sessile droplets, a negative Laplace pressure in a hydrophilic capillary bridge pulls the solid–liquid interface, leading to an increased contact angle. A hydrophilic capillary bridge would be expected to move from thicker regions of a soft layer to thinner areas, exhibiting behavior opposite that of a sessile droplet. The interplay between soft layer deformation and contact angle modulation provides valuable insights into controlling droplet motion through elastocapillarity.","PeriodicalId":50,"journal":{"name":"Langmuir","volume":"10 1","pages":""},"PeriodicalIF":3.9,"publicationDate":"2025-02-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143077043","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":"Protein Orientation and Polymer Phase Separation Induced by Poly(methyl methacrylate) Tacticity","authors":"Natalia Janiszewska, Joanna Raczkowska, Katarzyna Gajos, Kamil Awsiuk","doi":"10.1021/acs.langmuir.4c04699","DOIUrl":"https://doi.org/10.1021/acs.langmuir.4c04699","url":null,"abstract":"Stereochemistry may affect the physicochemical and biological properties of polymer films that are important for their applications, including substrates for the fabrication of protein microarrays. In this study, we investigated the effect of poly(methyl methacrylate) (PMMA) tacticity on the interaction of polymer thin films with proteins and on the phase separation process in blends with poly(<i>tert</i>-butyl methacrylate) (PtBMA). Thin films of isotactic, atactic, and syndiotactic PMMA were studied for topography, surface chemistry, and protein adsorption. Secondary ion mass spectrometry and contact angle measurements revealed a lower surface exposure of polar ester functional groups for iso-PMMA, resulting in the reduced adsorption of albumin and fibrinogen proteins. We also showed that changes in surface chemistry alter the orientation of proteins adsorbed on iso-PMMA through hydrophobic and electrostatic interactions. In addition, blends composed of PMMA and PtBMA, both of different tacticities, were investigated in terms of protein microarray fabrication. The two-dimensional domain structure was obtained by a phase separation process for at-PtBMA blends prepared on silicon substrates modified with amino-silane. Finally, for an isotropic and regular polymer pattern of iso-PMMA/at-PtBMA, the possibility of protein microarray formation on this blend was demonstrated, showing selective adsorption to PtBMA domains and perfect mirroring of the polymer patterns.","PeriodicalId":50,"journal":{"name":"Langmuir","volume":"39 1","pages":""},"PeriodicalIF":3.9,"publicationDate":"2025-02-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143077044","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":"Mechanical Properties and Fracture Mechanisms of Nanocomposites of Metal and Graphene with Overlapping Edges","authors":"Lujuan Li, Qianqian Cao, Xin Hu, Yongze Ma","doi":"10.1021/acs.langmuir.4c03746","DOIUrl":"https://doi.org/10.1021/acs.langmuir.4c03746","url":null,"abstract":"The fracture mechanism and mechanical response of Ni/graphene nanocomposites under nanoindentation are investigated by molecular dynamics simulations. We analyze the effect of the overlapping area on the microstructural transition, HCP atomic fraction, dislocation density, load–displacement relationship, and stress distribution. It was found that the maximum indentation depth of embedded graphene has a nonlinear dependence relation with the overlapping area, and it becomes smaller at the overlapping width comparable to the indenter diameter. The graphene layer is able to hinder the expansion of the dislocation into the interior of the Ni matrix in the initial stage. The densities of HCP atoms and dislocations in the composite gradually increase with increasing indentation depth. The stress concentration tends to cause nucleation of dislocations below the indentation surface. When the graphene is ruptured, the elastic recovery to some extent occurs in the deformed substrate. This work sheds light on modifying the mechanical properties of metal/graphene composites by tuning the overlapping boundary of graphene.","PeriodicalId":50,"journal":{"name":"Langmuir","volume":"33 1","pages":""},"PeriodicalIF":3.9,"publicationDate":"2025-02-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143083734","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":"Silica Janus Particle-Based Coating Applicable to Multiple Substrates Shows Durable Superhydrophobicity, Wear