Synthesis, surface properties and cytotoxicity evaluation of nonionic urethane fluorinated surfactants with double short fluoroalkyl chains

Abstract

Developing suitable alternatives to long fluoroalkyl chain surfactants has drawn considerable attention on account of the concerns over the environmental safety and human health. However, low surface activity, poor water solubility and complex preparation process of most currently reported alternatives restrict their widespread applications. Herein, a series of nonionic urethane fluorinated surfactants (FmEGnFm) were synthesized by one-pot method using poly (ethylene glycol) (PEG), isophorone diisocyanate (IPDI) and short chain fluorinated alcohol as raw materials. The surfactant molecule is composed of two short fluoroalkyl chains connected to a PEG molecule via two IPDI spacers. Benefit from the special molecular structure design, these fluorinated surfactants displayed high surface activities, which could reduce the surface tensions of 17.8–28.7 mN/m and had low critical micelle concentrations of 0.17–0.98 mmol/L. These fluorinated surfactants showed good salt and pH resistance. Furthermore, contact angle and emulsifying experiments demonstrated that these fluorinated surfactants possessed excellent wetting and emulsifying properties at an extremely low concentration of 0.1 wt%. More importantly, the cytotoxicity experiment verified that these fluorinated surfactants had no obvious cytotoxicity. The ideal properties coupled with a simple and green preparation process make this strategy a new avenue to fabricate sustainable alternatives to long fluoroalkyl chain surfactants.