Browsing by Author "Srikanta Moharana"

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Enhanced dielectric and electrical properties of polystyrene-2% divinyl benzene (PDB) embedded in SrTiO3-Poly (vinylidene fluoride) three phase composite films
(Elsevier GmbH, 2022) N.P. Yadav; Bibhuti B. Sahu; Tarun Yadav; Rajneesh Kumar; Amit Pathak; G.N. Pandey; Srikanta Moharana
A facile solution casting technique has been employed to fabricate ceramic SrTiO3; STO particle and polystyrene-2% divinyl benzene (PDB) filled three phase composite films using poly(vinylidene fluoride) (PVDF) matrix. The frequency dependence of dielectric and electrical properties of the three phase PVDF-STO-PDB composite films of various weight percentage of PDB (fPDB) were analyzed. With the small change in the AC conductivity and dielectric loss the dielectric constant of the PVDF-STO-PDB composite systems is improved noticeably. The experimental results suggested that, the introduction of 10 wt% of PDB particles in the PVDF-STO composites enhanced the dielectric constant (≈76) and suppressed dielectric loss value (< 0.5) at 100 Hz. This may be attributed to the addition of PDB particles improved the establishment of polarization. The morphological analysis depicts that the PDB particles are uniformly dispersed and well compatibility between filler particles and polymer matrix which may be ascribed to the minimization of dielectric loss of the resultant composites. Further, the strong interaction between PDB particles and PVDF matrix at the interface is the crucial factor in the improvement of the dielectric and electrical properties. The percolation theory was used to elucidate the dielectric and electrical performance of PVDF-STO-PDB composites. It is noticed that the three phase PVDF-STO-PDB composite films exhibited an insulator-conductor transition with percolation threshold of fPDB = 5 wt%. The three phase composites with high dielectric constant (≈76) at percolation threshold might be helpful to understand the influence of PDB particles on the interfaces between the ceramics and polymer matrix. This work will provide an easy and effective solution to fabricate high performance three phase composites to the development of high energy storage applications. © 2022 Elsevier GmbH
Enhanced dielectric and electrical properties of tri-phase percolative PVDF–BiFeO3–Carbon Black (CB) composite film
(Springer, 2021) Srikanta Moharana; Tarun Yadav; Parvez Ahmad Alvi; Amit Pathak; R.N. Mahaling
A tri-phase polymer composite film with a multiferroic phase (BiFeO3) and conductive carbon black (CB) deposited on the BiFeO3 (BF) and poly(vinylidene fluoride) (PVDF) matrix were prepared by using a solution casting technique. The dielectric and electrical performance of BF–PVDF composites with various weight percentages of CB content was studied. It has been observed that the incorporation of high loading of CB to the BF–PVDF composite system led to a significant improvement in the dielectric constant with suppressed dielectric loss (< 0.5). The high dielectric constant of 69 at 100 Hz, which is 11 times greater than that of neat PVDF film with a lower dielectric loss of 0.41, is obtained for PVDF–BF–CB composites as CB content (8 wt%) approached the percolation threshold. Furthermore, the improvement of dielectric and electrical performance of the PVDF–BF–CB composites may be due to the synergistic effect of the multiferroic phase BF and conductive phase CB as a result of homogeneous dispersion within the polymer matrix. These high dielectric constant and suppressed dielectric loss PVDF–BF–CB composites might be suitable for potential applications in the field of future thin-film capacitors. © 2021, The Author(s), under exclusive licence to Springer Science+Business Media, LLC part of Springer Nature.
