Coarse-graining and self-assembly of associating polymers in confined geometry

The central focus of my dissertation is to investigate the physical properties innherent in Amphiphilic Diblock Copolymer Stars (ADC stars) under planar confinement. A single ADC star is composed of f diblock copolymer chains uniformly grafted around a spherical colloid. Each chain is composed by two kind of monomers: A-type monomers, in good solvent conditions, and B-type monomers, in bad solvent conditions. The latter are always located at the outer end of each polymer chain and their relative abundance is set by the parameter α = Nb / (Na + Nb). While A-A and A-B effective interactions are repulsive and modeled via a truncated and shifted, repulsive Lennard-Jones potential, the B-B effective interactions are modeled via an attractive Lennard-Jones potential. In the latter potential, a parameter λ, defines the strength of the attractive interaction. Depending on the α and λ, monomers from different chains may aggregate and form clusters. Following Capone et al, we name these clusters “patches”. Within a certain parameter range these ADC stars are able to self-assemble into soft and flexible nanoparticles with a well-defined number of patches. These units when dispersed in a solution are expected to be able to form extended structures by means of bonds between the patches. Limiting the bonding valence is nowadays considered among the key ingredients to create complex structures with tailored properties; unfortunately, the synthesis of colloids with limited valence is often plagued by high polydispersity and non-scalability. These limitations can be overcome by employing molecular building blocks undergoing a hierarchical self-assembly process. This is relevant because ADC-Stars belong to this class of system and therefore possess potential applications in material science (for example to build a quasicrystal) and medicine. Using a coarse grained model and computational simulations to capture the most important features of the ADC stars it is possible to use the results to study the interactions of the system to understand if it is possible to create building blocks for possible two-dimensional quasicrystal phases. In this dissertation I present under other the results of the Coarse-grained model.