Berlin 2024 – wissenschaftliches Programm

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CPP: Fachverband Chemische Physik und Polymerphysik

CPP 3: Crystallization, Nucleation and Self-Assembly I

CPP 3.2: Vortrag

Montag, 18. März 2024, 10:00–10:15, H 0110

Crystallizability of free and tethered chains in nanometer-sized droplets — •Wing Kit Or, Alaa Hassan, and Martin Tress — Peter Debye Institute for Soft Matter Physics, Leipzig University, Leipzig, Germany

Although the crystallization of polymers has been investigated for decades, it is not yet fully understood. One way to gain more insight is to study the differences between bulk and confined polymer, focusing on how crystallization characteristics change depending on the size and type of confinement. Until now, most studies have used confinement in thin films, small droplets, or nanopores. We prepared separated aggregates as small as ten chains on average each to characterize their individualized crystallization by probing the change in orientational polarization using a nanostructured electrode arrangement. For that, a regular pattern of well separated gold nanodots was deposited on a silicon substrate to chemically graft end-functionalized polymer chains to these nanodots. In contrast to nanometer-sized spin-cast polymer droplets (prepared as reference), the grafted aggregates exhibit no signs of crystallization. This may be attributed to several constraints like restricted chain configuration, limited chain motion, too wide chain spacing, or altered interfacial energy due to the presence of the gold surface. Preliminary results suggest that spatial constraints which prevent crystalline conformations are dominating. In principle, this approach will enable to study aggregates of fewer chains down to individual ones, which until now was accessible only to computer simulations.

Keywords: polymer; crystallization; dielectric; grafting