Functional Materials from Used PPEs for Energy Harvesting Applications and their Recycling
(Springer Nature, 2024) Srikanta Moharana; Bibhuti B. Sahu; Krishna Kumar; Alekha Kumar Sutar; Tungabidya Maharana
Coronavirus disease (COVID-19) is a widely spreading ailment through an upsurge in the number of cases and deaths around the globe after the first positive case was detected in the city of Wuhan, China in the year 2019 in the last month. The biosphere has been confronted with the utmost problematic epidemic of the contemporary age, that of severe acute respiratory syndrome coronavirus contamination, which caused coronavirus ailment and affects over 3.5 crore people worldwide. In the battle against COVID-19 disruptions, preventive and mitigating measures are crucial. Personal Protective Equipment (PPEs) are an important effective measure against infection. PPEs are pieces of equipment or clothes that a person wears to protect themselves against infectious illnesses. The broad use of material improvements that improve performance and provide adaptable new capabilities has marked a significant change in PPE development. A major shift in PPE development has been the widespread use of material advancements, which enhance performance to provide new capabilities in terms of flexibility and more protectiveness. There are several PPEs that have been extensively developed with the incorporation of functional materials (Graphene Oxide, Carbon nanotubes, TiO2, and Ag Nanoparticles) and polymers including polypropylene, polycarbonate, and poly(ethylene terephthalate), which are providing excellent protection. These functional materials can be of immense use in the domain of energy harvesting and stowage of energy applications obtained from the used PPEs. This typical chapter provides an overview of PPEs, the enhancement of PPEs performance by using functional materials, and the applicability of functional materials from used PPEs in the field of energy storage & harvesting followed by recycling challenges of PPEs. © The Author(s), under exclusive license to Springer Nature Singapore Pte Ltd. 2024.
Indium(III) and organotin(IV) 2-(methoxycarbonyl)benzenethiolates: Synthesis, structure and properties
(Elsevier B.V., 2022) Krishna Kumar; Priyanka Tiwari; Srikanta Moharana; Rajni Kant; Subrato Bhattacharya
Two compounds In(mts)3, 1 and triphenyltin(mts), 2 [where mts = 2-(methoxycarbonyl) ben- zenethiolate] were synthesized and characterized. Both the compounds crystallize in the monoclinic system; 1 with space group P21/c and 2 with space group P21/n. Molecule 1 has a distorted trigonal bipyramidal geometry around the In(III) center. In the case of 1, out of the three mts ligands, two bind (S and O) bidentately while the third one binds mainly through its S atom, whereas 2 has a tetrahedral geometry around Sn(IV) center in which the mts ligand is bonded through its S atom only. Hirshfeld analyses were carried out to understand the nature of weak interactions responsible for the deviation from the ideal geometry of both compounds. Quantum chemical calculations were carried out at the DFT level using B3LYP functional in order to get the optimized geometry and vibrational frequencies. Natural bond orbital analyses (NBO) were performed to explore hyper-conjugative interaction energies, HOMO-LUMO, and various inter and intramolecular transitions. The thermodynamic profiles and electrostatic potential surfaces of the compounds have been investigated. Bulk properties such as dielectric loss/constant and AC conductivities have also been explored. © 2022 Elsevier B.V.
Molecular geometries, vibrational spectra and electronic properties of biphenyl nematic liquid crystals: a quantum chemical analysis
(Taylor and Francis Ltd., 2023) Nagendra Prasad Yadav; Anil Kumar Vishwkarma; Ajit Kumar Maddheshiya; Tarun Yadav; Srikanta Moharana; Rajneesh Kumar; Amit Pathak; Pankaj Kumar Tripathi
The present work reports the vibrational spectroscopic signature, thermodynamics, and natural bond orbital analysis (NBO) of 4-Cyano-4-pentylbiphenyl (5CB) and 4-Cyano-4'-hexyl diphenyl (6CB) liquid crystals. The optimization of both compounds (5CB and 6CB) has been performed at DFT/B3LYP/6-31++G(d, p) level of theory. Most of the vibrational modes have wavenumbers in the expected range. The comparison of vibrational frequencies of both compounds has been made. Subsequently, the different thermodynamical parameters and electronic properties have been calculated and discussed in detail. The NBO analysis has been performed to check the stability of the electronic structures. The UV visible, HOMO- LUMO, MEP, and charge analysis has been performed. Moreover, the strong electronic transition from HOMO to LUMO (97% of MO contribution) has been predicted for 5CB and 6CB at 289 nm with oscillator strengths of 0.7242 and 0.7286, respectively. The MEP plots of both 5CB and 6CB are almost the same and show that strong electrophilic substitution would take place near the N atom attached to the CN group. The energy gap of 5CB and 6CB compounds is found to be 4.65eV. Molecules with large energy gaps are less polarizable and are termed as hard molecules, having low chemical reactivity and high kinetic stability. © 2023 Informa UK Limited, trading as Taylor & Francis Group.
