Multimodal Light-Harvesting Soft Hybrid Materials: Assisted Energy Transfer upon Thermally Reversible Gelation

Abstract

Multimodal light-harvesting soft systems able to absorb UV-to-NIR radiations and convert into visible emissions have drawn much attention in the last years in order to explore new areas of application in energy, photonics, photocatalysis, sensors and so forth. Here, we present a new hybrid system combining a supramolecular photonic gel of naphthalimide-derived molecules self-assembled into fibers and upconverting NaYF 4 :Yb/Tm nanoparticles (UCNPs). The hybrid system presented here manipulates light reversibly as a result of an optical communication between the UCNPs and the photoactive gel network. Upon UV irradiation, the system shows the characteristic emission at 410 nm from the photoactive organomolecule. This emission is also activated upon 980 nm excitation thanks to an efficient energy transfer from the UCNPs to the fibrillary network. Interestingly, the intensity of this emission is thermally regulated during the reversible assembly or disassembly of the organogelator molecules, in such a way that gelator emission is only observed in the aggregated state. Additionally, the adsorption of the UCNPs with the supramolecular gel fibers enhance their emissive properties, a behavior ascribed to the isolation from solvent quenchers and surface defects, as well as an increased IR light scattering promoted by the fibrillary network. The reported system constitutes a unique case of a thermally regulated, reversible, dual UV and IR light harvesting hybrid soft material.3

Easy Formation of Functional Liposomes in Water Using a pH‐Responsive Microbial Glycolipid: Encapsulation of Magnetic and Upconverting Nanoparticles

“…Due to their oleic coating, they aggregate in water, either sedimenting or immediately adsorbing on the glass vial. NaYF 4 : Yb/Er and NaYF 4 :Yb/Tm UCNP are prepared according to a standard procedure; [50] their typical XRD pattern ( Figure S6a) depicts a classical mixture of hexagonal and cubic crystal structures, while the corresponding TEM micrographs ( Figure S6b) show a polydisperse set of sub-50 nm nanoparticles (size distribution is given in Figure S6c). The oleic hydrophobic coating is shown by DTA analysis (red profile in Figure S6e).…”

Incorporation of Upconverting LiYF4:Yb3+, Tm3+ Nanoparticles with High Quantum Yield in TiO2 Metallogels for Near Infrared-Driven Photocatalytic Dye Degradation

“…Self-assembled hybrid materials containing both molecules and appropriately functionalized nanoparticles is a new and exciting way of fabricating soft materials with significant advantages. − This multiscale self-assembly strategy makes it possible to obtain synergetic properties and to arrange the various components in a complex hierarchical architecture allowing, for example, the modulation of optical, electronic, and mechanical performances. The possibility to enhance the upconversion-induced photocatalysis depends on the material’s ability to absorb and transfer as much light as possible.…”

Hierarchical Assembly of l-Phenylalanine-Terminated Bolaamphiphile with Porphyrin Show Tunable Nanostructures and Photocatalytic Properties

“…With the growth of research related to new energy and environmental protection, the photocatalytic systems based on supramolecular assemblies are attracting increased interests recently. − Theoretically, bolaamphiphiles should be very good building blocks for the fabrication of functional supramolecular architectures. However, the only known bolaamphiphilic assembly for photocatalytic applications was developed by Lee, et al, wherein the bolaamphiphiles containing odd number alkyl chains can form nanoparticles upon co-assembly with porphyrins .…”