Nanoimprinted, Submicrometric, MOF-Based 2D Photonic Structures: Toward Easy Selective Vapors Sensing by a Smartphone Camera

International audience2D photonic metal–oxide-framework-based homo- and hetero-structures are fabricated by soft lithographic approaches. As shown by A. Cattoni, M. Faustini and co-workers, these materials can be used as selective photonic sensing platforms. Detection of toxic vapors such as styrene are performed using an easy transduction method, compatible with smart-phone camera technologies

3e journée d\u27étude du Comité français Unimarc

La 3e Journée d\u27étude du Comité français Unimarc présente les nouveautés des formats pour les notices bibliographiques et d\u27autorité, publiés en 2008 et 2009 respectivement, et aborde les mutations de l\u27environnement normatif dans lequel s\u27inscrit Unimarc. La journée se divise en quatre temps : L\u27activité du CfU, les évolutions d\u27Unimarc, Unimarc dans le contexte normatif international, le catalogage du livre ancien dans Unimarc. Les notices des interventions, en français, proposent à la fois l\u27enregistrement audio et le diaporama accompagnant la communication

One-dimensional metal-organic framework photonic crystals used as platforms for vapor sorption.

We present the fabrication of one-dimensional photonic crystals (Bragg stacks) based on a microporous metal–organic framework material and mesoporous titanium dioxide. The Bragg stack heterostructures were obtained using two complementary synthesis approaches utilizing the bottom-up assembly of heterogeneous, i.e. two-component photonic crystal multilayer structures. Zeolitic imidazolate framework ZIF-8 and mesoporous titanium dioxide were chosen as functional components with different refractive indices. While ZIF-8 is intended to impart molecular selectivity, mesoporous TiO2 is used to ensure high refractive index contrast and to guarantee molecular diffusion within the Bragg stack. The combination of micro- and mesoporosity within one scaffold endows the 1D-MOF PC with characteristic adsorption properties upon exposure to various organic vapors. In this context, the sorption behavior of the photonic material was studied as a function of partial pressure of organic vapors. The results show that the multilayered photonic heterostructures are sensitive and selective towards a series of chemically similar solvent vapors. It is thus anticipated that the concept of multilayer heterogeneous photonic structures will provide a versatile platform for future selective, label-free optical sensors

Does functionalisation enhance CO2 uptake in interpenetrated MOFs? An examination of the IRMOF-9 series

The effect of pore functionalisation (-I, -OH, -OCH3) on a series of topologically equivalent, interpenetrated metal-organic frameworks (MOFs) was assessed by both simulation and experiment. Counter-intuitively, a decreased affinity for CO2 was observed in the functionalised materials, compared to the non-functionalised material. This result highlights the importance of considering the combined effects of network topology and chemical functionality in the design of MOFs for enhanced CO2 adsorptionRavichandar Babarao, Campbell J. Coghlan, Damien Rankine, Witold M. Bloch, Gemma K. Gransbury, Hiroshi Sato, Susumu Kitagawa, Christopher J. Sumby, Matthew R. Hill and Christian J. Doona

Analysis of high and selective uptake of CO2 in an oxamide-containing {Cu2(OOCR)4}-based metal-organic framework

The porous framework [Cu2(H2O)2L].4H2O.2DMA ((H¬4¬L = oxalylbis(azanediyl)diisophthalic acid; DMA = N,N-dimethylacetamide), denoted NOTT-125, is formed by connection of {Cu2(RCOO)4} paddlewheels with the isophthalate linkers in L4-. A single crystal structure determination reveals that NOTT-125 crystallises in monoclinic cell with a = 27.9161(6) Å, b = 18.6627(4) Å and c = 32.3643(8) Å, space group P2 (1)/c. The structure of this material shows fof topology, which can be viewed as the packing of two types of cages (Cage A and Cage B) in 3-dimensional space. Cage A is constructed by twelve {Cu2(OOCR)4} paddlewheels and six linkers to form an ellipsoid-shaped cavity approximately 24.0 Å along its long axis and 9.6 Å across the central diameter. Cage B consists of six {Cu2(OOCR)4} units and twelve linkers with a spherical diameter of 12.7 Å taking into account the van der Waals radii of the atoms. NOTT-125 incorporates oxamide functionality within the pore walls, and this, combined with high porosity in the desolvated NOTT-125a, is responsible for excellent CO2 uptake (40.1 wt% at 273 K and 1 bar) and selectivity for CO2 over CH4 or N2. Grand canonical Monte Carlo (GCMC) simulations show excellent agreement with the experimental gas isotherm data, and a computational study into the specific interactions and binding energies of both CO2 and CH4 with the linkers in NOTT-125 reveals a set of strong interactions between CO2 and the oxamide motif, which are not possible with a single amide

