Name: SPP 2171 Workshop: "Wetting of Flexible, Adaptive, and Switchable Substrates"
Start: 2022-12-05T11:00:00+01:00
End: 2022-12-08T15:05:00+01:00
Location: Tagungszentrum an der Sternwarte, Göttingen

SPP 2171 Workshop: "Wetting of Flexible, Adaptive, and Switchable Substrates"

from Monday, December 5, 2022 (11:00 AM) to Thursday, December 8, 2022 (3:05 PM)

Monday, December 5, 2022

12:30 PM Lunch & registration
Lunch & registration
12:30 PM - 2:00 PM
2:00 PM Charging and adaptation after wetting - Hans-Jürgen Butt (Max Planck Institute for Polymer Research)
Charging and adaptation after wetting
- Hans-Jürgen Butt (Max Planck Institute for Polymer Research)
2:00 PM - 2:45 PM
tba.
2:45 PM Solid-liquid work of adhesion - Rafael Tadmor
Solid-liquid work of adhesion
- Rafael Tadmor
2:45 PM - 3:30 PM
We discuss the problem of solid liquid adhesion and in particular we will focus on a tool for direct measurements of the work needed to separate a liquid from a solid. The method mimics a pendant drop that is subjected to a gravitational force that is slowly increasing until the solid−liquid contact area starts to shrink spontaneously. The work of adhesion is then calculated in analogy to Tate’s law. The values obtained are intensive (independent of drop size) and in agreement with Dupré’s theory.
3:30 PM Coffee break
Coffee break
3:30 PM - 4:00 PM
4:00 PM Poster Session
Poster Session
4:00 PM - 6:00 PM
Contributions

4:00 PM Fluorescent Techniques to Measure in Real-Time Water Diffusion Through Polymeric Surfaces - Karina Catalán (Sandoval)

4:00 PM Photoresponsive Wetting of Polymerbrushes containing Arylazopyrazoles - Niklas Björn Arndt

4:00 PM Deep learning to analyze sliding drops - Sajjad Shumaly (Max Planck institute for polymer research )

4:00 PM Stimuli effects on different responsive polymer brushes - Simon Schubotz

4:00 PM Vesicles adhered to flexible and adaptive surfaces - Lucia Wesenberg

4:00 PM Schroeder's paradox in polymeric surfaces - Guido Ritsema van Eck (University of Twente)

4:00 PM Dynamic mesoscopic model for two-component compound drops - Jan Diekmann

4:00 PM Photoswitchable soft substrates for droplet behavior evaluation upon on-demand softness alteration - Niloofar Nekoonam

4:00 PM Gradient Dynamics Model for Liquid Drops on Elastic Substrates - Capturing prominent Soft Wetting Phenomena using a simplified Approach - Christopher Henkel

4:00 PM Spreading and Evaporation of Nanodroplets on Soft and Rigid Surfaces - Nikolai Kubochkin (Institute for Technical Thermodynamics, Technische Universität Darmstadt)

4:00 PM Synthesis of diblock copolymer brush surfaces to control the adaptation time to water - Benjamin Leibauer

4:00 PM The Interplay of Spreading, Imbibition and Evaporation of Droplets at Nanoporous Surfaces - Laura Gallardo Domínguez (TUHH)

4:00 PM Sliding water contact electrification on plasma-treated surface - Fahimeh Darvish (Max Planck Institute for Polymer Research, Ackermannweg 10, D-55128, Mainz, Germany)

4:00 PM Spreading of volatile oils on swelling hydrophobic polymer brush layers - Sander Reuvekamp (University of Twente, SPC group) Vincent Siekman (University of Twente, PCF group)

