NSF-DFG MISSION: in situ and operando probing of soft materials at buried interfaces

• Applicant: Professor Dr. Peter Müller-Buschbaum
• Subject Area: Physical Chemistry of Solids and Surfaces, Material Characterisation ; Experimental and Theoretical Physics of Polymers
• Term: since 2024
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 542459311

In our NSF-DFG MISSION project, the collaborating U.S. (Univ Massachusetts Amherst) and German (Technical Univ of Munich) researchers will focus on buried interfaces in the context of soft materials structure and orientation. Through in situ and operando methods, our team will study the impacts of interfacial interactions and the electronic effects of disparate materials interfaces in contact with one another (i.e., polymer-metal, polymer-semiconductor, and polymer-polymer interfaces). A detailed understanding of such interfaces, while crucial for elevating electronic device performance, is presently lacking and will be improved markedly with focus on in situ and operando techniques. Such studies are inherently challenging, since: 1) the buried interface is located well below the surface of an overlayer (e.g., polymer) and 2) the amount of material at an interface is minute relative to the surrounding material. Despite these challenges, this problem is critically important for in-depth studies, as these interfaces critically dictate chemical and physical properties across a breadth of application areas, including electronic transport, catalysis, separations, and wetting. Working together, with focus on the key fundamental science needed to characterize buried interfaces, our team will build a new, in-depth international collaboration from which the participating students gain the unique foundation of an international network of coworkers. In more detail, with focus on in situ and operando characterization of interfaces, our MISSION team will merge materials chemistry with transmission and grazing incidence resonance soft x-ray and neutron scattering techniques, including GISANS, GISAXS, and GIXD, and will develop patterned-enhanced scattering methods to detail interface evolution over time. For example, interfacial contact between polymer zwitterions and metal electrodes offers simultaneous modulation of 1) work function of an electrode and 2) charge transport with an adjacent polymer layer. The orientation and spatial location of zwitterionic dipoles will strongly influence surface interactions, and in situ studies will allow us to probe this hypothesis as orientation evolves over time. Strategic insertion of functional moieties into the polymers will enhance our ability to investigate spatial location and orientation with advanced and new scattering methods.

• DFG Programme: Research Grants
• International Connection: USA
• Cooperation Partners: Professor Dr. Todd Emrick; Professor Dr. Thomas P. Russell