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Self-assembled Nanostructures of Noncovalent Giant Amphiphilic Molecules Composed of Hydrophobic Isobutyl BPOSS and Hydrophilic POM in Different Cosolvents
IF 3.9 2区 化学
Langmuir Pub Date : 2025-02-21 DOI: 10.1021/acs.langmuir.4c04842
Fengfeng Feng, Dongcheng Xiao, Fan Yang, Hao Liu, Minghai Qu, Weijie Wang
{"title":"Self-assembled Nanostructures of Noncovalent Giant Amphiphilic Molecules Composed of Hydrophobic Isobutyl BPOSS and Hydrophilic POM in Different Cosolvents","authors":"Fengfeng Feng, Dongcheng Xiao, Fan Yang, Hao Liu, Minghai Qu, Weijie Wang","doi":"10.1021/acs.langmuir.4c04842","DOIUrl":"https://doi.org/10.1021/acs.langmuir.4c04842","url":null,"abstract":"The self-assembly of giant amphiphilic molecules with diverse topological structures has been widely investigated in bulk, solution, and interfacial environments because it can lead to interesting geometric patterns. However, many giant molecules or their self-assembling units are built by covalent bonds, which may limit the movement of the molecular blocks, affecting the self-assembly process and microstructure. In contrast, the self-assembly of giant units with noncovalent interactions can lead to interesting nanomorphologies and nanostructures. In this study, we built giant amphiphilic molecules (BPOSS&POM) by forming electrostatic interactions between hydrophobic isobutyl polyhedral oligomeric silsesquioxanes (BPOSSs) and hydrophilic polyoxometalates (POMs) to investigate the self-assembly behavior in water/acetone, water/THF, and hexane/acetone cosolvents. By controlling the solvent parameters, BPOSS&POM self-assembled into nanosheet, nanobelt, nanosphere, and nanocrumb structures. The morphology and detailed nanostructure of the different self-assemblies were revealed by performing transmission electron microscopy (TEM), scanning electron microscopy (SEM), and small-angle X-ray scattering (SAXS) measurements. The TEM and SAXS results indicated that the self-assembly microphase exhibited a lamellar structure and an interlayer distance of about 3 nm. The microphase structure of the self-assembly was alternatively organized by layers of BPOSS and POM according to their size and dimension. The polarity of the solvents substantially affected the morphology of the nanoassemblies but not the aggregation behavior of BPOSS and POM. This research offers insights into the preparation of nanomaterials with diverse micromorphologies by simply adjusting the solution components.","PeriodicalId":50,"journal":{"name":"Langmuir","volume":"11 1","pages":""},"PeriodicalIF":3.9,"publicationDate":"2025-02-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143463200","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}
引用次数: 0
Designing Highly Flame-Retardant Wood Through an In Situ Chemical Modification Strategy
IF 3.9 2区 化学
Langmuir Pub Date : 2025-02-21 DOI: 10.1021/acs.langmuir.4c04605
Yi Sun, Wenlong Sun, KangKang Zhang, Siyu Cui, Xiong Shao, Jian Qiu, Yushan Yang, Jun Li
{"title":"Designing Highly Flame-Retardant Wood Through an In Situ Chemical Modification Strategy","authors":"Yi Sun, Wenlong Sun, KangKang Zhang, Siyu Cui, Xiong Shao, Jian Qiu, Yushan Yang, Jun Li","doi":"10.1021/acs.langmuir.4c04605","DOIUrl":"https://doi.org/10.1021/acs.langmuir.4c04605","url":null,"abstract":"In order to improve the specimens’ flame-retardant qualities, ethyl orthosilicate was impregnated into them using a combination of the delignification process and the in situ growing approach. Lignification has been demonstrated to increase the cellular gap of the specimen and to maximize the impregnation of ethyl orthosilicate. Moreover, the in situ growth method results in the combination of specimens containing silica manufactured from ethyl orthosilicate, thereby forming a composite material with enhanced flame-retardant properties. The examination of the changes in the properties of the specimens before and after modification was conducted using FTIR spectroscopy, XRD, XPS, SEM, and other experimental techniques. The modified specimens exhibited higher properties in comparison to the untreated specimens. Furthermore, the modified specimens