scholarly journals Metal Organic Frameworks Derived Sustainable Polyvinyl Alcohol/Starch Nanocomposite Films as Robust Materials for Packaging Applications

Polymers ◽  
2021 ◽  
Vol 13 (14) ◽  
pp. 2307
Author(s):  
Naveed Ahmed Khan ◽  
Muhammad Bilal Khan Niazi ◽  
Farooq Sher ◽  
Zaib Jahan ◽  
Tayyaba Noor ◽  
...  

Bio-nanocomposites-based packaging materials have gained significance due to their prospective application in rising areas of packaged food. This research aims to fabricate biodegradable packaging films based upon polyvinyl alcohol (PVA) and starch integrated with metal-organic frameworks (MOFs) or organic additives. MOFs offer unique features in terms of surface area, mechanical strength, and chemical stability, which make them favourable for supporting materials used in fabricating polymer-based packaging materials. zeolitic imidazolate frameworks (ZIFs) are one of the potential candidates for this application due to their highly conductive network with a large surface area and high porosity. Present research illustrates a model system based on ZIF-67 (C8H10N4Co) bearing 2–10 wt.% loading in a matrix of PVA/starch blend with or without pyrolysis to probe the function of intermolecular interaction in molecular packing, tensile properties, and glass transition process. ZIF-67 nanoparticles were doped in a PVA/starch mixture, and films were fabricated using the solution casting method. It was discovered through scanning electron microscopy (SEM), X-ray diffraction (XRD), thermogravimetric analysis (TGA), and Fourier transform infrared spectroscopy (FTIR) that addition of ZIF-67 and pyrolyzed ZIF-67 changed and enhanced the thermal stability of the membrane. Moreover, 2–10 wt.% loading of ZIF-67 effected the thermal stability, owing to an interlayer aggregation of ZIF-67. The membranes containing pyrolyzed ZIF-67 showed mechanical strength in the order of 25 MPa in a moderate loading of pyrolyzed ZIF-67 (i.e., at 4 wt.%). The crystallinity enhanced by an increment in ZIF-67 loading. On the other hand, pyrolyzed ZIF-67 carbon became amorphous because of the inert environment and elevated temperature. The surface area also increased after the pyrolysis, which helped to increase the strength of the composite films.

Author(s):  
Jiajun Song ◽  
Jianzhong Zheng ◽  
Anneng Yang ◽  
Hong Liu ◽  
Zeyu Zhao ◽  
...  

Two-dimensional (2D) conductive metal-organic frameworks (MOFs) can not only inherit the high porosity and tailorability of traditional MOFs but also exhibit unique charge transport properties, offering promising opportunities for applications...


Sensors ◽  
2021 ◽  
Vol 21 (5) ◽  
pp. 1679
Author(s):  
Roberta Puglisi ◽  
Anna L. Pellegrino ◽  
Roberto Fiorenza ◽  
Salvatore Scirè ◽  
Graziella Malandrino

Gadolinium metal-organic frameworks (Gd-MOFs) and Eu-doped Gd-MOFs have been synthesized through a one-pot green approach using commercially available reagents. The 1,4-benzenedicarboxylic acid (H2-BDC) and 2,6-naphthalenedicarboxylic acid (H2-NDC) were chosen as ditopic organic linkers to build the 3D structure of the network. The Gd-MOFs were characterized using powder X-ray diffraction (XRD), FT-IR spectroscopy, field emission scanning electron microscopy (FE-SEM) and N2 adsorption–desorption analysis. The Gd-MOF structures were attributed comparing the XRD patterns, supported by the FT-IR spectra, with data reported in the literature for Ln-MOFs of similar lanthanide ionic radius. FE-SEM characterization points to the effect of the duration of the synthesis to a more crystalline and organized structure, with grain dimensions increasing upon increasing reaction time. The total surface area of the MOFs has been determined from the application of the Brunauer–Emmett–Teller method. The study allowed us to correlate the processing conditions and ditopic linker dimension to the network surface area. Both Gd-MOF and Eu-doped Gd-MOF have been tested for sensing of the inorganic ions such as Fe3+ and Cr2O72−.


