Controlling the Interactions between Soft Colloids via Surface Adsorption

Abstract

By employing monomer-resolved computer simulations and analytical considerations based on polymer scaling theory, we analyze the conformations and interactions of multiarm star polymers strongly adsorbed on a smooth, two-dimensional plane. We find a stronger stretching of the arms as well as a stronger repulsive, effective interaction than in the three dimensional case. In particular, the star size scales with the number of arms f as ∼ f effective interaction as ∼ f 2 , as opposed to ∼ f 1/5 and ∼ f 3/2 , respectively, in three dimensions. Our results demonstrate the dramatic effect that geometric confinement can have on the effective interactions and the subsequent correlations of soft colloids in general, for which the conformation can be altered as a result of geometrical constraints imposed on them.

Interactions and Stress Relaxation in Monolayers of Soft Nanoparticles at Fluid-Fluid Interfaces

“…The equilibrium behavior and mechanical response of nanoparticle monolayers have important consequences in many emerging applications that exploit nanoparticles at fluid-fluid interfaces, for instance, in the making of 2D nanomaterials with tunable optical properties [13,14] where precise control of interactions and stability is crucial for obtaining reversible properties. Our experimental method for the measurement of interactions between nanocolloids at fluid interfaces makes it possible to validate simulation studies not only of the mean-field interaction potential between ligand-coated nanoparticles [9] but also of the effect of 2D confinement on the interaction potential between star polymers [28] and other soft nanoparticles.…”

Formation of cluster crystals in an ultra-soft potential model on a spherical surface

“…It is interesting to note that the realization of such a system is already possible through existing techniques, currently employed in the synthesis of drug carriers with enhanced durability 29,30 . However, it is fair to say that, even for an isolated pair of dendrimers, the two-dimensional substrate is expected to affect the form of the effective interaction with respect to that in the bulk, as shown for star polymers confined on a plane 31 . This is true a fortiori in the present case of a curved substrate, especially when, as in the present study, the size of the effective particles cannot be considered small with respect to the sphere radius.…”

Two-dimensional crystals of star polymers: a tale of tails

“…In this paper, we attempt to further bridge the gap between simulations and experiments in the quest for self-organised particlebased metamaterials. We explore the phase behavior of twodimensional systems of star polymers strongly adsorbed to a planar interface, parameterised by previously developed potentials for surface-adsorbed star polymers 25 . In three dimensions, star polymers and star-like micelles are known to exhibit a rich phase behavior, exhibiting body-centered orthogonal and diamond crystal structures [26][27][28][29][30][31][32] .…”

“…In some cases, the tail of the potential is presumed to decay exponentially, in the form of a Yukawa potential, with a decay length set by the blob size at the periphery of the star-shaped polymer 26,27 , depending on the number of arms and the effective star diameter 33 . In other cases, the tail of the pair potential is presumed to have a Gaussian shape 25,28 . This is based on the observation that for 3D linear chains the interaction potential is Gaussian 34 .…”