NANOPARTICLES SELF-ASSEMBLY GROUP

Contact: Prof. Marco Lattuada

The research activity of our group is devoted to the rational design and the synthesis of nanoparticles and to the investigation of their self-assembly behavior by a balanced combination of experiments and simulations, with the objective of creating new materials with tailored properties. In the last decades, enormous progresses have been made in understanding and predicting the self-assembly behavior of spherical isotropic nanoparticles and its dependence on interparticle interactions, often invoking the similarities between spherical particles and atoms. It is however very clear from a material science perspective that isotropic nanoparticles offer a limited variety of structures accessible via self-assembly. By taking a look at molecules and proteins, one immediately recognizes that their ability to create highly complex and organized assemblies lies in their anisotropy. For example, molecules form a well-defined number of bonds in specific directions, while proteins possess hydrophilic and hydrophobic patches that control their interaction patterns. Our objective is therefore to engineer polymer-based or composite nanoparticles that can mimic the behavior of simple molecules or proteins. To achieve this goal, we aim at creating nanoparticles with anisotropic properties and functionalities, starting from the simplest example of two-faced (Janus) nanoparticles, and proceeding towards more complex patchy particles with well defined structure. We also make use of external fields, such as magnetic fields, which generate dipolar interactions that can drive on-demand the self-assembly of nanoparticles towards different pathways. A crucial aspect of our work is to develop simple synthetic techniques that permit the preparation of sufficiently large amounts of complex nanoparticles, in order to investigate their unique behavior under concentrated conditions and make them appealing for applications. We closely combine our experimental work with a modeling activity based on Monte-Carlo and Brownian Dynamics simulations to develop a quantitative understanding of the self-assembly of the nanoparticles and to have a tool that allows one to predict the behavior of our nanoparticles, to rationalize the relationship between their structure and behavior and eventually to better engineer them.

silica monolith

Silica monolith prepared using magnetic nanocolloid templating agents in presence of a magnetic field

bownian motion simulation

Brownian dynamic simulation result: magnetic nanocolloids self-assembly in the presence of a magnetic field

Janus nanoparticle

TEM picture of a PLGA-magnetite Janus composite nanoparticle

Adolphe Merkle Institute
Rte de l'Ancienne Papeterie CP 209 CH-1723 Marly 1
Phone +41 26 / 300 92 54 - Fax +41 26 / 300 96 24              Swiss University