Langmuir最新文献

{"title":"Preparation, Acidity, and Catalytic Activity of Synthetic Montmorillonites in α-Pinene Isomerization","authors":"Elena Yu. Brazovskaya, Alexander Yu. Sidorenko, Tatyana V. Khalimonyuk, Yulia A. Alikina, Kristina A. Belyaeva, Shamil O. Omarov, Anatoly V. Dobrodumov, Olga Yu. Golubeva","doi":"10.1021/acs.langmuir.4c04825","DOIUrl":"https://doi.org/10.1021/acs.langmuir.4c04825","url":null,"abstract":"A series of montmorillonites with different Mg and Al contents (Na_2<i>x</i>(Al_{2(1–<i>x</i>)},Mg_2<i>x</i>)Si₄O₁₀(OH)₂·<i>n</i>H₂O, where 0 &lt; <i>x</i> ≤ 1) were prepared by the hydrothermal method and characterized by MAS NMR, XRD, N₂ adsorption–desorption, FTIR with pyridine, TPD-NH₃, SEM, and thermal analysis techniques. The material obtained without aluminum (<i>x</i> = 1), or with a minimum amount of it (<i>x</i> = 0.9) is a trioctahedral saponite becoming a fully dioctahedral montmorillonite at its highest content (<i>x</i> = 0.1). The introduction of aluminum into the montmorillonite structure during its synthesis leads to the appearance of pronounced Brønsted acidity, the highest concentration of which was in montmorillonite with <i>x</i> = 0.1. In contrast, the Al-free sample is practically a Lewis acid (L/B of 71.3). The studied materials possessed catalytic activity in the isomerization of α-pinene, which correlated with the strength of the acid sites. Al-containing montmorillonites yielded camphene with a selectivity of 50–53%, and the presence of medium and strong Brønsted sites favored its formation. In contrast, Mg-montmorillonite with almost exclusively Lewis acidity demonstrated an unusually high selectivity to limonene (44.5%). To the best of our knowledge, this is the first work describing the catalytic activity of synthetic Al–Mg montmorillonite. However, the ease of varying the nature and strength of acid sites in synthetic materials opens up the prospect of their use in a number of reactions, including those for renewable terpene compounds.","PeriodicalId":50,"journal":{"name":"Langmuir","volume":"108 1","pages":""},"PeriodicalIF":3.9,"publicationDate":"2025-04-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143814143","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":"Sulfone-Modulated Aqueous Polymerization-Induced Self-Assembly: Tailoring Adaptive Nanostructures via Competing Supramolecular Interactions","authors":"Tiancheng Xia, Tinghao Zhang, Meng Huo","doi":"10.1021/acs.langmuir.5c00721","DOIUrl":"https://doi.org/10.1021/acs.langmuir.5c00721","url":null,"abstract":"The integration of supramolecular chemistry with polymerization-induced self-assembly (PISA) offers a promising avenue to advance the design and functionality of nanomaterials. Here, we elucidate the role of sulfone bonding in aqueous block copolymer (BCP) self-assembly by evaluating the aqueous PISA behaviors of sulfone-functionalized BCPs and the stimuli-responsive properties of the resulting assemblies. A series of 2-(alkylsulfonyl)ethyl acrylamides were designed for aqueous PISA, in which the sulfone moiety not only enhances monomer water solubility but also stabilizes polymer assemblies through sulfone bonding. Systematic variation of the alkyl tail revealed distinct PISA behaviors, where shorter tails favored sulfone-bond-dominated assembly, while longer tails introduced competitive hydrophobic interactions. This interplay between sulfone bonding and hydrophobicity enabled the fabrication of polymer assemblies with programmable ion-responsive morphology transitions. Our findings provide fundamental insights into the role of supramolecular interactions in PISA and establish a versatile strategy for engineering adaptive nanomaterials.","PeriodicalId":50,"journal":{"name":"Langmuir","volume":"250 1","pages":""},"PeriodicalIF":3.9,"publicationDate":"2025-04-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143814210","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":"Optimization of Material Composition for Improving Mechanical Properties of Fly Ash-Slag-Based Geopolymers: A Deep Learning Approach","authors":"Hang Yu, Yongqi Zhou, Wenjing Xia, Tao Xu","doi":"10.1021/acs.langmuir.4c04969","DOIUrl":"https://doi.org/10.1021/acs.langmuir.4c04969","url":null,"abstract":"Geopolymer is regarded as a novel type of eco-friendly material that may replace cement. To improve the prediction accuracy of mechanical properties of fly ash-slag-based geopolymer (FASGG), as well as optimize material composition and mix design, this study utilizes seven key parameters as variables, and compressive and flexural strengths were as outputs. Deep learning techniques were applied to train and predict 600 sets of experimental data, developing a novel predictive model of MK–CNN–GRU, which integrated Maximal Information Coefficient-K-median algorithm, Convolutional Neural Network, and Gated Recurrent Unit algorithms. Results indicated that the ranking of input parameters which were related with compressive strength was curing age, Ca/Si ratio, fly ash-to-slag ratio, Si/Al ratio, water-to-binder ratio, alkali