Browsing by Author "Mufutau A. Salawu"

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    Characterizations of some discarded shells particles polymer-based composites for ceilings and particles board applications
    (Nigerian Society of Physical Sciences, 2023) Mufutau A. Salawu; Ibrahim K. Ayinla; Mashood A. Salahudeen; Joshua A. Adeoye; Peter T. Jegede; Sabastine C. Ezike; Oluwatoyin O. Olasanmi; Francis O. Omoniyi; Aderemi B. Alabi
    Sea-shells, periwinkle-shells, and snail-shells were pulverized into 35.5 µm particle sizes. Using a two-roll Rheomixer with a rotor speed of 60 rpm for 10 minutes, the particles were thoroughly mixed with the binders in ratio 2:1 and placed in the compression mold of dimension 15 cm by 3 cm by 3 cm using a force of 1.5 kN. The Rockwell hardness tester on scale B with a 1.56 mm steel ball, optical microscope and Flexural tester were used to characterize the composites. Thermo-gravimetric analyzer and Fourier Transform Infrared (FTIR) Spectrometer were used to characterize the shell particles. According to the results, epoxy resin (bisphenol-A-diglycidyl ether poly) and hardener (isophoromediamine) composites containing periwinkle shell particles had the highest hardness number of 48 and could withstand maximum flexural load of 5.5 MPa with a maximum flexural extension of 0.05 mm. The epoxy resin (bisphenol-A-diglycidyl ether poly) and hardener (isophoromediamine) proved to be the best epoxy resin. All the shell particleS functional groups were visible in the FTIR analysis with varying transmittances at their respective wavenumbers. Optical micrographs of the composites showed uniform distribution of the reinforcement and the matrix, thermo-gravimetric analyses demonstrated good thermal stability of the shell-particles up to 250 ◦C.
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    Investigation of the Effect of Deposition Time and Annealing on the Structural and Optical Properties of Chemically Deposited ZnS Thin Films
    (Deanship of Research & Graduate Studies, Yarmouk University, Irbid, Jordan, 2023) Oluwatoyin Osanyinlusi; Anthony I. Mukolu; Aderemi B. Alabi; Muyiwa M. Orosun; Mufutau A. Salawu; Kamaldeen A. Yusuf; Adebayo. A. Adeyinka
    The Chemical bath deposition (CBD) technique was successfully used to deposit ZnS thin films. The effects of deposition time and annealing on the structural and optical properties of the obtained thin films were investigated by X-ray diffraction (XRD), and UV-Vis spectrophotometer, respectively. The XRD pattern for the as-deposited ZnS thin films deposited for 30 min showed three peaks at 2θ values of 28.75o , 48.05o , and 56.47o corresponding to (111) (main peak), (220), and (311) reflection planes, indicating cubic structure. Comparing these peaks with that of the films prepared for 60 min, the latter have narrower widths, are more intense, sharper, and produce another weak peak at 2θ angle of 33.51o. Post-annealing treatment results in even more intense and sharper peaks, with their width narrowing further, causing an improvement in the crystallinity. The grains detected from the SEM micrograph are well-defined with spherical shapes of varying sizes. The grain shape changes after annealing due to coalescence of the grains. According to the EDX result, Zn and S were present in the prepared film. The as-deposited films showed a maximum transmittance of 82.1% at the visible region, which increased to 89.2% after annealing. The optical energy band gap was found to be in the ranges of 3.58 - 3.75 eV and 3.41 - 3.73 eV for the as-deposited and annealed films, respectively, signifying that the energy band gap decreases with annealing.