Fluorinated MOF-808 with various modulators to fabricate high-performance hybrid membranes with enhanced hydrophobicity for organic-organic pervaporation

A fluorescent sensor based on pentafluoropropanoic acid-functionalized UiO-66-NH2 for enhanced selectivity and sensitivity of dicloran detection

A pentafluoropropionic acid-functionalized fluorescent metal-organic framework material (UiO-66-NH2-PFPA) is prepared by a simple post-synthetic modification (PSM) strategy for the sensitive and selective detection of dichloran (DCN). The results of fluorescence experiments demonstrate that the sensitivity of UiO-66-NH2-PFPA (limit of detection, LOD = 0.478 μM) to DCN is nearly 10.93 times higher than that of UiO-66-NH2 (LOD = 5.225 μM) and the material has good selectivity and anti-interference ability. After the addition of DCN, the blue fluorescence of UiO-66-NH2-PFPA is obviously quenched. Therefore, the possible quenching mechanism is further discussed in combination with relevant experiments and density functional theory calculations. Moreover, the sensor is applied to the detection of DCN in fruit samples with a satisfactory recovery of 101.1-107.9%, which implies that UiO-66-NH2-PFPA is expected to be a candidate material for the detection of DCN in food.

Synthesis of Thiol Functionalized MOF-808 and its Efficiency for Mercury Removal

A thiol-functionalized MOF-808 was produced and used to remove mercury by post-synthetic modification using 6-mercaponicotinic acid (6mna). Parent MOF-808 was impregnated for varied periods in the 6mna solution to create modified MOF-808 materials, known as MOF-808-6mna-x, where x refers to the impregnation time. Diffraction and several spectroscopic techniques were employed to quantify and confirm the coordination of 6mna into MOF-808 framework. The amount of grafted 6man and the ability for adsorption of mercury (Hg) was shown to be linearly associated; the functionalized MOF-808-6mna-36 demonstrated improved Hg(II) removal, with an adsorption capacity of 250 mg/g.

Cellulose acetate based sustainable nanostructured membranes for environmental remediation

Membrane-based gas separation has a great potential for reducing environmentally hazardous carbon dioxide (CO₂) gas. The polymeric membranes developed for CO₂ capturing have some limitations in their selectivity and permeability. There is a need to overcome these issues and developed such membranes having high-performance CO₂ capture with cost-effectiveness. The present study aimed to synthesize mixed matrix membranes (MMMs) having improved properties CO₂ adsorption performance and stability than that of pure polymer. Further, the effect on CO₂ adsorption by increasing the filler concentration in MMMs was investigated. The MMMs were synthesized by incorporating (1-5 wt%) Cu-MOF-GO composites as filler into cellulose-acetate (CA) polymer matrix by adopting the solution casting method. The performance of MMMs was studied by changing the Cu-MOF-GO composite concentration (1-5 wt%) in the polymer matrix at 45 °C up to 15 bar. Morphological analysis by using SEM confirms that by increasing the concentration of Cu-MOF-GO more than 3% will result in their agglomeration in MMM. The successful incorporation of MOF within the polymer matrix of MMMs was confirmed through the presence of functional groups using FTIR and Raman spectroscopy. XRD analysis revealed that pure CA changes its semi-crystalline behaviour into crystalline by the addition of Cu-MOF-GO. The maximum tensile stress and strain rate of MMMs was 45.1 N/mm² and 12.8%. In addition, with an increase in (4-5 wt%) Cu-MOF-GO concentration the hydrophilicity of MMMs decreases. The maximum uptake rate of CO₂ was 1.79 mmol/g and 7.98 wt% at 15 bar. The adsorption results conclude that Cu-MOF-GO composite and CA-based MMM can be effective for CO₂ capture.

Pervaporation as a Successful Tool in the Treatment of Industrial Liquid Mixtures

Pervaporation is one of the most active topics in membrane research, and it has time and again proven to be an essential component for chemical separation. It has been employed in the removal of impurities from raw materials, separation of products and by-products after reaction, and separation of pollutants from water. Given the global problem of water pollution, this approach is efficient in removing hazardous substances from water bodies. Conventional processes are based on thermodynamic equilibria involving a phase transition such as distillation and liquid-liquid extraction. These techniques have a relatively low efficacy and nowadays they are not recommended because it is not sustainable in terms of energy consumption and/or waste generation. Pervaporation emerged in the 1980s and is now becoming a popular membrane separation technology because of its intrinsic features such as low energy requirements, cheap separation costs, and good quality product output. The focus of this review is on current developments in pervaporation, mass transport in membranes, material selection, fabrication and characterization techniques, and applications of various membranes in the separation of chemicals from water.