Effect Of Metal Organic Frameworks Research Articles

Dose-Dependent Effect on Plant Growth of Exposure to Metal-Organic Framework MIL-101(Cr).

With the increasing use of metal-organic frameworks (MOFs), they will inevitably enter the environment intentionally or unintentionally. However, the effects of MOFs on plant growth are poorly understood. Here, we investigated the effects of exposure of the rhizosphere to MOFs on plant growth. MIL-101(Cr) was selected as a research model due to its commercial availability and wide use. Soybean plants at the two-leaf stage were subjected to various durations (1-7 days) and concentrations (0-1000 mg/L) of exposure in hydroculture with a control group treated with ultrapure water. We found that MIL-101(Cr) had a positive effect on soybean growth at a lower dose (i.e., 200 mg/L); however, at higher doses (i.e., 500 and 1000 mg/L), it exhibited significant toxicity to plant growth, which is evidenced by leaf damage. To investigate the mechanism of this effect, we used Cr as an indicator to quantify, track, and image MIL-101(Cr) in the plant with laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS). Results indicated that MIL-101(Cr) primarily accumulated in the cortex of roots (up to 40 times higher than that in stems), with limited translocation to stems and negligible presence in leaves and cotyledons. In addition, metabolomic analysis of soybeans indicated that low-dose MIL-101(Cr) could increase the sucrose content of soybean roots to promote plant growth, while a high dose could induce lipid oxidation in roots. This study provides valuable insights into the ecological toxicology of MOFs and underscores the importance of assessing their environmental impact for sustainable agricultural practices.

The Effect of MOFs on Carbon Dioxide Adsorption

With the rapid increase in carbon dioxide emissions, the development of efficient treatment technologies is urgent. Metal organic frameworks (MOFs) are utilized in various fields, such as gas storage, gas adsorption, drug delivery, and more, making them a highly promising material. MOFs also play a crucial role in CO2 adsorption. This article begins with a brief introduction to the principles of carbon dioxide adsorption, explaining the basic characteristics and fundamental adsorption mechanisms of MOFs. It then provides a more specific understanding of MOFs by discussing several aspects, including the synthesis methods, crystal structures, properties of various MOFs, and the influence of branch additions on their performance. This facilitates readers in gaining a more concrete impression and a better understanding of MOFs. However, despite the good performance of MOFs in carbon dioxide adsorption, there are still certain shortcomings in terms of stability, selectivity, and large-scale applications, which will be elaborated on in detail in the later prospects analysis.

Effect of metal organic framework on crystallization and ultraviolet protection ability of biobased PA5,6

Because of metal organic frameworks high surface area and good compatibility with polyamide 5,6(PA5,6), HKUST-1 was chosen as a nucleating agent and UV resistant agent for PA5,6 to improve its performances. The addition of HKUST-1 improves the crystallinity and crystallization rate of PA5,6 by increasing the intramolecular hydrogen bonds in PA5,6. In addition, after the addition of HKUST-1, PA5,6 has low ultraviolet (UV) transmittance and good UV resistance (ultraviolet protection factor is 15+) because the reflection, absorption, and scattering of UV light are enhanced by the effects of HKUST-1. Therefore, HKUST-1 is good nucleating agent for PA5,6 and enhances its UV resistance.

Effect of Pyrolysis on iron-metal organic frameworks (MOFs) to Fe3C @ Fe5C2 for diesel production in Fischer-Tropsch Synthesis.

The Fischer-Tropsch Synthesis (FTS) is a significant catalytic chemical reaction that produces ultra-clean fuels or chemicals with added value from a syngas mixture of CO and H2 obtained from biomass, coal, or natural gas. The presence of sulfur is not considered good for producing liquid fuels for(FTS). In this study, we reveal that the presence of sulfur in ferric sulfate Fe2(SO4)3 MOF provides the high amount, 52.50% of light hydrocarbons in the carbon chain distribution. The calcined ferric nitrate Fe(NO₃)₃ MOF reveals the highest 93.27% diesel production. Calcination is regarded as an essential factor in enhancing liquid fuel production. Here, we probed the calcination effect of Metal Organic Framework (MOF) on downstream application syngas to liquid fuels. The XRD results of MOF. N and P. MOF.N shows the formation of the active phase of iron carbide (Fe5C2), considered the most active phase of FTS. The scanning electron microscopy (SEM) images of iron sulfate MOF catalyst (P.MOF.S) reveals that the existence of sulfur creates pores inside the particles due to the reaction of free water molecules with the sulfur derivate. The surface functional groups of prepared MOFs and tested MOFS were analyzed by Fourier transforms infrared spectroscopy (FT-IR). The thermal stability of prepared MOFS was analyzed by Thermo gravimetric analysis (TGA). The surface areas and structural properties of the catalysts were measured by N2-Physiosorption technique.

