Diffusion limited aggregation of polymers with anisotropic interactions and phase transition
摘要
We model polymers with anisotropic sites on a square lattice, consisting of head monomers that are hydrophobic (labelled as A) and neutral tail monomers (labelled as B). Our study focuses on diffusion-limited aggregation through on-lattice simulations involving polymers with anisotropic interactions. In this work, we consider four different types of copolymers with aspect ratio, a = 4: ABBB, AABB, BAAB, and ABBA and also varied the number of hydrophobic monomer, Na from 1 to 3. We found that grafted polymers, specifically ABBB, undergo aggregation in solution and form micellar-like structures, in contrast to polymers with isotropic interactions. However, this system leads to an ‘absorbing state,’ similar to phenomena observed in non-equilibrium phase transitions. Additionally, we observed that the growth rate of clusters is higher in di-block AABB copolymers compared to triblock BAAB copolymers. Interestingly, the ABBA type copolymer exhibits a constant growth rate and reaches an ‘active’ state. We also show that the number of particle depositions increases as the proportion of hydrophobic head monomers increases. Our study is relevant for understanding the aggregation of anisotropically interacting polymers under non-equilibrium conditions.