exhibited enhanced mechanical properties, characterized by an augmented compressive strength of 34.9 MPa and a strength-to-weight ratio of 158 MPa·cm·g<sup>–1</sup>, in comparison to specimens that did not undergo the modification process. The results of experiments show that proposed green technology provides a new method for producing flame-retardant composites and could significantly improve the mechanical and flame-retardant qualities of wood.","PeriodicalId":50,"journal":{"name":"Langmuir","volume":"25 1","pages":""},"PeriodicalIF":3.9,"publicationDate":"2025-02-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143463059","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}
引用次数: 0
Retraction of “RNA-Mediated Synthesis of Palladium Nanoparticles on Au Surfaces”
IF 3.9 2区 化学
Langmuir Pub Date : 2025-02-21 DOI: 10.1021/acs.langmuir.5c00361
Dage Liu, Lina A. Gugliotti, Tong Wu, Magda Dolska, Alexander G. Tkachenko, Mathew K. Shipton, Bruce E. Eaton, Daniel L. Feldheim
{"title":"Retraction of “RNA-Mediated Synthesis of Palladium Nanoparticles on Au Surfaces”","authors":"Dage Liu, Lina A. Gugliotti, Tong Wu, Magda Dolska, Alexander G. Tkachenko, Mathew K. Shipton, Bruce E. Eaton, Daniel L. Feldheim","doi":"10.1021/acs.langmuir.5c00361","DOIUrl":"https://doi.org/10.1021/acs.langmuir.5c00361","url":null,"abstract":"The Editor retracts this article (DOI: 10.1021/la060426c) due to its reliance on findings from a previously published article, “RNA-Mediated Metal–Metal Bond Formation in the Synthesis of Hexagonal Palladium Nanoparticles” (DOI: 10.1126/science.1095678) which was retracted (DOI: 10.1126/science.351.6273.569-a) following an investigation by the U.S. National Science Foundation’s (NSF) Office of Inspector General. The experiments presented in the article are based on retracted premises, and concerns about the integrity of the research findings remain unresolved, as the authors could not be reached for a response. As such, the article is being retracted. The original article was published on May 17, 2006, and was retracted on February 21, 2025. This article has not yet been cited by other publications.","PeriodicalId":50,"journal":{"name":"Langmuir","volume":"20 1","pages":""},"PeriodicalIF":3.9,"publicationDate":"2025-02-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143463060","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}
引用次数: 0
Enhanced Flotation for the Removal of Pharmaceutical Contaminants from Water Systems Using Graphene Oxide–CTAB Nanocomposites
IF 3.9 2区 化学
Langmuir Pub Date : 2025-02-21 DOI: 10.1021/acs.langmuir.4c04066
Gowri Pooja, Ponnusamy Senthil Kumar, Chitra Boobalan, Gayathri Rangasamy
{"title":"Enhanced Flotation for the Removal of Pharmaceutical Contaminants from Water Systems Using Graphene Oxide–CTAB Nanocomposites","authors":"Gowri Pooja, Ponnusamy Senthil Kumar, Chitra Boobalan, Gayathri Rangasamy","doi":"10.1021/acs.langmuir.4c04066","DOIUrl":"https://doi.org/10.1021/acs.langmuir.4c04066","url":null,"abstract":"This study investigates the removal of pharmaceutical contaminants ibuprofen and diclofenac from aqueous solutions using graphene oxide (GO) coated with cetyltrimethylammonium bromide (CTAB) as a nanocomposite in a fully pressurized dissolved air flotation process. This novel approach leverages the surface-active properties of GO–CTAB to efficiently eliminate pharmaceuticals under optimized conditions. Characterization techniques, including Fourier transform infrared (FTIR), ζ-potential, particle size analysis, surface tension measurements, contact angle assessment, Brunauer–Emmett–Teller (BET) analysis, Gas chromatography–mass spectrometry (GC–MS), and Field emission scanning electron microscopy (FE-SEM) Energy-dispersive X-ray spectroscopy (EDS), validated the successful synthesis and efficacy of the GO–CTAB nanocomposite in pollutant removal. The process parameters were optimized, with the highest removal efficiencies achieved at a pH of 5 for ibuprofen and pH 4 for diclofenac, a surfactant dosage of 0.4 g, a pressure of 15 psig, and a rate of flow of 0.5 L/min. Under these conditions, removal efficiencies of 99.29% for ibuprofen and 95.31% for diclofenac were obtained, demonstrating the high performance of the GO–CTAB nanocomposite in treating low-concentration pharmaceutical contaminants. This study underscores the potential of the GO–CTAB flotation process as a sustainable, eco-friendly, and highly effective solution for pharmaceutical wastewater treatment, offering sustainability while minimizing chemical usage and environmental impact.","PeriodicalId":50,"journal":{"name":"Langmuir","volume":"3 1","pages":""},"PeriodicalIF":3.9,"publicationDate":"2025-02-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143463201","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}
