Scholarly work in the Department of Indstrial Chemistry

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Browsing Scholarly work in the Department of Indstrial Chemistry by Author "Oyedeji Folashade Olatunbosun"

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    A green facile one-pot approach to the phytochemical assisted synthesis of 3-D Silicon(IV) oxide nanosheets using the aqueous leaf extract of Azadirachta indica (Neem)
    (Journal of Materials and Environmental Sciences, 2019) Bankole-Ojo Olufunso Samuel; Oyedeji Folashade Olatunbosun
    The present study reports on a green approach for the synthesis of silicon(IV) oxide (SiO2) nanoparticles from SiF62- complexes using phytochemicals from Azadirachta indica as capping and stabilizing agents. The Ultraviolet-Visible spectroscopic analysis indicated a broad peak at 380 nm which increased as reaction time increased. Fourier Transform Infrared analysis revealed the presence of Si-O-Si content, and the appearance of phytochemicals such as primary amine and alcohol groups as capping agents. X-ray Diffraction studies showed sharp peaks that confirmed that the nanoparticles were crystalline. Scanning Electron Microscopy analysis showed the formation of sheets of SiO2 nanoparticles arranged in a pattern with the sides facing up and sheet thickness ranging from 35 to 50 nm without any agglomeration among the particles. Energy dispersive X-ray analysis showed a 38 weight percentage of silicon content in the sample and a complete absence of fluorine and potassium which indicated a complete hydrolysis of the precursor.
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    Comparative evaluation of the antipsoriatic activity of Acalypha wilkesiana, Culcasia scandens with Kigelia africana using the mouse tail model
    (African Journal of Pure and Applied Chemistry, 2017) Bankole-Ojo Olufunso Samuel; Oyedeji Folashade Olatunbosun
    The mouse tail model was used to measure and compare antipsoriatic activity of Acalypha wilkesiana and Culcasia scandens with that of earlier reported Kigelia africana stem methanol extract by the same authors, with the objective of finding out which of these plant extracts can be a better drug option for the treatment of psoriasis. The results obtained showed that topically administered extracts (50-200 mg/ml) induced a significant and dose-dependent increase in %orthokeratosis in the epidermis of the mice tails. % orthokeratosis values were 35.5-43.4 (A. wikesiana), 29.7-47.4 (K. africana), 31.9-36.5 (C. scandens) for the methanol ointments; 29.3-36.2 (A. wikesiana), 32.3-58.2 (K. africana), 29.40-56.2 (C. scandens) for the hexane extracts. In general, the methanol extracts produced higher % othokeratosis. No deterioration in the general condition of the mice in any group was observed. However, erythema was observed on the tails of the mice on which the K. africana stem methanol extract ointment (200 mg/ml) was applied. No tail erythema was observed in any other group. Application of the ointments resulted in the softening of the tails. In general, the irritation potentials of the ointments were relatively low when compared to that induced bym dithranol a drug commonly used in the treatment of psoriasis. Only the A. wilkesiana methanol extract ointment (200 mg/ml) showed greater than 40% drug activity. Thus, A. wilkesiana appears to be the better plant for use in possible drug development for the management and cure of psoriasis because A. wilkesiana ointment showed more prospects of being an antipsoriatic topical agent when compared to C. scandens or K. africana, as the drug activity of the methanol extract of this plant was greater than 40% and quite similar to that of K. africana without the corresponding irritation potential or erythema.
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    Fluorescent carbon quantum dots from Phoenix Dactylifera fruit pulp for UV radiation protection
    (Journal of Applied Surfaces and Interfaces, 2022) Bankole-Ojo Olufunso Samuel; Oyedeji Folashade Olatunbosun
    Carbon quantum dots (CQDs) have attracted significant attention due to their wide range of applications. These include biosensing, bioimaging, wound healing and antibacterial applications. In this study, we examine the potential Ultraviolet (UV) radiation protection role of CQDs towards the development of viable sunscreens. The CQDs will serve as a less toxic and bio-compatible alternative to the more toxic sunscreen actives used in commercial products. Phoenix dactylifera (date) fruit pulp was used as a promising precursor for the synthesis of fluorescent CQDs. The effects of reaction temperature and reaction time on the mass yield, hydrodynamic size and zeta potential were evaluated. The morphology and surface groups were studied before and after dialysis. The optical properties of the CQDs were examined spectrophotometrically, and the sun protection factor was calculated to obtain an insight into whether the CQDs are suitable for use as filters for the development of new sunscreens. From the results obtained, considerable sun protection factor values were obtained at small CQDs concentrations. This potentiates their use for the development of viable and less toxic sunscreens.
