Likewise, the unfavourable polyamine (either DETA or TEPA) adsorption around the edge, relative to iso-octane, agrees with the positive enthalpy values found for small ξ values in Figure . To better understand the adsorption energies from Table , we compute the electron density difference plots (shown in Figure ) and the Bader charges corresponding to each polyamine chain. The results show that there is no charge transfer between the adsorbate and the deposit, which is characteristic of Van der Waals-based physisorption, underpinning the very small PIBSI free energies found in MD simulations, see Figure .