Polyzwitterion-grafted UiO-66-PEI incorporating polyimide membrane for high efficiency CO2/CH4 separation

Electrochemical determination of synephrine by using nafion/UiO-66/graphene-modified screen-printed carbon electrode

“…The peaks at 1631 cm −1 and 1142 cm −1 were designated as the stretching mode of C=C skeletal ring and stretching vibration of C–O alkoxy ( Thota et al, 2021 ). In the spectrum of UiO-66 (Blue line), the peaks at 1658 cm −1 , 1580 cm −1 , 1388 cm −1 , and 743 cm −1 were respectively related to the stretching vibration of carboxyl groups, the asymmetric stretching of O–C–O, the symmetric stretching of O–C–O and the O–H bending ( Niu et al, 2018 ; Liu et al, 2021 ). Moreover, the bands at 657 cm −1 , 547 cm −1 , and 475 cm −1 were assigned to the μ 3 -O stretching, Zr-(OC) stretching, and μ 3 -OH stretching, respectively ( Shangkum et al, 2018 ).…”

Metal–Organic Frameworks (MOFs)‐Based Mixed Matrix Membranes (MMMs) for Gas Separation: A Review on Advanced Materials in Harsh Environmental Applications

“…Besides, Liu et al compared the gas separation performance of MMMs in dry and humid tests with UiO-66-NH 2 /6FDA-ODA MMMs and UiO-66-PEI@pSBMA/6FDA-ODA MMMs (pSBMA: sulfobetaine methacrylate). [139] The perm-selectivity of UiO-66-PEI@pSBMA/6FDA-ODA MMMs was higher in the humid test than the dry state with CO 2 permeability of 140 Barrer and CO 2 /CH 4 selectivity of 58, attributed to the strong electrostatic and hydrogen bond interactions between water and zwitterion in MOFs that subsequently improved CO 2 solubility in the MMMs. Similarly, the Cu(dhbc) 2 (bpy)•H 2 O/PEBAX MMMs developed by Ying et al also displayed better CO 2 permeability under a humid condition where the CO 2 permeability and CO 2 /N 2 selectivity were ≈450 Barrer and ≈70, respectively.…”

“…Mixed gas permeation in the presence of water vapor can be tested with feed gas and sweep gas (e.g., Ar, He) through a humidifier. [49,64,139,142] The separation performance of MIL-96(Al)/6FDA-DAM MMMs remained stable after exposure to 2 cycles of water adsorption and desorption, with a CO 2 permeability of 851 Barrer and CO 2 /N 2 selectivity of 27, indicating there was a negligible influence of humidity on these MMMs. [49] UiO-66 is a type of MOFs that is suitable for humid gas application as it exhibits high water stability up to 12 months.…”

“…However, in some cases, water vapor could also have a positive effect on the separation performance. [138][139][140] Besides, although some of the membrane materials possess high adsorption selectivity, their poor water stability causes difficulties in scaling up for industrial applications (e.g., Cu-BTC). [141] Herein, several MMMs tested under humid conditions were intensively discussed to elucidate the effect of water vapor toward the MMMs permselectivity and stability.…”

Preparation of High‐Strength and High‐Permeability EC/PI/MOF Mixed Matrix Membrane**

“…FT-IR spectrum shows a vibration peak of À NH 2 at 3455 cm À 1 , which proves the existence of amino groups in the membranes. [36] More importantly, the FT-IR peak of C=O in the mixed matrix membranes show an upward shift, which are related to the formation of hydrogen bonds between the filler and EC. [37] These peaks prove the successful blending of EC/PI matrix membrane.…”