The invention provides polymers, methods of preparing polymers, and compositions that include polymers, wherein said polymers include a plurality of two-carbon repeating units in a polymer chain, wherein one or more of the two-carbon repeating units of the polymer chain have tertiary amine or pyridine-containing substituents; and at least about 10% of the nitrogen atoms of the tertiary amine or pyridine-containing substituents are quaternized with alkyl groups or with an alkyl group that contains one or more ethylene glycol groups. The alkyl or ethoxylated alkyl groups can also be at least partially fluorinated. The polymers can be used to provide antimicrobial surfaces and antifouling coatings.