Chen Yu, Hu Xiaohong, Chen Wenjun, Liu Chong, Qiao Kepan, Zhu Meijing, Lou Yanyan, Mu Tiancheng
Department of Chemistry and Material Science, Langfang Normal University, Langfang 065000, Hebei, P. R. China.
Phys Chem Chem Phys. 2021 Jan 28;23(3):2193-2210. doi: 10.1039/d0cp05885h.
High volatility would lead to a highly flammable hazard, explosion danger, low regeneration efficiency and air pollution. Eutectic solvents (ESs) are assumed to be nonvolatile; however, the assumption is not correct. Here, we, for the first time, find that superbase-derived ESs are highly volatile. Even at room temperature (i.e., 25 °C) and atmospheric pressure, the mass loss of ESs could reach as high as 43.5% after 20 h of exposure. Superbase-derived ESs are promising solvents for CO2 capture, and they are also highly volatile after CO2 capture. We found that typical ethylene glycol : 1,8-diazabicyclo[5.4.0]undec-7-ene (EG : DBU (4 : 1)) has a three-stage volatilizing mechanism. EG and DBU volatilize first by breaking weak hydrogen-bonding interactions (1st stage), followed by the destruction of strong hydrogen-bonding interactions (2nd stage), and finally by destroying much stronger hydrogen-bonding interactions (3rd stage). This work presents a new horizon that ESs and their mixture with CO2 are highly volatile, which is helpful for mitigating laboratory explosion, combustion hazards, air pollution and designing new types of ESs with negligible volatility.