引用次数: 0
Temperature-Enhanced Ordering in Plate-like Semicrystalline Block Copolymer Single-Crystal Suspensions Studied by Real-Time SAXS/WAXS
IF 3.9 2区 化学
Langmuir Pub Date : 2025-02-20 DOI: 10.1021/acs.langmuir.4c03853
Enyi Chi, Haiying Huang, Fajun Zhang, Tianbai He
{"title":"Temperature-Enhanced Ordering in Plate-like Semicrystalline Block Copolymer Single-Crystal Suspensions Studied by Real-Time SAXS/WAXS","authors":"Enyi Chi, Haiying Huang, Fajun Zhang, Tianbai He","doi":"10.1021/acs.langmuir.4c03853","DOIUrl":"https://doi.org/10.1021/acs.langmuir.4c03853","url":null,"abstract":"Self-assembly of hard platelet colloids into liquid crystalline phases is typically driven by entropy, making them less sensitive to temperature changes. However, soft interaction potentials often exist in real colloidal systems, which can lead to temperature-sensitive phase transitions. Despite significant progress in understanding phase behavior in the past 2 decades, studies on temperature-dependent phase behavior remain rare, and there is limited knowledge about how soft interactions influence phase transitions upon temperature changes. In this work, we investigated a platelet colloid system in isotropic and nematic phases using small- and wide-angle X-ray scattering techniques (SAXS/WAXS) and polarized optical microscopy (POM). The system consisted of polystyrene-<i>block</i>-poly(<span>l</span>-lactide) (PS-<i>b</i>-PLLA) block copolymer single crystals (BCSCs) with varying sizes dispersed in <i>p</i>-xylene. These crystals were truncated lozenge-shaped with effective diameters of 500 and 1000 nm and a uniform dry thickness of 18.0 nm. The ordering behaviors of BCSC500 in the isotropic phase and BCSC1000 in the N phase were monitored through SAXS/WAXS during heating, quenching, self-seeding, crystal growth, and final quenching. Enhanced ordering, specifically face-to-face correlation, was observed during heating prior to crystal melting. For BCSC500, ordering emerged at 105 °C during heating. In the case of BCSC1000 in the N phase, ordering was enhanced with increased heating and reached up to the ninth order of correlation peaks, indicating the formation of lamellar domains within the N phase. After seeding and crystal growth, both systems exhibited ordering. However, during the final cooling to room temperature, ordering disappeared for BCSC500 but persisted for BCSC1000. POM observations revealed that for both systems, initial heating resulted in a decrease in overall brightness; however, enhanced nematic domains or tactoids emerged prior to melting. Subsequent thermal treatments did not induce noticeable changes in the observed order. While both techniques revealed increased order, discrepancies were noted. SAXS indicated intensified short-range correlations, while POM showed the formation of local nematic domains or tactoids. We propose three distinct ordering regimes to reconcile these observations: large-scale nematic order, enhanced short-range order, and short-range clusters. We attributed the temperature-enhanced ordering phenomenon to lateral interactions between the BCSCs, annealing, and memory effects during melting and crystallization.","PeriodicalId":50,"journal":{"name":"Langmuir","volume":"49 1","pages":""},"PeriodicalIF":3.9,"publicationDate":"2025-02-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143463061","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}
引用次数: 0
Optimizing and Regulating Electric-Induced Breakup of Salt-Containing Droplets through Magnetic Field Coupling: Insights from Molecular Dynamics Simulations.