Resistance, and Corrosion Inhibition","authors":"Chuangye Wang, Jianing Ge, Mengyu Cui, Jintang Xue, Huili Liu, Xinrong Song, Xinyi Zhang","doi":"10.1021/acs.langmuir.4c05345","DOIUrl":"https://doi.org/10.1021/acs.langmuir.4c05345","url":null,"abstract":"The present work reports the fabrication of a durable superhydrophobic coating based on silica Janus particles. One side of the silica particles was modified by (3-aminopropyl)triethoxysilane to have a reactive alkylamine group, and the other side was treated with octadecyltrimethoxysilane to be hydrophobic. These Janus particles were held together by binder molecules that reacted with the amines attached to the Janus particles and adhered to different substrates, forming superhydrophobic coatings. The water contact angles of the coatings were higher than 158°, whereas their sliding angles were as low as 2°. Their hydrophobicity was preserved even after 200 cycles of intensive abrasion or after 60 days of immersion in 3.5% NaCl solution, evidencing their durable resistance to abrasion and corrosion. The most remarkable property of the presented Janus silica particle-based coating is that it can strongly adhere to multiple substrates such as active metal aluminum, flat substrate glass, biological material wood, and organic polymer with low surface energy polyperfluoroethylene. Moreover, the hydrophobicity, antiwear resistance, and corrosion inhibition ability of the fabricated coating were independent of the substrates. This superiority enables this coating to cover many substrates with different surface properties to fulfill a variety of technical demands.","PeriodicalId":50,"journal":{"name":"Langmuir","volume":"125 1","pages":""},"PeriodicalIF":3.9,"publicationDate":"2025-02-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143077045","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":"Innovative Electrochemical Nano-Robot: Integrating Printed Nanoelectronics with a Remote-Controlled Robotic for On-Site Underwater Electroanalysis","authors":"Shima Kamran Haghighi, Saba Mohammadlou, Shayan Angizi, Amir Hatamie","doi":"10.1021/acs.langmuir.4c05035","DOIUrl":"https://doi.org/10.1021/acs.langmuir.4c05035","url":null,"abstract":"Smart and remote sensing technologies offer significant advantages across various applications. This study introduces an innovative approach integrating printed electrochemical nanosensors with a remotely controllable underwater robot, creating a “Robo-sensor” for underwater and surface water sensing. Unlike conventional underwater sensors, the Robo-sensor operates in three dimensions, both on the surface and underwater, targeting specific locations such as coastal areas and deep-sea environments while transmitting data to an external analytical unit. To achieve this, we developed a conductive nanoink by combining graphite, silver nanorods (AgNRs; diameter: 30 ± 20 nm, length: 2 ± 0.2 μm), nail polish as a cohesive agent, and an organic solvent. This ink was used to fabricate an electroanalytical system on the mini-robot’s body. The Robo-sensor, connected to a portable potentiostat, demonstrated linear responses to hydroquinone (HQ) and nitrite ions, with detection ranges of 5.0–1356.0 and 3.0–1200.0 μM, respectively, under artificial seawater conditions (High salinity). Its repeatability (RSD &lt;6%), stability (up to 40 continuous applications with an error &lt; ± 10%), and sensitivity were thoroughly evaluated. The Robo-sensor’s practical applications included detecting chemical leaks in underwater pipelines containing HQ, a hazardous chemical relevant to coastal industries such as petrochemicals. Additionally, it analyzed surface water contaminated with NO₂^– near and far from a wastewater discharge pipeline, providing valuable insights for environmental and ecosystem investigations. In conclusion, the developed Robo-sensor enables on-site analysis both on the surface and underwater, reducing time, costs, and risks in high-hazard environments like deep waters. With further modifications, this strategy could be adapted for diverse applications, including offshore oil and petrochemical operations, corrosion studies, and underwater environmental monitoring, thus expanding the real-world impact of electrochemical science.","PeriodicalId":50,"journal":{"name":"Langmuir","volume":"59 1","pages":""},"PeriodicalIF":3.9,"publicationDate":"2025-02-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143083787","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}