Particle interactions in bio-colloidal systems: Unlike simple liquids, colloidal solutions are intrinsically complex due to the presence of different components, such as ions and solvent molecules. However, this complexity makes it possible to modify the effective interaction between colloidal particles at will, allowing one to obtain a variety of macroscopic behaviors. It is this tunability that makes colloidal systems so important in our everyday lives. Furthermore, the collective behavior of colloidal systems also plays a fundamental role in processes such as protein crystallization, viscosity changes, gelation, and glass transitions. Properties of materials confined in nano-scale structures: Although storing and releasing molecules in porous media is an old topic, it has been increasingly important nowadays due to applications such as energy storage and drug delivery. This renewed interest has led to many newly developed porous materials, such as porous crystals and open colloidal particles. When molecules are confined in porous nano-structures, the confined materials often demonstrate new properties, very different from those of the bulk material. These new properties are not only important for real applications, but also interesting to serve as test beds to explore fundamental scientific principles.”
My research relates to self-assembly of nanostructures in soft matter systems. The materials of interest include polymers, proteins, and surfactants, both in solution and in the gel state. Small-angle scattering is used as a key technique for investigating the structures, interactions, and kinetics in the systems. I am interested in both instrumentation, and in advanced data analysis, which can be applied to obtain a better fundamental understanding of a material’s response to factors such as temperature, ionic strength, and shear. Currently I work on polymer gels, relating cross-linking, and homogeneity to the rheological properties. This is crucial to understand how to best make and process a gel for a specific purpose. Furthermore, I study assembly of various proteins and peptides in solution, which is relevant for formulation of drugs, but also for development of functional materials based on biological molecules.
I have a strong background in Crystallogenesis and X-ray/Neutron crystallography, that I have often put at the service of the experimental determination of the average position of all atoms in crystals of biological macromolecules. Neutron diffraction is a non-destructive structural probe with a strong sensitivity to hydrogen atoms: ideal for the studies of molecules where enzymatic mechanisms, structural stabilization, or both, are impacted by the most abundant element in biological macromolecules. At present, I work at the NIST Center for Neutron Research where I use small angle neutron scattering to broaden the crystallography perspective towards studies in solutions and other phases for various materials: antibodies, protein/DNA complexes, viral particles, extremophile proteins, among others. Furthermore, I am interested in how complex colloidal systems behave under extreme conditions of pressure and temperature, relevant to food and pharmaceutical storage and processing, as well as to a more fundamental understanding of biological adaptation to different environments.