Berlin 2018 – scientific programme
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CPP: Fachverband Chemische Physik und Polymerphysik
CPP 14: Interfaces and Thin Films I
CPP 14.4: Talk
Monday, March 12, 2018, 15:45–16:00, C 264
Controlling Adhesion and Friction on Cyclodextrin Assemblies — •Johanna Blass1,2, Marcel Albrecht3, Gerhard Wenz3, and Roland Bennewitz1,2 — 1INM - Leibniz-Institute for New Materials, Campus D2 2, Saarland University, 66123 Saarbrücken, Germany — 2Physics Department, Saarland University, Campus D2 2, Saarland University, 66123 Saarbrücken, Germany — 3Organic Macromolecular Chemistry, Campus C4 2, Saarland University, 66123 Saarbrücken, Germany
Controlling and understanding adhesive interactions on the molecular scale is one of the main challenges in the field of nanotechnology. We developed a new surface functionalization based on assemblies of cyclodextrin molecules to control adhesive forces and study the molecular mechanisms underlying dynamic effects of adhesion and friction. The dynamics of the molecular system were studied with respect to multivalency effects, single bond kinetics and flexibility of the attachment. By varying the compliance of the surface attachment, the relation between adhesion and friction and their dynamic rupture characteristics can be tuned. The rupture force of single bonds in thermodynamic equilibrium increases proportional to the square root of the force probe stiffness and is not determined by the stiffness of the molecular linker. The applicability of the surface functionalization was demonstrated when attaching cyclodextrin molecules onto stiff polymers to bridge the surface roughness of real contacts. Active control of adhesion and friction was achieved using photosensitive connector molecules which are sensitive to external light stimuli.