and $\epsilon_{F,i}$ the characteristic interaction energy of Fib with the protein $i$. The protein-protein interaction with the Fib along the short axis is chosen energetically unfavorable with respect to that along the long axis, because the latter offers more binding points to the surface.

Since both (monoclonal) IgG [@Galisteo1994] and Fib [@Malmsten1997] have an IEP at approximately pH 5.5, at the chosen pH 5.0 they are charged. Following other authors, e.g., Ref. [@Mucksch2011], we consider that the charged proteins, IgG and Fib, have an effective interaction with the surface modelled by a Lennard-Jones potential $$V_{i,S}(z)\equiv
 4\epsilon_{i,S}\left(\left(\frac{\sigma_{i}}{z}\right)^{12}-\left(\frac{\sigma_{i}}{z}\right)^{6}\right)$$ where $\epsilon_{i,S}$ is the attractive energy between the protein $i=I, F$ and the surface, and $\sigma_{i}\equiv R_i/2^{1/6}$ accounts for the possible distortion of the protein in contact with the surface.

When adsorbed, each protein occupies a surface $2\pi R_i^2$, including the “standing up” conformation of Fib, while the Fib in its “lying down” conformation occupies a surface $2\pi \delta_F^2$. To account for the different diffusive behaviors of different proteins in absence of external flow, we calculate the hydrodynamic radius $R^{H}_i$ of each protein $i$, under the assumption that the proteins can be approximated by a sphere, through the Einstein-Stokes equation $D_i=\frac{k_{B}T}{6\pi\eta  R^{H}_{i}}$, where $D_i$ 