polyolefin particles are chemically modified by oxidation to provide a large surface area and high loading . the particles result in low back pressure in column systems , and are economical to manufacture . the particles are useful as supports in a wide range of applications including general organic as well as biopolymer synthesis , library methods , purification processes and enzyme mediated processes . in a preferred embodiment , polyethylene or polypropylene particles are oxidized in a solution containing trifluoroacetic acid or trifluoromethane sulfonic acid , chromium trioxide and sulfuric acid to provide the particles with a chemically reactive irregular surface and open channels that extend below the surface and up to essentially the length of the radius of the particles resulting in increased surface area and decreased density . the particles have pendant functional groups produced by the oxidation and / or by subsequent chemical reaction . the pendant functional groups may be attached to spacer arms that are attached to the surface of the particles . biological material such as proteins , enzymes and whole cells may be immobilized on the particles .