Chemical composition of nanopolymer structures

Zwitterionic terpolymer nanopolymers, composed of N-(2-hydroxypropyl) methacrylamide (HPMAA), carboxybetaine methacrylamide (CBMAA), and sulfobetaine methacrylamide (SBMAA), exhibit exceptional antifouling properties. We investigate the atomic composition of these nanopolymers using X-ray photoelectron spectroscopy (XPS) in combination with Ar cluster ion beam (ArCIB) sputtering for depth profiling. This methodology allowed us to quantify the atomic composition of nanopolymers, specifically, ratio of carboxyl (O=C-OH, O=C-O⁻) and quaternary ammonium (C-N⁺) ions. The knowledge is important for the functionalization of the nanopolymer surfaces for biomedical applications.