IF 3.7 2区 化学
Langmuir Pub Date : 2025-02-20 DOI: 10.1021/acs.langmuir.4c04208
Mofan Li, Donghai Yang, Qing Li, Yuejiu Liang, Chaohui Chen, Limin He
{"title":"Optimizing and Regulating Electric-Induced Breakup of Salt-Containing Droplets through Magnetic Field Coupling: Insights from Molecular Dynamics Simulations.","authors":"Mofan Li, Donghai Yang, Qing Li, Yuejiu Liang, Chaohui Chen, Limin He","doi":"10.1021/acs.langmuir.4c04208","DOIUrl":"https://doi.org/10.1021/acs.langmuir.4c04208","url":null,"abstract":"<p><p>Droplet electrodispersion is a fundamental phenomenon in various fields, such as electric demulsification, electrospray, and microfluidic manipulation. Electric-magnetic coupling technology, as an emerging noncontact method, shows substantial potential in modulating droplet electrohydrodynamics, yet the influence characteristics and mechanisms of coupled magnetic fields on droplet electrodispersion remain poorly understood. To address this gap, we conducted a detailed molecular dynamics simulation comparing the breakup dynamics of salt-containing droplets under a single electric field versus an electric-magnetic coupling field. Our results demonstrate that salty droplets in the electric-magnetic coupling field exhibit longer breakup response times and greater stretching deformation. This behavior is attributed to changes in ion migration speed and enrichment regions due to additional Lorentz forces. Furthermore, this effect of coupling field is observed only for ion numbers <i>N</i><sub>ion</sub> > 0, with a marked attenuation at higher concentrations (<i>N</i><sub>ion</sub> = 200), which is related to the hydration effect enhanced by magnetic field. When the electric capillary number Ca ranges from 0.88 to 3.91, the critical value triggering a shift in the breakup mode is enhanced in the coupling field. However, this effect diminishes as Ca approaches 8.8, at which point the coupled field no longer inhibits breakup. Additionally, as the dimensionless electric field frequency <i>f</i>* increases from 0.21 to 4.19, the ion migration trajectories become shorter and less able to accumulate at the interface, thereby limiting the effectiveness of the coupling field. Our study advances the fundamental understanding of salt-containing droplet breakup dynamics under an electric-magnetic coupling field and provides novel insights for controlling and suppressing electrodispersion in related technologies.</p>","PeriodicalId":50,"journal":{"name":"Langmuir","volume":" ","pages":""},"PeriodicalIF":3.7,"publicationDate":"2025-02-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143456272","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}
引用次数: 0
From Structure to Power: Monolithic Carbon Air Cathodes with an Optimized Active Distribution for Direct-Formate Fuel Cells
IF 3.9 2区 化学
Langmuir Pub Date : 2025-02-20 DOI: 10.1021/acs.langmuir.4c04711
Yudong Zhang, Menghan Liang, Wei Yang, Min Du, Shaojian Han, Xiaojie Li, Xiaorui Dong
{"title":"From Structure to Power: Monolithic Carbon Air Cathodes with an Optimized Active Distribution for Direct-Formate Fuel Cells","authors":"Yudong Zhang, Menghan Liang, Wei Yang, Min Du, Shaojian Han, Xiaojie Li, Xiaorui Dong","doi":"10.1021/acs.langmuir.4c04711","DOIUrl":"https://doi.org/10.1021/acs.langmuir.4c04711","url":null,"abstract":"Non-noble metal cathodes often suffer from limited oxygen reduction reaction (ORR) activity due to poor mass transport and insufficient active site availability, which restricts their application. This study presents a carbon-based air cathode featuring a monolithic, binder-free design aimed at enhancing the mass transfer and distribution of active sites. Characterization results indicate that the carbon-based monolithic air cathodes with a thickness of 1.5 mm (Fe@AC-1.5) possess a well-distributed pore structure that improves the oxygen transport capacity, thereby facilitating catalytic activity. Additionally, evaluation of the active site distribution of the cathode with a thickness of 2.4 mm (Fe@AC-2.4) revealed a comparable exponential distribution pattern. Furthermore, the findings demonstrate that the 1.5 mm thick monolithic air cathode prepared with agar (Fe@AC-1.5) contains numerous active sites for the ORR and an optimal pore distribution, resulting in an improved ORR activity. The direct-formate fuel cell utilizing Fe@AC-1.5 achieves a maximum power density of 22.63 mW cm<sup>–2</sup>. This study introduces easily prepared carbon-based monolithic air cathodes with remarkable ORR properties and offers insights into active site distribution, thereby guiding future enhancements in the ORR performance.","PeriodicalId":50,"journal":{"name":"Langmuir","volume":"50 1","pages":""},"PeriodicalIF":3.9,"publicationDate":"2025-02-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143463233","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}
