Institut Charles Sadron Membre

1. Home
2. Equipes
3. TSP
4. William Fall

william.fall@cnrs.fr / william.fall@ics-cnrs.unistra.fr

Group Webpage, GoogleScholar, LinkedIn 

 

---

Research Themes & Contributions

---

• Polymer crystallisation: Use of molecular dynamics simulations to study how polymers (especially polyethylene) crystallise, how branching or molecular architecture influences lamellar thickness, tie chains, entanglements, etc.
  
• Liquid crystals & nanoparticle grafting: Understanding how shape-uniform nanoparticles (e.g., cellulose nanocrystals) with polymer grafts self‐assemble into smectic or other phases.
  
• Soft‐matter phase transitions: Melting of polymer monolayers touching on fundamental issues in phase transitions, e.g., first‐order vs continuous behaviour in polymer melting.
  
• Simulations & modelling: Combination of coarse-grained modelling, Monte Carlo, MD, sometimes mean‐field theory—bringing computational tools to bear on materials/soft‐matter physics.
  
• Bridging theory and simulation: Explicit comparison of analytical/mean‐field models with simulations and theoretical grounding of computational works.
  

---

Job Openings

---

• Applications are invited for the following PhD project through Ecole Doctoral de Strasbourg. Self-funded PhD students are also encouraged to enquire. Profiling PBTTT8O Polymer Polymorphs with MD Simulations.
  
• One Masters 2 Physics Student for a 6 month internship at the Institut Charles Sadron (Strasbourg). Probing the Molecular Mechanism of Melting on Cooling using Molecular Dynamics Simulations.
• One Masters 2 Physics Student for a 6 month internship (fully funded) at the Institut Charles Sadron (Strasbourg). The project involves molecular dynamics simulations of pre-oriented amorphous polymers [MD-POP], aiming to better understand their structural and mechanical behavior at the molecular scale. You’ll join a collaborative research environment and work closely with experts in polymer physics and molecular modelling. More details about the project can be found here. 
  
• Two Masters 1 Physics Students for 20 days at the Institut Charles Sadron (Strasbourg). The project involves analysing ultra-large semi-crystalline polyethylene crystals grown in molecular dynamics simulations to address two outstanding problems in polymer physics. (1) Resolving the Density Anomaly in Polyethylene Crystallisation & (2) Role of Intra-Crystalline Chain Diffusion (ICD) in Amorphous Thickness Selection. You will gain hands-on experience with molecular dynamics simulations and develop/implement analytical tools to determine the extent of adjacent re-entry folding, entanglements and ICD to understand their role in (1) & (2). More details about the projects can be found in (1-Density Anomaly) & (2-Intra Crystalline Chain Diffusion). 

There are currently no open fully-funded PDRA or PhD positions. Enquiries are welcomed all year round.

---

Short CV

---

Positions Held:

• 2025 : Chargé de Recherche Classe Normale, Institut Charles Sadron, France
  
• 2022 : Chercheur, Laboratoire de Physique des Solides, Orsay, France (H. Wensink)
  
• 2021 : Chercheur, Institut Charles Sadron, Strasbourg, France (H. Meyer & J. Baschnagel)
  
• 2020 : Post Doctoral Research Associate, The University of Sheffield, England, UK (B. Chakrabarti & B. Mukherjee)
  
• 2019 : Visiting Exchange Student, Xi’an Jiaotong University, China (G. Ungar & F. Liu)

Education:

• 2020 : Ph.D. Theoretical Physics, The University of Sheffield, England, UK (X.Zeng, G. Gehring & G. Ungar)
  
• 2016 : MPhys Theoretical Physics, Swansea University, Wales, UK (B. Lucini)

Current Project Supervision:

• Eleanora Foschino (PhD)  : TU/e Eindhoven (Co-supervised by R. Tuinier & M. Vis)

Former Project Supervision:

• Dr Kutlwano Gabana (PhD)  2024  :  The University of Sheffield  (Co-supervised by X.Zeng, G. Gehring & G. Ungar) (Thesis)
• Yannis Wypych  (ICAM Intern)  2024  :  The University of Strasbourg  (Co-supervised by H.Meyer, J.Baschnagel & O. Benzerara)  [Now Data Scientist PhD, Divalto]
  
• Dr Maxine M. McCarthy  (MPhys) 2019  :  The University of Sheffield  (Co-supervised by G.Gehring)  [Now PhD, Sheffield, UK]
  
