Langmuir最新文献_第6页

Experimental Study of Gas–Liquid Compound Droplet Impact on Superhydrophobic Surface

IF 3.9 2区化学

Langmuir Pub Date : 2025-02-03 DOI: 10.1021/acs.langmuir.4c04983

Lei Xing, Jinming Zhang, Yang Gao, Minghu Jiang, Lixin Zhao, Shuai Guan

{"title":"Experimental Study of Gas–Liquid Compound Droplet Impact on Superhydrophobic Surface","authors":"Lei Xing, Jinming Zhang, Yang Gao, Minghu Jiang, Lixin Zhao, Shuai Guan","doi":"10.1021/acs.langmuir.4c04983","DOIUrl":"https://doi.org/10.1021/acs.langmuir.4c04983","url":null,"abstract":"The impact dynamics of gas–liquid compound droplets (GLCD) on surfaces play a crucial role in optimizing processes such as atomization, coating, and microencapsulation. The dynamic behaviors of GLCD impacting superhydrophobic surfaces under varying impact heights, viscosities, and gas–liquid volume ratios (Φ) were investigated via high-speed photography. Three collision categories are defined according to GLCD morphology evolution under different parameters, i.e., oscillation-breakup, rebound collision, and impact-breakup. As the impact height increases, the occurrence of droplet breakup shifts progressively from the retraction stage to the spreading stage. Notably, the maximum rebound coefficient of the compound droplet initially increases and then decreases with increasing impact height, and finally increases again due to the bubble breakup, which differs from the behavior of the homogeneous droplets. Furthermore, the maximum spreading and rebound heights of the GLCD are suppressed by increasing the liquid-phase viscosity. For Φ = 0.48 GLCD, increasing the liquid-phase viscosity from 4.7 to 5.5 mPa·s raises the critical breakup impact height from 90 mm to 120 mm. Meanwhile, the average dimensionless breakup time also increases from 0.54 to 1.72. As the Φ increases, the liquid film of the GLCD gradually thins, resulting in a decrease in the maximum spreading coefficient and enhanced probability of droplet breakup. Additionally, increasing the Φ from 0.48 to 0.56 leads to an increase in the average dimensionless breakup time by 0.88. This study provides a fundamental understanding of the dynamic behavior of compound droplets and offer valuable insights for related engineering applications.","PeriodicalId":50,"journal":{"name":"Langmuir","volume":"36 1","pages":""},"PeriodicalIF":3.9,"publicationDate":"2025-02-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143083785","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

A Free Energy Model for the Plateau Shear Modulus in Thermosensitive Microgel Suspensions

IF 3.9 2区化学

Langmuir Pub Date : 2025-02-03 DOI: 10.1021/acs.langmuir.4c04528

Maxime Bergman, Yixuan Xu, José Muñéton Díaz, Chi Zhang, Thomas G. Mason, Frank Scheffold

{"title":"A Free Energy Model for the Plateau Shear Modulus in Thermosensitive Microgel Suspensions","authors":"Maxime Bergman, Yixuan Xu, José Muñéton Díaz, Chi Zhang, Thomas G. Mason, Frank Scheffold","doi":"10.1021/acs.langmuir.4c04528","DOIUrl":"https://doi.org/10.1021/acs.langmuir.4c04528","url":null,"abstract":"Polymer microgels exhibit intriguing macroscopic flow properties arising from their unique microscopic structure. Microgel colloids usually comprise a cross-linked polymer network with a radially decaying density profile, resulting in a dense core surrounded by a fuzzy corona. Notably, microgels synthesized from poly(N-isopropylacrylamide) (PNIPAM) are thermoresponsive and capable of adjusting their size and density profile based on temperature. Above the lower critical solution temperature (<math display=\"inline\"><msub><mrow><mi>T</mi></mrow><mrow><mi>LCST</mi></mrow></msub><mo>∼</mo><mn>33</mn></math> °C), the microgel’s polymer network collapses, expulsing water through a reversible process. Conversely, below 33 °C, the microgel’s network swells, becoming highly compressible and allowing overpacking to effective volume fractions exceeding one. Under conditions of dense packing, microgels undergo deformation in distinct stages: corona compression and faceting, interpenetration, and finally, isotropic compression. Each stage exhibits a characteristic signature in the dense microgel suspensions’ yield stress and elastic modulus. Here, we introduce a model for the linear elastic shear modulus by minimizing a quasi-equilibrium free energy, encompassing all relevant energetic contributions. We validate our model by comparing its predictions to experimental results from oscillatory shear rheology tests on microgel suspensions at different densities and temperatures. Our findings demonstrate that combining macroscopic rheological measurements with the model allows for temperature-dependent characterization of polymer interaction parameters.","PeriodicalId":50,"journal":{"name":"Langmuir","volume":"246 1","pages":""},"PeriodicalIF":3.9,"publicationDate":"2025-02-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143083783","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