Nouveautés de la 3e édition anglaise d\u27Unimarc - Diaporama

Diaporama accompagnant la présentation de caroline Demessence, Bibliothèque nationale de France, à propos des grandes nouveautés de la 3e édition anglaise d\u27Unimarc

Investigation of the synthesis, activation, and isosteric heats of CO₂ adsorption of the isostructural series of metal-organic frameworks M₃(BTC)₂ (M = Cr, Fe, Ni, Cu, Mo, Ru)

The synthesis, activation, and heats of CO₂ adsorption for the known members of the M₃(BTC)₂ (HKUST-1) isostructural series (M = Cr, Fe, Ni, Zn, Ni, Cu, Mo) were investigated to gain insight into the impact of CO₂–metal interactions for CO₂ storage/separation applications. With the use of modified syntheses and activation procedures, improved BET surface areas were obtained for M = Ni, Mo, and Ru. The zero-coverage isosteric heats of CO₂ adsorption were measured for the Cu, Cr, Ni, Mo, and Ru analogues and gave values consistent with those reported for MOFs containing coordinatively unsaturated metal sites, but lower than for amine functionalized materials. Notably, the Ni and Ru congeners exhibited the highest CO₂ affinities in the studied series. These behaviors were attributed to the presence of residual guest molecules in the case of Ni₃(BTC)₂(Me₂NH)₂(H₂O) and the increased charge of the dimetal secondary building unit in [Ru₃(BTC)₂][BTC].Massachusetts Institute of Technology. Energy Initiative (Seed Fund

Porphyrin-Based MOF Thin Film on Transparent Conducting Oxide: Investigation of Growth, Porosity and Photoelectrochemical Properties

[EN] Synthesizing metal-organic frameworks (MOFs) composites with a controlled morphology is an important requirement to access materials of desired patterning and composition. Since the last decade, MOF growth from sacrificial metal oxide layer is increasingly developed as it represents an efficient pathway to functionalize a large number of substrates. In this study, porphyrin-based Al-PMOF thin films were grown on conductive transparent oxide substrates from sacrificial layers of ALD-deposited alumina oxide. The control of the solvent composition and the number of atomic layer deposition (ALD) cycles allow us to tune the crystallinity, morphology and thickness of the produced thin films. Photophysical studies evidence that Al-PMOF thin films present light absorption and emission properties governed by the porphyrinic linker, without any quenching upon increasing the film thickness. Al-PMOF thin films obtained through this methodology present a remarkably high optical quality both in terms of transparency and coverage. The porosity of the samples is demonstrated by ellipsometry and used for Zn(II) insertion inside the MOF thin film. The multifunctional transparent, porous and luminescent thin film grown on fluorine-doped tin oxide (FTO) is used as an electrode capable of photoinduced charge separation upon simulated sunlight irradiation.This research was funded by the French National Research Agency grant (ANR-17-CE09- 0029-01 and ANR-10-LABX-0064), and the Region Auvergne Rhone Alpes for the Subvention SCUSI. The authors thank the French Ministry of National Education, Research and Technology, the University Lyon 1 and the CNRS for financial support. S.N. thanks the support of grant PID2021-123856OBI00 funded by MCIN/AEI/10.13039/501100011033 and by ERDF A way of making Europe.Gikonyo, B.; Liu, F.; Hawila, S.; Demessence, A.; Garcia-Baldovi, H.; Navalón Oltra, S.; Marichy, C.... (2023). Porphyrin-Based MOF Thin Film on Transparent Conducting Oxide: Investigation of Growth, Porosity and Photoelectrochemical Properties. Molecules. 28(15). https://doi.org/10.3390/molecules28155876281