It is often easy to observe the ability of polymorphic materials to undergo a phase transition through changes in colour, conductivity, photovoltaic efficiency, or other functional properties. In contrast, it is challenging to control under which external stimuli, such as stress, temperature, and adsorption, these materials switch. Yet, enabling such polymorphic materials design would be a game changer for pressing societal challenges, from access to drinking water to producing green energy. This requires a firm understanding of how changing a material’s structure impacts its polymorphism and macroscopic function.
STRAINSWITCH aims to transform polymorphic material design by establishing the strain engineering concept. The central characteristic in this in silico approach is strain: the extent to which a material deforms due to external or internal triggers. On the one hand, external stimuli generate strain, even before they activate a phase transition. On the other, spatial disorder in a structure, tuneable from the atom to the device scale, also induces strain that interferes with external strain fields. The key hypothesis is that it is possible to systematically predict which disorder is needed to ensure polymorphism only occurs under well-defined external triggers by balancing these internal and external strain fields.
To confirm this hypothesis, we will develop new in silico methods with the goal to:
- understand how disorder induces strain fields in a material that propagate through both space (3D) and time (+1D) to enable 4D design;
- predict which internal strain fields activate a material’s polymorphism under specific external stimuli.
STRAINSWITCH will combine both goals to establish fundamental disorder-strain-function relationships that can be validated experimentally for metal-organic frameworks and metal halide perovskites. They will pave the way for 4D polymorphic material design with application in water harvesting, photovoltaic devices, and more.
More background information
The first strain engineering results were published in Matter, a Cell Press journal:
- Absorbing stress via molecular crumple zones: Strain engineering flexibility into the rigid UiO-66 materials
- Sven M.J. Rogge, Sander Borgmans, and Veronique Van Speybroeck
- Matter 6(5): 1435-1462, 2023 http://doi.org/10.1016/j.matt.2023.02.009
Want to join our group?
Researchers specialising in developing and applying computational modelling tools for nanostructured materials who wish to be part of Sven’s research team are encouraged to visit this page and apply.
A1-publications
Challenges and Best Practices in Modeling Anisotropic Stresses in Soft Polymorphic Materials
Soft polymorphic materials, such as metal–organic frameworks (MOFs) and covalent organic frameworks (COFs), often display distinct anisotropy. Yet, their phase transition behavior has been predominantly characterized under isotropic stimuli, such as temperature or pressure variations, up to now. In this work, we employed the Cauchystat to investigate how MIL-53(Al) and COF-5, two prototypical soft porous crystals, respond to anisotropic stresses instead.
Maximizing Porosity and Water Sorption in Covalent Organic Frameworks via β-Ketoenamine Linkages
Controlling the crystallinity and porosity of 2D covalent organic frameworks (2D COFs) is crucial for their applications in science and technology. Herein, the construction of 2D COFs, COF-TP-X, is reported using a multicomponent reaction strategy that introduces β-ketoenamine linkages into isostructural imine-linked COFs. This approach yields materials with exceptional crystallinity, stability, and tunable hydrophilicity.
Artificial Intelligence Paradigms for Next-Generation Metal–Organic Framework Research
After the development of the famous “Transformer” network architecture and the meteoric rise of artificial intelligence (AI)-powered chatbots, large language models (LLMs) have become an indispensable part of our daily activities. In this rapidly evolving era, “all we need is attention” as Google’s famous transformer paper’s title [Vaswani et al., Adv. Neural Inf. Process. Syst. 2017, 30] implies: We need to focus on and give “attention” to what we have at hand, then consider what we can do further. What can LLMs offer for immediate short-term adaptation?
Talks
- [Poster] Material-transferable design rules for defective metal-organic frameworks and metal halide perovskites through strain engineering
- [Talk] Designing functional 4D polymorphism in nanostructured materials through strain engineering
- [Poster] Challenges and best practices in modelling anisotropic stresses in soft polymorphic materials
- [Poster] Towards a fundamental understanding of forced liquid intrusion for shock absorption using machine learned interatomic potentials
- [Talk] Challenges and best practices in modelling anisotropic stresses in soft polymorphic materials
- [Invited talk] Designing functional 4D polymorphism in nanostructured materials through strain engineering
- [Talk] Modelling elusive order-disorder phase transitions in metal–organic frameworks
- [Invited talk] Exploring the opportunities in strain engineering: From introducing flexibility in rigid MOFs to classifying elusive amorphous states
- [Invited talk] Exploring the opportunities in strain engineering: From introducing flexibility in rigid MOFs to classifying elusive amorphous states
- [Talk] Exploring the opportunities in strain engineering: From introducing flexibility in rigid MOFs to classifying elusive amorphous states
- [Invited talk] MOFs under "pressure"
- [Invited talk] Investigating cooperative and correlated multiscale phenomena in reticular materials through the micromechanical model: MicMec
- [Talk] Exploring the opportunities in strain engineering: From introducing flexibility in rigid MOFs to classifying elusive amorphous states