Langmuir最新文献

{"title":"Engineering Ag-Modified BiOCl as an Efficient and Effective Catalyst for Solar Light-Driven Organic Pollutant Degradation and Hydrogen Production.","authors":"Preety Yadav, Neeraj Dhariwal, Manju Kumari, Amit Sanger, Vinod Kumar, Om Prakash Thakur","doi":"10.1021/acs.langmuir.4c03550","DOIUrl":"10.1021/acs.langmuir.4c03550","url":null,"abstract":"<p><p>The direct conversion of solar energy into clean fuels has emerged as an effective approach for future energy production and addressing environmental challenges. This research focuses on the synthesis of BiOCl using a straightforward hydrothermal method with Ag modification achieved through green synthesis. These materials were applied to enhance photocatalytic processes and hydrogen (H₂) evolution. Comprehensive characterization of the synthesized photocatalysts was performed by using techniques, such as XRD, SEM, BET, XPS, and UV-vis spectroscopy. The Ag/BiOCl composite demonstrated impressive photocatalytic performance, achieving degradation rates of 96% for RhB, 87.7% for TC, and 85% for HQ under 18 min of solar irradiation. Additionally, a high mineralization rate of 92% was observed through Total Organic Carbon (TOC) analysis. Furthermore, the Ag/BiOCl composite exhibited a significant H₂ evolution rate of 565 μmol g^-1 h^-1, which is nearly double that of pure BiOCl. The interaction between Ag and BiOCl was found to enhance the generation of O₂- radicals, as confirmed by radical trapping experiments, with the underlying mechanism elucidated using LC-HRMS. The nanoparticles also demonstrated excellent degradation of industrial waste, highlighting the potential of Ag/BiOCl for use in the purification and sterilization of industrial effluents.</p>","PeriodicalId":50,"journal":{"name":"Langmuir","volume":null,"pages":null},"PeriodicalIF":3.7,"publicationDate":"2024-11-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142542893","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 Coordination Environment in the Silver(I)- and Ruthenium(II)-<i>N</i>-Heterocyclic Carbene Complexes in Instigating the Electrocatalytic Hydrogen Evolution Reaction.","authors":"Monica Vijayakumar, Jan Grzegorz Małecki, Doddahalli H Nagaraju, Rangappa Sangappa Keri, Srinivasa Budagumpi","doi":"10.1021/acs.langmuir.4c03248","DOIUrl":"10.1021/acs.langmuir.4c03248","url":null,"abstract":"<p><p>The quest for cost-efficient and high-performance electrocatalysts towards electrocatalytic water splitting is a key and an interdisciplinary area of study. Considerable progress is being driven by developments in the field of energy research. In a fundamental study, we have synthesized NHC precursors (<b>6</b> and <b>7</b>) and corresponding metal-NHC complexes of silver(I)- (<b>8</b> and <b>9</b>) and ruthenium(II)- (<b>10</b> and <b>11</b>) of a N-heterocyclic carbene-based ligand type incorporating coumarins. These NHC precursors and metal-NHC complexes were characterized through various analytical and spectral techniques. The silver(I)-NHC complexes <b>8</b> and <b>9</b> displayed a linear coordination geometry with a center of inversion, which is evidenced by the single-crystal X-ray diffraction technique. Both the series of complexes were assessed for their efficacies in the hydrogen evolution reaction (HER). The results demonstrated that attributed to its peculiar coordination geometry, high electrical conductivity the silver(I)- and ruthenium(II)-NHC complexes exhibited exemplary electrocatalytic activity. Activities of the hydrogen evolution reaction on two differently modified electrode substrates with metal-NHC complexes have been studied. To attain the benchmark HER current density of 10 mA cm^-2, in 1.0 M KOH, an overpotential of -375 to -527 mV vs RHE was required for the metal-NHC complexes. Based on the analysis of the Tafel slope values, the rate-determining step was the adsorption of hydrogen as investigated in the potential window. The molecular electrocatalyst <b>10</b> presented a superior stability and maintained the electrocatalytic activity for a duration of 18 h with complex <b>8</b> and 24 h with respect to complex <b>10</b> in 1.0 M KOH. Apace with these studies, hydrogen oxidation studies were examined in 0.5 M H₂SO₄ by a substantial current density at the platinum ring electrode. This research offers feasible guidance for developing organometallic-based molecular electrocatalysts with good electrocatalytic performance.