activator modulus, and alkali equivalent. Three classical models were selected as benchmarks for predicting compressive strength at different curing ages. The MK–CNN–GRU model could fully exploit the internal features of experimental data and learn its variation patterns, resulting in more stable predictive performance. An ablation study of the submodels confirms that MK–CNN–GRU model considers temporal dependencies, long- and short-term features, as well as local dependencies and hierarchical feature representations within the data. Experimental data suggested an exponential relationship between flexural and compressive strengths of FASGG. The predictions for flexural strength indicated that the MK–CNN–GRU model effectively captured variations, demonstrating good generalization ability and applicability. This model enhances the estimation accuracy regarding the mechanical behavior of FASGG, offering a theoretical framework for refining its composition and mix design.","PeriodicalId":50,"journal":{"name":"Langmuir","volume":"19 1","pages":""},"PeriodicalIF":3.9,"publicationDate":"2025-04-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143814207","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":"Engineering the Bioactive Profile of Medicinal Peptides by Multiarm Polyethylene Glycol Conjugation","authors":"Haonan Chen, Yuhang Dong, Feng Shi, Feng Li","doi":"10.1021/acs.langmuir.5c00462","DOIUrl":"https://doi.org/10.1021/acs.langmuir.5c00462","url":null,"abstract":"PEGylation plays a crucial role in peptide modification and has been widely applied in the field of biomedicine, demonstrating significant potential for enhancing peptide drug performance. Herein, we synthesized melittin peptides modified with single arm, double arm, and four arm of PEG12, utilizing lysine side chains as branching points, to systematically investigate the effects of multiarm PEGylation on toxicity, hemolytic activity, stability, and membrane-disrupting ability. Our results revealed that increasing the number of PEG arms significantly reduced the cytotoxicity and hemolytic activity of melittin (with IC₅₀ increasing approximately 20-fold) while simultaneously enhancing serum stability. These effects were attributed to the improved water solubility and altered hydrophilicity/hydrophobicity balance at the N-terminus, which modulated the interactions with cell membranes and reduced the membrane penetration capacity. Meanwhile, the steric hindrance effect that was caused by multiarm PEG modification prevented the destruction of cell membranes by melittin. The strategy of terminal PEGylation was expected to minimize systemic toxicity and in vivo degradation. Collectively, our findings highlight the critical role of the topological structure PEG in fine-tuning peptide drug performance, providing valuable insights for the design of safer and more effective peptide-based therapeutics.","PeriodicalId":50,"journal":{"name":"Langmuir","volume":"1 1","pages":""},"PeriodicalIF":3.9,"publicationDate":"2025-04-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143798588","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":"Regional Characteristics in Ultradeep MXene Slit Nanopores: Insights from Molecular Dynamics Simulation","authors":"Kaiqing Sun, Daqian Wang, Guohui Zhou, Xiaomin Liu","doi":"10.1021/acs.langmuir.5c00435","DOIUrl":"https://doi.org/10.1021/acs.langmuir.5c00435","url":null,"abstract":"The presence of slit nanopores in MXene materials inevitably influences the electrochemical performance of supercapacitor electrodes. However, most studies focus on experimental approaches, lacking microscopic-scale analysis. Here, we performed molecular dynamics (MD) simulations to thoroughly analyze and predict the ion transport pathways and energy storage mechanisms of MXene/ionic liquid (IL) supercapacitors with ultradeep slit nanopores. The simulation results indicate that during the charging process, counterions migrate from the bulk region into the electrode pores, forming a counterion layer near the electrode surface, while some co-ions gradually exit the pores. When charging is completed, a distinct ion layering structure emerges. As the interlayer spacing varies, the ion distribution in the electrode pores exhibits regional characteristics: in the ordered region near the bulk region, a stable electrical double-layer (EDL) structure is maintained, whereas in the deeper mixed region, persistent co-ion presence and significant disorder are observed. Dominated by the mixed region, the total energy variation of the electrode decreases as the interlayer spacing decreases, with energy changes of 8526.52, 7443.52, and 6640.99 kJ·mol^–1 at interlayer spacings of 1.2, 1.0, and 0.8 nm, respectively, representing reductions of approximately 12.7 and 22.1% compared to 1.2 nm. In the mixed region, after compensating for the interaction between counterions, the contribution of the interaction between counterions and electrode increases with decreasing interlayer spacing, reaching 123, 153, and 176% at 1.2, 1.0, and 0.8 nm, respectively. An increasing