Zwischen Ärtzepflicht und Patientenautonomie

Competitive Adsorption of Functionalized Polymers

The adsorption and desorption of functionalized polystyrene-block-polybutadiene diblock copolymers from dilute solutions in toluene onto silicon wafers are investigated by means of null ellipsometry. The short polybutadiene block is functionalized by a reaction with 4-(3,5-dioxo-1,2,4-triazolidin-4-yl)benzoic acid. On the average there are six functional groups per chain. The polystyrene block does not adsorb on the surface. The adsorption depends on the length of the polystyrene block, and chains with short polystyrene blocks yield higher surface coverage than larger ones. When short and long chains are put together, the short chains displace the long ones in equilibrium conditions nearly …