</p>","PeriodicalId":50,"journal":{"name":"Langmuir","volume":null,"pages":null},"PeriodicalIF":3.7,"publicationDate":"2024-11-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142556637","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":"Influence of SHMP Concentration on Rutile Flotation in BHA System: Guiding the Separation of Rutile and Hornblende.","authors":"Pengfei Song, Liuyi Ren, Shenxu Bao, Yimin Zhang, Wenqing Qin, Anh V Nguyen, Bo Chen","doi":"10.1021/acs.langmuir.4c03027","DOIUrl":"10.1021/acs.langmuir.4c03027","url":null,"abstract":"<p><p>Sodium hexametaphosphate (SHMP) is a common depressant used in rutile flotation, especially for silicate gangue minerals such as amphibole. However, the experiment found that in the benzyl hydroxamic acid (BHA) system, SHMP of small concentrations affected the flotation recovery of rutile. In this work, the influence mechanism of SHMP concentration on the flotation of rutile in the BHA system was studied by flotation test, adsorption capacity determination, ζ potential determination, infrared spectrum analysis, and X-ray photoelectron spectroscopy (XPS) analysis. The test results show that in the BHA system, SHMP chemically adsorbs on the rutile surface, hindering the effect of BHA on the rutile surface, and hydrolyzes in the pulp to form hydrophilic colloids. When the concentration of BHA is 40 mg/L and that of SHMP is 6 mg/L, the effect of SHMP is the most obvious. However, with the increase of SHMP concentration to 8-10 mg/L, its effect on the recovery of rutile became very weak. When the concentration of SHMP is lower than 6 mg/L, the SHMP anion-metaphosphate ion (SHMP^-) interacts with the hydrophilic colloidal particles on the surface of rutile, which affects the combination of BHA and the active sites on the surface of rutile, thus affecting the recovery of rutile. When the concentration of SHMP continues to increase, the SHMP^- adsorbed on the rutile surface is removed from the rutile surface due to the charge repulsion and the competitive adsorption of BHA.</p>","PeriodicalId":50,"journal":{"name":"Langmuir","volume":null,"pages":null},"PeriodicalIF":3.7,"publicationDate":"2024-11-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142491164","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":"Ab Initio Molecular Dynamics Investigation of Water and Butanone Adsorption on UiO-66 with Defects.","authors":"Brianne Boyd, Deep Choudhuri, N Scott Bobbitt","doi":"10.1021/acs.langmuir.4c02502","DOIUrl":"10.1021/acs.langmuir.4c02502","url":null,"abstract":"<p><p>Volatile organic compounds (VOCs) are harmful chemicals that are found in minute quantities in the atmosphere and are emitted from a variety of industrial and biological processes. They can be harmful to breathe or serve as biomarkers for disease detection. Therefore, capture and detection of VOCs is important. Here, we have examined if the Zr-based UiO-66 metal-organic framework (MOF) can be used to capture butanone─a well-known VOC. Toward that end, we have performed Born-Oppenheimer ab initio molecular dynamics (AIMD) at 300 and 500 K to probe the energetics and molecular interactions between butanone [CH₃C(O)CH₂CH₃] and open-cage Zr-UiO-66. Such interactions were systematically interrogated using three MOF structures: defective MOF with a missing 1,4-benzene-dicarboxylate linker and two H₂O; pristine MOF with two H₂O; and pristine dry MOF. These structures were loaded with one and four molecules of butanone to examine the effect of concentration as well. One-molecule loading interacted favorably with the defective structure at 300 K, only. In comparison, interactions with four-molecule loading were energetically favorable for all conditions. Persistent hydrogen bonds between the O atom of butanone, H₂O, and μ₃-OH hydroxyl attachments at Zr nodes substantially contributed to the intermolecular interactions. At higher loadings, butanone also showed a pronounced tendency to diffuse into the adjoining cages of Zr-UiO-66. The effect of such movement on interaction energies was rationalized using simple statistical mechanics-based models of interacting and noninteracting gases. Broadly, we learn that the presence of prior moisture within the interstitial cages of Zr-UiO-66 significantly impacts the adsorption behavior of butanone.