The Journal of Physical Chemistry B最新文献

{"title":"","authors":"Kiichi Sugie, Yuki Kato, Ryo Nagao and Takumi Noguchi*, ","doi":"","DOIUrl":"","url":null,"abstract":"","PeriodicalId":60,"journal":{"name":"The Journal of Physical Chemistry B","volume":"129 25","pages":"XXX-XXX 2305–2315"},"PeriodicalIF":2.8,"publicationDate":"2025-06-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://pubs.acs.org/doi/pdf/10.1021/acs.jpcb.5c02806","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144480042","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"CO₂ Capture by Porous Polymeric Sorbents: From New <i>cis-</i>/<i>trans</i>-Oxovanadium(IV) Catalyst to Functional Materials.","authors":"Kacper Pobłocki, Marzena Białek, Katarzyna N Jarzembska, Mateusz A Baluk, Radosław Kamiński, Przemysław Rybiński, Krzysztof Matus, Joanna Drzeżdżon, Barbara Gawdzik, Dagmara Jacewicz","doi":"10.1021/acs.jpcb.5c01060","DOIUrl":"10.1021/acs.jpcb.5c01060","url":null,"abstract":"<p><p>The challenge of ever-increasing greenhouse gas emissions correlates with intensive research into the development of new CO₂ sorbents. The research aimed to propose a new generation of porous polymer sorbents that contribute to decarbonization. Among all oligomers and (co)polymers, the 3-buten-2-ol oligomer showed the highest CO₂ sorption properties (0.82 mmol g^-1). The heat of adsorption of CO₂ by oligo(3-buten-2-ol) was equal to 8.51 kJ mol^-1. Polyolefins and polar oligomers were synthesized using a new, innovative, and highly active oxovanadium(IV) precatalyst. An easy, one-step method for the synthesis of <i>cis</i>/<i>trans</i>-[VO(acac)₂(3-ppy)] provides a unique coordination compound containing two molecules that are reciprocal geometric isomers with a spatial arrangement of acetylacetonate ligands (<i>cis</i> and <i>trans</i>). The complex shows very active catalytic properties in the polymerization reactions of olefins (83,400 kg_PE mol_V^-1 h^-1) and polar monomers, for example, 2-propen-1-ol (1060 kg mol_V^-1 h^-1). A physicochemical study was also conducted to determine the stability constant of the complex formation, log β₁₂₁₀ = 27.82.</p>","PeriodicalId":60,"journal":{"name":"The Journal of Physical Chemistry B","volume":" ","pages":"6253-6264"},"PeriodicalIF":2.8,"publicationDate":"2025-06-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144281642","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":"Direct Measurement of the Effect of Cholesterol and 7-Dehydrocholesterol on Membrane Dipole Electric Field in Single and Mixed Sterol Vesicles Using Vibrational Stark Effect Spectroscopy.","authors":"Sydney C Povilaitis, Jessica A Hector, Morgan E Mantsch, Lauren J Webb","doi":"10.1021/acs.jpcb.5c00279","DOIUrl":"10.1021/acs.jpcb.5c00279","url":null,"abstract":"<p><p>Cholesterol is an important contributor to the properties, structure, and function of biological membranes. An immediate biosynthetic precursor to cholesterol, 7-dehydrocholesterol (7DHC), differs only in a single double bond, yet defects in the conversion of 7DHC to cholesterol result in metabolic disorders. The membrane dipole field, <i>F⃗</i>_d, is the greatest contributor to the total membrane electric field and arises from the alignment of interfacial lipids and water molecules. We have previously shown, using vibrational stark effect (VSE) spectroscopy, that the magnitude of membrane dipole field decreases with increasing cholesterol content and that sterol structure can differentially affect <i>F⃗</i>_d. Here, we employ VSE spectroscopy to directly measure <i>F⃗</i>_d in small unilamellar vesicles (SUVs) composed of DMPC and 0-40% cholesterol or 7DHC. Our results show that cholesterol and 7DHC influence <i>F⃗</i>_d in a similar way, reducing the magnitude of <i>F⃗</i>_d with increasing sterol content in a trimodal manner corresponding to phase transitions in DMPC/sterol bilayers. To probe <i>F⃗</i>_d in membranes that better model diseased states, VSE measurements were performed on SUVs with 40% total sterol, but mixed compositions of cholesterol and 7DHC. <i>F⃗</i>_d was bimodal in these systems, reflecting a 7DHC-like field at 10% cholesterol/30% 7DHC but a cholesterol-like content at 15% cholesterol (25% 7DHC) and above. We propose possible sources of these trimodal and bimodal effects and discuss the implications on our understanding of membrane electrostatics and cholesterol-related metabolic disorders.