1. Study of electric field-enhanced mass transfer and Li/Mg separation of N, N-bis (1-methylheptyl) acetamide/TBP-NaFeCl4 composite membrane.
- Author
-
Meng, Xiaorong, Sun, Chi, Liu, Xingfan, Huang, Jingyang, Li, Lu, and Ma, Xiaopeng
- Subjects
COMPOSITE membranes (Chemistry) ,ELECTRIC fields ,CONTACT angle ,POLYMERIC membranes ,PERMEABILITY - Abstract
Using N,N-bis(1-methylheptyl)acetamide (N503) synergized with TBP-NaFeCl 4 (T Fe), a ternary composite extraction membrane known as T Fe N-PIM was created. Under optimum membrane phase conditions, the mass transfer properties of T Fe N-PIM-Li(Ⅰ) and its Li/Mg selective separation performance by electric field augmentation were examined, and confirmed the mechanism of T Fe N-PIM-Li(Ⅰ) electric field enhanced mass transfer. The findings demonstrate a homogeneous distribution of [FeCl 4
- ] in the T Fe N-PIM membrane phase and a decrease in the water contact angle as the T Fe content increases. In the T Fe N-PIM membrane, the cation binding order of the composite carrier was H+ >Li+ >Na+ >Mg2+ , and the mass transfer was carried out at the interface of the two phases of the membrane through the mechanism of "cation exchange-neutralization", in which Li(Ⅰ) was bonded with the carrier in the form of 2N503-LiFeCl 4 -2TBP, and showed a fixed-site "hopping" mass transfer characteristics under the reinforcement of electric field. The mass transfer process of the T Fe N-PIM- Li(Ⅰ) system under electric field enhancement conforms to the first-order kinetic rate equation, and the voltage (5–45 V) is positively correlated with the permeability coefficient P Li(Ⅰ) but decreases the Li/Mg selectivity of T Fe N-PIM. The S Li(Ⅰ)/Mg(Ⅱ) of T Fe N-PIM was 9.18 at 3 V. After three cycles of 72 h cycling at 40 V, the decrease rate of P Li(Ⅰ) was <7.42 %, which showed good stability. [Display omitted] • A ternary composite extraction membrane (T Fe N-PIM) of N503 synergy with TBP-NaFeCl 4 (T Fe) was prepared. • The increase in permeability coefficient stabilization after T Fe /N503 > 2/1 (w/w) in T Fe N-PIM. • Voltage accelerates the "ion hopping" rate of Li(Ⅰ) in T Fe N-PIM. • Voltage positively correlates with permeability coefficient but reduces Li/Mg selectivity of T Fe N-PIM. • The separation factor of T Fe N-PIM for Li/Mg at 3 V was 9.18. [ABSTRACT FROM AUTHOR]- Published
- 2024
- Full Text
- View/download PDF