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Identifier

000425720

Title

Atomistic simulation study of star-shaped polystyrene melts

Alternative Title

Ατομιστικές προσομοιώσεις τηγμάτων αστεροειδών πολυμερών πολυστυρενίου

Author

Γκόλφη, Ειρήνη

Thesis advisor

Bacova, Petra
Χαρμανδάρης, Ευάγγελος

Reviewer

Αναστασιάδης, Σ.
Κομινέας, Σ.

Abstract

This work concerns a computational study of complex polymeric systems. We investigate the behavior of polystyrene (PS) star-shaped polymers with a variety of functionalities (number of arms) through atomistic molecular dy¬namic simulations. We simulate three types of systems, namely a) PS stars in melts, b) PS stars in blends with linear chains and c) PS stars in melts with modifications of the internal structure. Our atomistic model captures chemical characteristics of polystyrene, al¬lowing us to obtain quantitative information about the structural properties of the material that is not easily accessible by experiments or coarse-grained simulation models. We perform extensive equilibration and production runs in order to be able to compute a range of statistical quantities. The analysis focuses on the intramolecular structure and the morphology of the material. The results are analyzed as a function of the star functional¬ity. The obtained conformational characteristics are compared with well-known theoretical models. A comparison of the properties of stars in two external environments, i.e., in melt and in a blend with linear chains is also made. Ad¬ditionally, we study quantitatively the internal impenetrable region of the stars via a novel geometric algorithm. The impenetrable region is also present in the systems such as soft colloids or hairy particles and is responsible for a complex dynamical behavior of the material. The aim of our study is to bridge the gap between the theoretical models and the experimentally observed phenomena of star-shaped polymers by providing an insight into the morphology of polystyrene stars at nanoscale.

Language

Greek, English

Subject

Computational mathematics

Computer simulation

Molecular dynamics

Molecular simulations

Polymers

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