</p>","PeriodicalId":60,"journal":{"name":"The Journal of Physical Chemistry B","volume":" ","pages":"6127-6137"},"PeriodicalIF":2.8,"publicationDate":"2025-06-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144300700","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":"Mechanisms of Reduced Surface Mobility in Liquid Silicon.","authors":"Jinping Luo, Junhong Pei, Jianfei Xiang, Zaoyang Li, Jin-Ho Choi, Lijun Liu","doi":"10.1021/acs.jpcb.5c02295","DOIUrl":"https://doi.org/10.1021/acs.jpcb.5c02295","url":null,"abstract":"<p><p>The surface diffusion properties of liquid silicon play a critical role in applications, such as semiconductor manufacturing and nanotechnology. Using molecular dynamics (MD) simulations based on two different popular empirical potentials, this study investigates the surface and bulk diffusion coefficients of liquid silicon. First-principle molecular dynamics simulation is also applied to provide validations. Results reveal that the size effect of the diffusion coefficient in the cubic system with surfaces will deviate from the theoretical relation (i.e., it decreases linearly with 1/<i>L</i>) to lower values. This effect is caused by an unusual phenomenon: the surface diffusion coefficients are lower than the bulk diffusion coefficients in liquid silicon, contrary to typical trends in other materials. This phenomenon is explained by analyzing the microstructure of the liquid surface including coordination number (<i>CN</i>) distributions and atomic mobility heterogeneity.</p>","PeriodicalId":60,"journal":{"name":"The Journal of Physical Chemistry B","volume":" ","pages":""},"PeriodicalIF":2.8,"publicationDate":"2025-06-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144493124","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":"Validation of the \"Stoichiometric Hydration Ice-Bridge Model\" Provides Method To Predict Protein Folding Energetics.","authors":"Gary D Fullerton, Andres Rahal","doi":"10.1021/acs.jpcb.5c01583","DOIUrl":"https://doi.org/10.1021/acs.jpcb.5c01583","url":null,"abstract":"&lt;p&gt;&lt;p&gt;The hydration of macromolecules plays a critical role in powering functional macromolecular shape changes to open/close cellular pores, clip protein chains, and perform a myriad of other functions critical to life. This study of collagen \"bound water\" offers insight into these processes by quantifying protein hydration energetics powered by ice-bridge formation on protein backbones. Quantification of ice-bridge properties on rat tail tendon is uniquely possible because the elevated stability of mammalian collagen at laboratory temperature provides 100% at-rest in vitro occupancy of backbone tripeptide units serving as ice nucleation sites. Full occupancy &lt;i&gt;p&lt;/i&gt;&lt;sub&gt;o&lt;/sub&gt;=100% provides &lt;i&gt;stoichiometric hydration ice-bridge counts&lt;/i&gt; to calculate enthalpy using known properties of the collagen molecule and bulk water-ice. &lt;i&gt;SHIM&lt;/i&gt; theory predicts the specific enthalpy of native collagen melting, Δ&lt;i&gt;H&lt;/i&gt;&lt;sub&gt;m&lt;/sub&gt; = 70.31 J/g&lt;i&gt;-collagen&lt;/i&gt;, in close agreement with experimental measures. This provides, for the first time, a molecular definition of protein-bound water. We used measures of peak temperature of melting &lt;i&gt;T&lt;/i&gt;&lt;sub&gt;m&lt;/sub&gt; to calculate specific entropy of melting Δ&lt;i&gt;S&lt;/i&gt;&lt;sub&gt;m&lt;/sub&gt; = Δ&lt;i&gt;H&lt;/i&gt;&lt;sub&gt;m&lt;/sub&gt;/&lt;i&gt;T&lt;/i&gt;&lt;sub&gt;m&lt;i&gt;.&lt;/i&gt;&lt;/sub&gt; These measurements show 100% of collagen entropy of melting Δ&lt;i&gt;S&lt;/i&gt;&lt;sub&gt;m&lt;/sub&gt; = 0.2084 J/g&lt;sub&gt;c&lt;/sub&gt;°K in native collagen results from restrictions of the first monolayer water mobility. Penetration of acetate ion from acetic acid used by many to obtain independent tropocollagen molecules increased Δ&lt;i&gt;S&lt;/i&gt;&lt;sub&gt;m&lt;/sub&gt; = 0.2251 J/g&lt;sub&gt;c&lt;/sub&gt;°K by altering the molecular first monolayer to form a hydration slurry. The somewhat speculative character of this first paper on collagen ice-bridges has been validated by successful extension of SHIM theory to ectotherm collagen and globular proteins, where interesting changes of partial occupancy, &lt;i&gt;p&lt;/i&gt;&lt;sub&gt;o&lt;/sub&gt;&lt;100%, manipulate functional protein conformations. These papers will be published shortly. Significance. This study of the energetics of water interactions with collagen provides the calculational foundation to quantify water interactions with macromolecules in general. Preliminary studies of globular proteins, DNA, RNA, and cellulose show similar but incomplete ice-bridge formation that makes bridge-quantification on those molecules more difficult. The maximized content of ice-bridges on the ice-nucleation sites of mammalian collagen appears to be unique. The melting and refreezing of ice-bridges on macromolecular backbones provide the molecular mechanism to convert thermal energy into shape change-induced mechanical movements. The molecular constants and associated calculational methodology developed here should allow for more rapid progress in understanding the response of macromolecules to water and important cosolutes such as glucose. The role of glucose in collagen hydration slurry formation clearly plays