Photon upconversion (UC) based on triplet-triplet annihilation is a very promising phenomenon with potential application in several areas, though, due to the intrinsic mechanism, the achievement of diffusion-limited solid materials with air-stable UC is still a challenge. Herein, we report UC coordination polymer nanoparticles (CPNs) combining sensitizer and emitter molecules especially designed with alkyl spacers that promote the amorphous character. Beyond the characteristic constraints of crystalline MOFs, amorphous CPNs facilitate high dye density and flexible ratio tunability.
View Article and Find Full Text PDFLuminescent lanthanide metal-organic frameworks (Ln-MOFs) have been shown to exhibit relevant optical properties of interest for practical applications, though their implementation still remains a challenge. To be suitable for practical applications, Ln-MOFs must be not only water stable but also printable, easy to prepare, and produced in high yields. Herein, we design and synthesize a series of ( = 0-1) MOFs using a highly hydrophobic ligand CBL1: 1,7-di(4-carboxyphenyl)-1,7-dicarba--dodecaborane.
View Article and Find Full Text PDFGreen light photoactive Ru-based coordination polymer nanoparticles (CPNs), with chemical formula [[Ru(biqbpy)](bis)](PF) (biqbpy = 6,6'-bis[N-(isoquinolyl)-1-amino]-2,2'-bipyridine; bis = bis(imidazol-1-yl)-hexane), were obtained through polymerization of the trans-[Ru(biqbpy)(dmso)Cl]Cl complex (Complex ) and bis bridging ligands. The as-synthesized CPNs (50 ± 12 nm diameter) showed high colloidal and chemical stability in physiological solutions. The axial bis(imidazole) ligands coordinated to the ruthenium center were photosubstituted by water upon light irradiation in aqueous medium to generate the aqueous substituted and active ruthenium complexes.
View Article and Find Full Text PDFDespite the recent advances in the field of thermofluorochromism, the fabrication of thermoresponsive multicolor-emissive materials in a simple, low-cost and versatile manner still remains a challenge. Herein we accomplish this goal by expanding the concept of matrix-induced thermofluorochromism, where a sudden two-state variation of dyes' emission is promoted by the solid-liquid transition of a surrounding phase change material (, paraffins). We demonstrate that this behavior can be transferred to the nanoscale by the synthesis of dye-loaded solid lipid nanoparticles, different types of which can then be combined into a single platform to obtain multicolor thermofluorochromism using a single type of emitter.
View Article and Find Full Text PDFHypothesis: Nanoparticles removal from seawage water is a health and environmental challenge, due to the increasing use of these materials of excellent colloidal stability. Herein we hypothesize to reach this objective through complex coacervation, a straightforward, low-cost process, normally accomplished with non-toxic and biodegradable macromolecules. Highly dense polymer-rich colloidal droplets (the coacervates) obtained from a reversible charge-driven phase separation, entrap suspended nanomaterials, allowing their settling and potential recovery.
View Article and Find Full Text PDFACS Appl Mater Interfaces
October 2020
From smart self-tightening sutures and expandable stents to morphing airplane wings, shape memory structures are increasingly present in our daily life. The lack of methods for synthesizing intricate structures from them on the micron and submicron level, however, is stopping the field from developing. In particular, the methods for the synthesis of shape memory polymers (SMPs) and structures at this scale and the effect of new geometries remain unexplored.
View Article and Find Full Text PDFColor-tunable white-light-emitting materials are currently attracting much attention because of their potential applications in artificial lighting, sensing, and imaging. However, preparation of these systems from organic emitters is often cumbersome due to the interchromophoric interactions occurring upon solvent drying in the final solid materials, which can be hardly predicted and may lead to detrimental effects. To circumvent these obstacles, we have developed a new fabrication methodology that relies on dye encapsulation within liquid-filled capsules, thus enabling direct transfer of the luminescent properties from solution to the solid state and as such, rational design of miniaturized white-light-emitting materials.
View Article and Find Full Text PDFHerein, we report a novel, straightforward, and universal strategy to achieve solid materials with highly tunable reverse photochromism. This was accomplished by means of commercially available spiropyran dyes, which can produce different types of stable merocyanine states (i.e.
View Article and Find Full Text PDFAngew Chem Int Ed Engl
November 2016
A novel strategy to achieve thermally switchable photochromism in solid materials is reported, which relies on the preparation of polymeric core-shell capsules containing solutions of photochromic dyes in acidic phase-change materials. Upon changing the phase (solid or liquid) of the encapsulated medium, one of the two photochromic states of the system is selectively stabilized on demand, allowing for reversible interconversion between direct and reverse photochromism when thermally scanning through the melting temperature of the phase-change material. This strategy, which does not require the addition of external agents or chemical modification of the dyes, proved to be general for different spiropyran photochromes and to be applicable to the fabrication of a variety of functional materials by simply embedding the capsules obtained into a solid matrix of choice.
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