Dresden 2020 – scientific programme
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CPP: Fachverband Chemische Physik und Polymerphysik
CPP 58: Modelling and Simulation of Soft Matter I (joint session CPP/DY)
CPP 58.5: Talk
Wednesday, March 18, 2020, 10:45–11:00, ZEU 255
Effect of the Backbone Chemical Composition and Monomer Sequence on Phenylene Polymer Persistence Lengths — •Nancy C. Forero-Martinez1, Björn Baumeier2, and Kurt Kremer1 — 1Max Planck Institute for Polymer Research, Ackermannweg 10, 55128 Mainz, Germany — 2University of Technology, P.O. BOX 513-5600 MB, Eindhoven, The Netherlands
The study of the physical properties of phenylene polymer precursors used in the fabrication of graphene nanoribbons poses open questions whose answers will contribute to the design of more efficient synthesis protocols. Particularly, size-exclusion chromatography combined with persistence length measurements assigns both, semiflexible to semirigid structures depending on the molecular weight of the precursor. Surprisingly, these results suggest an apparent structural change upon increasing the length of the polymer. In this work, we use a generic model to build phenylene polymer chains as random walks that take into consideration the nature of the arene substitutions along the backbone. In addition to conformational changes, this model allows one to study the backbone contribution to the persistence length by modifying a small set of parameters controlling chemical content and structure. We consider the flexibility of polyphenylene precursors in a theta-like solvent in terms of chain composition by building both, chains that are purely composed by meta or para connected repeat units, and randomly mixed chains with a given composition. We find that systems with apparently the same chemistry have different persistence length due to different monomer mixing ratios and sequence along the chain.