Jump to main content
Jump to site search
Access to RSC content Close the message box

Continue to access RSC content when you are not at your institution. Follow our step-by-step guide.

Issue 36, 2017
Previous Article Next Article

The effect of comb architecture on complex coacervation

Author affiliations


Complex coacervation is a widely utilized technique for effecting phase separation, though predictive understanding of molecular-level details remains underdeveloped. Here, we couple coarse-grained Monte Carlo simulations with experimental efforts using a polypeptide-based model system to investigate how a comb-like architecture affects complex coacervation and coacervate stability. Specifically, the phase separation behavior of linear polycation-linear polyanion pairs was compared to that of comb polycation-linear polyanion and comb polycation-comb polyanion pairs. The comb architecture was found to mitigate cooperative interactions between oppositely charged polymers, as no discernible phase separation was observed for comb-comb pairs and complex coacervation of linear-linear pairs yielded stable coacervates at higher salt concentration than linear-comb pairs. This behavior was attributed to differences in counterion release by linear vs. comb polymers during polyeletrolyte complexation. Additionally, the comb polycation formed coacervates with both stereoregular poly(L-glutamate) and racemic poly(D,L-glutamate), whereas the linear polycation formed coacervates only with the racemic polyanion. In contrast, solid precipitates were obtained from mixtures of stereoregular poly(L-lysine) and poly(L-glutamate). Moreover, the formation of coacervates from cationic comb polymers incorporating up to ∼90% pendant zwitterionic groups demonstrated the potential for inclusion of comonomers to modulate the hydrophilicity and/or other properties of a coacervate-forming polymer. These results provide the first detailed investigation into the role of polymer architecture on complex coacervation using a chemically and architecturally well-defined model system, and highlight the need for additional research on this topic.

Graphical abstract: The effect of comb architecture on complex coacervation

Back to tab navigation

Supplementary files

Article information

30 May 2017
23 Aug 2017
First published
23 Aug 2017

Org. Biomol. Chem., 2017,15, 7630-7642
Article type

The effect of comb architecture on complex coacervation

B. M. Johnston, C. W. Johnston, R. A. Letteri, T. K. Lytle, C. E. Sing, T. Emrick and S. L. Perry, Org. Biomol. Chem., 2017, 15, 7630
DOI: 10.1039/C7OB01314K

Social activity

Search articles by author