A Potassium Metal-Organic Framework based on Perylene-3,4,9,10-tetracarboxylate as Sensing Layer for Humidity Actuators

Abstract

We have synthesized a novel three-dimensional metal-organic-framework (MOF) based on the perylene-3,4,9,10-tetracarboxylate linker and potassium as metallic centre. We report the formation of this K-based MOF using conventional routes with water as solvent. This material displays intense green photoluminescence at room temperature, and displays an aggregation dependent quenching. Correlation of the optical properties with the crystalline packing was confirmed by DFT calculations. We also demonstrate its potential to build humidity actuators with a reversible and reproducible response, with a change of 5 orders of magnitudes in its impedance at about 40% relative humidity (RH). This 3D-MOF is based on an interesting perylene derivative octadentate ligand, a moiety with interesting fluorescent properties and known component in organic semiconductors. To the best of our knowledge, this is the first time to build such a printed and flexible actuator towards humidity with a reversible response, enabling precise humidity threshold monitoring.

2D-Coordination polymers based on 1H-indazole-4-carboxylic acid and transition metal ions: magnetic, luminescence and biological properties

“…The cells were cultured into a 96-well flat transparent plate (10 4 cells per well) for 48 hours. Then, the cells were exposed to different concentrations (10,25,50,75 and 100 μg mL −1 ) of compounds 1, 2, 3, 4 and 5 and the corresponding ligand. All the experiments were performed in triplicate.…”

“…In this sense, in recent years, our group and others have worked on the design of novel MOFs to study their properties in luminescence, 4 gas adsorption, 5 catalysis, 6 magnetism, 7 biology as drug-delivery systems, 8 cytotoxic agents 9 and sensing. 10 Bearing in mind the interest of our group in the study of MOFs based on nitrogen linkers with carboxylate groups, we decided to study the properties of this type of materials with the interesting 1H-indazole-4-carboxylic acid because, as far as we know, there are no coordination compounds synthesized with it. This ligand is an ideal candidate for forming CPs because of its multiple coordination possibilities derived not only from its carboxylate group but also from its indazole ring, 11 being able to show some interesting coordination modes (Scheme 1).…”

Fabrication and Characterization of Humidity Sensors Based on Graphene Oxide–PEDOT:PSS Composites on a Flexible Substrate

“…In this context, the number of sensing variables, whether environmental or biological, as well as the different ways they can be addressed, resulted in a wide range of studies, among which relative humidity (RH) sensors attracted notable attention given their importance for diverse processes and industries, such as food, biomedicine, and the living environment [3][4][5][6]. Numerous materials have been considered for the manufacturing of flexible RH sensors, such as carbon nanotubes (CNTs) [7], silicon nanosheets (SiNSs) [8], metal-organic frameworks (MOFs) [9], polymers [10], or oxides [11,12]. However, although some of these sensors reported auspicious results,…”

Carbon Dots as Sensing Layer for Printed Humidity and Temperature Sensors

“…In particular, the interdigitated electrode (IDE) has been extensively investigated to detect capacitive humidity sensors [6][7][8]. Many materials have been used to manufacture flexible relative humidity sensors in IDE systems, such as carbon nanotubes (CNTs) [9], metal and organic frameworks (MOFs) [10], and different polymers or oxides [11][12][13].…”