A5068202262- Fluid Dynamics and Thin Films
- Solidification and crystal growth phenomena
- Surface Modification and Superhydrophobicity
- Nonlinear Dynamics and Pattern Formation
- Fluid Dynamics and Heat Transfer
- Theoretical and Computational Physics
- nanoparticles nucleation surface interactions
- Micro and Nano Robotics
- Nanomaterials and Printing Technologies
- Block Copolymer Self-Assembly
- Rheology and Fluid Dynamics Studies
- Advanced Thermodynamics and Statistical Mechanics
- Adhesion, Friction, and Surface Interactions
- Pickering emulsions and particle stabilization
- Fluid Dynamics and Turbulent Flows
- Polymer Surface Interaction Studies
- Surfactants and Colloidal Systems
- Material Dynamics and Properties
- Advanced Mathematical Modeling in Engineering
- Phase Equilibria and Thermodynamics
- Heat Transfer and Boiling Studies
- Modular Robots and Swarm Intelligence
- Mathematical Biology Tumor Growth
- Cold Atom Physics and Bose-Einstein Condensates
- Liquid Crystal Research Advancements
University of Münster
2016-2025
Instituto de Física Teórica
2023
Nonlinear Control Strategies (United States)
2018
Loughborough University
2008-2017
Laboratoire Interdisciplinaire de Physique
2016
Centre National de la Recherche Scientifique
2016
Université Grenoble Alpes
2016
Max Planck Society
2001-2008
Max Planck Institute for the Physics of Complex Systems
1999-2008
Augsburg University
2008
Employing a two-species Cahn-Hilliard model with nonreciprocal interactions, we show that the interplay of nonreciprocity and conservation laws results in robust coexistence uniform stationary oscillatory phases as well crystalline phases. For nonequilibrium models spurious gradient dynamics structure, such coexistences between two or more resulting phase diagrams can, nevertheless, be predicted by Maxwell double-tangent construction. This includes sustained regular irregular...
Film rupture as the initial stage of dewetting is investigated for a volatile, spin-coated nonwetting film. During structure formation in liquid film thickness continuously reduced via evaporation. The dynamical character experiment allows study hole caused by distinct mechanisms occurring at different thicknesses. Both heterogeneous nucleation thick films well spinodal below 10 nm have been observed. balance between both processes can be shifted controlling ambient humidity. structures...
Unstable thin liquid films on solid substrates dewet by hole nucleation defects or a linear surface instability (spinodal dewetting). A system with destabilizing short-range and stabilizing long-range molecular interactions is investigated. We show that, for subrange within the linearly unstable film thickness range, determines final structure, whereas spinodal dewetting of negligible influence. The results are also applicable to decomposition binary mixtures.
Abstract We provide an overview of current techniques and typical applications numerical bifurcation analysis in fluid dynamical problems. Many these problems are characterized by high-dimensional systems which undergo transitions as parameters changed. The computation the critical conditions associated with transitions, popularly referred to ‘tipping points’, is important for understanding transition mechanisms. describe two basic classes methods analysis, differ explicit or implicit use...
Oscillatory behavior is ubiquitous in out-of-equilibrium systems showing spatiotemporal pattern formation. Starting from a linear large-scale oscillatory instability---a conserved-Hopf instability---that naturally occurs many active with two conservation laws, we derive corresponding amplitude equation. It belongs to hierarchy of such universal equations for the eight types instabilities homogeneous isotropic resulting combination three features: vs small-scale instability, stationary and...
We consider the time evolution of a sessile drop volatile partially wetting liquid on rigid solid substrate. Thereby, evaporates under strong confinement, namely, it sits one two parallel plates that form narrow gap. First, we develop an efficient mesoscopic thin-film description in gradient dynamics form. It couples diffusive vertically averaged vapour density gap to equation for profile drop. The underlying free energy functional incorporates wetting, interface and bulk energies gas...
Field theories for the one-body density of an active fluid, such as paradigmatic model B+, are simple yet very powerful tools describing phenomena motility-induced phase separation. No comparable theory has been derived underdamped case. In this work, we introduce I+, extension B+ to particles with inertia. The governing equations I+ systematically from microscopic Langevin equations. We show that, particles, thermodynamic and mechanical definitions velocity field no longer coincide that...
