“…Studies on interfacial properties of cationic surfactants are very important for many practical applications related to their solubilization ability, adsorption and aggregation properties, improvement of wetting and antimicrobial activity against bacteria, yeasts and molds [2,7,9,[11][12][13][14]. Nowadays, functionalized cationic surfactants are also used as protective materials on the surfaces of solids, lubricants, antistatic agents and fabric softeners because they adsorb onto textiles due to their negative-charged surfaces in water [10,11].A c c e p t e d M a n u s c r i p t As a continuation of our studies on new functionalized cationic surfactants and their properties [15][16][17][18], herein we describe synthetic methodology, surface activity and antielectrostatic properties, regarding the structure-performance relationships, of two homologous series of new soft cationic surfactants, diesterquat-type N, N-dimethyl-N,N-bis[2-(alkyloxycarbonyl)ethyl]ammonium bromides (2xC n E-Br, n = 10, 12) and diamidequat-type N, N-dimethyl-N,N-bis[2-(N-alkylcarbamoyl)ethyl]ammonium bromides (2xC n A-Br, n = 8, 10, 12) surfactants (all structures and the applied synthetic route are shown in Scheme 1).Common characteristics of obtained series of compounds is the presence of labile linkers -ester -COOR or amide -CONHR moieties -between the alkyl tails and the hydrophilic quaternary ammonium group. Both groups are vulnerable to hydrolytic degradation in acidic and basic aqueous media.…”