The goal of the symposium was to bring together scientists and engineers who share the common interest in creating functional materials using particles. The synthesis, processing and materials integration of particles into thin films, bulk matrices, fibers or other geometries are covered by this symposium.
Next year’s 10th PBM conference will take place in September/October at Universität Duisburg-Essen. Stay tuned!
How do a small number of larger colloidal particles behave when mixed with many smaller ones inside spherical droplets? We found that entropy alone drives the larger particles to the droplet surface, where they consistently settle at the twelve vertices of an icosahedral structure formed by the smaller particles. Using a combination of experiment and simulation, we showed that this trapping effect is robust and results from the system’s tendency to maximize free volume during self-assembly. These findings offer new insight into how complex structures can form without external guidance and support the design of programmable materials through simple physical principles.
The large colloids (red) get trapped at the icosahedral vertices.
Scientists have long known that the shape of tiny crystals (nanocrystals) can affect their properties, such as how they interact with light or how well they function as catalysts. However, precisely understanding how these shapes form has been challenging, since many factors are involved: temperature, chemicals in the solution, and even the arrangement of atoms at the crystal’s edges. In this study, the researchers introduced a theoretical and computational approach that focuses on the critical spots where atoms attach as the crystal grows. By examining the energy required to add atoms at these sites, they explain why certain shapes, including cubes, octahedra, or other symmetrical forms, often appear.
Beyond explaining why various shapes emerge, this method can guide experimental design. It enables scientists to predict which conditions favor different morphologies and to control crystal growth toward specific outcomes. The study shows that the first atom to grow on the surface, referred to as the adatom, dominates the process by creating temporary pathways that lead to particular shapes. This new understanding not only clarifies how nanocrystals form but also suggests ways to refine their shapes for targeted uses in technology and medicine.
The shape diagram summarizes the change of nanocrystal shape across growth parameters. Here: the growth rates of adatoms on the three major crystallographic facets.
The Engellab continued a scientific exchange with the group or Sudeep Punnathanam at the Indian Institute of Science (IISc). As part of this Indo-German exchange, multiple mutual visits were organized in 2023 and 2024.
IISc is a leading research university located in Bengaluru (Karnataka). The research of our Indian partner concerns Enhanced Computational Research in Phase Transitions (EnCRIPT). The exchange was funded by the German Academic Exchange Service (DAAD — Deutscher Akademischer Austauschdienst) over two years.
Our visitors on top of Fahnenstein in Tüchersfeld.Michael Engel behind the Chemical Engineering building at IISc.
Michael Engel attends the 2024 AIChE Annual Meeting in San Diego to present present his research and promote our department of Chemical and Biological Engineering of FAU. The department has an evening reception and participates in the recruitment fair.
Surface strain can help increase the performance of nanocatalysts, and we have designed a new strategy to stabilize the surface strain in materials. The groups of Yimo Han and Matthew R. Jones at Rice University synthesized nanoparticles and used four-dimensional scanning transmission electron microscopy (4D-STEM) to capture an electron diffraction pattern at each scan position, which produces detailed structural information. Molecular dynamics simulations of Alberto Leonardi investigated the inhibition of dislocation nucleation due to reduced shear stress at corners.
Michael Engel visited the Computational Statistical Physics lab of Masaharu Isobe at Nagoya Institute of Technology University from July 4 to July 17. NITech is a partner university of FAU in Japan. Discussions advanced our understanding of the hard disc problems, in particular using event-chain methods and Voronoi decomposition.
Michael Engel presents at NITech on structure formation in particulate matter.Mount Fuji from the Shinkansen from Nagoya to Tokyo.
The lab published two in-depth overview articles in the field of mesostructure formation:
Nanocrystal Assemblies: Current Advances and Open Problems
This review appeared in ACS Nano and is coauthored by 42 authors. The paper grew from discussions on these topics among the participants of the workshop “Nanoparticle Assemblies: A New Form of Matter with Classical Structure and Quantum Function”, held at the Kavli Institute for Theoretical Physics (KITP), Santa Barbara/CA, USA, from March 27 to May 19, 2023. This study is a broader-view study linking different scales, fundamentals, and methods, emphasizing open problems to inspire and push forward research in the field.
Mesomorphology of Clathrate Hydrates from Molecular Ordering
This perspective appeared in the Journal of Chemical Physics. The paper discusses the coupling of molecular ordering with the mesoscales, including (i) the emergence of porous patterns as a combined factor from the walk over the free energy landscape and 3D competitive nucleation and growth and (ii) the role of molecular attachment rates in crystallization–diffusion models that allow predicting the timescale of pore sealing. It discusses the use of discrete models (molecular dynamics) to build continuum models (phase field models, crystallization laws, and transport phenomena) to predict multiscale manifestations at a feasible computational cost.
The German Research Foundation just announced that CRC 1411 will receive funding until 2028.
The long-term vision of CRC1411 is to develop particle systems with controlled size, shape and composition. The innovative approach in CRC1411 is is that these materials are first developed and optimized for specific product properties in computer models. In the second step, the computer then predicts optimal synthesis conditions that lead to particles with these desired properties. This approach reverses typical manufacturing processes and promises fast and resource-efficient access to functional particle-based materials with optimal characteristics.
Michael Engel is among the 2% most cited scientists worldwide in 2022. The study by a team of researchers from Stanford University is based on data extracted from Scopus.