• Dr Emma Armstrong  (MPhys) 2018  :  The University of Sheffield  (Co-supervised by G.Gehring) [Now PhD, Leeds, UK]
  
• Mostafa Shagar (SURE)  2018  :  The University of Sheffield  (Co-supervised by G.Gehring) [Now PhD, INRS, Canada]
  
• Stefan Epler-Snow (SURE) 2017  :  The University of Sheffield  (Co-supervised by G.Gehring)
  
• Stephen J. Kearney (SURE) 2017  :  The University of Sheffield  (Co-supervised by G.Gehring) [Now PhD, UCL, UK]
  

---

Selected Publications

---

1. Spontaneous Chiral Symmetry Breaking in Polydisperse Achiral Near-Rigid Nematogens., William S. Fall ✉ & Henricus H. Wensink ✉, Physical Review Letters, 

   2025.
2. Branches, Tie Chains and Entanglements in Bimodal Polyethylene Single Crystals under Uniaxial Tensile Strain., William S. Fall ✉, Jorg Baschnagel & Hendrik Meyer, npj Soft Matter, 2025. 
   
3. Molecular Simulations of Quantized Lamellar Thickening in Polyethylenes with Regularly Spaced Brominated Groups., Kutlwano Gabana, Gillian A. Gehring, Hendrik Meyer, Goran Ungar, Xiangbing Zeng ✉ & William S. Fall ✉, Macromolecules, 2024.
   
4. Phase behavior of polymer dispersed liquid crystals, comparison between mean-field theory, and coarse-grained molecular dynamics simulations., William S. Fall, Hima Bindu Kolli, Biswaroop Mukherjee, Buddhapriya Chakrabarti ✉, Soft Matter, 2024.
   
5. Large-area, self-healing block copolymer membranes for energy conversion., Christian C. M. Sproncken, Peng Liu, Justin Monney, William S. Fall, Carolina Pierucci, Philip B. V. Scholten, Brian Van Bueren, Marcos Penedo, Georg Ernest Fantner, Henricus H. Wensink, Ullrich Steiner, Christoph Weder, Nico Bruns, Michael Mayer ✉ & Alessandro Ianiro ✉, Nature, 2024.
   
6. Complex Smectic Phases in Polymer Grafted Shape-Uniform Cellulose Nanocrystals., William S. Fall ✉, Henricus H. Wensink ✉, Macromolecules, 2024.
   
7. Molecular Simulations of Controlled Polymer Crystallisation in Polyethylene., William S. Fall ✉, Jorg Baschnagel, Olivier Lhost, Hendrik Meyer ✉, ACS Macro Letters, 2023.
   
8. Role of Short Chain Branching in Crystalline Model Polyethylenes., William S. Fall ✉, Jorg Baschnagel, Olivier Lhost, Hendrik Meyer ✉, Macromolecules, 2022.
   
9. Roughening Transition and Quasi-continuous Melting of Monolayers of Ultra-long Alkanes: Why Bulk Polymer Melting Is Strongly First-Order., Ruibin Zhang, William S. Fall, Kyle Wm Hall, Gillian A. Gehring, Xiangbing Zeng ✉, Goran Ungar ✉, Macromolecules, 2021.
   
10. Quasi-Continuous Melting of Model Polymer Monolayers Prompts Reinterpretation of Polymer Melting., Ruibin Zhang, William S. Fall, Kyle Wm Hall, Gillian A. Gehring, Xiangbing Zeng ✉, Goran Ungar ✉, Nature Communications, 2021. 
    
11. The Statistics of The Ordering of Chiral Ribbons on a Honeycomb Lattice., Maxine M McCarthy, William S. Fall, Xiangbing Zeng, Goran Ungar, Gillian A Gehring ✉, J. Stat. Mech., 2021.
    
12. An Ising Transition of Chessboard Tilings in a Honeycomb Liquid Crystal. William S. Fall, Constance Nürnberger, Xiangbing Zeng, Feng Liu, Stephen J. Kearney, Gillian A. Gehring, Carsten Tschierske ✉, Goran Ungar ✉, Molecular Systems Design & Engineering, 2019.
    
13. Molecular Ejection Transition in Liquid Crystal Columns Self-Assembled from Wedge-Shaped Minidendrons., William S. Fall, Ming-Huei Yen, Xiangbing Zeng, Liliana Cseh, Yongsong Liu, Gillian A. Gehring, Goran Ungar ✉, Soft Matter, 2019.