Sequential amine functionalization inducing structural transition in an aldehyde-containing zeolitic imidazolate framework: Application to gas separation membranes

Cacho-Bailo, Fernando (Universidad de Zaragoza) ; Etxeberría-Benavides, Miren ; Karvan, Oguz ; Téllez, Carlos (Universidad de Zaragoza) ; Coronas, Joaquín (Universidad de Zaragoza)

Resumen: A modification in the gas separation performance of zeolitic imidazolate framework (ZIF)-supported hollow fiber (HF) membranes by means of an imine-condensation functionalization reaction carried out by microfluidics is reported. The accommodation of voluminous amine molecules in the SIM-1, Zn(4-methyl-5-imidazolecarboxaldehyde)2, also known as ZIF-94, sod structure during the functionalization reaction caused the ZIF atoms to be rearranged in a less dense rho structure, with a wider pore diameter and a diminished CO2 affinity. These changes had effects on the membrane performance, resulting in an enhanced CO2 permeance while maintaining a good permeance-selectivity balance. ZIF aldehyde-containing SIM-1 membranes were earlier prepared on the inner side of polymeric P84® HF using a microfluidic approach. The SIM-1 membranes displayed very interesting results in the separation of gas mixtures of great relevance to the natural gas field. High selectivities in the separation of He/CH4 (160), H2/CH4 (136) and CO2/CH4 (38) mixtures were achieved, and these are the first SIM-1 membranes with such a high separation performance to the best of our knowledge. These SIM-1 membranes were in situ stepwise functionalized with long-chain amine solutions, namely, hexyl- and nonylamine. Microfluidics allowed the easy sequential implementation of this post-reaction step in the membrane fabrication procedure. An imine-condensation reaction took place between the aldehyde groups in the 4-methyl-5-imidazolecarboxaldehyde ligand forming SIM-1 and the corresponding amines. The extent of the reaction was analyzed by FTIR, TGA and XRD, together with the changes in the textural properties and the adsorption capacities.

Idioma: Inglés

DOI: 10.1039/c7ce00086c

Año: 2017

Publicado en: CRYSTENGCOMM 19 (2017), [20 pp.]
ISSN: 1466-8033

Factor impacto JCR: 3.304 (2017)

Categ. JCR: CHEMISTRY, MULTIDISCIPLINARY rank: 62 / 171 = 0.363 (2017) - Q2 - T2
Categ. JCR: CRYSTALLOGRAPHY rank: 8 / 26 = 0.308 (2017) - Q2 - T1

Factor impacto SCIMAGO: 0.998 - Chemistry (miscellaneous) (Q1) - Materials Science (miscellaneous) (Q1) - Condensed Matter Physics (Q1)

Financiación: info:eu-repo/grantAgreement/ES/DGA/T05
Financiación: info:eu-repo/grantAgreement/ES/MINECO/MAT2013-40566-R
Financiación: info:eu-repo/grantAgreement/ES/MINECO/MAT2016-77290-R

Tipo y forma: Artículo (PostPrint)

Área (Departamento): Área Ingeniería Química (Dpto. Ing.Quím.Tecnol.Med.Amb.)