</p>","PeriodicalId":50,"journal":{"name":"Langmuir","volume":null,"pages":null},"PeriodicalIF":3.7,"publicationDate":"2024-11-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142542892","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":"Kinetics of Adsorption-Induced Deformation of Microporous Carbons.","authors":"Andrei L Kolesnikov, Andrey V Shkolin, Ilya E Men'shchikov, Gennady Y Gor","doi":"10.1021/acs.langmuir.4c02779","DOIUrl":"10.1021/acs.langmuir.4c02779","url":null,"abstract":"<p><p>Equilibrium and kinetic behavior of adsorption-induced deformation have attracted a lot of attention in the last few decades. The theoretical and experimental works cover activated carbons, coals, zeolites, glasses, etc. However, most of the theoretical works describe only the equilibrium part of the deformation process or focus on the time evolution of the adsorption process. The present paper aims to cover the existing gap using the thermodynamic framework combined with the diffusion-based description of adsorbate time evolution inside an adsorbent. We obtained self-consistent equations describing equilibrium and out-of-equilibrium adsorption, as well as deformation processes. Further, the obtained equations were verified on the experimental data of carbon dioxide and methane on activated carbons. The model is capable of describing both equilibrium and kinetic adsorption and adsorption-induced deformation data. Additionally, we studied the possible influence of slow relaxation processes in the adsorbent on the adsorption process. The current work helps to interpret experimental data for time-dependent adsorption-induced deformation.</p>","PeriodicalId":50,"journal":{"name":"Langmuir","volume":null,"pages":null},"PeriodicalIF":3.7,"publicationDate":"2024-11-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142542894","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":"Strong Affinity between Astatine and Silver: An Available Approach to Anchoring ²¹¹At in Nanocarrier for Locoregional Oncotherapy.","authors":"Ruitong Hou, Tianzhen Ye, Yilin Qin, Long Qiu, Jie Lyu, Fuyuan Tan, Yuanyou Yang, Songji Zhao, Ning Liu, Feize Li","doi":"10.1021/acs.langmuir.4c02150","DOIUrl":"10.1021/acs.langmuir.4c02150","url":null,"abstract":"<p><p>Recently, ²¹¹At-related endoradiotherapy has emerged as an important oncotherapy strategy. Conjugating ²¹¹At with a nanocarrier provides a vital candidate for radionuclide therapy of various malignant tumors. In this study, we proposed utilizing the intrinsically high affinity of heavy halogens and sulfhydryl compounds for metallic silver to achieve highly efficient conjugation between ²¹¹At and Ag-based nanoparticles in a simple way. ²¹¹At@Ag-PEG-FA was obtained via a one-pot assembly of ²¹¹At, Ag, and SH-PEG-FA in extremely high radiolabeling yield (>95%) within 15 min and maintained excellent stability in simulated physiochemical media. Additionally, the prepared ²¹¹At@Ag-PEG-FA demonstrated specific binding to the breast cancer cell line (4T1), with a high endocytosis rate and low reflux, leading to significant cell growth inhibition. ²¹¹At@Ag-PEG-FA exhibits an excellent antitumor effect that completely suppressed tumor growth during the first week, effectively prolonging the median survival of mice to 44 days, relative to 18 days in the control group. All of the mice exhibited minimal side effects from ²¹¹At@Ag-PEG-FA in the experiment, indicating its acceptable biosafety. Our work shows that the strong affinity of Ag can be utilized to produce radioactivated nanomedicines with excellent stability and high efficiency, which also provides some valuable insights for the ²¹¹At radiolabeling of general compounds.