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    pH-tuneable phyto-synthesized hierarchical Hausmannite nanostructures for rapid and efficient removal of methylene blue from aqueous solutions
    (Journal of Materials and Environmental Sciences, 2021) Bankole-Ojo Olufunso Samuel; Oyedeji Folashade Olatunbosun
    Hierarchical Mn3O4 nanostructures were successfully synthesized through a phytomediated route. Phytochemicals from the aqueous extract of Azadirachta indica acted as both capping and stabilizing agents during synthesis. An average crystallite size of 53.01±1.89 nm was obtained from XRD studies for hierarchical nanostructures. FESEM highlighted the effects of reaction pH on the morphology of the nanoparticles. Reaction pH values of 6, 8 and 10 resulted in rod-like nanoparticles while reaction pH 12 gave rise to hierarchical structures. The profiles of the degradation of methylene blue in the presence of H2O2 showed that the calcined nanoparticles performed better than assynthesized nanoparticles. Degradation ability of the nanoparticles generally increased with increasing reaction pH. Hierarchical nanoparticles exhibited superior degradation ability of 89% after 100 minutes. In principle, the hierarchical Mn3O4 nanostructures might be envisaged as efficient oxidants for the treatment of organic dye-containing wastewater under similar degradation conditions.
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    Salt spray resistance of superhydrophobic waterborne polyurethane/carbon dots nanocomposites
    (Journal of Materials and Environmental Science, 2022) Bankole-Ojo Olufunso Samuel; Oyedeji Folashade Olatunbosun; Raju K.V.S.N.; Ramanuj N.
    In this study, novel carbon quantum dots (cqds) has been synthesized through the thermal decomposition of the aqueous extract of Phoenix dactylifera fruit pulp. Silane functionalized carbon quantum dots (Scqds) were prepared through the attachment of silane derivatives from tridecafluorooctyltriethoxysilane to the surface of the cqds. Results obtained from FTIR spectroscopy, DLS and TGA studies reveal that silane compounds adhered to the cqds to give Scqds. Silane modification of the cqds changed the wettability from hydrophilicity to hydrophobicity from contact angle measurements. WPU/cqds and WPU/Scqds showed excellent thermal stability from TGA and DTA and exhibited hydrophilicity and superhydrophobicity respectively. Steel substrates coated with WPU/Scqds exhibited superior anti-corrosion properties when compared with steel substrates coated with WPU/cqds. Less than 5% corroded area was obtained for steel substrates coated with WPU/Scqds 0.2% and WPU/Scqds 0.25% after 96 hours when subjected to salt spray test. The intrinsic hydrophobicity of WPU/Scqds appear beneficial to inhibit the permeation of corrosive medium and consequently slow down the corrosion rate.
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    Superhydrophobic siloxane functionalized zirconia, stannia and ceria nanoparticles synthesized through a phyto-mediated route
    (Journal of Applied Surfaces and Interfaces, 2021) Bankole-Ojo Olufunso Samuel; Oyedeji Folashade Olatunbosun; Ramanuj N.
    The suitability of phyto-synthesized metal oxide nanoparticles for producing super-hydrophobic coatings for potential biomedical, agricultural and industrial applications was studied for the first time. ZrO2, CeO2 and SnO2 nanoparticles were synthesized through a green and facile method by using the aqueous leaf extract of the widely distributed Azadirachta indica as capping agent with over 60 % percentage mass yield. Organic groups acting as capping/stabilizing agents and siloxane attachments were identified using Fourier transform infra-red (FTIR). Tiny spherical ZrO2 nanoparticles, angular shaped CeO2 particles and a bed of tiny SnO2 particles with overall predominant particle sizes less than 15 nm were observed using field emission scanning electron microscope (FESEM). As expected, non-wettability of surfaces generally increased with increasing siloxane coupling of the nanoparticles. At a nanoparticle to fluoroalkylsilane mole ratio of 1:1, non-wettable, highly non-wettable and super-hydrophobic surfaces were obtained for CeO2, SnO2 and ZrO2 nanoparticles, respectively. The extent of initial phytochemical adsorption, size of the nanoparticles and extent of agglomeration are major factors that influence the coupling of fluoroalkylsilanes and consequently, the wettability of surfaces produced.
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    Synthesis of zinc oxide nanoparticles using Dieffenbachia seguine aqueous leaf extract for dye degradation
    (Maghrebian Journal of Pure and Applied Science, 2023) Bankole-Ojo Olufunso Samuel; Oyedeji Folashade Olatunbosun
    Dye pollution became a serious environmental and health challenge in many industrialized cities of the world. Natural dye degradation process takes a long time and thus, dye wastewater requires treatment before release into the environment. Zinc oxide (ZnO) nanoparticles were readily synthesized for photocatalytic dye degradation using phytochemicals from the leaves of Dieffenbachia seguine Linn. The phytochemicals present in the aqueous leaf extract of dumb cane or Dieffenbachia seguine (L) were used as reducing and stabilizing agents for the synthesis of ZnO nanoparticles (ZnONPs). The ZnONPs shows effective capping and stabilization by the phytochemicals as observed by the Fourier-Transform Infrared Spectroscopy. The particle size of the synthesized ZnONPs was studied using transmission electron microscopy. In this study, we used phytosynthesized ZnONPs for the degradation of Methylene Blue under UV Light. The ZnONPs photocatalyst showed excellent activity with over 95% of the dye degraded within 30 minutes. This highlights the strong potential of the ZnONPs as photocatalyst for the treatment of dye wastewater.