Multimodal Splitting and Reciprocating Transport of Droplets on a Reprogrammable Functional Surface

IF 3.9 2区化学

Langmuir Pub Date : 2025-02-03 DOI: 10.1021/acs.langmuir.4c04726

Ming Liu, Runan Chen, Jin Yuan, Cheng Chen, Zhilong Peng, Shaohua Chen

{"title":"Multimodal Splitting and Reciprocating Transport of Droplets on a Reprogrammable Functional Surface","authors":"Ming Liu, Runan Chen, Jin Yuan, Cheng Chen, Zhilong Peng, Shaohua Chen","doi":"10.1021/acs.langmuir.4c04726","DOIUrl":"https://doi.org/10.1021/acs.langmuir.4c04726","url":null,"abstract":"Droplet manipulations have important applications in many fields, especially droplet splitting and transport in aseptic operations or biochemical reagent analysis. However, droplet splitting or transport on existing functional surfaces is limited to predesigned microstructures or fixed patterns. It remains a challenge to realize reprogrammable surface microstructures for freely controllable droplet splitting and transport. In this study, a flexible technique for both the multimodal splitting and reciprocating transport of droplets on one surface is proposed. Such a surface is prepared with a facile fabrication method by premixing magnetic particles and softener into the polymer solvent matrix and immersing the solidified matrix in a lubricant. The movable wettability gradient is generated on the surface by an external magnetic field, which can act as an invisible “air knife” to split the droplet in multiple modes. The mechanism and critical conditions of droplet splitting are analyzed and revealed theoretically. Furthermore, the microstructural configurations and surface wettability can be reprogrammed by modulating the magnetic field strength and gradient. Accordingly, the splitting behavior of the droplet is transformed into the reciprocating transport behavior. The influencing factors of such behavior have also been analyzed. The reported reprogrammable manipulation of the droplet on one surface provides a versatile prototype for the actuation of droplets in microfluidic and biological analysis devices.","PeriodicalId":50,"journal":{"name":"Langmuir","volume":"5 1","pages":""},"PeriodicalIF":3.9,"publicationDate":"2025-02-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143083784","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

Novel Electrochemical Sensor Based on Cu-MOF/MWCNT-COOH for the Simultaneous Detection of Ascorbic Acid and Dopamine

