Self-assembly of nanoparticles into clusters and stripes

Speaker(s)

Jakub Pękalski

Affiliation

Instytut Chemii Fizycznej PAN, Zakład układów złożonych i chemicznego przetwarzania informacji

Language of the talk

English

Date

Dec. 14, 2012, 12:15 p.m.

Information about the event

3

Title in Polish

Self-assembly of nanoparticles into clusters and stripes

Seminar

Seminar Mathematical Models of Gene Expression and Regulatory Networks

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Most of biologically relevant macromolecules or particles in soft-matter systems are charged and repel each other with screened electrostatic forces. On the other hand, complex solvents in biological systems may induce effective attraction between macromolecules.

I will present generic lattice models for systems containing particles interacting with short-range attraction and long- range repulsion (SALR)potentials, and describe results obtained in one dimension and in two dimensions on a triangular lattice. In both cases, the ground state was found analytically and  phase diagram was determined in Mean Field approximation. Moreover, in one dimension the equation of state and the correlation function were calculated exactly, and the two dimensional model was studied be means of Monte Carlo simulations (Metropolis algorithm). The phase behaviour of the model  is very rich. When the repulsion is sufficiently strong, periodic ordering of self-assembled
clusters or stripes  is obtained for some range of thermodynamic states. We find coexistence of ordered phases with the same symmetry but different degree of order, and reentrant melting upon decreasing temperature or increasing density. Finally, I will describe effects of confinment on the ordered structure.
 

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