Catégorie d'actualités : IMAP

Proton conductive materials are of significant importance and highly desired for clean energy-related applications. Discovery of practical metal-organic frameworks (MOFs) with high proton conduction remains a challenge due to the use of toxic chemicals, inconvenient ligand preparation and complication of production at scale for the state-of-the-art candidates. Herein, we report a zirconium-MOF, MIP-202(Zr), constructed from natural α-amino acid showing a high and steady proton conductivity of 0.011 S cm−1 at 363 K and under 95% relative humidity. This MOF features a cost-effective, green and scalable preparation with a very high space-time yield above 7000 kg m−3 day−1. It exhibits a good chemical stability under various conditions, including solutions of wide pH range and boiling water. Finally, a comprehensive molecular simulation was carried out to shed light on the proton conduction mechanism. All together these features make MIP-202(Zr) one of the most promising candidates to approach the commercial benchmark Nafion.

Pour plus d’informations, consultez notre communiqué de presse : Produire de l’énergie « verte » avec un matériau hybride à base d’acide aminé naturel !

References:
A Robust Zirconium Amino Acid Metal-Organic Framework for Proton Conduction
Sujing Wang, Mohammad Wahiduzzaman, Louisa Davis, Antoine Tissot, William Shepard, Jérôme Marrot, Charlotte Martineau-Corcos, Djemel Hamdane, Guillaume Maurin, Sabine Devautour-Vinot and Christian Serre
Nature Communications volume 9, Article number: 4937 (2018)
DOI: 10.1038/s41467-018-07414-4

The discovery of more-efficient and stable water adsorbents for adsorption-driven chillers for cooling applications remains a challenge due to the low working capacity of water sorption, high regeneration temperature, low energy efficiency under given operating conditions and the toxicity risk of harmful working fluids for the state-of-the-art sorbents. Here we report the water-sorption properties of a porous zirconium carboxylate metal–organic framework, MIP-200, which features S-shaped sorption isotherms, a high water uptake of 0.39 g g⁻¹below P/P₀ = 0.25, facile regeneration and stable cycling, and most importantly a notably high coefficient of performance of 0.78 for refrigeration at a low driving temperature (below 70 °C). A joint computational–experimental approach supports that MIP-200 may be a practical alternative to the current commercially available adsorbents for refrigeration when its water adsorption performance is combined with advantages such as the exceptional chemical and mechanical stability and the scalable synthesis that involves simple, cheap and green chemicals.

Consultez le communiqué de presse associé à cet article : Un solide nanoporeux pour une réfrigération plus efficace

References :
A Robust Energy-Efficient Metal-Organic Framework Adsorbent for Refrigeration
Sujing Wang, Ji Sun Lee, Mohammad Wahiduzzaman, Jaedeuk Park, Mégane Muschi, Charlotte Martineau-Corcos, Antoine Tissot, Kyung Ho Cho, Jérôme Marrot, William Shepard, Guillaume Maurin*, Jong-San Chang*, and Christian Serre*
Nature Energy 2018
DOI: 10.1038/s41560-018-0261-6

In the past few years, numerous studies have demonstrated the great potential of nano particles of metal-organic frameworks (nanoMOFs) at the preclinical level for biomedical applications. Many of them were reported very recently based on their bioactive composition, anticancer application, or from a general drug delivery/theranostic perspective. In this review, the authors aim at providing a global view of the studies that evaluated MOFs’ biomedical applications at the preclinical stage, when in vivo tests are described either for pharmacological applications or for toxicity evaluation. The authors first describe the current surface engineering approaches that are crucial to understand the in vivo behavior of the nanoMOFs. Finally, after a detailed and comprehensive analysis of the in vivo studies reported with MOFs so far, and considering the general evolution of the drug delivery science, the authors suggest new directions for future research in the use of nanoMOFs for biomedical applications.

References:
Nanoparticles of Metal-Organic Frameworks: On the Road to In Vivo Efficacy in Biomedicine
Teresa Simon-Yarza, Angelika Mielcarek, Patrick Couvreur & Christian Serre
Adv. Mater. 2018, 1707365
DOI: 10.1002/adma.201707365

Porous titanium oxide materials are attractive for energy-related applications. However, many suffer from poor stability and crystallinity. Here we present a robust nanoporous metal–organic framework (MOF), comprising a Ti₁₂O₁₅ oxocluster and a tetracarboxylate ligand, achieved through a scalable synthesis. This material undergoes an unusual irreversible thermally induced phase transformation that generates a highly crystalline porous product with an infinite inorganic moiety of a very high condensation degree. Preliminary photophysical experiments indicate that the product after phase transformation exhibits photoconductive behavior, highlighting the impact of inorganic unit dimensionality on the alteration of physical properties. Introduction of a conductive polymer into its pores leads to a significant increase of the charge separation lifetime under irradiation. Additionally, the inorganic unit of this Ti-MOF can be easily modified via doping with other metal elements. The combined advantages of this compound make it a promising functional scaffold for practical applications.

Pour plus d’informations, consultez le commniqué de presse associé à cet article :
À la recherche d’un oxyde de titane poreux !

References:
A phase transformable ultrastable titanium-carboxylate framework for photoconduction
Sujing Wang, Takashi Kitao, Nathalie Guillou, Mohammad Wahiduzzaman, Charlotte Martineau-Corcos, Farid Nouar, Antoine Tissot, Laurent Binet, Naseem Ramsahye, Sabine Devautour-Vinot, Susumu Kitagawa, Shu Seki, Yusuke Tsutsui, Valérie Briois, Nathalie Steunou, Guillaume Maurin, Takashi Uemura and Christian Serre
Nature Communications, 9, 1660 (2018)
DOI: 10.1038/s41467-018-04034-w