Janus dumbbells near surfaces modified with tethered chains

Abstract

Adsorption of dumbbell-shaped particles on polymer-tethered surfaces is studied using molecular dynamics simulations. The bonded layers are built of chains containing "active groups", while the particles consist of two "chemically" different monomers. We analyze the structure of the surface layers, the excess adsorption isotherms of the dumbbells and their retention in a chromatographic process. We discuss how selected parameters affect the behavior of Janus dumbbells near the polymer layers. We show that the structure of the surface layer mainly depends on the position of the active groups in the chains and the assumed particle-chain interactions. The particles penetrate the polymer layer and accumulate close to the active groups.

Adsorption on Ligand-Tethered Nanoparticles

“…The molecules are adsorbed also "on the brush" (ternary adsorption [15,33]). Similar results have been obtained for the flat surfaces modified with tethered short chains using the functional density theory [26][27][28][29] and molecular dynamics simulations [41]. For geometrical reasons, a direct comparison of the density profiles around the core with those calculated near the flat surface is impossible.…”

“…All energy parameters ε ij = ε (i, j = c, s, P) except for the particle-segment energy parameter, which is varied (ε Ps = 1.5ε and 3.0ε ). The motivation for choosing these values originates from the fact that similar parameters have already been used for planar brushes [27,28,41] and hairy particles [50]. In the framework of the implicit solvent model, these parameters correspond to the good solvent conditions [19].…”

“…Most of this research has focused on particles near flat surfaces modified with tethered chains. The adsorption of small molecules [26][27][28][29][30], polymers [31][32][33][34], peptides, proteins [35][36][37][38][39] and Janus particles [40,41] on the flat brushes was interpreted in the framework of different approaches. It has been shown how the adsorption depends on the grafting density, the chain length, and interactions between all species [19,[26][27][28][29][30][31][32][33][34].…”