an importa","PeriodicalId":60,"journal":{"name":"The Journal of Physical Chemistry B","volume":" ","pages":""},"PeriodicalIF":2.8,"publicationDate":"2025-06-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144482522","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":"Mapping Ion-Pair Dissociation Across the Hydration Spectrum of [HMIM][Cl]: A Molecular Dynamics Perspective.","authors":"Sheng Xu, Yumei Zhao, Zhiling Xin, Qingwei Gao","doi":"10.1021/acs.jpcb.5c01934","DOIUrl":"https://doi.org/10.1021/acs.jpcb.5c01934","url":null,"abstract":"<p><p>Molecular dynamics was utilized to investigate the dissociation process of the 1-hexyl-3-methylimidazolium chloride ionic liquid ([HMIM][Cl] IL). To further study the mechanism at the molecular scale, the local microstructure variation in the mixtures with the increase of water content was analyzed in detail. The simulation results show that there are still 35.89% of free ions in pure ILs. With the increase in water content, water molecules preferentially bind to free ions. When the water content is greater than 0.8, the water molecules gradually insert the anion and cation from the periphery of the cation-anion pair and finally almost replace the anion around the cation. The analysis of spatial distribution function, solvent accessible area, and ion diffusion coefficient further confirmed this conclusion. These quantitative ion pairing and dissociation mechanisms shed light on the rational design of the IL aqueous toward their applications in the chemical-related fields and provide key parameters for the modeling of IL aqueous solution.</p>","PeriodicalId":60,"journal":{"name":"The Journal of Physical Chemistry B","volume":" ","pages":""},"PeriodicalIF":2.8,"publicationDate":"2025-06-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144493122","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":"Self-Assembly of 2-Hydroxyethyl-1H-imidazolium-Based Surface Active Ionic Liquids and Utilization of Their Aqueous Solution in Superactivity of Cytochrome-c.","authors":"Manpreet Singh, Rajwinder Kaur, Sugam Kumar, Vinod Kumar Aswal, Gurbir Singh, Tejwant Singh Kang","doi":"10.1021/acs.jpcb.5c01449","DOIUrl":"https://doi.org/10.1021/acs.jpcb.5c01449","url":null,"abstract":"<p><p>Imidazolium-based surface active ionic liquids (SAILs) appended with a hydroxyethyl moiety at a cationic headgroup at a position opposite to an alkyl chain ([C₁₂ImOH][Br] and [C₁₆ImOH][Br]) and alkyl chain functionalized with amide ([C₁₂AImOH][Br]) and ester ([C₁₂EImOH][Br]) groups have been synthesized. Different techniques, i.e., surface tension, ionic conductance, fluorescence, dynamic light scattering, small angle neutron scattering, and isothermal titration calorimetry, have been exploited for establishing their micellization behavior, followed by the utilization of aqueous SAILs to offer enhanced enzymatic activity to cytochrome-c (Cyt-c). The hydrophobic hydration of the hydroxyethyl group retards the micellization in bulk but disturbs the water structure at and beneath the air-solution interface, resulting in better surface-active behavior as compared to their nonhydroxyethyl functionalized counterparts. The variation of characteristic micellar properties, i.e., cmc, counterion binding (β), aggregation number (<i>N</i>_agg), size, compactness, and thermodynamic parameters of micellization, is supported by the increasing hydrophobicity of the cationic SAIL along with contrastingly different <i>H</i>-bonding and stiffness of ester or amide moiety present near the cationic headgroup. The aqueous solutions of SAILs (below cmc) favored the enzyme activity governed predominantly by hydrophobic as well as polar interactions between SAILs and Cyt-c corroborated by molecular docking and circular dichroism (CD) spectroscopy investigations. Cyt-c shows a retarded activity in aqueous micelles of SAILs (above cmc) with the exception of [C₁₂AImOH][Br], where enzyme activity increased further to ∼2.1-fold compared to that observed in buffer. It is anticipated that the current results would pave a new way to synthesize SAILs not only to be used for enzyme activation and prolonged storage in aqueous medium but also for other biological applications.</p>","PeriodicalId":60,"journal":{"name":"The Journal of Physical Chemistry B","volume":" ","pages":""},"PeriodicalIF":2.8,"publicationDate":"2025-06-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144482520","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":"The Debye Layer as a Transmission Line in the 4 Hz-100 kHz Frequency Range.","authors":"Thanh-Trị Châu, Giovanni Zocchi","doi":"10.1021/acs.jpcb.5c01795","DOIUrl":"https://doi.org/10.1021/acs.jpcb.5c01795","url":null,"abstract":"<p><p>We report measurements on the electrical double layer at a gold electrode in several electrolytes. In the experiments, the Debye layer transmits a damped voltage wave along the electrode, which we use to probe the electrode-electrolyte interface. We compare the measurements with traditional impedance models, which schematize the Debye layer as a capacitance. We find good agreement not only for very dilute electrolytes but also for an ionic liquid. However, the same model fails for the concentrated electrolyte, as ion-solvent-ion interactions become important.