</p>","PeriodicalId":50,"journal":{"name":"Langmuir","volume":null,"pages":null},"PeriodicalIF":3.7,"publicationDate":"2024-11-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142542898","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":"Inhibition of Polyphenol Oxidase Activity by Mesoporous Silica Nanoparticles and Multiwalled Carbon Nanotubes Modified with Surfactants.","authors":"Xiaonan Fan, Xin Xu, Shuhuai Xia, Yanrong Cheng, Xia Guo","doi":"10.1021/acs.langmuir.4c03850","DOIUrl":"10.1021/acs.langmuir.4c03850","url":null,"abstract":"<p><p>Polyphenol oxidase (PPO) is the culprit behind the browning of fruits and vegetables. Therefore, how to reduce the thermal deactivation temperature of PPO or use as few safe reagents as possible to inhibit enzymatic browning has practical significance. Mesoporous silica nanoparticles (MSNs) and multiwalled carbon nanotubes (MWCNTs) are stable and have high biosafety. In the present study, efficient PPO inhibitors were developed based on MSNs and MWCNTs. It is found that after modification with a very small amount of dodecyl trimethylammonium bromide (DTAB, ≥60 μg/mL), MSNs can significantly inhibit the activity of PPO although single MSNs and single DTAB show very limited effect on PPO activity. After modification with a very small amount of sodium dodecyl sulfate (SDS, 5.7-9.5 μg/mL), MWCNTs almost completely inactivate PPO. However, SDS@MSN and DTAB@MWCNT cannot decrease PPO activity significantly.</p>","PeriodicalId":50,"journal":{"name":"Langmuir","volume":null,"pages":null},"PeriodicalIF":3.7,"publicationDate":"2024-11-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142556639","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":"Quantitative Analysis of TPU Microstructure and Performance Optimization across Various Processing Conditions.","authors":"Guangzhi Jin, Yuzhen Gong, Jun Wang, Min Wang, Jiadong Wang, Runguo Wang, Xuan Qin, Yonglai Lu","doi":"10.1021/acs.langmuir.4c03093","DOIUrl":"10.1021/acs.langmuir.4c03093","url":null,"abstract":"<p><p>Thermoplastic polyurethane (TPU) is essential in resource exploration, healthcare, automotive, and high-end recreational sports. Despite extensive research on TPU's microstructures and their macroscopic properties, the impact of processing conditions like compression and injection molding remains underexplored. This study investigates the influence of processing conditions on TPU by preparing samples with varying hard segment contents using compression molding at 205 °C and injection molding at melt temperatures of 205, 210, 215, and 220 °C, followed by heat treatment at 120 °C for 12 h. Results indicate that injection-molded TPU at 205 °C exhibits lower hydrogen bonding, crystallinity, long period, interfacial thickness, and lamella thickness than compression-molded TPU, leading to higher Young's modulus but lower elongation at break. As melt temperatures increase, these microstructural parameters decrease, reducing Young's modulus and increasing elongation at break. Post heat treatment, microstructural parameters increase, aligning Young's modulus with that of compression-molded samples, while elongation at break surpasses them. This suggests that heat treatment enhances microphase separation by rearranging hard and soft segments. our research reveals a consistent pattern across TPUs with varying hard segment contents, indicating that adjusting processing parameters can effectively regulate microstructure and performance, offering valuable insights for developing high-performance polyurethanes.