TY - JOUR

T1 - Defibrillation of soft porous metal-organic frameworks with electric fields

AU - Knebel, A.

AU - Geppert, B.

AU - Volgmann, K.

AU - Kolokolov, D. I.

AU - Stepanov, A. G.

AU - Twiefel, J.

AU - Heitjans, P.

AU - Volkmer, D.

AU - Caro, J.

N1 - Funding Information: Supported by the Deutsche Forschungsgemeinschaft in the priority program SPP 1928 COORNETs (Coordination Networks: Building Block for Functional Systems), grant no. CA 147/20-1 (J.C.), VO 829/12-1 (D.V.), Russian Science Foundation project no. 17-73-10135 (D.I.K.), Russian Academy of Sciences project no. 0303-2016-0003 for the Boreskov Institute of Catalysis (A.G.S.), and by a Niedersachsen Professorship (P.H.). All data are reported in the main paper and supplement. The authors declare no competing financial interest.

PY - 2017/10/20

Y1 - 2017/10/20

N2 - Gas transport through metal-organic framework membranes (MOFs) was switched in situ by applying an external electric field (E-field). The switching of gas permeation upon E-field polarization could be explained by the structural transformation of the zeolitic imidazolate framework ZIF-8 into polymorphs with more rigid lattices. Permeation measurements under a direct-current E-field poling of 500 volts per millimeter showed reversibly controlled switching of the ZIF-8 into polar polymorphs, which was confirmed by x-ray diffraction and ab initio calculations. The stiffening of the lattice causes a reduction in gas transport through the membrane and sharpens the molecular sieving capability. Dielectric spectroscopy, polarization, and deuterium nuclear magnetic resonance studies revealed low-frequency resonances of ZIF-8 that we attribute to lattice flexibility and linker movement. Upon E-field polarization, we observed a defibrillation of the different lattice motions.

AB - Gas transport through metal-organic framework membranes (MOFs) was switched in situ by applying an external electric field (E-field). The switching of gas permeation upon E-field polarization could be explained by the structural transformation of the zeolitic imidazolate framework ZIF-8 into polymorphs with more rigid lattices. Permeation measurements under a direct-current E-field poling of 500 volts per millimeter showed reversibly controlled switching of the ZIF-8 into polar polymorphs, which was confirmed by x-ray diffraction and ab initio calculations. The stiffening of the lattice causes a reduction in gas transport through the membrane and sharpens the molecular sieving capability. Dielectric spectroscopy, polarization, and deuterium nuclear magnetic resonance studies revealed low-frequency resonances of ZIF-8 that we attribute to lattice flexibility and linker movement. Upon E-field polarization, we observed a defibrillation of the different lattice motions.

UR - http://www.scopus.com/inward/record.url?scp=85032496887&partnerID=8YFLogxK

U2 - 10.1126/science.aal2456

DO - 10.1126/science.aal2456

M3 - Article

C2 - 29051376

AN - SCOPUS:85032496887

VL - 358

SP - 347

EP - 351

JO - Science

JF - Science

SN - 0036-8075

IS - 6361

ER -