Influence of Dipole Orientation on Solution Properties of Polyzwitterions
2016-01-19T00:00:00Z (GMT) by
We have studied the influence of segmental dipole orientation on the solution properties of polyzwitterions using dynamic and static light scattering of poly(2-methacryloyloxyethyl phosphorylcholine) (PMPC), <i>n</i>-butyl-substituted choline phosphate polymers (PMBP), and their diblock (PMPC-<i>b</i>-PMBP) copolymers in solutions of different salt concentration. We find that these three structures exhibit dramatically different aggregation behaviors. For the conditions in our study, PMPC is a swollen excluded-volume chain without significant presence of dipolar correlations as evident from the lack of sensitivity to the ionic strength of the solution. In contrast, PMBP self-assembles into finite-sized structures in solution, which are stabilized by electrostatic dipole–dipole interactions. Evidence of these interactions is also present in the diblock polymer, PMPB-<i>b</i>-PMPC, which self-assembles into two distinct, stable aggregates in addition to unaggregated chains. These results contribute to the breadth of understanding of polyzwitterions in solution and provide a platform for future simulation and experimental explorations.