In this presentation we will discuss recent theoretical work describing the properties of responsive polymer layers. Namely, polymers that reversible respond to changes in the environment, such as temperature for thermo-reversible polymers, pH and ionic strength for weak polyelectrolytes and pH, ionic strength and applied potential for redox polymers modifying metal electrodes. The theoretical predictions are in very good agreement with experimental observations in a variety of systems. We will concentrate our attention on the coupling that exists between different interactions and how the ability of the layers to change their behavior can be used to adsorb nanoparticles. Following the case of planar polymer layers, we will describe the behavior of mixed tethered polymer layers coating nanoparticles and how the mixed polymers can be used to manipulate the interactions and binding between the coated nanoparticles and surfaces. In particular we will present the differences that exist between polymers chemically grafted to the nanoparticle surface as compared to polymers that are mobile, as for example in lipidic micelles used for drug delivery. Finally, we will show the structure and electrochemical behavior of electrodes modified with redox polymers. The equilibrium current-potential curves predicted by the theory are in very good agreement with experimental observations. We will discuss the relationship between electrochemical response and polymer layer structure. General remarks on how these finding can be used for the design of polymer as surface modifiers will be provided.