Modified surface polymer fibers, webs constructed thereof, and/or filters constructed thereof, and/or devices constructed thereof. The use of modified surface polymers for the adsorption, extraction, isolation, purification, removal, separation, and/or controlled release, desorption, injection, recovery and/or supply of target entities from or into a fluid medium. The use of modified surface polymers to treat fluids including air, aqueous solutions, automotive fluids. aviation fluids, gases, liquids, extracts, hydrocarbons, bodily fluids, process fluids, oils, vegetable oils, beverages, drinks, mashes and other liquids containing one or more target entity