IF 3.9 2区化学

Langmuir Pub Date : 2025-02-03 DOI: 10.1021/acs.langmuir.4c04455

Guoping Wang, Tian Tang, Ruichen Liu, Jingwen Li, Yi Xu, Sen Liao

{"title":"Novel Electrochemical Sensor Based on Cu-MOF/MWCNT-COOH for the Simultaneous Detection of Ascorbic Acid and Dopamine","authors":"Guoping Wang, Tian Tang, Ruichen Liu, Jingwen Li, Yi Xu, Sen Liao","doi":"10.1021/acs.langmuir.4c04455","DOIUrl":"https://doi.org/10.1021/acs.langmuir.4c04455","url":null,"abstract":"By utilizing carboxylated multiwalled carbon nanotubes (MWCNT-COOH) to strengthen the interaction between the electrode and the analytes and improve the conductivity of the composite material and in conjunction with the superior catalytic properties of copper-based metal–organic framework (MOFs), a novel electrochemical sensor was fabricated from a Cu-MOF/MWCNT-COOH composite, specifically designed for the simultaneous and distinct detection of ascorbic acid (AA) and dopamine (DA). Electrochemical analyses were conducted on the innovative Cu-MOF/MWCNT-COOH electrode through both CV and DPV, revealing unique electrochemical behaviors for AA and DA. The sensor not only showed exceptional electrocatalytic properties but also distinguished itself by its broad dynamic response ranges, covering concentrations from 3 to 1800 μM for AA and from 2 to 180 μM for DA, with detection limits (S/N = 3) of 3.00 μM for AA and 0.32 μM for DA. Furthermore, this electrochemical detection platform exhibited robust reproducibility and selectivity. Examinations of serum samples yielded the recovery rates of AA and DA which were 101.9% and 102.1%, respectively, confirming the sensor’s capability to perform reliably under varied biological conditions. The findings confirm the sensor’s potential of the proposed method for the simultaneous, sensitive, and reliable detection of AA and DA. In conclusion, the electrochemical sensor has a promising potential for practical applications.","PeriodicalId":50,"journal":{"name":"Langmuir","volume":"6 1","pages":""},"PeriodicalIF":3.9,"publicationDate":"2025-02-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143083786","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

Mechanism of High Hydrocarbon-Fuel-Gelation Performance of Ultralow-Concentration Bis-urea-Based Gellants

IF 3.9 2区化学

Langmuir Pub Date : 2025-02-02 DOI: 10.1021/acs.langmuir.4c05128

Yan Xu, Kang Xue, Yi Chen, Chongjun Li, Huaiyu Li, Xiaolei Guo, Ruijie Gao, Chengxiang Shi, Xiangwen Zhang, Ji-Jun Zou, Lun Pan

{"title":"Mechanism of High Hydrocarbon-Fuel-Gelation Performance of Ultralow-Concentration Bis-urea-Based Gellants","authors":"Yan Xu, Kang Xue, Yi Chen, Chongjun Li, Huaiyu Li, Xiaolei Guo, Ruijie Gao, Chengxiang Shi, Xiangwen Zhang, Ji-Jun Zou, Lun Pan","doi":"10.1021/acs.langmuir.4c05128","DOIUrl":"https://doi.org/10.1021/acs.langmuir.4c05128","url":null,"abstract":"Bis-urea-based gellants have garnered considerable attention due to their capacity to form all kinds of gels in solvents for multiple applications. Nevertheless, the range of applicable solvents is limited, and the synthesis process is complicated. Herein, we report a one-step synthesis process of bis-urea-based gellants (Bu(n)) for gelling nonpolar organic solvents, including high-energy fuels. Importantly, the critical gelation concentration (CGC) of Bu(n) decreases with the increase of alkyl chain length, and that of Bu18 is lower than 0.1 wt % in various hydrocarbon fuels. The discrepant gelation performance of gellants in solvents was investigated by molecular dynamics simulation and spectral characterizations. The results indicate that the electrostatic interaction between urea groups is vital to constructing a gellant framework, and the wide van der Waals (vdW) surface provided by alkyl groups helps to immobilize solvents. The nonbonding interactions between gellant molecules facilitate the formation of a 3D fibrous network structure, which further accumulates into a cambium layer structure. Due to the excellent gelation performance of gellants in fuels, the gel fuels perform the rheological characteristics of shear thinning and thixotropic recovering with calorific value remaining, thus demonstrating potential for application.","PeriodicalId":50,"journal":{"name":"Langmuir","volume":"38 1","pages":""},"PeriodicalIF":3.9,"publicationDate":"2025-02-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143077097","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

A Paintable, Scalable, and Durable Zwitterionic Hydrogel Coating for Enhanced Marine Antifouling Applications

IF 3.9 2区化学

Langmuir Pub Date : 2025-02-02 DOI: 10.1021/acs.langmuir.4c04595

Boyi Song, Ershuai Zhang, Yuanjie Shi, Hui Zhu, Wei Wang, Sheu-Jane Gallagher, Zhiqiang Cao