Nickel(II) carbothioate complex incorporated graphene oxide-polyvinylidene fluoride ternary composite film: Preparation, structural features, dielectric, and electrical characteristics
(Springer, 2023) Krishna Kumar; Srikanta Moharana; Akash Shrivastav; Subrato Bhattacharya
Graphene oxide-based materials are well known for their electrical properties. Novel ternary composite films (PVDF-GO-FK-31) were prepared by introducing a metal complex, for the first time, in a graphene oxide-PVDF polymer matrix (where PVDF = polyvinylidene fluoride; GO = graphene oxide; FK-31 = [Ni(PPh3)2(SCOf)2] (SCOf = furan-2-thiocarboxylate). In these composites, the graphene oxides show strong interfacial bonding with the PVDF matrix due to the incorporation of the FK-31 molecules. The experimental results showed that the incorporation of FK-31 into the PVDF-GO matrix greatly improved the dielectric constant and suppressed dielectric loss values. The composites thus may be used as dielectric materials for electronic capacitors. Graphical Abstract: For the first time, a ternary composite was prepared by incorporating a newly synthesized square planar nickel(II) complex in a graphene oxide-PVDF polymer matrix and its dielectric and electric properties were studied. With increasing concentration of the complex in the ternary composite its dielectric constant and electrical conductivity increases while the dielectric loss decreases.[Figure not available: see fulltext.]. © 2023, Indian Academy of Sciences.
Perovskite Metal Oxides: Synthesis, Properties, and Applications
(Elsevier, 2023) Srikanta Moharana; Tanmaya Badapanda; Santosh Kumar Satpathy; Ram Naresh Mahaling; Rajneesh Kumar
Perovskite Metal Oxides: Synthesis, Properties and Applications provides an overview on the topic, including the synthesis of various types of perovskites, their properties, characterization and application. The book reviews the applications of this category of materials for photovoltaics, electronics, biomedical, fuel cell, photocatalyst, sensor, energy storage and catalysis, along with processing techniques of perovskite metal oxides with a focus on low-cost and high-efficiency methods, including various properties and probable applications in academia and industry. Other sections discuss strategies to improve the functionality of perovskite metal oxide materials, including chemical methods and controlling the size, shape and structure of the materials. Finally, applications of perovskite metal oxides in energy conversion and storage, sensing and electronics are covered. © 2023 Elsevier Inc. All rights reserved.
Superior dielectric and electrical characteristics of poly(methylmethacrylate) (PMMA)-BiFeO3-Polystyrene-2% divinyl benzene (PDB) composites
(Elsevier GmbH, 2023) N.P. Yadav; Bibhuti B. Sahu; R.N. Mahaling; Tarun Yadav; Pankaj K. Tripathi; Srikanta Moharana
An extraordinarily high dielectric constant and low dielectric loss PMMA-BFO-PDB composite material was developed by mixing poly(methylmethacrylate) (PMMA) as the polymer matrix, bismuth ferrite (BFO), and polystyrene 2% divinyl benzene (PDB) as fillers using the solution casting process. The surface morphology analysis demonstrations the PDB particle uniformly dispersed in the PMMA matrix. The frequency dependent dielectric and electrical characteristics of the PMMA-BFO-PDB composite films on various weight percentages of PDB contents and wide range of frequency at room temperature were investigated. It is observed that the maximum dielectric constant of the PMMA-BFO-PDB composites was achieved around ≈ 108 and similarly dielectric loss factor of just about ≈ 1 for 20 wt% of PDB contents at 102 Hz. In addition, the PMMA-BFO-PDB composite achieved a dielectric constant of 108 at 102 Hz, which is 21 times higher than that of the pure PMMA matrix. PMMA-BFO-PDB composite films may be used as a high performance dielectric in future energy storage devices, such as high storage capacitors. © 2023 Elsevier GmbH