Dresden 2011 – wissenschaftliches Programm

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CPP: Fachverband Chemische Physik und Polymerphysik

CPP 13: Focused Session: Confinement of Polymers in Nanoscopic Layers - How Much do Properties Change? I

CPP 13.6: Vortrag

Dienstag, 15. März 2011, 12:45–13:00, ZEU 160

Polymer melt dynamics in confinement: Reduction of the inter-chain entanglement density close to an interface — •Oliver Bäumchen, Renate Fetzer, and Karin Jacobs — Department of Experimental Physics, Saarland University, D-66041 Saarbrücken, Germany

Fluids in confinement may exhibit properties that differ strongly from bulk behavior. One example is the reduction of the glass transition temperature in thin polymer films, whether above or below the entanglement length of the polymer. Another example is the inter-chain entanglement density in the bulk compared with the one in the vicinity of an interface. Dewetting experiments of thin (<200 nm) polystyrene films reveal that the inter-chain entanglement density close to an interface can be reduced by a factor 3 to 4, depending on interfacial properties [1,2]. Parameters that control the reduction will be detailed. Our findings shed new light on the solid/liquid boundary condition of liquid flow [3], on the molecular structure of this interface and possible reasons for a reduction of the glass transition temperature.

[1] O. Bäumchen, R. Fetzer and K. Jacobs, Phys. Rev. Lett. 103, 247801 (2009).

[2] O. Bäumchen and K. Jacobs, Soft Matter (2010), DOI: 10.1039/ C0SM00078G.

[3] O. Bäumchen and K. Jacobs, J. Phys.: Condens. Matter 22, 033102(21pp) (2010).