Adsorption and interaction of a graft copolymer of poly(ethylene imine) and poly(ethylene oxide)

• The adsorption of proteins and particles onto surfaces carrying firmly adsorbed or covalently bound chains of poly(ethylene oxide) (PEO) is generally very low. This makes it of fundamental and practical interest to learn about the structure of PEO-coatings and how PEO-coated surfaces interact with each other and e.g. proteins. A prerequisite for such studies is, of course, that stable PEO-coated surfaces can be obtained. For this purpose we employed a two-step method to coat negatively charged surfaces, such as mica or silica, with PEO. In the first reaction step, cationic poly(ethylene irnine) is adsorbed onto the negatively charged surface. In the next step, the adsorbed polyelectrolyte is reacted with a functionalized poly(ethylene oxide) chain. Both reaction steps were followed both by ellipsometry and by direct measurement of surface forces. From these measurements we obtained inforrnation of the adsorbed amount, the layer thickness, as well as the range and distance dependence of the interaction between two PEO-coated surfaces.

Nyckelord

Adsorption

graft copolymers

poly(ethylene imine)

poly(ethylene oxide)

surface interactions

Publikations- och innehållstyp

ref (ämneskategori)

art (ämneskategori)