Drug delivery by micro and meso metal-organic frameworks

Three metal-organic frameworks (MOFs), HKUST-1, MIL-53(Al) and MIL-101(Cr) were synthesized and applied as carriers for Thymol loading. The MOFs and designed drug delivery systems were characterized by scanning electron microscope, N2 sorption isotherm, X-ray diffraction and Fourier transform infrared. Thymol was incorporated by high pressure method into hosts. The amount of encapsulated drug could be calculated using thermogravimetric analysis. The release profile of drug was recorded in buffer media and two pHs (6.9 and7.4) by reading the absorbance of solution in λmax. Higuchi and first order release kinetic models were applied to the experimental data. Then, the effect of MOFs and designed drug delivery systems on human breast and lung cancer cell lines viability was evaluated. In studied weight range٬ the hosts alone revealed no toxicity to cell lines. But, Thymol encapsulated into MOFs indicated more inhibition of cell livability, when compared to the non-encapsulated drug. Among of applied hosts, MIL-53 shows not only high loading capacity but also controlled release. In addition, the inhibition of cell livability is more notably in lung cancer cell line.

Fast photocatalytic inactivation of Microcystis aeruginosa by metal-organic frameworks under visible light

In this work, Metal-organic Frameworks (MOFs) were applied to inactivate algae under visible light with low doses. Five MOFs with different compositions (Zn and Fe; carboxylates or imidazolates) were successfully synthesized and characterized by XRD, SEM and UV–vis. The effects of MOFs on Microcystis aeruginosa were evaluated with regard to morphology characteristics, physiological activity, cell integrity and pigment degradation. The results indicated that Ag/AgCl@ZIF-8 outperformed MOF-235, ZIF-8, Bi2WO6/MIL-100(Fe) and BiOBr/MOF-5 in the degradation of chlorophyll a at the dose of 10 mg L−1. After 6 h of irradiation, 93.1% of Microcystis aeruginosa died and was unable to regrow and reproduce, which was demonstrated by changes in cell morphology, damage of cell membrane integrity and antioxidant enzyme system. Besides, the intracellular organic matter (IOM) and extracellular organic matter (EOM) were proven to be efficiently removed by MOF-assisted photocatalytic inactivation. Superoxide radical (O2·-) was demonstrated to be the major reactive oxygen species. A probable mechanism was proposed that the electrons in the valence band of Ag/AgCl@ZIF-8 transfer into the conduction band under irradiation to produce O2·- which inactivated the algae cells. Furthermore, Ag/AgCl@ZIF-8 can effectively remove Microcystis aeruginosa under sunlight and is of great application prospects for algae removal in real water bodies.

Metal-organic framework anchored sulfonated poly(ether sulfone) as a high temperature proton exchange membrane for fuel cells

A proton-conducting sulfonated poly(ether sulfone)-metal-organic framework membrane with high proton conductivity at high temperature and anhydrous conditions was synthesized by anchoring the Cr-MIL-101-NH2 to the aromatic polymer backbone via a Hinsberg reaction. The effect of metal-organic frameworks as the pendant porous aminated moieties on membrane features such as water uptake, swelling ratio, mechanical, oxidative and thermal stabilities, morphology, acid retention capacity, ion exchange capacity, long-term durability, hydrogen crossover, proton conductivity and fuel cell performance was methodically studied. The presence of holes and -NH2 groups in the metal-organic frameworks structure enhanced the acid retention capacity of the sulfonated poly(ether sulfone)-metal-organic framework membrane. This behavior resulted in the satisfactory performance of the membrane at high temperatures and low humidity (the proton conductivity of the membrane was increased to 0.041 S cm−1 (as compared to Nafion = 0.003 S cm−1) at 160 °C). Moreover, the crosslinking process which produced by metal-organic frameworks increased the dimensional stability (the swelling ratio was reduced from 57% to 4%), oxidative resistance, tensile strength, water uptake, and hydrogen crossover of the polymer.

