Mohit AGARWAL

Light-Tunable Structures by Self-Assembly: In-situ SANS under irradiation

The creation of responsive nanostructures is of great interest, for example, to build smart carrier systems, sensors, or molecular motors. Due to the large potential lying in the conversion of sunlight into mechanical energy, light is an especially desirable trigger. Supramolecular nanoparticles have a large advantage offering the possibility of making use of a facile and versatile toolbox principle. A few years ago, we introduced electrostatic self-assembly as a new concept for the
formation of supramolecular nano-objects with a variety of shapes through the association of macroions and oppositely charged multivalent molecular ions in solution. The combination of electrostatics and secondary forces such as mutual π – π interaction of ionic dye molecules is used to direct the structure formation. A large set of techniques will be used for the characterization of the nanostructures, in particular, small-angle neutron scattering (SANS), static and dynamic light scattering (SLS & DLS), AFM, UV-Vis spectroscopy, Isothermal Titration Calorimetry (ITC), and ζ-potential measurements. Central will be the development of a novel photo-stirring sample cell for time-resolved SANS experiments to fundamentally elucidate structural effects that occur upon irradiation. Tying together scattering and thermodynamic information, a general understanding of the self-assembly under irradiation will be developed so that this project sets the key for a targeted structure triggering with potential in solar energy conversion, and drug delivery.