{"title":"A Paintable, Scalable, and Durable Zwitterionic Hydrogel Coating for Enhanced Marine Antifouling Applications","authors":"Boyi Song, Ershuai Zhang, Yuanjie Shi, Hui Zhu, Wei Wang, Sheu-Jane Gallagher, Zhiqiang Cao","doi":"10.1021/acs.langmuir.4c04595","DOIUrl":"https://doi.org/10.1021/acs.langmuir.4c04595","url":null,"abstract":"Marine biofouling has been a severe challenge since the increase of maritime trade, significantly impacting the efficiency of ships by increasing drag, fuel consumption, hull corrosion, and even problems related to navigational safety and biological invasions. Commercial antifouling coatings have been developed for many years, but a satisfactory solution has yet to be found due to problems, such as high toxicity, environmental pollution, or high costs. Zwitterionic materials, with their superhydrophilic properties, demonstrate excellent resistance to nonspecific adhesion alongside good biocompatibility, making them promising candidates for marine antifouling applications. However, their superhydrophilic nature makes it difficult to anchor onto hydrophobic substrates, limiting their use. In this study, we presented a paintable, scalable, and durable antifouling coating system made by zwitterionic hydrogel (PSDA-Z), which was covalently attached to substrates through an acrylated epoxy resin primer coat and maintained antifouling performance even after 3 months of high-speed water shearing, high-pressure sandpaper abrasion, and sharp scratching. This PSDA-Z could also easily be applied on various substrates without specific treatments, including epoxy resin, poly(vinyl chloride) (PVC), polyurethane (PU), and wood. More importantly, this coating system achieved excellent antifouling performance comparable to self-polishing coatings (SPCs), the current industry standard in marine antifouling coating, in the Atlantic Ocean field tests for 3 months, suggesting its promise as an effective and ecofriendly alternative for marine antifouling applications.","PeriodicalId":50,"journal":{"name":"Langmuir","volume":"23 1","pages":""},"PeriodicalIF":3.9,"publicationDate":"2025-02-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143077048","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

Engineering Protein-Based Lipid-Binding Nanovesicles via Catechol-Amine-Derived Coacervation with Their Underlying Interfacial Mechanisms 通过儿茶酚--氨产生的共凝作用及其潜在的界面机制设计蛋白型脂质结合纳米囊泡

IF 3.9 2区化学

Langmuir Pub Date : 2025-02-02 DOI: 10.1021/acs.langmuir.4c03941

Haibing Yang, Yao Song, Qiang Zhang, Moran Wang, Tianqi Jia, Qing Pan, Kanda Sun, Xiang Guan, Mingfei Pan, Feng Chen, Bin Yan

{"title":"Engineering Protein-Based Lipid-Binding Nanovesicles via Catechol-Amine-Derived Coacervation with Their Underlying Interfacial Mechanisms","authors":"Haibing Yang, Yao Song, Qiang Zhang, Moran Wang, Tianqi Jia, Qing Pan, Kanda Sun, Xiang Guan, Mingfei Pan, Feng Chen, Bin Yan","doi":"10.1021/acs.langmuir.4c03941","DOIUrl":"https://doi.org/10.1021/acs.langmuir.4c03941","url":null,"abstract":"The development of nonphospholipid nanovesicles has garnered tremendous attention as a viable alternative to traditional liposomal nanovesicles. Protein/peptide-based nanovesicles have demonstrated their potential to reduce immunogenicity while enhancing bioactivity. However, a fundamental understanding of how proteinaceous vesicles interact with lipids and cell membranes remains elusive. In this study, we engineered a series of protamine-based nonphospholipid nanovesicles by modulating intramolecular catechol–amine interactions. By grafting trihydroxybenzene (GA) and catechol (CA) groups onto the protamine (Prot), a salt-triggered coacervation was observed in an alkaline environment with the size of as-prepared vesicles ranging from 200 to 1200 nm. The bonding affinity to lipid interfaces followed the order of Prot-CA-Fe3+(25 μM) > Prot-CA-Fe3+(10 μM) > Prot-CA > original Prot with the underlying nanomechanics investigated by the lipid bubble force measurement. Direct quantification of interactions between the nanovesicles and living human gingival fibroblasts was performed by using surface charge difference mapping. Introducing trace amounts of Fe3+ (at 10 and 25 μM) enhanced vesicle–lipid interactions via the synergy of catechol–amine interactions and Fe3+-induced complexation. This work provides improved valuable insights into the interactions between nanovesicles and cell membranes, offering an energetic paradigm for modulating cell-target delivery processes via intramolecular short-range interactions.","PeriodicalId":50,"journal":{"name":"Langmuir","volume":"13 1","pages":""},"PeriodicalIF":3.9,"publicationDate":"2025-02-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143077386","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

