RESUMO
Nanoporous materials relying on supramolecular liquid crystals (LCs) are excellent candidates for size- and charge-selective membranes. However, whether they can be manufactured using printing technologies remained unexplored so far. In this work, we develop a new approach for the fabrication of ordered nanoporous microstructures based on supramolecular LCs using two-photon laser printing. In particular, we employ photo-cross-linkable hydrogen-bonded complexes, that self-assemble into columnar hexagonal (Colh) mesophases, as the base of our printable photoresist. The presence of photopolymerizable groups in the periphery of the molecules enables the printability using a laser. We demonstrate the conservation of the Colh arrangement and of the adsorptive properties of the materials after laser microprinting, which highlights the potential of the approach for the fabrication of functional nanoporous structures with a defined geometry. This first example of printable Colh LC should open new opportunities for the fabrication of functional porous microdevices with potential application in catalysis, filtration, separation, or molecular recognition.
RESUMO
On the occasion of this special issue, we start by briefly outlining some of the history and future perspectives of the field of 3D metamaterials in general and 3D mechanical metamaterials in particular. Next, in the spirit of a specific example, we present our original numerical as well as experimental results on the phenomenon of acoustical activity, the mechanical counterpart of optical activity. We consider a three-dimensional chiral cubic mechanical metamaterial architecture that is different from the one that we have investigated in recent early experiments. We find even larger linear-polarization rotation angles per metamaterial crystal lattice constant than previously and a slower decrease of the effects towards the bulk limit.