amount of energy is offset by interactions related to the co-ions, ultimately leading to the observed energy differences. These findings offer new insights into the impact of nanopore structure on supercapacitor performance and provide theoretical guidance for optimizing electrode design.","PeriodicalId":50,"journal":{"name":"Langmuir","volume":"74 1","pages":""},"PeriodicalIF":3.9,"publicationDate":"2025-04-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143798584","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":"Selective Recovery of Gold from Aqueous Media Using Magnetic PEG-Crosslinked Polystyrene","authors":"Seyed Mehdi Sajjadi, Sajad Ahmadi, Hossein Behniafar, Ehsan Nazarzadeh Zare","doi":"10.1021/acs.langmuir.5c00700","DOIUrl":"https://doi.org/10.1021/acs.langmuir.5c00700","url":null,"abstract":"PEG-cross-linked and triethylenetetramine (TETA)-terminated polystyrene chains were formed on the surface of magnetic nanoparticles through atom transfer radical polymerization (ATRP). The prepared organic–inorganic hybrid material (denoted as MNP-PEGPS-L) was used to adsorb Au(III) ions from aqueous solutions. The MNP-PEGPS-L adsorbent was characterized by Fourier transform infrared spectroscopy (FTIR), thermogravimetric analysis (TGA), scanning electron microscopy (SEM), energy-dispersive X-ray (EDX), X-ray diffraction (XRD), and vibrating-sample magnetometry (VSM). BET measurements showed that the particles have a porous structure, and their specific surface area was found to be 29.13 m²·g^–1. Dynamic light scattering (DLS) analysis revealed that the hydrodynamic diameter distribution of the adsorbent particles follows a bimodal pattern, with two peaks appearing at 705 nm and 4087 nm. The particles in an aqueous solution with pH = 3 exhibited the highest zeta potential value (+22 mV) and, therefore, showed greater resistance to agglomeration. In adsorption studies, the equilibrium concentrations of ions (<i>C</i>_e values) were measured using inductively coupled plasma optical emission spectrometry (ICP-OES). The equilibrium adsorption capacity (<i>Q</i>_e) was optimized in Au(III)-containing solutions at a pH of 3, an adsorbent dose of 0.2 mg·mL^–1, a contact time of 60 min, and a temperature of 25 °C. Examination of the adsorption kinetics indicated that the adsorption of Au(III) ions occurs via chemisorption. The maximum adsorption capacity (<i>Q</i>_max) obtained from the Langmuir isotherm model (monolayer adsorption), was measured to be approximately 280 mg·g^–1. Additionally, the study of the thermodynamics of adsorption demonstrated that the adsorption phenomenon is endothermic and occurs spontaneously. Overall, the prepared magnetic polymer adsorbent showed promising results in the recovery of gold ions from aqueous solutions due to its high hydrophilicity, high porosity, and excellent recyclability.","PeriodicalId":50,"journal":{"name":"Langmuir","volume":"37 1","pages":""},"PeriodicalIF":3.9,"publicationDate":"2025-04-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143798462","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":"Computational Insights into the Energetics of Single C2–C10 Aliphatic Moieties Adsorbed on the Hydrogenated Silicon (111) Surface","authors":"Francesco Buonocore, Sara Marchio, Simone Giusepponi, Massimo Celino","doi":"10.1021/acs.langmuir.4c05103","DOIUrl":"https://doi.org/10.1021/acs.langmuir.4c05103","url":null,"abstract":"Silicon’s versatility as a semiconductor renders it indispensable across various domains, including electronics, sensors, and photovoltaics. Modifying hydrogen-terminated silicon surfaces with moiety adsorption offers a method to tailor the material’s properties for specific applications. In this study, we employ ab initio density functional theory calculations to explore the energetics of single alkyl, 1-alkenyl, and 1-alkynyl moieties chemisorbed on the hydrogen-terminated silicon (111) surface. We analyze the interfacial dipole induced by Si–C bond formation that determines the Schottky barrier and examine the alignment of the frontier orbital energy levels with the silicon band structure to investigate charge transfer based on the tunneling mechanism. Our findings provide valuable insights into how aliphatic moiety functionalization affects interfacial electronic properties, offering clues for optimizing silicon-based devices.","PeriodicalId":50,"journal":{"name":"Langmuir","volume":"38 1","pages":""},"PeriodicalIF":3.9,"publicationDate":"2025-04-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143798422","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":"In-Situ Simple Fabrication of Superhydrophobic and Bacteriostatic Indole-Based Sponge via Strong π–π Stacking for Efficient Oil–Water Emulsion Separation","authors":"Rui Yuan, Dongjin Xie, Taolang Tang, Huijuan Zhang, Ying Huang, Tengning Ma, Li Yang, Qilong Cao, Guanjun Chang","doi":"10.1021/acs.langmuir.5c00054","DOIUrl":"https://doi.org/10.1021/acs.langmuir.5c00054","url":null,"abstract":"Sorbent materials for efficient oil–water separation are crucial due to the