Now we turn to a cationic ELP. For this, a polymer chain containing 200 monomers of which 20 are positively charged (a charge fraction ξ = 0.10) is simulated. Its radius of gyration R g and the standard free energy of the coil-to-globule transition as a function of salt concentration are shown in Figure ). Two distinct phenomena can be observed, depending on salt concentration. Screening of the electrostatic repulsion between the charged monomers by the ions onsets at low salt concentration ( 0.1 m). The polymer rapidly collapses from an extended coil (R g ≃ 4.7 nm) to a more compact conformation as the salt is added and the Debye length, κ -1 = (8πl B N A I) -1/2 , decreases. Here, N A is the Avogadro number and I is molar ionic strength. This screening strengthens with the increasing salt concentration in the polymer phase. Weakly hydrated ions with large polymer affinity, that is, having greater ε anion , are more attracted to the polymer and cause stronger screening. However, the collapse of the polymer chain beyond the size of the uncharged polymer in a salt-free solution, as in the case of ε anion = 0.9 k B T, cannot be explained by the charge screening alone and another effect has to be taken into account. As the electroneutrality condition is fulfilled inside the polymer volume, the concentration of the strongly attractive anions is significantly higher than the concentration of the repulsive cations. The average B 2 of the ion-mer interactions is thus shifted towards more negative, i.e., attractive, values, entering the bridging adhesion regime. The radial distribution functions of anions and cations in Figure (c) prove the greater abundance of strongly attractive anions compared to cations at low salt concentrations. Typical conformations of the polymer chain are shown in Figure ) for the repulsive, and attractive salt, respectively. As salt concentration increases ( 1 m), the salt specific effects begin to contribute to the interactions, resembling the case of the uncharged polymer, however with a notably different polymer size, cf. Figure ).