The variety of functionalities and porous structures inherent to metal-organic frameworks (MOFs) together with the facile tunability of their properties makes these materials suitable for a wide range of existing and emerging applications. Many of these applications are based on processes involving interaction of MOFs with guest molecules. To optimize a certain process or successfully design a new one, a thorough knowledge is required about the physicochemical characteristics of materials and the mechanisms of their interaction with guest molecules. To obtain such important information, various complementary analytical techniques are applied, among which vibrational spectroscopy (IR and Raman) plays an important role and is indispensable in many cases. In this review, we critically examine the reported applications of IR and Raman spectroscopies as powerful tools for initial characterization of MOF materials and for studying processes of their interaction with various gases. Both the advantages and the limitations of the technique are considered, and the cases where IR or Raman spectroscopy is preferable are highlighted. Peculiarities of MOFs interaction with specific gases and some inconsistent band assignments are also emphasized. Summarizing the broad analytical possibilities of the IR and Raman spectroscopies, we conclude that it can be applied in combinations with other techniques to explicitly establish the structure, properties, and reactivity of MOFs.

Power of Infrared and Raman Spectroscopies to Characterize Metal-Organic Frameworks and Investigate Their Interaction with Guest Molecules

Quantum chemical and experimental evaluation of the inhibitory action of two imidazole derivatives on mild steel corrosion in sulphuric acid medium

In this study, micron-sized hollow hexagonal prisms of SnO2 have been successfully synthesized based on a metal-organic framework material, Sn-MOF. The structure, morphology and gas sensing performance of prepared products were investigated by XRD, SEM, BET, XPS, TEM, Raman, FTIR and gas-sensing measurements. The experimental results show that metal oxides with high specific surface area can be obtained by calcining metal-organic framework materials. Specifically, a sensor based on hollow hexagonal prisms of SnO2 exhibited high response value (882) and short response time (19 s) to 2 ppm formaldehyde vapor at an optimal temperature of 120 ℃. This could be due to its larger specific surface area (46.42 m2/g).

High specific surface area SnO2 prepared by calcining Sn-MOFs and their formaldehyde-sensing characteristics

More effective antibiotics are needed to overcome the problem of multidrug resistance. The antibacterial efficacies of three Zn-based nano metal–organic frameworks (nMOFs) – IRMOF-3, MOF-5, and Zn-BTC – were explored, both alone and as mixtures with ampicillin and kanamycin. When tested against Escherichia coli, Staphylococcus aureus, Staphylococcus lentus, and Listeria monocytogenes, the nMOF/drug mixtures demonstrated synergistic (IRMOF-3/kanamycin) or additive (other nMOF/drug combinations) effects compared with the nMOFs or antibiotics alone. Zn-Based nMOFs can reduce the burden of the new discovery of antimicrobial pharmaceuticals by increasing the potency of existing antibiotics.

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Bioactive nano-metal-organic frameworks as antimicrobials against Gram-positive and Gram-negative bacteria.

CNTs/MOF-808 painted plates for extended treatment of pharmaceutical and agrochemical wastewaters in a novel photocatalytic reactor

FT-IR and FT-Raman spectra, normal coordinate analysis and ab initio computations of Trimesic acid.

NBO, HOMO, LUMO analysis and vibrational spectra (FTIR and FT Raman) of 1-Amino 4-methylpiperazine using ab initio HF and DFT methods.

Molecular structure, vibrational spectra (FTIR and FT Raman) and natural bond orbital analysis of 4-Aminomethylpiperidine: DFT study

Hydrothermal crystallization was used to synthesize an advanced hybrid system containing titania and molybdenum disulfide (with a TiO2:MoS2 molar ratio of 1:1). The way in which the conditions of hydrothermal treatment (180 °C/12 h) and thermal treatment (500 °C) affect the physicochemical properties of the products was determined. A physicochemical analysis of the fabricated materials included the determination of the microstructure and morphology (scanning and transmission electron microscopy—SEM and TEM), crystalline structure (X-ray diffraction method—XRD), chemical surface composition (energy dispersive X-ray spectroscopy—EDS) and parameters of the porous structure (low-temperature N2 sorption), as well as the chemical surface concentration (X-ray photoelectron spectroscopy—XPS). The MoS2@TiO2 electrode shows a high specific capacitance of 325 F g−1 at 2 A g−1 and after 5000 test cycles, 99.1% of the capacitance is retained indicating excellent cycle stability and good reversibility. Moreover, MoS2@TiO2//AC ASC presents a maximum energy density of 45.5 Wh/kg at power density of 730.7 W/kg and a high energy density of 20.8 Wh/kg is still retained even at high power density of 3700 W/kg. The presented results show an enhanced supercapacitor behavior of the MoS2@TiO2 electrodes prepared using a low-cost and simple scalable process and confirm their evident potential for energy storage/conversion applications. 

Design and Fabrication of High Performance Supercapacitor Based MoS2@TiO2 composite Electrode for Wide Range Temperature Applications

ABSTRACT Background: As more recent implant biomaterials, Zirconia ceramic and glass or carbon fibre reinforced PEEK composites have been introduced. In this study, bone stress and deformation caused by titanium, carbon fiber-reinforced polyetheretherketone (CFRPEEK), and zirconia ceramic implants were compared. Materials and Methods: In this in vitro finite element analysis study, a geometric model of mandibular molar replaced with implant supported crown was generated. The study used an implant that was 5 mm diameter and 11.5 length. Three implant assemblies made of CFR- polyetheretherketone (PEEK), zirconium, and titanium were created using finite element analysis (FEM). On the implant's long axis, 150 N loads were applied both vertically and obliquely. ANSYS Workbench 18.0 and finite element software were used to compare the Von Mises stresses and deformation produced with a significance level of P < 0.05. Results: With no discernible differences, all three implant assemblies that is CFR-PEEK, titanium, and zirconia demonstrated similar stresses and deformation in bone. Conclusion: It was determined that zirconia and PEEK and reinforced with carban fibres (CFR-PEEK) can be used as titanium-free implant biomaterial substitutes.

G. Mahalakshmi

Papers

FT-IR and FT-Raman spectra, normal coordinate analysis and ab initio computations of Trimesic acid.

NBO, HOMO, LUMO analysis and vibrational spectra (FTIR and FT Raman) of 1-Amino 4-methylpiperazine using ab initio HF and DFT methods.

Molecular structure, vibrational spectra (FTIR and FT Raman) and natural bond orbital analysis of 4-Aminomethylpiperidine: DFT study

Design and Fabrication of High Performance Supercapacitor Based MoS2@TiO2 composite Electrode for Wide Range Temperature Applications

Evaluation of stress and deformation in bone with titanium, CFR-PEEK and zirconia ceramic implants by finite element analysis