</p>","PeriodicalId":60,"journal":{"name":"The Journal of Physical Chemistry B","volume":" ","pages":""},"PeriodicalIF":2.8,"publicationDate":"2025-06-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144482521","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":"Flow Modification Effects and Mechanisms of Silicone Powder and PEG on UHMWPE/HDPE Blends: Insights from Experimental and Molecular Dynamics Simulations.","authors":"Gonghao Wang, Jie Liu, Shengxue Qin, Hongbin Zhang, Haiping Zhou","doi":"10.1021/acs.jpcb.5c02737","DOIUrl":"https://doi.org/10.1021/acs.jpcb.5c02737","url":null,"abstract":"<p><p>The high melt viscosity and poor flowability of ultrahigh molecular weight polyethylene (UHMWPE) hinder its spinning production efficiency and industrial-scale processing. In this study, a blend of UHMWPE and high-density polyethylene (HDPE) was modified by incorporating silicone powder and polyethylene glycol (PEG). By integrating experimental characterization with molecular dynamics simulations, this study investigates the effects and underlying mechanisms of flow modification induced by the individual and synergistic incorporation of PEG and silicone powder into UHMWPE/HDPE blends at both macroscopic and molecular levels. Experimental results showed that 1 wt % PEG provided the most significant modification effect on the UHMWPE/HDPE blend. Compared to the unmodified UHMWPE/HDPE blend, the processing torque and flow activation energy decreased by 22.1% and 34.57%, respectively, and the melt flow rate increased by 48.04%. However, a slight reduction in tensile properties was observed, with the tensile strength decreasing by 5.09%. Molecular dynamics simulations revealed that the addition of 1 wt % PEG notably enhanced the overall mobility of the molecular chains in the UHMWPE/HDPE blend, leading to the highest free volume fraction and diffusion coefficient, thus improving flowability. However, the intermolecular interactions within the blend were relatively weak, resulting in lower cohesive energy density and interaction energy, which, in turn, reduced mechanical properties. The experimental and simulation results are in good agreement and provide valuable insights into the modification effects and mechanisms of different flow additives, offering guidance for the selection and optimization of modification formulations for UHMWPE.</p>","PeriodicalId":60,"journal":{"name":"The Journal of Physical Chemistry B","volume":" ","pages":""},"PeriodicalIF":2.8,"publicationDate":"2025-06-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144482519","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":"Correlations Between Colloidal Stability and Peroxidase Activity of Prussian Blue Nanozymes in Salt Solutions.","authors":"Tamás Péter, Dóra Takács, Dániel Viczián, Bojana Katana, Nizar B Alsharif, István Szilagyi","doi":"10.1021/acs.jpcb.5c01256","DOIUrl":"https://doi.org/10.1021/acs.jpcb.5c01256","url":null,"abstract":"<p><p>Prussian blue (PB) nanozymes have emerged as durable enzyme-mimicking catalysts with broad applications across many fields. Practical uses often involve exposure to salinity that influences their colloidal and catalytic behaviors, yet the specific effects of ions on PB particles are underexplored. This study investigates how electrolyte type and concentration affect the colloidal stability and enzyme-like activity of PB nanozymes using monovalent (NaCl, KCl, CsCl) and multivalent ions (CaCl₂, LaCl₃). Electrophoresis and dynamic light scattering measurements revealed that both concentration and ion composition significantly affect stability with specific ion adsorption altering charge density and aggregation, consistent with the DLVO theory. Findings further indicate that higher ionic strengths compress the electric double layer, improving substrate accessibility and accelerating horseradish peroxidase (HRP)-like catalytic reactions. Remarkably, Cs⁺ ions substantially boost activity through their unique ability to disrupt water structure and integrate into PB's lattice. These findings highlight the importance of considering ion specificity when designing PB-containing dispersions for optimal stability and catalytic performance.</p>","PeriodicalId":60,"journal":{"name":"The Journal of Physical Chemistry B","volume":" ","pages":""},"PeriodicalIF":2.8,"publicationDate":"2025-06-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144493118","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}