引用次数: 0
Construction of Dual Active-Site NH2-MIL-125(Ti) for Efficient Selective Oxidation of Cyclohexylamine to Cyclohexanone Oxime
IF 3.9 2区 化学
Langmuir Pub Date : 2025-02-20 DOI: 10.1021/acs.langmuir.4c04786
Wenjin Ni, Xiang Liu, Qian Yang, Zhongliang Li, Jinfeng Fu, Liang Tan, Jiaming Zhang, Jian Liu
{"title":"Construction of Dual Active-Site NH2-MIL-125(Ti) for Efficient Selective Oxidation of Cyclohexylamine to Cyclohexanone Oxime","authors":"Wenjin Ni, Xiang Liu, Qian Yang, Zhongliang Li, Jinfeng Fu, Liang Tan, Jiaming Zhang, Jian Liu","doi":"10.1021/acs.langmuir.4c04786","DOIUrl":"https://doi.org/10.1021/acs.langmuir.4c04786","url":null,"abstract":"In this work, dual active-site Ti-incorporated metal–organic frameworks (MIL-125 and NH<sub>2</sub>-MIL-125) were synthesized by a simple solvothermal process and applied to prepare cyclohexanone oxime from cyclohexylamine oxidation. A low-temperature thermal calcination strategy was used for the modulation of surface properties while maintaining the crystal structure and morphology. The results demonstrated that novel bifunctional NH<sub>2</sub>-MIL-125@250 °C obtained from thermal calcination possessed a large surface area with both oxygen vacancies and surface hydroxyl-active sites, promoting the adsorption and activation of cyclohexylamine and oxygen molecules, respectively. Under the optimum conditions, the cyclohexylamine conversion was 44.3%, and the selectivity to cyclohexanone oxime was 83.0%. By comparison, the stability of MIL-125 and NH<sub>2</sub>-MIL-125 was investigated separately in cyclic tests, and the crystal structure and catalytic properties of NH<sub>2</sub>-MIL-125 have been shown to be more stable than those of MIL-125. Combined with density functional theory, it was further shown that NH<sub>2</sub>-MIL-125 displayed a higher adsorption and activation ability toward cyclohexylamine and oxygen than MIL-125 and had a more stable metal–organic ligand structure. Finally, a plausible reaction pathway for selective cyclohexylamine oxidation to cyclohexanone oxime was proposed. This work can give new insights into designing novel dual active-site catalysts for the efficient catalytic transformation of organic primary amines to corresponding oximes.","PeriodicalId":50,"journal":{"name":"Langmuir","volume":"50 1","pages":""},"PeriodicalIF":3.9,"publicationDate":"2025-02-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143463065","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}
引用次数: 0
Synthesis and Characterization of MO:ZnO/Fe2O3 Nanocomposite and Its Effectiveness in the Degradation of Green Malachite Dye: Molecular Dynamics and Electronic Properties Study of Green Malachite Adsorption
IF 3.9 2区 化学
Langmuir Pub Date : 2025-02-20 DOI: 10.1021/acs.langmuir.4c04609
Rihem Jemai, Zeshan Ahmed, Moez Hajji, Olfa Kamoun, Abdesslem Ben Haj Amara, Hafsia Ben Rhaiem
{"title":"Synthesis and Characterization of MO:ZnO/Fe2O3 Nanocomposite and Its Effectiveness in the Degradation of Green Malachite Dye: Molecular Dynamics and Electronic Properties Study of Green Malachite Adsorption","authors":"Rihem Jemai, Zeshan Ahmed, Moez Hajji, Olfa Kamoun, Abdesslem Ben Haj Amara, Hafsia Ben Rhaiem","doi":"10.1021/acs.langmuir.4c04609","DOIUrl":"https://doi.org/10.1021/acs.langmuir.4c04609","url":null,"abstract":"Nanocomposites have attracted significant attention from researchers due to their remarkable chemical, adsorptive, and thermal properties. This work focuses on the synthesis of the montmorillonite modified with octadecylamine (MO):ZnO/Fe<sub>2</sub>O<sub>3</sub> (MO:ZnO/Fe<sub>2</sub>O<sub>3</sub>) nanocomposite. The ZnO/Fe<sub>2</sub>O<sub>3</sub> nanocomposite and MO were mixed in solution to create the component. XRD, FTIR, BET, TEM, MEB, and UV–vis were used to characterize the materials. In