Mass and thickness changes

Changes in mass and/or thickness arise due to a number of different processes. The first and most important of these processes is physical adsorption (addition of mass to a surface) and desorption (removal of mass from a surface). These processes occur spontaneously at macroscopic interfaces, and also on dispersed interfaces, such as solid particles, emulsion droplets etc. In the latter case, the surface area to volume ratio is very high, and the surface therefore has a strong influence on the overall stability and behaviour of the complex system. Adsorption and desorption are driven by a range of phenomena, although entropy reduction is one of the most important.

Apart from simple physical adsorption, other surface confined processes include analyses of interaction between a surface confined ligand and dissolved analyte. This is the basis of “label-free” interaction analysis. Below are examples of application areas where instruments from the Biolin Scientific group can be used.

Swelling kinetics of a cellulose model film

Structural change of adsorbed protein layer