4:00 PM Intelligent Polymer Materials and Films for Electrochemical, Pharmaceutical & Soft Robotics Applications - Junqi Lu (University of Stuttgart)
Tuesday, December 6, 2022
9:00 AM Solvation and Wetting of Polymer Brushes in Air - Sissi de Beer (University of Twente)
Solvation and Wetting of Polymer Brushes in Air
- Sissi de Beer (University of Twente)
9:00 AM - 9:45 AM
For the development of brush-based functional surface-coatings, it is critical to understand their properties, because they will determine their performance and user-experience. Polymer brush solvation and wetting are key parameters in this. In this presentation we will show that brushes can display counter-intuitive wetting properties. We aim to unravel those by combining molecular dynamics simulations, contact angle goniometry and ellipsometry laboratory experiments.
9:45 AM Switchable and Adaptive Bioadhesion - Insights from Living Systems - Oliver Bäumchen (University of Bayreuth)
Switchable and Adaptive Bioadhesion - Insights from Living Systems
- Oliver Bäumchen (University of Bayreuth)
9:45 AM - 10:30 AM
Among all living species, microbes are the most abundant and diverse form of life on Earth. They have conquered almost all ecosystems of our planet by successfully adapting to their environment. Life on Earth has evolved under the exposure of sunlight and many species are equipped with a photosynthesis machinery enabling them to transform light into chemical energy. Their microhabitats include liquid-infused soil, porous rocks and microdroplets, featuring complex geometric architectures that support strong spatial and temporal fluctuations of light exposure. Thus, developing functionalities to rapidly respond to light fluctuations, far more than other environmental cues, has been pivotal for natural selection. In this presentation, I will show how experimental methods from soft matter physics and biophysics [1], in conjunction with theoretical concepts from non-equilibrium statistical physics, enable us to decipher fundamental physical principles of the light response of photosynthetic microorganisms. In particular, I will focus on the interactions of light-sensing microbes with abiotic surfaces [2] and discuss in detail, how the bioadhesion of living microbes can be highly adaptive [3,4] and even reversibly switchable within seconds [5] . [1] M. Backholm and O. Bäumchen, Nature Protocols 14, 594 (2019); [2] S. Till et al., Physical Review Research, accepted (2022); [3] C.T. Kreis et al., Soft Matter 15, 3027 (2019); [4] N. Xu et al., eLife 9, e58805 (2020); [5] C.T. Kreis et al., Nature Physics 14, 45 (2018).
10:30 AM Coffee break
Coffee break
10:30 AM - 11:00 AM
11:00 AM
11:00 AM - 12:30 PM
Contributions

11:00 AM Monitoring of Water Penetration in Polymer Brushes by Time-Resolved Fluorescence of Solvatochromic Dye - Sergey I. Druzhinin (Physical Chemistry I, Department of Chemistry and Biology and Research Center of Micro and Nanochemistry and (Bio)Technology (Cμ), University of Siegen)

11:30 AM Describing liquid drops on elastic substrates: Mesoscale model vs. macroscale model and experiment - Christopher Henkel (Institut für Theoretische Physik, Westfälische Wilhelms-Universität Münster, Wilhelm-Klemm-Str. 9, 48149 Münster, Germany) Martin H. Essink (Physics of Fluids Group, Faculty of Science and Technology, Mesa+ Institute, University of Twente, 7500 AE Enschede, The Netherlands)

12:00 PM Influence of surface chemistry on the charging of water drops moving on hydrophobic silicate substrates - Benjamin Leibauer
12:30 PM Lunch & discussion
Lunch & discussion
12:30 PM - 2:00 PM
2:00 PM
2:00 PM - 3:30 PM
Contributions

2:00 PM A High-Order Method for the Interaction of Fluids and Soft Substrates with Three-Phase Contact Lines - Florian Kummer (TU Darmstadt - FG Strömungsdynamik)

2:30 PM Molecular Kinetics and Dynamic Wetting of Self-Assembled Monolayers with Arylazopyrazole Photoswitches on Oxide Surfaces - Björn Braunschweig

