Confined Ionic Liquid-Built Gas Transfer Pathways for Efficient Propylene/Propane Separation

Abstract

The separation of light olefins from paraffins using membrane technology is highly desired; however, synthetic polymer membranes generally suffer a pernicious trade-off between permeability and selectivity. Herein, we show that this limitation can be overcome by constructing selective gas transfer pathways in a polymer matrix, as demonstrated by incorporating composites of ionic liquids and zeolitic imidazolate frameworks (ZIFs) to form mixed-matrix membranes. Using propylene/propane separation as a model system, dramatic improvements in the propylene permeability of 218.4 Barrer and propylene/propane separation factor of 45.7 were achieved compared to the values obtained using individual components as a filler. The synergy between the high solubility of the gas molecules in ionic liquids and the size screening ability of ZIF exacerbates the difference in the transmission of propylene and propane, thus leading to superior separation performance. This work presents a promising strategy for the design of membranes for efficient gas separation.

Hierarchical Yolk–Shell Porous Ionic Liquids with Lower Viscosity for Efficient C3H6/C3H8 Adsorption and Separation

“…Considering the high affinity of the anion [NTf 2 ] − for C 3 H 6 and C 3 H 8 in ionic liquids, as well as the suitable flowing property, to optimize the physicochemical properties of 1,10-bis­(3-buthylimidazolium-1-yl) decane bis­(trifluoromethylsulfonyl) amide ([C 10 BIm 2 ]­[NTf 2 ] 2 ) and ethyl ether bis­( N -methylimidazole) bis­(trifluoromethane)­sulfonamide ([C 2 OC 2 Im 2 ]­[NTf 2 ] 2 ) were employed as illustrated in Figures S4 and S5. Subsequently, [C 10 Bim 2 ]­[NTf 2 ] 2 and [C 2 OC 2 Im 2 ]­[NTf 2 ] 2 are confirmed by 1 H NMR as shown in Figure a,b .…”

“…Since C 3 H 6 and C 3 H 8 have extremely similar molecular sizes, polarizability, and volatilities, the separation of C 3 H 6 /C 3 H 8 usually is an extremely energy-intensive and costly process . Therefore, it is of great urgency to extend the pore sizes of MOFs to mesopores and even macropores to meet the growing demands in large-species C 3 H 8 /C 3 H 6 separation …”

“…9 Therefore, it is of great urgency to extend the pore sizes of MOFs to mesopores and even macropores to meet the growing demands in large-species C 3 H 8 /C 3 H 6 separation. 34 Motivated by the optimal hierarchical pores of YSPILs and the high affinity of [NTf 2 ] − -based ionic liquids, pure-component adsorption isotherms were collected to evaluate C 3 H 6 and C 3 H 8 adsorption performance at 25 °C. 34 As expected, the C 3 H 6 and C 3 H 8 sorption capacities of YSPILs are significantly higher than that of neat ILs solvents, which are attributed to the large size of the bulky solvents that prevented them from entering Z67@ PDA pores 40 (Figure 9a,b and Table S3).…”

“…34 Motivated by the optimal hierarchical pores of YSPILs and the high affinity of [NTf 2 ] − -based ionic liquids, pure-component adsorption isotherms were collected to evaluate C 3 H 6 and C 3 H 8 adsorption performance at 25 °C. 34 As expected, the C 3 H 6 and C 3 H 8 sorption capacities of YSPILs are significantly higher than that of neat ILs solvents, which are attributed to the large size of the bulky solvents that prevented them from entering Z67@ PDA pores 40 (Figure 9a,b and Table S3). The additional gas adsorption capacity depends on the free pore volumes of Z67@ PDA largely remaining in the YSPILs, which is calculated as 13 q q q g g g Z67@PDA YSPILs ILs 12…”

Preparation and properties of the aramid pulp/nitrile butadiene rubber composites with compatibilization of ionic liquids

“…[27] So far, ILs have been widely applied in the fields of analytical chemistry, [28,29] electrochemistry, [30][31][32] polymerization [33,34] and gas absorption/separation. [35][36][37][38] In the last decade, the potential applications as an effective and eco-friendly surface modification agent for fillers in rubber materials have also aroused great interest. Besides the traditional fillers (carbon black and silica, et al), [39,40] some high-performance or functional fillers were pretreated by ILs to improve the dispersibility and the interaction with the rubber matrix.…”