We briefly review recent advances in the hydrodynamic modeling of dynamics droplets on adaptive substrates, particular, solids that are covered by polymer brushes. Thereby, focus is long-wave and full-curvature variants mesoscopic models gradient form. After introducing approach for films/drops nonvolatile simple liquids a rigid smooth solid substrate, it first expanded to an arbitrary number coupled degrees freedom before considering specific case drops volatile brush-covered solids....
We consider two stacked ultrathin layers of different liquids on a solid substrate. Using long-wave theory, we derive coupled evolution equations for the free liquid-liquid and liquid-gas interfaces. Depending long-range van der Waals forces ratio layer thicknesses, system follows pathways dewetting. The instability may be driven by varicose or zigzag modes leads to film rupture either at interface predict that faster drives accelerate slower orders magnitude, thereby promoting rather thick films.
We consider a thin film consisting of two layers immiscible liquids on solid horizontal (heated) substrate. Both the free liquid–liquid and liquid–gas interface such bilayer liquid may be unstable due to effective molecular interactions relevant for ultrathin below 100-nm thickness, or temperature-gradient-caused Marangoni flows in heated case. Using long-wave approximation, we derive coupled evolution equations profiles general nonisothermal situation allowing slip at Linear nonlinear...
We have achieved highly localized control of pattern formation in two-dimensional nanoparticle assemblies by direct modification solvent dewetting dynamics. A striking dependence organization on the size atomic force microscope-generated surface heterogeneities is observed and reproduced numerical simulations. Nanoscale features induce a rupture solvent-nanoparticle film, causing local flow to carry nanoparticles into confinement. Microscale instead slow evaporation solvent, producing...
The growth of fingering patterns in dewetting nanofluids (colloidal solutions thiol-passivated gold nanoparticles) has been followed real time using contrast-enhanced video microscopy. instability on which we focus here arises from evaporatively driven nucleation and a nanoscopically thin precursor solvent film behind the macroscopic contact line. We find that well-developed isotropic structures only form for narrow range experimental parameters. Numerical simulations, based modification...
In the present contribution we review basic mathematical results for three physical systems involving self-organising solid or liquid films at surfaces. The may undergo a structuring process by dewetting, evaporation/condensation epitaxial growth, respectively. We highlight similarities and differences of based on observation that in certain limits all them be described using models similar form, i.e., time evolution equations film thickness profile. Those represent gradient dynamics...
The conserved Swift-Hohenberg equation with cubic nonlinearity provides the simplest microscopic description of thermodynamic transition from a fluid state to crystalline state. resulting phase field crystal model describes variety spatially localized structures, in addition different extended periodic structures. location these structures temperature versus mean order parameter plane is determined using combination numerical continuation one dimension and direct simulation two three...
We present a theory for the interfacial wetting phase behavior of binary liquid mixtures on rigid solid substrates, applicable to both miscible and immiscible mixtures. In particular, we calculate binding potential as function adsorptions, i.e., excess amounts each two liquids at substrate. The fully describes corresponding thermodynamics. Our approach is based classical density functional theory. Binary can exhibit complex bulk behavior, including liquid-liquid vapor-liquid separation,...
The Benney equation including thermocapillary effects is considered to study a liquid film flowing down homogeneously heated inclined wall. link between the finite-time blow-up of and absence one-hump travelling-wave solution associated dynamical system accurately demonstrated in whole range linearly unstable wavenumbers. Then boundary tracked space parameters accounting for flow rate, surface tension, inclination thermocapillarity. In particular, latter two can strongly reduce validity...
The present theoretical study focuses on the dynamics of a thin liquid film falling down vertical plate with nonuniform, sinusoidal temperature distribution. results are compared to those obtained in case uniform governing evolution equation for thickness profile based long-wave theory accounts two instability mechanisms related thermocapillarity. first mechanism is due an inhomogeneity at liquid–gas interface induced by perturbations thickness, when heat transfer gas phase present, while...
The time evolution of a thin liquid film flowing down heated solid porous substrate is investigated. Using the Navier–Stokes and Darcy–Brinkman equations in layer, respectively, problem reduced to study equation for free surface derived through long-wave approximation. A linear stability analysis base flow performed critical Reynolds Marangoni numbers are obtained. nonlinear using continuation techniques shows that yields stationary structures ranging from waves large amplitude resembling...