Molecular Effects of Zwitterionic Peptide on Monolayer Lipid Membranes upon Enzyme-Catalyzed Degradation

IF 3.9 2区化学

Langmuir Pub Date : 2025-02-02 DOI: 10.1021/acs.langmuir.4c04426

Bailin Feng, Shiyu Du, Yiqing Yang, Yuli Zhu, Nash McKeague, Binhua Lin, Wei Bu, Gang Cheng, Ying Liu

{"title":"Molecular Effects of Zwitterionic Peptide on Monolayer Lipid Membranes upon Enzyme-Catalyzed Degradation","authors":"Bailin Feng, Shiyu Du, Yiqing Yang, Yuli Zhu, Nash McKeague, Binhua Lin, Wei Bu, Gang Cheng, Ying Liu","doi":"10.1021/acs.langmuir.4c04426","DOIUrl":"https://doi.org/10.1021/acs.langmuir.4c04426","url":null,"abstract":"Secretory phospholipase A2 (sPLA2), an enzyme overexpressed in numerous diseases, has been used to trigger structural transformations in lipid-based drug delivery systems, enabling payload release at target sites. Zwitterionic peptides are known for their superior antifouling properties, often outperforming poly(ethylene glycol) (PEG) surface modification by resisting protein adsorption. In this study, we examined lipid monolayers at the water–vapor interface on a Langmuir trough, incorporating varying molar fractions of zwitterionic peptide-conjugated lipids or PEG-conjugated lipids. Synchrotron X-ray surface techniques, including X-ray reflectivity and grazing incidence X-ray diffraction, were employed to analyze molecular packing, enzyme adsorption, enzyme-catalyzed lipid degradation, and metabolite reorganization at the interface, and microscopy was used to observe domain morphologies. The results demonstrate that zwitterionic peptides exhibit a significantly greater efficiency than PEG in stabilizing the interfacial monolayer packing structure against enzyme-catalyzed lipid degradation. However, contrary to most studies reporting strong resistance of zwitterionic materials to nonspecific protein absorption, enzyme absorption to the interface, which is interfacial and phospholipids specific, was not impeded by the presence of zwitterionic peptides at low molar ratios (≤10 mol %).","PeriodicalId":50,"journal":{"name":"Langmuir","volume":"3 1","pages":""},"PeriodicalIF":3.9,"publicationDate":"2025-02-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143077046","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

Approach to Enantiomer Recognition during Adsorption by Different Adsorption Rates on Zeotype Borophosphate LiCu2[BP2O8(OH)2] with Spontaneously Emerged Chirality

IF 3.9 2区化学

Langmuir Pub Date : 2025-02-02 DOI: 10.1021/acs.langmuir.4c04695

Zhanna D. Uteeva, Elina R. Mansurova, Yuliya F. Sharafutdinova, Diana O. Bagdanova, Marat R. Agliullin, Timur A. Mukhametzyanov, Vladimir Yu Guskov

