Description |
Given sufficient mobility, polymer surfaces reorient in response to their local microenviroments so as to minimize their interfacial free energy with that environment. These effects are probably most pronounced in aqueous systems due to the high surface tension and cohesion in water. The interfacial restructuring of a polymer is apparently time-temperature dependent and probably depends on relaxation phenomena similar in principle to the well known bulk relaxations in polymers. Any significant change in the local microenvironment will, in principle, change the nature of the polymer surface. The adsorption of protein or other species at the polymer-water interface can lead to a different local orientation of the polymer surface, as well as to local conformational changes in the protein. When searching for correlations between surface properties of polymers and their biomedical behavior, it is necessary to characterize the surface properties in the environment of interest. Attempting to correlate surface characteristics measured in air or vacuum will often not be useful and may even be misleading. |