http://www.complexfluids.ethz.ch/snf19 This project is supported by the Swiss National Supercomputing Centre
The gas-liquid expanded phase transition of a Langmuir monolayer happens at very low surface concentrations which makes this phenomenon extremely expensive to explore in finite three-dimensional (3D) atomistic simulations. Starting with a 3D model reference system of amphiphilic surfactants at a 2D vapor-liquid interface, we apply our recently developed approach (Phys. Chem. Chem. Phys., 2018, 20, 16238) and map the entire system to an effective 2D system of surfactant center-of-masses projected onto the interface plane. The coarse-grained interaction potential obtained via a force-matching scheme from the 3D simulations is then used to predict the 2D gas-liquid phase equilibrium of the corresponding Langmuir monolayer. Monte Carlo simulations in the Gibbs ensemble are performed to calculate areal densities, chemical potentials and surface pressures of the gaseous and liquid coexisting phases within the monolayer. We compare these simulations to the results of a 2D density functional approach based on Weeks-Chandler-Anderson perturbation theory. We furthermore use this approach to determine the density profiles across the equilibrium gas-liquid dividing line and the corresponding line tensions. [Moghimikheirabadi, Ahmad; Kroger, Martin] Swiss Fed Inst Technol, Dept Mat, Polymer Phys, CH-8093 Zurich, Switzerland. [Sagis, Leonard M. C.] Wageningen Univ, Food Phys Grp, Bornse Weilanden 9, NL-6708 WG Wageningen, Netherlands. [Ilg, Patrick] Univ Reading, Sch Math Phys & Computat Sci, Reading RG6 6AX, Berks, England. Moghimikheirabadi, A (corresponding author), Swiss Fed Inst Technol, Dept Mat, Polymer Phys, CH-8093 Zurich, Switzerland. ahmad.moghimikheirabadi@mat.ethz.ch [hide]
Principal Investigators
Argyrios Karatrantos (PI)
Institute of Science and Technology, Luxembourg ►
Martin Kröger (PI)
Polymer Physics, ETH Zurich, Switzerland ►
Project Partners
Clement Mugemana
Institute of Science and Technology, Luxembourg ►
Jeremy Odent
Laboratory of polymeric and composite materials, Mons University, Belgium ►
Scientific Staff
Ahmad Moghimikheirabadi
Polymer Physics, ETH Zurich, Switzerland ►
Secretary
Patricia Horn
Polymer Physics, ETH Zurich, Switzerland ►
Enjoy your reading
M Kroger,
Developments in Polymer Theory and Simulation
POLYMERS English 12 (2020) 30 ►Selected conferences (co-)organized by project members
3rd Global Summit Nanotechnology & Nanomedicine
Sep 2019, 3rd Global Summit Nanotechnology & Nanomedicine, Barcelona, Spain ►
learn more ► Master student internship: Open position / Opening
Master Student Internship in Computational modelling of ionic polymer nanocomposites (M/F). A full description is available at https://euraxess.ec.europa.eu/jobs/457431. Apply online here.About this project
Fundamentally important to the processability and the material properties of polymer nanocomposites is the underlying interaction between polymer and nanoparticles, the resulting structure and dynamics. A high degree of nanoparticle dispersion is necessary for an effective reinforcement in a polymer matrix. A recent experimental approach to distributing nanoparticles into a polymer matrix is to let the interaction between nanoparticles and polymer chains to be of ionic nature.Ionic nanoparticles can impart charged polymers with unique mechanical and functional properties such as self-healing and shape memory. Upon studying a single model nanocomposite via molecular simulation, we found that nanoparticle dispersion can indeed be achieved due to the insertion of electrostatic charge, that nanoparticle diffusion slows down due to this electrostatic charge, and that the ionic nanoparticles move according to a hopping mechanism.
These recent findings have the potential to spur new studies in modelling ionic polymer nanocomposites containing ionic functionalized silica nanoparticles.
We hereby propose to focus in a more detailed and conclusive fashion on four combined experimental/theoretical research objectives:
Investigate the role of ionic interactions and calculate viscoelastic properties (viscosity, storage modulus, loss modulus) with nanoparticle loading, for differently charged and sequenced polymers.
Quantify the lifetime of dynamic crosslinks between nanoparticles and polymers, formed in ionic nanocomposites, during deformation processes.
Calculate the dynamics and structure of polymers and their entanglements for differently charged and filled polymer ionic nanocomposite models,
Resolve the role of nanosilica surface confinement on polymer entanglements and dynamics. The novelty of the proposed work stems from the combination of experiments, simulation and theoretical models to capture the interactions and polymer structural/dynamical, as well as rheological phenomena present in these ionic nanocomposites, who seem to offer qualitatively new properties worth being quantified and supplemented with an informed microscopic picture.
Lay-Summary (German only, as required by SNF)Hintergrund: Polymer-Nanokomposite (PNCs) stellen eine zunehmend wichtige Hybrid-Materialklasse dar. Das fehlende Verständnis der chemischen und physikalischen Mechanismen stellt seit Jahrzehnten ein Hindernis bei der weiteren Entwicklung dar. Für die Verarbeitung und die Eigenschaften von PNCs ist die Wechselwirkung zwischen Polymer und Nanoteilchen, sowie die resultierende Struktur und Dynamik von fundamentalem Interesse. Eine gute Dispersion der Nanoteilchen wird für die effiziente Verst&aauml;rkung von Polymer-Muttergewebe benötigt. Einer der neueren Ansätze, die diese Eigenschaft bewerkstelligen soll, ist die Verwendung von ionischen PNCs. Ionische Nanoteilchen können den ionischen Polymeren zudem neuartige mechanische und funktionelle Eigenschaften verleihen. Inhalt und Ziel des Forschungsprojekts ist ein besseres Verstädnis der ionischen PNCs. Dazu untersuchen wir die (i) Rolle von ionischen Wechselwirkungen und berechnen viskoelastische/mechanische Eigenschaften und ihre Abhäigkeit von System-Parametern (Konzentration, Ladungen, Ladungs-Sequenzen); (ii) Lebensdauer von Vernetzungspunkten in PNCs, isbesondere während Deformationsprozessen; (iii) Dynamik und Struktur der Polymere und deren Verschlaufungs-Netzwerke in Abhängigkeit der Ladungs-Sequenz; (iv) Rolle der Oberflächen-Beschaffenheit von Nano-Silikaten. Wissenschaftlicher und gesellschaftlicher Kontext des Forschungsprojekts. Wir möchten neuen Technologien für PNCs den Weg bereiten, die benötigt werden, um leichte, hoch-qualitative, und multifunktionelle Materialien weiter zu entwickeln. Ionische PNCs verprechen nicht nur die genannten mechanischen Eigenschaften, sondern auch ein Potential für Selstheilung, ionische Leitfähigkeit, und selektive Permeabilitä Simulationsmodelle erlauben uns, die genannten Abhäigkeiten im Detail zu untersuchen, und öffnen eue Horizonte für das Design ionischer PNCs für Anwendungen etwa in der Biomedizin, Biotechnologie, Energiespeicherung, Gastrennung.
24 April 2024 mk