AFM-based determination of interface and interphase interactions

• Applicant: Professor Dr. Thorsten Hugel
• Subject Area: Experimental and Theoretical Physics of Polymers
• Term: from 2008 to 2014
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 67458160

During the current funding period we used atomic force microscopy (AFM) to characterize the thickness and swelling behaviour of polyelectrolyte multilayers (PEMs) in collaboration with the group of Regine v. Klitzing. In addition, we established molecular probes consisting of a single molecule covalently attached to an AFM-tip and got first data on the adhesion energy profile of PEMs perpendicular to the surface (i.e. in the interphase). In the second funding period we will use our AFM-based molecular probes to complete adhesion energy and water content profiles in PEMs. The main focus will be on determining the lateral and perpendicular mobility throughout the multilayer with our AFM-based method. These measurements will be complemented by single molecule fluorescence measurements in my lab and scattering experiments in the group of Regine v. Klitzing. Of particular interest are the molecular weight dependence, charge dependence, the influence of the solid support and ions specific effects. These investigations will then be applied to other (uncharged) polymer interphases investigated in the SPP, namely polystyrene and polybutadiene based polymers. Finally, because of the small system size, the results can directly be compared to MD-simulations performed on the same system by Christian Holm.

• DFG Programme: Priority Programmes
• Subproject of: SPP 1369: Polymer Solid Contacts: Interfaces and Interphases