Design, synthesis and application of short-chained perfluorinated nitrogenous heterocyclic surfactants for hydrocarbon subphases

Abstract

• Short-chained perfluorinated surfactants with a semi-rigid phenylmethyl spacer were designed as vaporation suppressors for hydrocarbon subphases. • Surface tension measurements indicated the introduction of semi-rigid spacer has a great positive effect on the enhancement of surface activity. • The detailed formulation and the specific research technique of evaporation suppressor were firstly reported in this work. • The excellent performance suggested the synthesized surfactants are applicable in the field of petroleum storage and transportation. Long-chain perfluorocarbon surfactants are indispensible for use in many fields but restricted in production and application due to environmental concerns such as their bioaccumulation, non-degradation and high toxicity, making the development of new alternative surfactants an urgent need. In this article, a series of short-chain perfluorocarbon-containing surfactants were designed and synthesized, featuring the structural components of short-chain perfluoroalkylsulfonate, phenylmethyl linker, and N-heterocylic cation. These surfactants exhibit aqueous surface tensions ranging from 17 to 34 mN/m, comparable to that of similar long-chain counterparts. In addition, a formulation that contains one of the synthesized surfactants are capable of forming a type of partitioning film on liquid hydrocarbons such as cyclohexane, significantly suppressing the evaporation loss under ambient conditions to less than 20% during a testing period of 30 h. The results suggest that the formulations composed of these short-chain perfluorocarbon surfactants are applicable as promising evaporation suppressors in the field of petroleum storage and transportation.