The European Physical Journal E最新文献

{"title":"Tunable wetting properties of poly(3-hexylthiophene) films with different doping levels","authors":"Junqi Lu,&nbsp;David Neusser,&nbsp;David Moser,&nbsp;Pedro M. Resende,&nbsp;Christopher R. McNeill,&nbsp;Sabine Ludwigs","doi":"10.1140/epje/s10189-026-00608-5","DOIUrl":"10.1140/epje/s10189-026-00608-5","url":null,"abstract":"<div><p>This work systematically investigates the wetting properties of electrochemically doped poly(3-hexylthiophene) (P3HT) films at different oxidation states. In situ spectroelectrochemistry and ex situ opto-electronic characterization of the doped films confirm that the polaron and bipolaron states have successfully been obtained through electrochemical doping. Sessile drop and dynamic water contact angle measurements yield reproducible results that strongly depend on the applied electrochemical doping potential, with a maximum water contact angle variation of up to 43° from the neutral to the fully doped state. The evolution of wettability correlates with the doping states and is heavily influenced by morphological changes upon doping. Atomic force microscopy (AFM) and scanning electron microscopy (SEM) reveal that wrinkle-like structures appear at high doping levels which is consistent with predominant bipolaron formation accompanied by doping-induced swelling followed by drying. Complementary grazing-incidence wide-angle X-ray scattering (GIWAXS) shows that doping to the polaronic state leads to lamellar expansion with a contraction of the <i>π</i>–<i>π</i> stacking distance within crystalline domains. Despite these lattice changes, the edge-on orientation is largely preserved, indicating that the overall crystalline texture remains stable even at the highest studied doping levels.</p><h3>Graphical abstract</h3><div><figure><div><div><picture><source><img></source></picture></div><div><p>Electrochemically doped films show large differences in wettability due to surface morphology changes upon strong doping, while conductivity values remain high.</p></div></div></figure></div></div>","PeriodicalId":790,"journal":{"name":"The European Physical Journal E","volume":"49 8","pages":""},"PeriodicalIF":2.6,"publicationDate":"2026-07-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1140/epje/s10189-026-00608-5.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148459065","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Unveiling the fluorescence lifetime changes of a solvatochromic aurone probe dye upon wetting in an emissive polymer brush matrix by deconvolution of TCSPC data","authors":"Jonah L. Decker,&nbsp;Sören Steup,&nbsp;Sergey I. Druzhinin,&nbsp;Heiko Ihmels,&nbsp;Holger Schönherr","doi":"10.1140/epje/s10189-026-00597-5","DOIUrl":"10.1140/epje/s10189-026-00597-5","url":null,"abstract":"<div><p>The wetting processes of polymer brushes, embedded with a fluorescent probe, were investigated with time-correlated single photon counting. A suitable aurone dye was synthesized, which exhibits moderate fluorescence in aprotic solvents, poor fluorescence in protic solvents and practically no fluorescence in aqueous solution. Poly(diethylene glycol methyl ether methacrylate) (PDEGMA) brushes of ca. 200 nm thickness were obtained by polymerization from a Ti surface by surface-initiated atom transfer radical polymerization (SI-ATRP). The dye-loaded brushes show fluorescence of the dye comparable with the autofluorescence of the PDEGMA brushes and the subjacent α-bromoisobutyryl bromide (BiBB) functionalized polydopamine (PDA) layer. With a global analysis of fluorescence decays, the lifetimes of the complex multicomponent materials were deconvoluted. The dry polymer loaded with the dye possesses a five-exponential fluorescence decay with the characteristic decay times of ~ 3.0 ns for the dye, and ~ 6.0, 1.8 and 0.45 ns for PDEGMA brushes as well as &lt; 0.05 ns for the PDA-BiBB layer. Because of the strong decrease of the fluorescence lifetime of the dye down to ~ 2.4 ns when submersed in water and a concomitant decrease of the lifetimes of the matrix to 4.5, 1.3 and 0.40 ns, both dye and matrix fluorescence are feasible reporter probes for the analysis of wetting processes of polymers with fluorescence lifetime imaging. The contrast of the intensity images of the aurone, which is low because of background fluorescence, increases by a factor of 3.1 in the time-resolved imaging at certain time delay after excitation. Hence, the incorporation of the aurone in the polymer brushes is a promising and versatile system for the investigation of (de)wetting dynamics employing fluorescence lifetime imaging and nanosecond time-resolved fluorescence imaging microscopy.</p><h3>Graphical abstract</h3><div><figure><div><div><picture><source><img></source></picture></div><div><p>Incorporation of a fluorescent dye in polymer brushes allows monitoring of (de)wetting dynamics with time-resolved fluorescence imaging microscopy</p></div></div></figure></div></div>","PeriodicalId":790,"journal":{"name":"The European Physical Journal E","volume":"49 8","pages":""},"PeriodicalIF":2.6,"publicationDate":"2026-07-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1140/epje/s10189-026-00597-5.