Abstract: A surface of specific reactivity is formed by adsorbing a modified block polymeric surfactant of the Pluronic-type, i.e., containing pendant poly(ethylene oxide) blocks attached at an end to poly(propylene oxide) center blocks and with specifically reactive groups at the unattached ends of the poly(ethylene oxide) blocks, upon a hydrophobic surface.

Abstract: A method for producing products for separation, ion exchange or as basic material for the preparation of various derivatives designed for separation purposes and adsorption purposes by means of a polymer being activated with a reagent containing at least two bifunctional groups so that at least one of the reactive, functional groups in each molecule is bonded to the polymer while leaving a considerable amount of remaining groups unreacted but still reactive so that the activated polymer can be caused to react with thiosulphate after surplus reagent has been eliminated. The invention also relates to the produced products or their derivatives consisting of a water-soluble hydroxyl group or amino group containing polymer substituted with organic side-chains, each containing one or more thiosulphate groups or derivatives of such groups and the use of the products for purification of water, separation, immobilization of enzymes, etc.