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31.
Manikandan Elayaperumal Kavitha Gnanasekaran Mathew K. Moodley Bonex Wakufwa Mwakikunga Ravinder Gaur Siva Umapathy Rasiah Ladchumananandasivam Malik Maaza 《Journal of Raman spectroscopy : JRS》2021,52(11):1838-1846
Nanocomposite materials coating opens up tremendous opportunities in the development of commercial products for household to industrial applications. In this present article, we are reporting the formation of 10-nm carbon (C) layer underneath the 6-nm ZnO epitaxial thin-film grown on simple quarts or Si(100) substrate by pulsed laser deposition. As-obtained nanocrystalline carbon layers between the Si(100) and ZnO and above ZnO epitaxial film were studied by micro-Raman, secondary ion mass (SIMS), and resonant Rutherford backscattering (RRBS) spectroscopic methods. The carbon diffusivity analysis revealed that the diffusion at nanoscale is governed predominantly by a nonlinear Fick's law rather than the Soret-Ludwig law. Quantum diffusion dominates the classical diffusion and carbon diffusivity into ZnO layer and was found to be ~7.8 × 10−12 cm2 s−1. This diffusion explains the doping profiles of ZnO layer up to its surface where carbon packing suggests presence of ultrananocrystalline-diamond-like-carbon (UN-DLC) thin films revealed by Raman spectroscopy. 相似文献
32.
Dilawar Hassan Ali Talha Khalil Amber Rehana Solangi Ahmed El‐Mallul Zabta Khan Shinwari Malik Maaza 《应用有机金属化学》2019,33(8)
We report an eco‐friendly synthesis of α‐Cr2O3 nanoparticles (NPs) using Callistemon viminalis (Bottle Brush) flower extracts as an efficient reducing and capping agent. NPs of sizes 15 nm and 17 nm were synthesized by annealing them at 400°C and 500°C, respectively, which were characterized by X‐ray diffraction, UV–Vis, Fourier transform‐infrared, high‐resolution‐transmission electron microscopy/scanning electron microscopy, SAED, energy‐dispersive X‐ray spectroscopy and SQUID. Microplate‐based assay was used for examining antibacterial potential against 12 pathogenic bacterial strains, and their minimum inhibitory concentrations were calculated. MTT cytotoxic assay was accomplished on Leishmania tropica amastigotes and promastigotes, which revealed IC50 values of 44 μg/ml and 10.56 μg/ml, respectively. An IC50 value of 46.32 μg/ml was obtained for HepG2 cancer cells. Enzyme inhibition studies indicated good acetylcholinesterase, moderate butyrylcholinesterase and low alpha‐glucosidase inhibition. Hemolytic assay indicated hemocompatibility at low concentration. In addition, good DPPH radical scavenging and moderate reducing power and total antioxidant potential was revealed by α‐Cr2O3 NPs. 相似文献
33.
A.K.F. Haque M. Ismail Hossain M. Alfaz Uddin M. Atiqur R. Patoary A. K. Basak M. Maaza 《Molecular physics》2017,115(5):566-578
ABSTRACTThe differential, integrated elastic, total and momentum transfer cross sections along with Sherman function for the elastic scattering of electrons and positrons by cadmium atoms have been evaluated from the partial wave solution of the Dirac relativistic scattering equations for a projectile-atom complex potential at the energy range 6.4 eV < E < 1.0 keV. For various scattering quantities, a comparison of our results exhibits better agreement with the experimental data than the other available theoretical values. 相似文献
34.
Synthesis and characterization of cobalt chloride/poly(ethylene oxide) electrospun hybrid nanofibers
Adurafimihan A. Abiona John A. Ajao Samuel Chigome Jean B. Kana Kana Gabriel A. Osinkolu Malik. Maaza 《Journal of Sol-Gel Science and Technology》2010,55(2):235-241
Cobalt chloride (CoCl2)/poly(ethylene oxide) (PEO) hybrid nanofibers with diameters ranging from 500 to 700 nm were successfully synthesized by a simple and versatile approach of electrospinning. The CoCl2/PEO hybrid nanofibers were studied by different techniques such as Scanning Electron Microscopy (SEM), Atomic Force Microscopy (AFM), Fourier Transform Infrared (FTIR) and Thermogravimetric Analysis (TGA). One dimensional (1-D) surface roughness average (Ra1-D) along a typical nanofiber was analyzed to be 57 nm. The chemical interactions between the CoCl2 and PEO molecules showed that polar environment provided by CoCl2 for the PEO molecules aided the modification of CoCl2 molecule configuration. 相似文献
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36.
Mahmudul H. Khandker Nazifa T. Arony A. K. F. Haque M. Maaza M. Masum Billah 《Molecular physics》2020,118(14)
The differential, integrated elastic, inelastic, total, momentum transfer, viscosity, and ionisation cross sections for electron and positron scattering from the homonuclear diatomic nitrogen molecule over an incident energy range of 1?eV–10?keV are calculated using the additivity rule. Dirac partial wave analysis is employed to calculate the cross sections of the constituent atoms of molecules, using a complex optical model potential (OPM). Comparison of our results of the additivity rule with the available experimental data and other theoretical predictions is presented. Our findings produce reasonable results in intermediate and high energies. 相似文献
37.