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148459113","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Comprehensive analysis of open and isolated confined electrolyte systems","authors":"S. Mohammadi,&nbsp;H. Ameri,&nbsp;Mehrdad Saviz,&nbsp;R. Faraji-Dana","doi":"10.1140/epje/s10189-026-00610-x","DOIUrl":"10.1140/epje/s10189-026-00610-x","url":null,"abstract":"<p>In this paper, various aspects of the Poisson–Boltzmann (PB) equation, focusing on the roles of structural confinement and ionic conservation have been addressed. Specifically, this paper provides an analytical and well-behaved solution of the PB equation in finite and infinite structures for open and isolated electrolytic environments. A structure-dependent Debye length for confined systems and a generalized Debye length appropriate for isolated electrolytes are introduced. For an isolated symmetric (1:1) electrolyte, a generalized PB equation has been derived. In the literature, the solution to this equation within a finite region is often presented as complex mathematical expressions, typically constrained to particular scenarios. In this paper, a general solution to the PB equation is derived using a novel mathematical function yielding a simpler closed-form solution than existing analytical approaches. This solution is expressed explicitly in a fully analytical, closed form, and approximation free manner. The results presented yield a simple and general algorithm for treating the PB model under various conditions. Finally, using this framework, we examine the validity range of the Debye model, determine, through pressure analysis, when two immersed electrodes become effectively non-interacting and analyze the stored electrostatic energy in different geometries, highlighting the effect of system isolation on the stored energy.</p>","PeriodicalId":790,"journal":{"name":"The European Physical Journal E","volume":"49 7","pages":""},"PeriodicalIF":2.6,"publicationDate":"2026-07-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148434779","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Beyond confinement: conformational memory and the continuing legacy of Reiter and de Gennes in polymer films","authors":"Sivasurender Chandran","doi":"10.1140/epje/s10189-026-00595-7","DOIUrl":"10.1140/epje/s10189-026-00595-7","url":null,"abstract":"<p>Polymer films exhibit behaviour that cannot be explained by confinement effects alone. In 2001, Reiter and de Gennes proposed an alternative perspective, suggesting that preparation stages can imprint a form of conformational memory in polymer films. According to this view, polymers inherit nonequilibrium conformations during preparation, and the subsequent relaxation of this memory proceeds through a cascade of metastable states. This concept provided a rationale for several unusual behaviour, most notably the negative thermal expansion observed in freshly cast polymer films. Over the past two decades, experimental studies have accumulated strong evidence for preparation-induced conformational memory, often manifested through residual stresses and their slow relaxation. These advances have begun to establish preparation as a quantitative lever for probing nonequilibrium polymer physics. Despite this progress, several fundamental questions remain unanswered. In this article, I revisit the work of Reiter and de Gennes and summarize key experimental developments, emphasizing their continuing legacy. I will conclude by highlighting open questions whose answers would not only improve our fundamental understanding but also bring us closer to exploiting preparation as a quantitative lever to design programmable materials.</p><p>Spin cast glassy polymer films inherit conformations during preparation. These non-equilibrium conformations manifest into several unusual macroscopic behavior, including negative thermal expansion </p>","PeriodicalId":790,"journal":{"name":"The European Physical Journal E","volume":"49 7","pages":""},"PeriodicalIF":2.6,"publicationDate":"2026-07-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148395276","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Variational modeling and numerical simulations for evaporating thin droplets and coffee-ring effect","authors":"Yakun Li,&nbsp;Quan Zhao,&nbsp;Tiezheng Qian","doi":"10.1140/epje/s10189-026-00603-w","DOIUrl":"10.1140/epje/s10189-026-00603-w","url":null,"abstract":"<p>Sessile liquid droplets on solid surfaces are ubiquitously found in nature and engineered applications. They exhibit many intriguing properties and phenomena because of the three phases, i.e. liquid, gas, and solid, interacting with each other. Many physical processes are involved in droplet dynamics, presenting a complex problem for fundamental understanding and practical applications. Among those processes participating in the dynamics of evaporating sessile droplets, two have been of continuous interest. The first is the moving contact line at which the evolving liquid–gas interface intersects the solid surface, and the second is the evaporation at liquid–gas interface. Coupled to the moving contact line on the substrate and the liquid flow in the droplet, the interfacial evaporation plays a key role in the evolution of evaporating sessile droplets. Based on Onsager’s variational principle, we derive a continuum model for evaporating thin droplets. The variational approach ensures thermodynamical consistency in describing the coupling of multiple dissipative processes, including viscous momentum transport, contact line motion, evaporation, and vapor diffusion. A characteristic length scale is introduced by considering the competition between the liquid evaporation at liquid–gas interface and the vapor diffusion in gas space. Comparing this intrinsic length scale with that of the confinement geometry, a dimensionless parameter is identified that varies across two distinct dynamic regimes, namely the diffusion-limited regime and the transition-limited regime. Numerical results are presented for the evaporation flux and liquid flow, showing distinct characteristics in these two regimes. The coffee-ring effect is also numerically investigated for drying particle-laden droplets across different dynamic regimes with pinned and depinned contact lines.