Nanoalloys are nanometer-sized metal nanoparticles composed of two or more metal species. Nanoalloy properties, electronic and optical in particular, make them interesting for many applications, ranging from the development of efficient and low-cost catalyzers to the production of light-responsive coatings. Nanoalloy properties are driven by the atomic structure and chemical ordering of the metal components. We investigate the structural and chemical properties of nanoalloys using Global Optimization tools, and we study their thermodynamic behavior via Molecular Dynamics and enhanced sampling techniques.
The production and commercialization of nano-sized materials have constantly grown in the last decades. Safety is a major concern when new nanomaterials are produced. Properties of materials at the nanoscale are very different from those of bulk materials with the same chemical composition, and are difficult to predict. On the other hand, nanometer-size materials offer unprecedented opportunities in many fields of technology, including pharmaceutical and medical technology. At Nanocomp we develop nanomaterial models and study their interaction with the biological environment using Molecular Dynamics and enhanced sampling techniques.
The behavior of polymers at the nanoscale is relevant in many fields. Polymers constitute the matrix of innovative nanocomposite materials; biocompatible polymers are used as stealth or stimuli-responsive agents in biomedicine; polymer nanoparticles resulting from degradation of plastic materials cause environmental concern. We aim at the understanding of the physicochemical processes that drive the behavior of polymers in these different and complex situations. To achieve this objective, we often develop new coarse-grained models of polymers, which allow for the simulation of their dynamics over the relevant time and length scales.
Surfaces and interfaces
When nanomaterials meet the biological environment, their fate depends on the physico-chemical characteristics of the nanomaterial surface. Nanoparticles for biomedical use, for example, are often protected by a monolayer of chemisorbed or physisorbed molecules, which make them soluble and may provide specific functionalities. At Nanocomp we are interested in understanding the relationship between the interface properties (composition, structure, dynamics) and the nanoparticle behavior in the biological context.
Aggregation of colloids in suspensions plays an important role in the synthesis of ceramic materials. For these materials, the aggregation of oppositely charged colloids, known as heteroaggregation, is now used as the first step in preparing ceramics with specific properties, for example controlled porosity. At Nanocomp we are interested in developing models to study the key steps of colloidal aggregation. These models allow the interpretation of aggregation experiments and help in developing effective methods for materials processing.
Developing efficient algorithms is crucial for the study of complex systems. At nanocomp we are developing global optimization algorithms to find the lowest energy structures of nanoclusters ans nanoalloys, accelerated molecular dynamics techniques to study evolution phenomena, and tools based on machine learning techniques for structural recognition and characterization of nanoparticles