A polymeric material, methods of making the polymeric material, articles that include the polymeric material, and compositions that contain the polymeric material are provided. The polymeric material has a plurality of different pendant groups that include a first pendant group containing a —COOH group or a salt thereof, a second pendant group containing a poly(alkylene oxide) group, a third pendant group containing a silicon-containing group, and a fourth pendant group containing a quaternary amino group. The polymeric material can be used, for example, to provide coatings that can be antifouling, antimicrobial, or both.