Dresden 2011 – wissenschaftliches Programm

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CPP: Fachverband Chemische Physik und Polymerphysik

CPP 3: Interfaces and Thin Films I

CPP 3.7: Vortrag

Montag, 14. März 2011, 12:00–12:15, ZEU 160

Reversible structuring of azobenzene polymer films by surface plasmons — Tobias König and •Svetlana Santer — Department of Experimental Physics, Potsdam

Our group is interested in interactions between nano-particles and nano-structured polymer surfaces. We have shown that it is possible to move adsorbed nano-objects with relative ease, in large number and simultaneously without using external devices. The essential idea is not to put more effort in fighting against the prevailing surface forces but rather to utilize them - in clear contrast to current techniques of nano-manipulation with AFM [Santer, Adv Mat 2006]. For this, the topography should be reversible switching by changing the morphology at the scale of objects to be moved. In this work, we choose light for changing the polymer topography. Here we present azo thin films [Seki, Chem Soc Jpn 2007] with integrated optically active elements supposed to support and steer the response of polymer films to external illumination. During irradiation surface plasmon polarizations (SPP) are generated on a metallic mask. The interaction of the SPP with azo polymers results in printing of near field intensity distributions into topography with the pattern size below the diffraction limit. The topography can be driven reversible. This allows us to analyze different patterns by changing polarization or wavelength at the same position. We also examine the structuring process depending on different metallic patterns like nanogab, nanohole and hexagonal pattern. By confirmation with FDTD simulation we are able to analyze the forces which are responsible for the imprints at the azo air interface.