title: Bond flexibility and low valence promote finite clusters of self-aggregating particles.
abstract: Systems of complex particles such as proteins or colloidal particles have a widely observed tendency to form nonconnected nanometer-size clusters at steady state, but the underlying mechanisms remain poorly understood. We report here a numerical study on the self-aggregation of low-valence particles with flexible bonds (i.e., free bond orientations) in two dimensions and predict the formation of a stable cluster phase for average valences ranging from 2 to 3.6. For the intermediate case of trivalent particles, we show that a cluster phase is present over a wide range of concentrations and interaction energies. The clusters are polydisperse in size, have a fractal dimension of 1.5, and tend to fully saturate their bonds at high interaction energies. The number of unformed bonds scales linearly with the number of particles in a cluster, which implies the absence of phase transition in the explored region of interaction energies and concentrations. We discuss possible implications of our model for membrane protein clustering.
authors.affiliation: Institut de Biologie du Développement de Marseille-Luminy, UMR CNRS/Aix-Marseille Université, Campus de Luminy, France.
authors.forename: Olga
authors.initials: O
authors.lastname: Markova
authors.forename: Jonathan
authors.initials: J
authors.lastname: Alberts
authors.forename: Edwin
authors.initials: E
authors.lastname: Munro
authors.forename: Pierre-François
authors.initials: PF
authors.lastname: Lenne
mesh_terms: D016000:Cluster Analysis; D003102:Colloids / Q000737:chemistry*; D008565:Membrane Proteins / Q000737:chemistry*; D008956:Models, Chemical; D008958:Models, Molecular; D010316:Particle Size; D013816:Thermodynamics
chemical_list: D003102:Colloids; D008565:Membrane Proteins