Open Access

ARTICLE

CO₂-Responsive Smart Foams Stabilized by an Extremely Rigid Bio-Based Surfactant

by Weishan Tang, Xin Feng, Caiyun Lin, Xiaoping Rao^*

College of Chemical Engineering, Huaqiao University, Xiamen, 361021, China

* Corresponding Author: Xiaoping Rao. Email:

(This article belongs to the Special Issue: Renewable Biomass as a Platform for Preparing Green Chemistry)

Journal of Renewable Materials 2023, 11(2), 523-538. https://doi.org/10.32604/jrm.2022.022809

Received 27 March 2022; Accepted 19 May 2022; Issue published 22 September 2022

Abstract

Environment friendly and intelligent surfactants have attracted great attention in recent years. A bio-based CO₂ responsive surfactant rosin acid dimaleimide choline (R-BMI-C) with an extremely rigid skeleton was prepared using rosin and choline as raw materials by Diels-Alder addition reaction and acid-base neutralization reactions. Its structure was confirmed by IR and ¹H NMR spectra. The foams’ properties of R-BMI-C could be adjusted by bubbling CO₂/N₂ to change the structure of the surfactant. At pH 10.4, R-BMI-C forms an unstable foam with a half-life of 1.5 h. When the pH was reduced to 7.4 by bubbling CO₂, R-BMI-C forms an extremely stable foam with a half-life of 336 h. The surfactant R-BMI-C changed from bola type to conventional type when bubbling CO₂. And the internal aggregation structure of R-BMI-C aqueous solution changed from spherical micelles to laminar micelles according to the cryogenic-transmission electron microscope. We know that the lamellar structure tends to adsorb at the air/water interface or is trapped in the foam film, which slows down the foam coarsening and agglomeration process, resulting in a significant increase in foam stability. R-BMI-C could be used in oil extraction, fire-fighting and chemical decontamination due to its excellent foaming, stabilization and defoaming properties.

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