On the contribution of the chain ends to the surface tension of a polymer melt
“Molecular Landscapes, Biophotonic Horizons” Group IMMM, CNRS, UMR 6283, Université du Mans, Le Mans, France
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Accepted: 29 May 2018
Published online: 12 June 2018
We propose a physical picture describing the mechanisms by which chain ends affect the surface tension of a mono-dispersed polymer melt with chain length N. The driving effect is the adsorption equilibrium of chain ends within a bulk slice adjoining the surface and acting as a confined end reservoir. The thickness of that limited space is a characteristic length of the melt. This picture conforms to a previous approach proposed years ago by de Gennes. However, the characteristic length that we consider is different from the one that he considered. Our choice is carefully argued. The resulting model correctly reflects the transition between the two N regimes reported in experimental studies, with the correct exponents. Stretching contributions are also considered, and appear small compared to the above-mentioned adsorption equilibrium effects. We think that the usefulness of the newly introduced characteristic length might exceed the specific problem addressed in the present paper. The equilibrium state of a lamellar diblock copolymer is briefly discussed for illustration.
Key words: Polymers: From Adsorption to Translocation - Topical Issue in Memoriam Loïc Auvray (1956-2016)
© EDP Sciences, SIF, Springer-Verlag GmbH Germany, part of Springer Nature, 2018