The adsorption process -which does not happen for the other motifs. Indeed, according to DFT, its strength is as large as the TEPA chain, on which the PIBSI chemistry for detergency (although targeting different deposit precursors, e.g. more acidic species) has been based for decades. However, the underpinning mechanisms are different for the carboyxlate group when the adsorption takes place around the edge or on top of the deposit. Concerning the edge binding, it is a case of ion-dipole interactions governed by classical electrostatics, where the negative charge of the carboxylate group is oriented to maximise the interaction with the positive pole of the PAH structure. When adsorption occurs on top, it consists of a somewhat counterintuitive attraction between an anion and the π-electron rich region of space, through non-covalent anion-π interactions. The electron density difference plot for the edge adsorption of acetate on circumovalene is presented in Figure . The basal site adsorption is shown in the Supporting Information (Figure ), with an ensuing discussion on the directionality of the charge transfer of anionπ interactions. The acetate ion shows more prominent regions of charge accumulation and depletion between adsorbate and deposit relative to Figure , with Bader charges transfer of 0.50 e and 0.53 e in the basal and edge adsorption scenarios, respectively. The mild charge transfer from the deposit to the adsorbate is responsible for the adsorption energy value from Table , similar to the dispersion-dominated TEPA polyamine chain, despite being a much smaller motif. The cation-π interactions are addressed via the TMA cation, which mimics the quaternary ammonium in the zwitterionic DCA used in MD simulations. In TMA, N carries a partial negative charge, whereas the positive charge is mostly attributed to the H atoms in the methyl groups. We carry out simulations considering the monodendate (i.e. one methyl group pointing towards the deposit), bidendate, and tridendate adsorption structures. The electron density difference plot for the most stable basal adsorption of TMA on circumovalene is shown in Figure . Other conformations are shown in the Supporting Information (Figure ). As observed elsewhere in the literature using different levels of theory, the adsorption energies correlate with the number of methyl groups directly interacting with the deposit, with E ads values of -42.4 kcal mol -1 , -46.7 kcal mol -1 , and -49.9 kcal mol -1 for the monodendate, bidendate, and tridendate structures, respectively. Similar Bader charge transfer of about -0.93 e (the charge is transferred from the adsorbate onto the deposit) are found for the three geometries, from where one can deduce that dispersion forces contribute to further stabilising the tridendate conformation. This stronger Bader charge transfer is illustrated in Figure , from which the regions of electronic accumulation and depletion are larger than in other electron density difference plots. The bottom line from TMA results is that, regardless of the geometric conformation captured in time-dependent MD simulations, the binding energy from the quaternary cation will very likely be the most relevant one for the PMF. This might help to explain why, in turn, the zwitterionic DCA is associated with a much stronger PMF in Figure , as the key functional groups (namely, cation and anion) are going to strongly interact with the deposit, regardless of the adsorptive configuration.