</p><p>A characteristic length scale, arising from the competition between evaporation and vapor diffusion, defines a dimensionless parameter that identifies two distinct dynamic regimes. </p>","PeriodicalId":790,"journal":{"name":"The European Physical Journal E","volume":"49 7","pages":""},"PeriodicalIF":2.6,"publicationDate":"2026-07-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1140/epje/s10189-026-00603-w.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148389808","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"What is active wetting?","authors":"Uwe Thiele","doi":"10.1140/epje/s10189-026-00590-y","DOIUrl":"10.1140/epje/s10189-026-00590-y","url":null,"abstract":"<p> In recent years, the term <i>active wetting</i> has gained some traction in works describing, analyzing, and modeling a wide variety of wetting phenomena, for instance, in the contexts of biomolecular condensates, of cell layers or cell aggregates, and of active Brownian particles. The present perspective discusses a coarse classification of wetting phenomena that accounts for this. First, different categories of static and dynamic wetting of passive liquids are briefly introduced, in particular, distinguishing equilibrium wetting, relaxational wetting, driven wetting, and reactive wetting. Second, an overview is given of the various phenomena recently described as active wetting. We conclude by discussing a possible definition of active wetting together with a number of caveats that one might want to keep in mind when using such classifications.</p>","PeriodicalId":790,"journal":{"name":"The European Physical Journal E","volume":"49 7","pages":""},"PeriodicalIF":2.6,"publicationDate":"2026-07-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1140/epje/s10189-026-00590-y.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148374212","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Metallic microresonator spectral modes with inhomogeneously twisted nematic in magnetic field","authors":"Vladimir A. Gunyakov,&nbsp;Anton S. Zuev,&nbsp;Alexander M. Parshin,&nbsp;Vitaly S. Sutormin,&nbsp;Ivan V. Timofeev,&nbsp;Victor Ya. Zyryanov,&nbsp;Vasily F. Shabanov","doi":"10.1140/epje/s10189-026-00598-4","DOIUrl":"10.1140/epje/s10189-026-00598-4","url":null,"abstract":"<p>A common, but not the only method for the spectral resonance shift in a microresonator is to change the cavity’s optical path. A fundamentally different approach to separate polarized modes at the fixed optical path consists in inhomogeneous twisting of a medium within the cavity, which allows for the creation of high-sensitivity devices such as sensors, filters, microlasers, modulators, phase shifters, etc. An experimental and theoretical study of the polarization and spectral properties of a Fabry–Pérot microresonator formed by a pair of flat metallic mirrors with a planar-oriented nematic liquid crystal layer between them has been carried out. The specific chirality of the liquid crystal structure is induced by a magnetic field in the <i>T</i>-effect regime and is characterized by inhomogeneous twisting and the presence of a plane at the center of the nematic layer where the local director reverses the twist sign. Despite the small resulting deformation, these factors enhance the nonadiabatic propagation of light waves in the resonator, which, in turn, leads to significant anomalous shifts of the polarized resonant modes in the transmittance spectrum. The obtained experimental spectral shifts of the modes are consistent with the data of the numerical simulation using the 4 <span>(times )</span> 4 transfer matrix method and are explained by the contribution of the geometric phase, which paves the way to novel topological photonics devices.</p><p>Metallic microresonator with a specific chirality of the nematic liquid crystal in magnetic field</p>","PeriodicalId":790,"journal":{"name":"The European Physical Journal E","volume":"49 7","pages":""},"PeriodicalIF":2.6,"publicationDate":"2026-06-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148343640","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Dynamics of a three-dimensional oil drop driven by a surface acoustic wave over topography","authors":"Mark Fasano,&nbsp;Yifan Li,&nbsp;Javier A. Diez,&nbsp;Ofer Manor,&nbsp;Linda J. Cummings,&nbsp;Lou Kondic","doi":"10.1140/epje/s10189-026-00604-9","DOIUrl":"10.1140/epje/s10189-026-00604-9","url":null,"abstract":"<p>We perform three-dimensional simulations of SAW-driven spreading of silicone oil drops on flat substrates and over solid obstacles. The resulting model takes the form of a three-dimensional long-wave thin-film equation