Janne-Mieke Meijer

Colloidal Soft Matter

The colloidal soft matter group of Janne-Mieke Meijer focuses on complex colloids and their self-assembly to understand how building block properties, interactions and overall assembly kinetics influence superstructures that form. The group combines quantitative real-space microscopy investigations with light and x-ray scattering techniques to obtain unique insights into the underlying microscopic structure, physical mechanisms and dynamics of colloidal self-assembly from a single-particle to a bulk material level. The ultimate goal of our research is to control the spontaneous self-organization of colloids to develop new materials with unique mechanical, optical, or electronic properties.

The ultimate goal of our research is to control the spontaneous self-organization of colloids to develop new materials with unique mechanical, optical, or electronic properties

Our research focusses on the spontaneous assembly of colloidal particles into larger superstructures. Colloidal particles are small particles with one of their dimensions in the range of 1-1000 nm. When dispersed in a liquid these particles show thermal (Brownian) motion. Due to this motion the properties of colloidal dispersions are similar to molecular systems and exhibit diffusion, gas-liquid condensation and crystallization. Due to the larger size of colloids, the length and time scales of the structural dynamics are easily observable on single particle levels using optical microscopy and allows us to gain direct insight into different self-assembly processes. Today, thanks to advances in synthesis the shape and interaction potential of the colloidal particles can now be tuned with extreme precision, making colloids as complex as their molecular counterparts! Their availability opens up the possibility to study assembly processes of complex particles on a single particle level and allows us to learn how different aspects of the building blocks influence the self-assembly process. ​

SELF-ASSEMBLY & TRACKING OF ANISOTROPIC COLLOIDS

Using anisotropic colloids we study the fundamental question: how does anisotropy in building block properties such as shape and interactions influence the self-assembly process? We take advantage of the abundance of anisotropic colloidal shapes now available thanks to advances in synthesis and the exciting development of 3D nano-printing. We follow nucleation and growth of superstructures to reveal the self-assembly kinetics and pathways but also when and how disordered and meta-stable phases arise. We further assess the (equilibrium) phase behavior in dense systems and verify if unique structures predicted by theory and found in simulations can be experimentally achieved. In addition, we explore the orientational and translational degrees of freedom in dense (out-of-equilibrium) phases and we aim to shed light on jamming and glass formation in these complex systems. 
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Meet some of our Researchers

Assistant Professor

Janne-Mieke Meijer

DEFECTS & DYNAMICS IN COLLOIDAL CRYSTALS

The presence of defects, structural imperfections in the lattice, crucially influence the functional properties of colloidal crystals. We study the real-space structures of defects with microscopy, x-ray scattering techniques and in-situ SAXS investigations. At the moment we particularly focus on the dynamics of defect formation, their interactions and collective effects as well as defects in complex systems. For this we are developing novel experimental strategies that can actively induce and tune local defect structures in colloidal crystals. These strategies allow us to study defect diffusion on a single-particle level and to reveal the forces at play. We further explore the role of the defects on the macroscopic crystal properties, i.e. mechanical, optical and electrical properties. We aim to gain insights into the underlying physical mechanisms of defect formation and diffusion phenomena that are crucial for the development of self-assembled nano- and microparticle materials.

Student Opportunities

Are you a BEP or MEP student looking for a project? We are always looking for people to join our team. Please contact me for more information on available projects. 

DRIVEN SELF-ASSEMBLY & ACTIVE COLLOIDS

We investigate the self-assembly of colloids directed by external driving forces as a means to engineer novel functional superstructures. At the moment we focus on three different routes:

  1. Composite microgel systems that can be tuned with external stimuli, promising for switchable optical materials.
  2. The controlled solvent evaporation of colloidal dispersions of interest for the fabrication of functional coatings
  3. The development of active (self-propelling) colloids for self-organization into dynamic materials, similar to biological systems.

By investigating the driven self-assembly process in-situ on a single-particle and bulk level, we aim to reveal the microscopic details of how the interaction between external forces and particle characteristic determine the final superstructure. We want to understand and provide new ways to control driven self-assembly processes and help adjust and improve the rational design of functional colloidal materials. 

Recent Publications

Our most recent peer reviewed publications

Contact

  • Visiting address

    Flux 5.116
    Groene Loper 19
    5612 AP Eindhoven
    Netherlands

  • Postal address

    Flux
    P.O. Box 513
    5600 MB Eindhoven
    Netherlands