Berlin 2015 – wissenschaftliches Programm
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CPP: Fachverband Chemische Physik und Polymerphysik
CPP 13: Focus: Field Controllable Functional Polymers II
CPP 13.8: Vortrag
Montag, 16. März 2015, 17:15–17:30, C 264
Branched structures in dipolar hard sphere fluids: junctions revisited. — •Sofia Kantorovich1,2, Alexey Ivanov2, Lorenzo Rovigatti1, Jose Maria Tavares3, and Francesco Sciortino4 — 1University of Vienna, Vienna, Austria — 2Ural Federal University, Ekaterinburg, Russia — 3University of Lisbon, Lisbon, Portugal — 4University of Rome "La Sapienza", Rome, Italy
To clarify the scenario of temperature-induced structural transitions in magnetic nanocolloids of moderate concentrations we developed a theoretical approach and performed an extensive Monte Carlo simulations study. Our theoretical approach is based on the density-functional theory, where single nanoparticles can self-assemble in primary "defect-free" chains and rings as well as in "defect structures" in which primary structures are merged with the help of specific "defect particles". We are able to limit the amount of possible branching points (defects) to three main types, using a thorough numerical and visual analysis of simulation results (Rovigatti et al., J. Chem. Phys., 2013). The defects of types X and Y are serving as cross-linkers between primary structures, whereas defect of type Z could only appear within chains and rings. One of the key findings here is that at high dipolar strength (very low temperature) all Y defects are to be replaced by more energetically advantageous and infinitesimally magnetoresponsive defect structures made of two rings cross-linked by X defect (in contrast to the predictions of Tlusty and Safran, Science, 2000).