TY  - EJOU
AU  - Tang, Weishan 
AU  - Feng, Xin 
AU  - Lin, Caiyun 
AU  - Rao, Xiaoping 

TI  - CO<sub>2</sub>-Responsive Smart Foams Stabilized by an Extremely Rigid Bio-Based Surfactant
T2  - Journal of Renewable Materials

PY  - 2023
VL  - 11
IS  - 2
SN  - 2164-6341

AB  - Environment friendly and intelligent surfactants have attracted great attention in recent years. A bio-based CO<sub>2</sub> 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 <sup>1</sup>H NMR spectra. The foams’ properties of R-BMI-C could be adjusted by bubbling CO<sub>2</sub>/N<sub>2</sub> 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 CO<sub>2</sub>, 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 CO<sub>2</sub>. 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.
KW  - Rosin; bio-based; surfactant; CO<sub>2</sub>-responsive; foams

DO  - 10.32604/jrm.2022.022809