N. Mongwaketsi S. Khamlich B. Klumperman R. Sparrow M. Maaza 《Physica B: Condensed Matter》2012,407(10):1615-1619
Energy transfer and electron transfer events as they occur between well arranged light harvesting antenna molecules, the reaction center and other factors determine the function of natural photosynthesis. The overall small reorganization energy and the well-balanced electronic coupling between each component bear key characters for the unique efficiency of natural photosynthesis. Such aspects permit the design and assembly of artificial systems that efficiently process solar energy, replicating the natural processes. The rich and extensive transitions seen in porphyrin-based materials hold great expectation as light harvesting building blocks in the construction of molecular architectures, allowing an efficient use of the solar spectrum. Hence in this study porphyrin nanorods are synthesized and characterized for future application in the construction of the artificial light harvesting system. Understanding the sizes and growth mechanism of porphyrins nanorods by self-assembly and molecular recognition is essential for their successful implementation in nanodevices. Spectroscopic and microscopic studies were carried out to investigate the effect that time, concentration and solvents have on the fabrication of porphyrin nanorods by ionic self-assembly of two oppositely charged porphyrins. We investigate in details the heteroaggregate behavior formation of [H4TPPS4]2− and [SnTPyP]2+ mixture by means of the UV–vis spectroscopy and aggregates structure and morphology by transmission electron microscopy (TEM). This study demonstrates the potential for using different concentrations and solvents to influence the physical and optical properties of porphyrin based nanorods. 相似文献
38.
Solomon U. Offiah Mary O. Nwodo Assumpta C. Nwanya Sabestine C. Ezugwu Solomon N. Agbo Paulinus U. Ugwuoke Rose U. Osuji Maaza Malik Fabian I. Ezema 《Optik》2014
Room temperature deposition of PVP capped nanostructured NiO/Ni(OH)2 thin film, the morphological and optical characterizations by solution growth technique are reported. The nanostructured thin films which were deposited on optical glass substrates were annealed at different temperatures and then subjected to structural, morphological and optical characterizations. X-ray diffraction measurements of the films revealed that higher temperatures during the thermal treatment enhanced the crystallinity of the thin films. The SEM surface micrographs show non-interconnected uniformly deposited fibre-like structures with approximate lengths between 400 and 1200 nm. The optical band gap energy roughly decreased from about 2.7 eV to about 2.2 eV with thermal treatment. The absorbance of the thin films annealed at 300 and 400 °C was as high as 90% in the visible region of the electromagnetic spectrum. These materials could be useful in solar thermal conversion processes. 相似文献
39.
Samson O. Aisida Ishaq Ahmad Ting-kai Zhao Malik Maaza Fabian I. Ezema 《Journal of Macromolecular Science: Physics》2020,59(5):295-308
AbstractSpinel ferrite based nanoparticle material has been at the forefront of contemporary nanotechnology for use in various industrial and biomedical applications. The preparation and characterization of zinc ferrite nanoparticles (ZFNPs) doped with polyvinyl alcohol (PVA) are reported in this work. The formulated ZFNP/PVAs were characterized using powder X-ray diffraction (XRD), scanning electron microscopy (SEM), UV-visible spectroscopy, photoluminescence (PL) and a vibrating sample magnetometer (VSM). The XRD established the cubic spinel crystal structure of the as-prepared and calcined sample with an increase in the crystallite size after the calcination. The SEM analysis showed a spherical morphology within the range of 10-40?nm after calcination. The bandgap energy was enhanced after calcination. The PL analysis revealed a prominent peak in the UV band, which showed the characteristics of the formulated nanostructure. Transformation to a superparamagnetic nature was observed after calcination. It is noteworthy that after calcination of the formulated ZFNP/PVAs, the structural, optical, bandgap energy, morphology, photoluminescence and the magnetic properties were influenced and enhanced for various applications, chiefly for hyperthermia, magnetic resonance imaging, drug delivery and allied disciplines. 相似文献
40.
Ugochi K. Chime Agnes C. Nkele Sabastine Ezugwu Assumpta C. Nwanya N.M. Shinde Mesfin Kebede Paul M. Ejikeme M. Maaza Fabian I. Ezema 《Current Opinion in Electrochemistry》2020
In recent years, interest in nanostructured electrode materials for use in supercapacitors has been on the rise. Nickel oxide has been reported as a good candidate for supercapacitor applications due to its high theoretical capacitance and low cost. However, its poor electrical conductivity has resulted in actual poor specific capacitance and cycling ability. Over the years, researchers have studied various techniques to modify the structure and composition of NiO with the aim of improving its electrochemical performance. In this review, we opine that NiO-based electrodes can be fabricated using different approaches and different composite forms in order to obtain cells of high efficiency and specific capacitances. We discuss the recent advances in NiO-based electrodes fabricated using different approaches. 相似文献