Highlights

The cobalt framework composite obtained responds efficiently to magnetic stimuli. A luminescent functionality is added, showing that multifunctional MOF devices can be prepared. This new generation of adaptive material is tested as a position-controlled molecular sensor. Metal organic frameworks (MOF) are very promising ultra-porous materials for a variety of significant applications, such as sensing, detecting, gas storage and separation catalysis and drug delivery. The high surface area in the thousands of square meter per gram, and the controlled pore size and pore size distribution of MOFs are relevant features for the fabrication of devices that rely on highly controlled transport properties materials. In addition, recent investigations describe MOFs as adaptive materials because they respond to a variety of stimuli (e.g. molecular and environmental). Despite the interesting intrinsic properties of these ultra-porous materials, different strategies are currently under investigation to achieve spatial control of MOF position on a variety of substrates.

The different proposed routes involve controlled crystal sizes for subsequent growth, surface functionalization, soft lithography and seeding approaches through heterogeneous nucleation. This latter approach has been shown to allow exogenous functionality to be coupled with the properties intrinsic to MOFs. In the present study we utilise functionality gained through synthesis of MOF with magnetic nanoparticles in order to control the location of MOF crystal growth and to dynamically position 3-D MOF forms for use in reconfigurable engineering devices. X-ray diffraction patterns taken at the Austrian SAXS beamline revealed the MOF-5 structure for the composite material.

Retrieve article

Dynamic Control of MOF-5 Crystal Positioning Using a Magnetic Field;
P. Falcaro, F. Normandin, M. Takahashi, P. Scopece, H. Amenitsch, S. Costacurta, C.M. Doherty, J.S. Laird, M.D.H. Lay, F. Lisi, J.A. Hill, D. Buso;
Advanced Materials 23 (34) 3901-3906 (2011).
10.1002/adma.201101233