Structures and interfacial behaviour of nanoparticles

Among the different nanoparticles reported in literature, N-isopropylacrylamide(NIPAM)-based nanogels are widely studied because of their thermoresponsive properties, that can be fine-tuned for the target application, and the fact that these materials can form stable colloidal solutions and are surface active. The soft character of the matrix, which can be controlled easily by the degree of cross-linker, leads to a confined packing structure at the interface due to extended interfacial conformations. The adsorption dynamics and structural changes of nanogels at the interface, together with interaction mechanisms, at the molecular level are not fully understood. Our work in this area is focused on acquiring new knowledge on the relationship between chemical composition and interfacial behaviour of covalently cross-linked nanogels, in bulk solution, air-water interface and modified solid-liquid interface. The characterisation of nanogels is focused on particle size, zeta potential, volume-phase transition temperatures and surface tension properties,  and where possible on the study of adsorption dynamics, structural conformation and interaction mechanisms at air-liquid and  solid-liquid interfaces using Neutron Reflectivity.