terms of their textural, morphological, and structural characteristics, interesting results were found. After 30 min of sunlight exposure, 96.12% of the GM dye can be degraded using just 0,02 g of MO:ZnO/Fe<sub>2</sub>O<sub>3</sub> (1:2(1/0.05)). In contrast, ZnO NPs exhibited the highest percentage of degradation under UV light, achieving 91.85%. The greater efficiency of MO:ZnO/Fe<sub>2</sub>O<sub>3</sub> under sunlight is attributed to its narrower band gap of 2.25 eV, which enables better utilization of visible light. Next using the Forcite and CASTEP modules in the Material Studio software, the GM dye’s adsorption behavior on the surface of the as-prepared nanocomposite was analyzed. The results demonstrate that the GM/MO interaction is of the chemisorption type, predominantly governed by hydrogen bonding, electrostatic interactions, and π–π interactions between GM molecules. The ZnO (100) surface exhibits the highest density of active sites for GM degradation via a chemisorption adsorption process. Molecular dynamics simulations at 289.15 K reveal that the redox processes responsible for the degradation of the GM pollutant and its conversion into CO<sub>2</sub> gas are exothermic. For ZnO, the electronic properties yield a band gap of 2.686 eV. For GM/ZnO (100) and GM/ZnO (101), the band gaps were determined to be 0.291 and 2.704 eV, respectively, by using a 340 eV cutoff energy and the GGA RPBE pseudofunctional.","PeriodicalId":50,"journal":{"name":"Langmuir","volume":"47 1","pages":""},"PeriodicalIF":3.9,"publicationDate":"2025-02-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143463062","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}
引用次数: 0
High-Throughput Screening Identifies Anionic Polymer Supports that Improve Enzyme Activity at Low pH and High Temperature
IF 3.9 2区 化学
Langmuir Pub Date : 2025-02-20 DOI: 10.1021/acs.langmuir.4c04851
Evan A. Bisirri, Joel L. Kaar, Daniel K. Schwartz
{"title":"High-Throughput Screening Identifies Anionic Polymer Supports that Improve Enzyme Activity at Low pH and High Temperature","authors":"Evan A. Bisirri, Joel L. Kaar, Daniel K. Schwartz","doi":"10.1021/acs.langmuir.4c04851","DOIUrl":"https://doi.org/10.1021/acs.langmuir.4c04851","url":null,"abstract":"Elevated temperatures and nonoptimal pH can destabilize enzyme structure or change the protonation state of catalytic residues resulting in attenuated catalytic performance. Enzyme immobilization on polymer supports enables the fine-tuning of highly varied vicinal chemistries to improve enzyme performance by promoting correctly folded enzyme structure and adjusting the local microenvironment to more favorable conditions. Herein, we sought to investigate how multicomponent random copolymer brushes composed of monomers with anionic, cationic, neutral (zwitterionic, and mixed-charge), and aromatic properties stabilize covalently tethered lipase A from<i>Bacillus subtilis</i> at low pH and high temperature. Polymer brush compositions were screened using a high-throughput approach involving the combinatorial synthesis of random copolymer brushes and in situ characterization of immobilized lipase function. Although cationic supports provided a modest improvement over soluble lipase in maximum activity and thermal stability at low pH, more substantial enhancements in lipase stability were observed for anionic and neutral zwitterionic polymer supports, resulting in increases in temperature optima as great as 40 °C (from 40 to 80 °C) and an increase in maximum activity by more than 300%. These observations were counter to expectations regarding the role of surface charge on local pH and were attributed instead to the preservation of enzyme structure due to stabilizing electrostatic interactions between negatively charged polymer moieties and the net positively charged surface of lipase A. Our findings suggest that the stabilization of enzyme structure by charged polymers may offset unfavorable local changes in pH in certain situations, while in other situations these effects may be synergistic.","PeriodicalId":50,"journal":{"name":"Langmuir","volume":"73 1","pages":""},"PeriodicalIF":3.9,"publicationDate":"2025-02-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143463063","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}
引用次数: 0
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