Synthesis of a novel cationic short-chain fluorocarbon surfactant and its synergistic effect with hydrocarbon surfactants for enhanced foam performance

Abstract

Short-chain fluorocarbon surfactants are key alternatives to long-chain fluorocarbon surfactants, while the research on their cationic formulations remains limited. This study synthesizes a novel quaternary ammonium cationic short-chain fluorocarbon surfactant ( PFH-QAC ) and enhances its performance by compounding with hydrocarbon surfactants of different ionic characteristics, including anionic sodium dodecyl sulfate (SDS), cationic dodecyl trimethyl ammonium chloride (DTAC), and zwitterionic N , N -dimethyldodecylamine- N -oxide (OB-2). The results reveal that PFH-QAC exhibits excellent thermal stability, surface activity, and foaming ability. Compounding PFH-QAC with hydrocarbon surfactants greatly reduces the critical micelle concentration ( cmc ) of PFH-QAC system. Particularly, PFH-QAC /SDS systems exhibit strong positive synergistic interactions, with cmc decreased by 64.67-96.74%, leading to higher foaming ability and foam stability through electrostatic attraction. Conversely, when compounded with DTAC or OB-2, PFH-QAC systems show deteriorating foam performance at higher concentrations, attributed to weak intermolecular interaction or unfavorable electrostatic repulsion that leads to competitive adsorption and weakened foam films. This study provides a valuable reference for the developing cationic short-chain fluorocarbon surfactants and a practical basis for environmental-friendly foam fire extinguishing agents.