The present disclosure provides a copolymer comprising monomer units represented by formulas (I) and/or (II) as disclosed and defined herein which are useful in antibacterial and/or antifouling coatings. The present disclosure further provides methods of synthesizing said copolymers.

A photochromic article is provided, containing a polymer and a polyoxometalate derivative anion and counter cation complex distributed in the polymer. A method of forming a photochromic film is also provided, including forming a composition containing a polymer or a precursor of the polymer and a polyoxometalate derivative and counter cation complex and preparing a film from the composition, the film containing the polyoxometalate derivative and counter cation complex distributed in the polymer. Further, a precursor composition is provided, including a polymer or a precursor of the polymer and a polyoxometalate derivative anion and a counter cation.

A photochromic article is provided, containing a polymer and a polyoxometalate derivative anion and counter cation complex distributed in the polymer. A method of forming a photochromic film is also provided, including forming a composition containing a polymer or a precursor of the polymer and a polyoxometalate derivative and counter cation complex and preparing a film from the composition, the film containing the polyoxometalate derivative and counter cation complex distributed in the polymer. Further, a precursor composition is provided, including a polymer or a precursor of the polymer and a polyoxometalate derivative anion and a counter cation.