Activities during the reported period (overview of the whole project):
1) Building up a team of young researchers.
2) Evaluation, selection, purchase, and setting up of equipment for the planned research activities. This included the purchase of an XRD, an AFM, and a Raman microscope. Improvements were made to existing equipment, (e.g. Dip Coater).
3) Since the project started, progress has been made on all WPs of POPCRYSTAL, and all the main objectives have been now completed. The following points highlight the main results:
a) the development of a protocol for the automatic deposition of aligned Cu(OH)2 nanobelts (NBs). This new method produces highly oriented samples with minimal variability. A manuscript that describes this protocol was published in Adv.Mat.Interf. 2021.
b) the understanding of the key compositional variables for an optimized conversion from Cu(OH)2 NBs to aligned Cu-based MOF crystals. This investigation allowed us to develop protocols for 12 heteroepitaxially oriented MOF film systems. Selected outcomes: Chem.Sci. 2020, 11, 8005; Advanced Materials 2023,35, 2211478; Adv. Mater. Interfaces 2023, 10, 2202461; Chemical Science 2023, 14, 12056; Advanced Materials 2024, 2309645.
c) The extension of POPCRYSTAL through the use of chemically functionalized ligands to tune functional properties of MOFs. The conversion of Cu(OH)2 nanobelts to Cu2(L)2(DABCO) MOFs (using different ligands, e.g. L= BDC, 1,4-NDC, 2,6-NDC, Br2BDC, BPDC, N3BPDC) was investigated. Importantly, the halogen (Br-) and azide (N3-) functional groups endowed the MOF films with photosensitive properties used for patterning and cross-linking. Outcomes: Adv. Mater., 2023,35, 2211478; Adv. Mater. 2024, 2404384.
d) Since the project started, we successfully fabricated different classes of MOF-based devices. Below we highlight some of them:
d1) 3D-oriented fluorescent MOF micropatterns with anisotropic optical response and diffraction-grating properties. Adv. Mater. 2023, 2211478.
d2) 3D-oriented fluorescent polymer micropatterns with anisotropic optical response (photonic applications) and superior chemical stability. Adv. Mater. 2024, 2404384.
d3) MOF-based printed photoluminescent oxygen sensor. Adv. Mater. 2024, 202408770.
d4) A colorimetric biogenic amine sensor printed on flexible substrates to monitor food decomposition. Adv. Mater. 2024, 202408770.
d5) A 23 µm thick MOF as a separator membrane in a Li-S battery. Adv.Sc. 2020.
d6) A vapor sensor based on a MOF micro-pattern. Nat.Mater. 2020.