3:00 PM Fast contact line on soft solids - Hansol Jeon (Max Planck Institute for Dynamics and Self-Organization)
3:30 PM Coffee break
Coffee break
3:30 PM - 4:00 PM
4:00 PM Climate crisis: Impressions from the UN Climate Change Conference, COP 27. Our role as scientists. - Doris Vollmer (Max Planck Institute for Polymer Research)
Climate crisis: Impressions from the UN Climate Change Conference, COP 27. Our role as scientists.
- Doris Vollmer (Max Planck Institute for Polymer Research)
4:00 PM - 5:00 PM
Evening talk: report from the recent climate conference COP27.
Wednesday, December 7, 2022
9:00 AM Lift at low Reynolds number - Thomas Salez (LOMA @ CNRS & Univ. Bordeaux)
Lift at low Reynolds number
- Thomas Salez (LOMA @ CNRS & Univ. Bordeaux)
9:00 AM - 9:45 AM
Soft and wet contact arises in a range of phenomena that spans many length and time scales, and includes: landslides, aquaplaning of tires, wear of industrial bearings, ageing of synovial and cartilaginous joints, cell motion in blood vessels or microfluidic devices, and atomic-force or surface-force rheology. Therein, the coupling between boundary elasticity and confined viscous flow leads to a striking zoology of counterintuitive emergent effects. From the canonical situation of a free particle that can simultaneously sediment, slide, and roll in a viscous fluid, and near a soft wall, we study a range of novel inertial-like (despite the low-Reynolds-number flow) features, such as: enhanced sedimentation, elas- tohydrodynamic bouncing, roll reversal, emergent lift and torque, dynamical adhesive-like forces.
9:45 AM Biological Applications of the Thin-Film-Equation: From cellular motility to lateral spreading of biofilms - Karin John (Université Grenoble-Alpes, CNRS, LIPhy, 38000 Grenoble, France)
Biological Applications of the Thin-Film-Equation: From cellular motility to lateral spreading of biofilms
- Karin John (Université Grenoble-Alpes, CNRS, LIPhy, 38000 Grenoble, France)
9:45 AM - 10:30 AM
In biological systems activity can manifest itself in different forms; as individual motility or as growth and production processes. I will present two different applications of the thin film equation coupled to active processes. In both scenarios, the (reductionist's) model equations represent a gradient dynamics derived from a potential energy supplemented by bioactive terms which break the symmetry of the gradient dynamics. In the first scenario, I introduce a model for invidual cell motiliy driven by active stress. Eukaryotic cells may translocate on homogeneous substrates by employing their cytoskeleton, an assembly of polar filaments and molecular motors. I will discuss this model within the context bistability observed in keratocytes, which may coexist as immotile and motile cells. In the second scenario, I will introduce a model for lateral biofilm spreading. When encountering surfaces or interfaces, many bacteria transition from a planktonic to a community lifestyle. The thereby formed bacterial colonies grow by cell division and spread as flat films along the interface. Here I will highlight the importance of passive surface forces and osmotic fluxes, compared to individual bacterial motility, for biofilm spreading on agar substrates under air.
10:30 AM Coffee break
Coffee break
10:30 AM - 11:00 AM
11:00 AM Stimulus-Induced Wetting of Polymer Brushes with Lipid Vesicles: Experimental Challenges and Perspectives - Motomu Tanaka (Ruprecht-Karls-Universität Heidelberg)
Stimulus-Induced Wetting of Polymer Brushes with Lipid Vesicles: Experimental Challenges and Perspectives
- Motomu Tanaka (Ruprecht-Karls-Universität Heidelberg)
11:00 AM - 11:45 AM
Adhesion of biological cells and lipid vesicles shares common features with wetting droplets. The main difference from the droplets of simple liquid is that the deformation is not only driven by tension but also by bending elasticity of membranes. Inspired by proteins, we designed polymer brushes that switch the conformation by complexation with heavy metal ions. The switching of thickness, density and interfacial roughness was detected by high energy X-ray reflectivity, and the switching of interfacial viscoelasticity was monitored under systematic variation of heavy metal ion concentrations. The detailed shape and height fluctuation of vesicles were determined by microinterferometry, while the global shape of vesicle was reconstructed from confocal images. From the height fluctuation of the bottom surface of vesicles, we determined the critical threshold that induces a transition from "non-wetting" to "wetting", and the precise shape analysis near the contact line yielded the free energy of adhesion. Recently, we successfully observed the "dynamic" switching of wetting vesicles in a microfluidic chamber, which opens a possibility to investigate the kinetics of switchable wetting with lipid vesicles.
11:45 AM
11:45 AM - 12:45 PM
Contributions