incorporating capillary, gravitational, and SAW-induced acoustic stresses. A key feature of the formulation is a smooth attenuation function that localizes acoustic forcing within the bulk drop while avoiding spurious transverse discontinuities. Comparisons with results of earlier 2D formulations demonstrate qualitatively similar dynamics, albeit the additional spatial dimension permits transverse mass redistribution driven by capillarity, which leads to slower streamwise spreading and slightly lower drop apexes than predicted by 2D models. The model is applied to SAW induced dynamic wetting of flat substrates and solid obstacles and is representative of experimental geometries. Quantitative comparisons with experimental observations show good agreement for front propagation and obstacle climbing dynamics. In particular, improved agreement with the experimentally observed dependence of the liquid climbing time over obstacles on SAW amplitude is obtained when the fully three-dimensional formulation is used.</p>","PeriodicalId":790,"journal":{"name":"The European Physical Journal E","volume":"49 7","pages":""},"PeriodicalIF":2.6,"publicationDate":"2026-06-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1140/epje/s10189-026-00604-9.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148343702","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Perspective on the paper: GDR MiDi. On dense granular flows","authors":"Hans J. Herrmann,&nbsp;Stefan Luding","doi":"10.1140/epje/s10189-026-00589-5","DOIUrl":"10.1140/epje/s10189-026-00589-5","url":null,"abstract":"<div><p>The study <b><i>\"On dense granular flows\"</i></b> by GDR MiDi, published in 2004 in The European Physical Journal E 14, 341–365, stands as a seminal collective work that significantly advanced the understanding of dense granular materials. Remarkably, the names of the contributing authors are not listed; only the name of the consortium is given—a brave statement for joint efforts like this!. The GDR Midi (Groupement de Recherche sur les Milieux Divisés) was a CNRS-led consortium of French laboratories. Its mission was to bring together diverse scientific communities—including solid mechanics, fluid mechanics, physics, and geophysics—around the study of granular media, in order to promote collaboration through frequent, informal meetings held typically four times per year (see group photograph of a meeting in Carry Le Rouet in 2005). This approach enabled the identification of key scientific challenges as the need to compare and consolidate data across different configurations, between experiments and simulations, and across different research groups, ultimately inspiring the work that led to the collective GDR Midi paper.</p><h3>Graphical abstract</h3>\u0000<div><figure><div><div><picture><source><img></source></picture></div><div><p>Group photograph of the GdR Midi meeting 2005 in Carry Le Rouet. This\u0000perspective will explore its initial importance, its enduring relevance as reflected by more than\u00002500 citations [google scholar, Jan. 2026], and the future directions it continues to inspire.</p></div></div></figure></div></div>","PeriodicalId":790,"journal":{"name":"The European Physical Journal E","volume":"49 7","pages":""},"PeriodicalIF":2.6,"publicationDate":"2026-06-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1140/epje/s10189-026-00589-5.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148343713","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Resolvability parameters in molecular graphs of antimalarial drugs","authors":"Natarajan Chidambaram,&nbsp;Yashika Vadivel,&nbsp;Shivaragavi R,&nbsp;Vignesh Ravi","doi":"10.1140/epje/s10189-026-00596-6","DOIUrl":"10.1140/epje/s10189-026-00596-6","url":null,"abstract":"<p>Chemical graph theory facilitates the understanding of the complex structure of molecules. Researchers can achieve a thorough understanding of the physical science, chemical properties, and bio-organic characteristics of pharmaceuticals through the calculation of resolvability and topological parameters in drug design. The resolvability constraints for graph <span>(G=(V, E))</span> constitute a complex domain in which the framework is structured so that each vertex (atom) or edge (bond) denotes a distinct position. This study aims to utilize molecular graph theory to identify specific graph-theoretic parameters associated with the molecular graphs of eight medications used in malaria treatment. This paper presents resolvability parameters, including metric dimension (MD) and edge metric dimension (EMD), for eight medications used in malaria treatment. We demonstrate that the resolvability parameters for the specified drugs are both bounded and constant. This property facilitates molecular identification, verifies graph isomorphism, and functions as a valuable topological descriptor in QSAR/QSPR modeling. Furthermore, it improves chemical database indexing and feature generation for machine learning, facilitating efficient structure-based analysis in drug discovery and material design.</p><p>Resolvability Parameters in Anti-Malarial Drugs</p>","PeriodicalId":790,"journal":{"name":"The European Physical Journal E","volume":"49 7","pages":""},"PeriodicalIF":2.6,"publicationDate":"2026-06-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148323965","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}