</p>","PeriodicalId":50,"journal":{"name":"Langmuir","volume":null,"pages":null},"PeriodicalIF":3.7,"publicationDate":"2024-11-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142556642","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":"Fatigue Behavior of Polymer Nanocomposites under Low-Strain Cyclic Loading: Insights from Molecular Dynamics Simulation.","authors":"Tongkui Yue, Hengheng Zhao, Jiajun Qu, Liqun Zhang, Jun Liu","doi":"10.1021/acs.langmuir.4c02769","DOIUrl":"10.1021/acs.langmuir.4c02769","url":null,"abstract":"<p><p>Understanding the structural evolution and bond-breaking behavior under cyclic loading is crucial for designing polymer nanocomposites (PNCs) with superior fatigue resistance. Coarse-grained models of PNCs filled with spherical carbon black nanoparticles (NPs) at varying filling fractions of φ were successfully constructed using molecular dynamics simulations. Structural and dynamic simulation results reveal that higher φ leads to increased aggregation of NPs and markedly restricts the relaxation behavior of the polymer matrix. Subsequently, fatigue testing of PNCs was conducted under low-strain cyclic tensile deformation, and the real-time bond-breaking behavior was tracked. The decay behavior of the bond number autocorrelation function was found to be accurately described by the KWW equation, enabling precise determination of the characteristic lifetime τ_<i>f</i>. With increasing φ, the dominant factor influencing bond-breaking behavior gradually shifts from the polymer network, including entanglements and cross-linking networks, to the filler network. This suggests the presence of a critical filling fraction φ_<i>c</i> where τ_<i>f</i> is maximized. For low-strain failure mechanisms, temperature field observations at varying cycles reveal that localized temperature rise emerges as the predominant factor. Furthermore, the mobility of both polymers and NPs increases with cycles. Specifically, the diffusion coefficient of polymer monomers shows a clear power-law relationship with the bond-breaking rate, characterized by <math><mi>D</mi><mo>∼</mo><msup><msub><mi>f</mi><mi>broken</mi></msub><mn>1.5</mn></msup></math>. Finally, the stiffness of polymer chains significantly influences the fatigue behavior, evidenced by an initial increase followed by a decrease in the τ_<i>f</i> with increasing bending energy <i>k</i>. This behavior is attributed to the competitive relationship between high entanglement density at low <i>k</i> and enhanced preorientation at high <i>k</i>. In summary, this study provides a general paradigm for describing failure behavior under cyclic deformation and offers insights into fatigue mechanisms at the molecular level, thereby guiding the development of improved fatigue-resistant PNCs.</p>","PeriodicalId":50,"journal":{"name":"Langmuir","volume":null,"pages":null},"PeriodicalIF":3.7,"publicationDate":"2024-11-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142566408","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 of Raspberry-like PMMA Particles In a Ternary Solvent Mixture with Binary Initiators","authors":"Ruisi Li, Shuying Han, Peiyuyao Gong, Hua Zou","doi":"10.1021/acs.langmuir.4c02861","DOIUrl":"https://doi.org/10.1021/acs.langmuir.4c02861","url":null,"abstract":"There is continuing interest in the synthesis of raspberry-like polymer particles, among which most of the reports have tended to focus on polymer composite particles, while there are relatively few examples of polymer particles with a single component. In this study, raspberry-like poly(methyl methacrylate)(PMMA) particles were synthesized by a one-step method in a ternary solvent mixture with binary initiators. The effects of different polymerization parameters, including the solvent composition, the initiator composition, the stabilizer component, the polymerization temperature, the stirring rate, and the nature of the monomer, on the morphology and size of the resulting particles were studied. A plausible mechanism for raspberry-like particle formation was suggested based on the monitoring data of the polymerization kinetics. The raspberry-like PMMA particles have a high dispersion stability in a salty aqueous environment.","PeriodicalId":50,"journal":{"name":"Langmuir","volume":null,"pages":null},"PeriodicalIF":3.9,"publicationDate":"2024-11-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142599638","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}