fig1

Figure 1. (A) Classification of zwitterionic electrolytes: Category (i) and Category (ii); (B) Cationic groups; (C) Anionic groups. Molecular structures of (D) polybetaines; (E) α-amino acid; and (F) other derived zwitterionic polymers. SB: Sulfobetaine; CB: carboxybetaine; PMPC: poly (2-methacryloyloxyethyl phosphorylcholine); TMAO: trimethylamine N-oxide derived polymer; VBIPS: 3-(1-(4-vinylbenzyl)-1H-imidazol-3-ium-3-yl) propane-1-sulfonate; PVPB: polyzwitterions based on poly (4-vinylpiridine).