{"title":"Approach to Enantiomer Recognition during Adsorption by Different Adsorption Rates on Zeotype Borophosphate LiCu2[BP2O8(OH)2] with Spontaneously Emerged Chirality","authors":"Zhanna D. Uteeva, Elina R. Mansurova, Yuliya F. Sharafutdinova, Diana O. Bagdanova, Marat R. Agliullin, Timur A. Mukhametzyanov, Vladimir Yu Guskov","doi":"10.1021/acs.langmuir.4c04695","DOIUrl":"https://doi.org/10.1021/acs.langmuir.4c04695","url":null,"abstract":"Zeotype borophosphates are porous adsorbents with a 3D open framework. The unique feature of borophosphates is noncentrosymmetric or even chiral structures. The chirality emerged as an asymmetrical arrangement of atoms in crystals and can be referred to the supramolecular, not molecular, chirality hierarchy level. In this work, the zeotype copper borophosphate LiCu2[BP2O8(OH)2] was studied as a promising adsorbent for enantiomer separation. LiCu2[BP2O8(OH)2] has a rare feature: without any external source of chirality, crystals with only [CD(−)284] and [CD(−)760] Cotton effects are synthesized. Tryptophan enantiomer adsorption on LiCu2[BP2O8(OH)2] was studied. At almost all tryptophan concentrations, enantioselectivity was observed. At nonequilibrium conditions, enantioselectivity coefficients were higher than at adsorption equilibrium. In some cases, chiral recognition was not observed at equilibrium but occurred before equilibrium. In a nonequilibrium area of amount of adsorbed substance vs adsorption time curve, a phenomenon of very high enantioselectivity was discovered. The enantioselectivity coefficient values were 3–5, and even 11.8. Such extremely high enantioselectivity values were caused by the nontrivial kinetic curve for l-tryptophan. A far from the equilibrium, a plateau was observed on the curve. At the end of the plateau, the maximal enantioselectivity was observed. This mechanism of enantioselectivity enhancement can be useful for chromatographic separations, chemical sensors, and catalysts.","PeriodicalId":50,"journal":{"name":"Langmuir","volume":"207 1","pages":""},"PeriodicalIF":3.9,"publicationDate":"2025-02-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143077049","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

Magnetic Capture of Functionalized Nanoscale Zerovalent Iron for Soil Remediation: A Feasibility Study on Transport Control

IF 3.9 2区化学

Langmuir Pub Date : 2025-02-02 DOI: 10.1021/acs.langmuir.4c04720

Wei Ming Ng, Wai Hong Chong, Ahmad Zuhairi Abdullah, JitKang Lim

{"title":"Magnetic Capture of Functionalized Nanoscale Zerovalent Iron for Soil Remediation: A Feasibility Study on Transport Control","authors":"Wei Ming Ng, Wai Hong Chong, Ahmad Zuhairi Abdullah, JitKang Lim","doi":"10.1021/acs.langmuir.4c04720","DOIUrl":"https://doi.org/10.1021/acs.langmuir.4c04720","url":null,"abstract":"Nanoscale zerovalent iron (nZVI) has been proposed as a promising nanomaterial for soil remediation. However, injecting nZVI into contaminated sites to target and treat pollutant sources may pose potential environmental risks due to its colloidal stability and mobility in the environment. In this regard, this study assessed the feasibility of implementing magnetic capture of surface-functionalized nZVI in soil environments under the influence of the convective flow current. Here, functionalized nZVI particles were prepared by introducing carboxymethyl cellulose (CMC) as a stabilizing agent during the synthesis of nZVI by using the liquid-phase reduction method. The functionalized nZVI particles were then injected into a two-dimensional flow column containing a sand matrix with a high gradient magnetic trap (HGMT) embedded within the system. Particle transports in both the absence and presence of a magnetic field were recorded by using a digital camera, and the breakthrough curves were generated from the data collected spectrophotometrically. The results showed that the relative breakthrough concentration of nZVI decreased from 0.92 to nearly zero, with a delayed breakthrough time as the applied magnetic field strength increased from zero (no magnetic field) to 0.093 T, demonstrating a 100% capture efficiency. It was found that the magnetic capture for the nZVI particles was contributed by two mechanisms: (1) low gradient magnetic separation (LGMS), driven by the penetrating magnetic field from the permanent magnets, and (2) high gradient magnetic separation (HGMS), which occurred near the wire surfaces within the HGMT section magnetized by the permanent magnets. Findings in this work have proven the feasibility of magnetic separation as a control strategy for nanoparticle applications in environmental remediation.","PeriodicalId":50,"journal":{"name":"Langmuir","volume":"22 1","pages":""},"PeriodicalIF":3.9,"publicationDate":"2025-02-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143077050","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