Hydrogen adsorption in metal- organic frameworks (MOFs): Effects of adsorbent architecture

In this work, the effect of metal-organic framework (MOF) structure of MOF-5 was investigated in hydrogen adsorption based on the degree of solvent exploitation and/or sample preparation procedures. In this regard, the characterization analyses of FT-IR, BET and PXRD pattern of MOF-5 samples were used to compare their architectures with different specific surface area and porosity in hydrogen adsorption. The results show that the pore size distribution of samples is related to the main peaks in the micropores, mesopores and macropores regions. One can found that the adsorption of hydrogen at room temperature (296 K) is controlled by diffusion of adsorbed hydrogen inside the pores of the crystals. Larger diffusivities at a given pressure are expected due to diffusion in macroporous. The values of heats of adsorption on prepared sample are calculated as 3.68 and 12.45 kJ mol−1 for meso and macroporous regions, respectively. These results are suggesting that weak interactions between the adsorbed hydrogen molecules and MOF crystals is occur in mesoporous regions and the adsorption into macroprous which are filling in high temperature shows strong interaction.

Study on the poly(lactic acid)/nano MOFs composites: Insights into the MOFs-induced crystallization mechanism and the effects of MOFs on the properties of the composites

This work aims to develop the poly(lactic acid) (PLA) composites with fast crystallization rate and improved mechanical properties utilizing some unique properties of metal-organic frameworks (MOFs). The MOFs comprised of Zn-O-Zn dinuclear units and multidentate pyridine-2, 5-dicarboxylate linkers were synthesized. SEM and AFM were used to study the distribution of MOFs in PLA matrix and the results indicated MOFs dispersed well in PLA matrix. The significant impacts of MOFs on the crystallization of PLA were observed by DSC and POM. The tensile strength, storage modulus and Tg were improved owing to the reinforcement of MOFs crystals in the PLA/MOFs composites. The tensile strength, storage modulus at 40°C and Tg of the PLA/MOFs composites with 1wt% MOFs are increased to 56MPa, 3425MPa and 77.9°C compared with 49MPa, 1507MPa and 66.2°C for neat PLA, respectively.

An easy and cheap chemical route using a MOF precursor to prepare Pd–Cu electrocatalyst for efficient energy conversion cathodes

Carbon supported bimetallic palladium–copper nanoparticles (PdCu/C) were prepared using a copper metal–organic framework (MOF) as sacrificial precursor. The effect of MOF was investigated by comparing the PdCu/C synthesized from a simple metal chloride precursor (CuCl2). The PdCu/C nanoparticles are nanorod-like particles in both cases. Based on the analysis from Warren planar defect and size-strain isotropic models, in the MOF-derived PdCu/C sample, the crystallite size, stacking-fault and micro-strain parameters increase, whereas lattice parameter decreases, with reference to both the CuCl2-derived PdCu/C and Pd/C nanoparticles. This assesses a solid solution in the MOF-derived PdCu/C sample, while the alloying is less evident in the CuCl2-derived sample, as supported by inductively coupled plasma and X-ray photoelectron spectroscopy data. A better oxygen reduction reaction activity obtained on MOF-derived PdCu/C, as compared to other homemade and commercial samples, is correlated to Pd surface modification induced by alloying, further proved by CO-stripping voltammograms.

Spectral Characteristics and Applications of Metal–Organic Frameworks Based on Copper Cyanide and Quinoline Bases

Two metal–organic frameworks (MOF), [(CuCN)2.(6-mquin)2], 1 and [Me3SnCu(CN)2.(quina)2(H2O)2], 2, where (6-mquin) = 6-methyl quinoline and (quina) = quinaldic acid, have been synthesized and structurally characterized. MOFs 1 and 2 have been characterized by IR, UV-visible, and NMR spectra, as well as TGA. The emission spectra and the thermodynamic parameters from TGA of MOFs 1 and 2 were discussed. MOFs 1 and 2 were used as heterogeneous catalysts for the oxidative discoloration of Rhodamine B dye (RhB) by H2O2. The cytotoxic effect of MOFs 1 and 2 on the viability of MCF-7 cells was also determined by MTT assay. MOFs 1 and 2 have potentially good inhibition activity to MCF-7 cells.