| Abstract: | The main energetic and entropic factors determining the adsorption behaviour of neutral polymers, polyelectrolytes, and proteins are discussed. The driving force is the segment adsorption energy, opposing forces are the loss of chain conformation entropy and the entropy of (de)mixing. Mutual interactions between the segments play an important role, especially if the macromolecules carry charged groups. Several examples are given of the dependency of the adsorption of flexible macromolecules on the adsorption energy, the solvent quality, the salt concentration, and the surface charge. In the case of proteins, the internal coherency of the molecule largely determines the adsorption behaviour. For relatively flexible proteins like HPA, entropic contributions are important and sometimes dominant; the nature of the surface is less critical. For rigid proteins like RNAse, the adsorption is mainly energetically determined, depending largely on the electrostatic interaction between protein and surface. |
