(a) A digital photograph of the poly(4-styrene sulfonate sodium salt) (PSS) and poly(diallyldimethyl ammonium chloride) (PDADMAC) complex coacervates prepared in increasing salt concentrations. The numbers at the cap of each vial were the as-prepared KBr concentration. Adapted with permission from ref. [49]; copyright © 2014 American Chemical Society. Further permissions related to the material excerpted should be directed to the ACS. (b) Plots of tan(δ) and the normalized phase angle 2δ/π on the PSS/PDADMAC complexes and coacervates as a function of as-prepared salt concentration. Data were shown for oscillation frequencies from 1–100 rad/s indicated by the arrows. The star highlighted a frequency-invariant point marking the transition between solid-to-liquid in complexes. Adapted with permission from ref. [77]; copyright © 2017 Royal Society of Chemistry.