increasing discharge of industrial and environmental oil pollutants. Herein, we report the fabrication of a superhydrophobic and bacteriostatic poly(triazatruxene) (PTAT)-coated melamine sponge (MF@PTAT) via a one-step in situ polymerization method, utilizing strong π–π stacking interactions between the triazatruxene rings and melamine skeleton. The MF@PTAT material displayed a water contact angle of 158.6°, high porosity, and excellent compression recovery, with an outstanding ability to absorb oils and organic solvents, up to 186.7 g/g. Furthermore, the material demonstrated excellent performance in separating oil–water emulsions, achieving an impressive efficiency of 99.3%. In addition, MF@PTAT demonstrated significant antibacterial performance, effectively inhibiting bacterial growth. The combination of a simple fabrication method, superior oil–water separation efficiency, and strong antibacterial properties makes the low-cost MF@PTAT material highly promising for oil contaminant treatment across various applications.","PeriodicalId":50,"journal":{"name":"Langmuir","volume":"38 1","pages":""},"PeriodicalIF":3.9,"publicationDate":"2025-04-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143806223","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":"Comprehensive Analysis of the Structural Evolution and Dynamic Mechanical Behavior of Ferrofluids through Coarse-Grained Molecular Dynamics and Experimental Testing","authors":"Penghui Zhao, Ning Ma, Tianxiang Du, Xufeng Dong","doi":"10.1021/acs.langmuir.4c04390","DOIUrl":"https://doi.org/10.1021/acs.langmuir.4c04390","url":null,"abstract":"Understanding and predicting the relationship between the dynamic structure and dynamic mechanical behavior of ferrofluids at the mesoscale presents a significant challenge. Therefore, in this study, a ferrofluid model that considered the molecular structure of the carrier liquid was constructed to perform coarse-grained molecular dynamics simulations of the mesoscale structural evolution and internal particle arrangement characteristics of ferrofluids under the influence of a magnetic field. Subsequently, oscillatory shear deformation was applied to further investigate the mechanical properties of ferrofluids under dynamic strain, as well as the deformation and disruption of their orientational structures. The simulations show that the columnar aggregation of magnetic particles imparts typical viscoelastic characteristics to the ferrofluid, and these aggregated structures gradually deform and break down as the strain amplitude increases. During dynamic oscillatory shear deformation, the enhancement of the magnetic field allows the aggregated structure of magnetic particles to exhibit better resistance to deformation, thereby improving the absorption and dissipation of mechanical energy. The dynamic mechanical properties of ferrofluids obtained from coarse-grained simulations closely align with the experimental results under moderate to high magnetic fields, allowing for a certain degree of predictive capability regarding the dynamic mechanical behavior of ferrofluids.","PeriodicalId":50,"journal":{"name":"Langmuir","volume":"30 1","pages":""},"PeriodicalIF":3.9,"publicationDate":"2025-04-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143798398","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":"Photothermal Superhydrophobic Zinc Oxide Cotton Fabric Based on an Impregnation Method","authors":"Guangli Chen, Yuxuan Zhang, Kangwei Zhang, Wenjun Lv, Zaosheng Lv, Xiaofang Gao, Yanfen Huang","doi":"10.1021/acs.langmuir.5c00316","DOIUrl":"https://doi.org/10.1021/acs.langmuir.5c00316","url":null,"abstract":"Superhydrophobic materials have applications such as oil–water separation, antifouling, and antibacterial properties. At present, most of the manufacturing process of superhydrophobic coatings not only is costly but also causes pollution to the environment, which is not in line with the concept of green and sustainable development. In this work, we have prepared a superhydrophobic coating using green and environmentally friendly chitosan, nanozinc oxide, γ-aminopropyl triethoxysilane (KH550), and stearic acid. The prepared cotton fabric showed remarkable superhydrophobic properties. Under simulated sunlight, the surface temperature of the superhydrophobic cotton fabric can increase to 50 °C. The superhydrophobic surface sustained its superhydrophobic property after at least 80 tape peeling tests, 50 occurrences of sandpaper friction, 3.5 h of washing, and 24 h of high-temperature heat treatment. Besides, the coating can be utilized for oil–water separation and is reusable. The oil–water separation effectiveness of the coating reaches more than 95%. Therefore, this inexpensive and ecofriendly nanozinc oxide/chitosan-based superhydrophobic coating has remarkable application potential.","PeriodicalId":50,"journal":{"name":"Langmuir","volume":"24 1","pages":""},"PeriodicalIF":3.9,"publicationDate":"2025-04-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143798399","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}