11:45 AM Water droplets on liquid crystal-infused porous surfaces - Uroš Tkalec (University of Ljubljana)

12:15 PM Bistable moving and resting drops in an active thin-film model - Fenna Stegemerten (WWU Münster)
12:45 PM Lunch & discussion
Lunch & discussion
12:45 PM - 2:00 PM
2:00 PM
2:00 PM - 3:30 PM
Contributions

2:00 PM Equilibrium droplets between experiment and theoretical predictions - Khalil REMINI (Saarland University) Leonie Schmeller

2:30 PM Photoswitchable porous substrates for on demand wetting patterns creation - Niloofar Nekoonam

3:00 PM How friction develops during the sliding of drops - Xiaomei Li (Max-Planck-Institut für Polymerforschung)
3:30 PM Coffee break
Coffee break
3:30 PM - 4:00 PM
4:00 PM
4:00 PM - 5:30 PM
Contributions

4:00 PM Dilute suspensions of chemically active particles in thin liquid films - Tilman Richter (Helmholtz-Institut Erlangen-Nürnberg für Erneuerbare Energien)

4:30 PM An ALE-Phase-Field Method for simulations of wetting on elastic shells in flow - Marcel Mokbel (TU Freiberg)

5:00 PM Steering droplets on substrates with plane-wave wettability patterns and deformations - Josua Grawitter (Technische Universität Berlin, Institut für Theoretische Physik)
Thursday, December 8, 2022
9:00 AM Wetting and Swelling of soft fibres - Camille Duprat (Ecole Polytechnique)
Wetting and Swelling of soft fibres
- Camille Duprat (Ecole Polytechnique)
9:00 AM - 9:45 AM
We consider the morphologies adopted by liquid in fibrous assemblies, and in particular the coupled effects of geometry, elasticity and swelling on the liquid distribution. For favorable solvants that are absorbed by the fibers, the induced swelling strongly affects the liquid distribution, for exemple inducing transient motions or even coalescence of the drops. When the fibers are flexible, the force exerted by the drop may deform them. Swelling can induce a spontaneous collapse of the fibers and a forced imbibition, which we rationalize with a model coupling poroelasticity and elasto-capillarity.
9:45 AM Cloaking Induced Variation in Droplet Surface Tension - Rodrique Badr (JGU Mainz) Lukas Hauer (MPIP Mainz)
Cloaking Induced Variation in Droplet Surface Tension
- Rodrique Badr (JGU Mainz)
- Lukas Hauer (MPIP Mainz)
9:45 AM - 10:30 AM
Cloaking of surface material (e.g. oligomers in PDMS coatings) on contacting droplets is a phenomenon that directly affects static and dynamic wetting. Of the multitude of changes that the system undergoes with cloaking, the change in the effective droplet surface tension is the most conspicuous. The small length scale of the cloak (in the order of nanometers) together with the imposed curvature of the droplet surface makes direct experimental monitoring (static and dynamic) challenging. Here, we tackle this problem with a combination of MD simulations and surface tension measurements. The former resolves locally the degree of the cloak while the latter resolves the temporal evolution of the cloak using the surface tension as a proxy. The analysis is finally supplemented with a theoretical framework, motivated by the results.
10:30 AM Coffee break
Coffee break
10:30 AM - 11:00 AM
11:00 AM
11:00 AM - 12:30 PM
Contributions

11:00 AM Memory effects of PNiPAAm brushes in different atmospheres - Simon Schubotz

11:30 AM Dip-coating a soft layer - Vincent Bertin (University of Twente)

12:00 PM Gradient dynamics model for sessile drop evaporation in a gap: from simple to applied scenarios - Simon Hartmann
12:30 PM Lunch & discussion
Lunch & discussion
12:30 PM - 2:00 PM