2016 ◽  
Vol 12 (1) ◽  
pp. 14
Author(s):  
Prapti Rahayu ◽  
Witri Wahyu Lestari

<p>Metal-organic frameworks (MOFs) are porous coordination polymer containing bi-or polidentate organic linker coordinated with inorganic part, such as metal oxide cluster or metal cation as node which called as secondary building unit (SBU) to form infinite structure. Due to high porosity and surface area, good thermal stability as well as the availability of unsaturated metal center or the linker influence attracts the interaction with gases, thus MOFs have potential to be applied as hydrogen storage material. One type of MOFs that have been widely studied is [Zn<sub>4</sub>O(benzene-1,4-dicarboxylate)<sub>3</sub>], namely, MOF-5.Various synthesis method have been developed to obtain optimum results. Characterization of MOF-5 from various synthesis method such as crystallinity, capacity, stability, and quantum dot behavior of MOF-5 have been summarized in this review.</p>


CrystEngComm ◽  
2021 ◽  
Author(s):  
Jiaqi Wang ◽  
Yiling Quan ◽  
Guoxiang Wang ◽  
Dazhi Wang ◽  
Jie Xiao ◽  
...  

Metal–organic frameworks (MOFs) attracted considerable attention through their large specific surface area and excellent adjustable voids. A one-step solvothermal method is proposed herein to fabricate the 3D hollow cage copper-cobalt...


2019 ◽  
Vol 31 (3) ◽  
pp. 367-388 ◽  
Author(s):  
Ayesha Rehman ◽  
Sarah Farrukh ◽  
Arshad Hussain ◽  
Erum Pervaiz

The most important environmental challenge that the world is facing today is the control of the quantity of CO2 in the atmosphere, because it causes global warming. Increase in the global temperature results in greenhouse gas emission, interruption of the volcanic activity, and climatic changes. The alarming rise of the CO2 level impels to take some serious action to control these climatic changes. Various techniques are being utilized to capture CO2. However, chemical absorption and adsorption are supposed to be the most suitable techniques for post-combustion CO2 capture, but the main focus is on adsorption. The aim of this study is to provide a brief overview on the CO2 adsorption by a novel class of adsorbents called the metal–organic framework. The metal–organic framework is a porous material having high surface area with high CO2 adsorption capacity. The metal–organic frameworks possess dynamic structure and have large capacity to adsorb CO2 at either low pressure or high pressure due to its cavity size and surface area. Adsorption of CO2 in the metal–organic framework at various pressures depends upon pore volume and heat of adsorption correspondingly. In this review, different synthesis methods of the metal–organic framework such as slow evaporation, solvo thermal, mechanochemical, electrochemical, sonochemical, and microwave-assisted synthesis are briefly described as the structure of the metal–organic frameworks are mostly dependent upon synthesis techniques. In addition to this, different strategies are discussed to increase the CO2 adsorption capacity in the metal organic-framework. [Formula: see text]


2018 ◽  
Vol 10 (11) ◽  
pp. 9332-9341 ◽  
Author(s):  
Hsuan-Lan Wang ◽  
Hsin Yeh ◽  
Yi-Chen Chen ◽  
Yen-Chih Lai ◽  
Chih-Yuan Lin ◽  
...  

2008 ◽  
Vol 61 (10) ◽  
pp. 813 ◽  
Author(s):  
En-Cui Yang ◽  
Qing-Qing Liang ◽  
Xiu-Guang Wang ◽  
Xiao-Jun Zhao

To explore the effects of a co-ligand on the construction of mixed-ligand metal–organic frameworks (MOFs), two new triazole-based complexes with a flexible dicarboxylate as a co-ligand, {[Zn4(trz)4(gt)2(H2O)2](H2O)2}n 1 and {[Cd2(trz)2(gt)(H2O)2](H2O)4}n 2 (Htrz = 1,2,4-triazole; H2gt = glutaric acid), were synthesized and their structures were fully characterized by elemental analyses, IR spectroscopy, and single-crystal X-ray crystallography. Their thermal stability and luminescence emissions were further investigated to establish their structure–property relationship. Crystal structure determination showed that 1 is a neutral two-dimensional pillared-bilayer network consisting of 14-membered hydrophobic channels, whereas 2 is an infinite three-dimensional framework constructed from tetranuclear [Cd4(trz)4]4+ subunits. Interestingly, the overall structure of both MOFs can be solely supported by ZnII/CdII and trz anions, and were further consolidated by the introduction of a flexible gt co-ligand. In addition, the carboxylate groups in the co-ligand can also serve as a weak O–H···O hydrogen-bond acceptor to capture guest water molecules. The synchronous weight-loss behaviour of trz and gt anions presented by thermogravometric curves suggest their cooperative contributions to the thermal stability of the MOFs. In contrast, the fluorescence emissions of two complexes are significantly dominated by the core trz ligand, rather than the gt co-ligand and metal ions.


2020 ◽  
Vol 5 (40) ◽  
pp. 12398-12406
Author(s):  
Jagannath Panda ◽  
Satya Narayan Sahu ◽  
Rasmirekha Pati ◽  
Prasanna Kumar Panda ◽  
Bankim Chandra Tripathy ◽  
...  

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