A CO2-responsive smart fluid based on supramolecular assembly structures varying reversibly from vesicles to wormlike micelles

Chunming Xiong; Falin Wei; Qiang Zhou; Kang Peng; Zhengrong Ye; Haiyang Yang

doi:10.1039/d0ra03854g

A CO₂-responsive smart fluid based on supramolecular assembly structures varying reversibly from vesicles to wormlike micelles

RSC Adv. 2020 Jul 3;10(42):25311-25318. doi: 10.1039/d0ra03854g. eCollection 2020 Jun 29.

Authors

Chunming Xiong^{1

2}, Falin Wei^{1

2}, Qiang Zhou^{1

2}, Kang Peng^{1

2}, Zhengrong Ye^{1

2}, Haiyang Yang^{1

2}

Affiliations

¹ Research Institute of Science and Technology, China National Petroleum Corporation Beijing 100083 P. R. China.
² CAS Key Laboratory of Soft Matter Chemistry, School of Chemistry and Materials Science, University of Science and Technology of China Hefei 230026 P. R. China yhy@ustc.edu.cn pengkang@mail.ustc.edu.cn.

Abstract

CO₂-responsive smart fluids have been widely investigated in the past decade. In this article, we reported a CO₂-responsive smart fluid based on supramolecular assembly structures varying from vesicles to wormlike micelles. Firstly, oleic acid and 3-dimethylaminopropylamine reacted to form a single-chain weak cationic surfactant with a tertiary amine head group, N-[3-(dimethylamino)propyl]oleamide (NDPO). Then, 1,3-dibromopropane was used as the spacer to react with NDPO to form a gemini cationic surfactant, trimethylene α,ω-bis(oleate amide propyl dimethyl ammonium bromide) (GCS). By controlling the feed ratio of 1,3-dibromopropane and NDPO, we found that the mixtures of GCS and NDPO with the molar ratio of 7 : 3 approximately could form vesicles in aqueous solution by supramolecular self-assembly. After bubbling CO₂, the tertiary amine of NDPO was protonated. The packing parameter of the mixed surfactants reduced accordingly, accompanied by the transition of aggregates from vesicles to wormlike micelles. As a result, the zero-shear viscosity of the solution increased by more than four orders in magnitude. When the solid content of GCS/NPDO mixtures was higher than 5 wt% in solution, the sample treated by CO₂ behaved as a gel over a wide frequency range with shear-thinning and self-healing properties. In addition, the sol-gel transition could be repeatedly and reversibly switched by cyclically bubbling CO₂ and N₂. Our effort may provide a new strategy for the design of CO₂-responsive smart fluids, fostering their use in a range of applications such as in enhanced oil recovery.