The invention provides a method for modifying the surface of a solid material (e.g. a polymeric matrix). The method is versatile and can be used to prepare polymeric matrices having altered, improved, or specifically engineered properties. Additionally, the method can be used to prepare polymeric matrices that have reactive groups that can be used to immobilize upon the matrices a variety of other "ligand" groups, e.g. a bio-selective affinity group, a chromophore, a dye, an amphiphile, a chiral group, a peptide, a protein, an antibody, an amino acid, an ion exchange group, a detectable group, a carbohydrate, a nucleic acid, a catalyst, a substrate for enzyme binding thereto, an enzyme inhibitor or enzyme co-factor for enzyme binding, or the like.