Coarsening Kinetics of Complex Macromolecular Architectures in Bad Solvent

Abstract

This study reports a general scenario for the out-of-equilibrium features of collapsing polymeric architectures. We use molecular dynamics simulations to characterize the coarsening kinetics, in bad solvent, for several macromolecular systems with an increasing degree of structural complexity. In particular, we focus on: flexible and semiflexible polymer chains, star polymers with 3 and 12 arms, and microgels with both ordered and disordered networks. Starting from a powerful analogy with critical phenomena, we construct a density field representation that removes fast fluctuations and provides a consistent characterization of the domain growth. Our results indicate that the coarsening kinetics presents a scaling behaviour that is independent of the solvent quality parameter, in analogy to the time–temperature superposition principle. Interestingly, the domain growth in time follows a power-law behaviour that is approximately independent of the architecture for all the flexible systems; while it is steeper for the semiflexible chains. Nevertheless, the fractal nature of the dense regions emerging during the collapse exhibits the same scaling behaviour for all the macromolecules. This suggests that the faster growing length scale in the semiflexible chains originates just from a faster mass diffusion along the chain contour, induced by the local stiffness. The decay of the dynamic correlations displays scaling behavior with the growing length scale of the system, which is a characteristic signature in coarsening phenomena.

Effects of alignment activity on the collapse kinetics of a flexible polymer

“…[26][27][28][29][30][31][32][33][34][35][36][37][38][39][40] Here, interest is primarily focused on the dynamics of the collective behavior, 26,27,31,33 but to date still relatively little is known on the kinetics of the collapse transition of a single active polymer and the emerging structures during the associated coarsening process. For passive polymers, on the other hand, along with the equilibrium aspects of this transition, [41][42][43][44] the latter nonequilibrium phenomena [45][46][47][48][49][50][51][52][53][54] have been studied extensively for many years. By exploiting the analogy to particle and spin systems, 55,56 various scaling properties of nonequilibrium statistical physics have been established with a fair degree of quantitative accuracy (for a recent review, see ref.…”

Defining Swelling Kinetics in Block Copolymer Thin Films: The Critical Role of Temperature and Vapour Pressure Ramp

“…Although swelling and the related in situ studies of polymers have received considerable attention for several decades [ 36 , 37 , 38 , 39 , 40 , 41 , 42 , 43 , 44 , 45 , 46 , 47 , 48 , 49 , 50 , 51 , 52 , 53 , 54 ], studies of BCP swelling kinetics during solvent exposure are less common [ 4 , 5 , 6 , 33 , 34 , 55 , 56 ]. Lundy et al [ 57 ] studied how the annealing conditions (annealing time, bubbler temperature, solvent vapour saturation) affect the phase segregation kinetics of poly(styrene)- block -poly(4-vinylpyridine) (PS- b -P4VP) films, enabling the minimising of the annealing times while maintaining pattern fidelity over large areas.…”

Kinetics of charged polymer collapse in poor solvents

“…Many simulation studies [30][31][32][33][34][35][36][37][38][39] have investigated the collapse of neutral polymers in terms of two-and three-stage kinetic models. In reference [40] a thorough analysis on the coarsening kinetics emerging during the collapse of complex macromolecular architectures in bad solvent has been presented. Recently, finite-size scaling analysis has been employed to characterize the coarsening dynamics and aging along the collapsed trajectories of neutral homopolymers [41,42].…”