Browsing by Author "Adeniyi AG"

Now showing 1 - 3 of 3
  • Thumbnail Image
    Item
    Development and characterization of microstructural and mechanical properties of hybrid polystyrene composites filled with kaolin and expanded polyethylene powder
    (2022) Adeniyi AG; Abdulkareem SA; Emenike EC; Abdulkareem MT; Iwuozor KO; Amoloye MA; Ahmed II; Awokunle OE
    This study investigated the microstructural and mechanical properties of hybrid composites developed by the reinforcement of solvated polystyrene with expanded polyethylene powder and kaolin. The hybridized composites were synthesized using hand layup and cold mixing methods, and cured at room temperature for 3 days. The characterization was done using Fourier transform infrared spectroscopy (FTIR) and the scanning electron microscope coupled with energy dispersive spectroscopy (SEM-EDS), while the mechanical characteristics of the developed composites were evaluated by the Rockwell Hardness ASTM D785 standard. It was observed that an increase in kaolin content, at the expense of the polyethylene powder, increases the hardness strength of the composites, with the hardest composite (96.3 HRB) being obtained at a 25% kaolin mixer. The FTIR results revealed the presence of various functional groups, while the SEM analysis showed that the smoothness of the composite's surfaces increases with increase in kaolin content. The EDS analysis revealed the presence of several elements, mostly from the kaolin filler, suggesting the reason for its high density impacted on the kaolin/polyethylene filler composites. The importance of the study is the conversion of more than one solid waste into new and useful products.
  • Thumbnail Image
    Item
    Microwave exfoliation of a biochar obtained from updraft retort carbonization for supercapacitor fabrication
    (2022) Saliu OD; Adeniyi AG; Mamo M; Ndungu P; Ramontja J
    Biochar can offer a sustainable and renewable solution to energy storage problems. In this work, a biochar (which we refer to as an exfoliated biochar) with well-formed edge and basal planes was developed and characterized, and its electrochemical properties were tested. Using a three-electrode configuration for study purposes, the original specific capacitance (Csp) of 283 Fg−1 increased to 517 Fg−1 after exfoliation, with an energy density (Ed) of 258.5 WhKg−1, while retaining 95% of its capacity after 5000 cycles with an average charge time of 120 s. The CPE fitting of the EIS showed an ‘n’ value of 0.773, confirming diffusion-based charge storage and a very low ESR. In a two-electrode real world test using a PAT El-cell, a retention capacity of 96.5% was obtained, with a charge time of 210 s. In addition, Csp and Ed values of 493 Fg−1 and 246 WhKg−1 were obtained. The self-discharge profile showed a two-stage self discharge before exfoliation (0.75–0.2–0.08 A), and a one-stage stable self-discharge profile from 0.9 to 0.18 A after exfoliation, demonstrating the high stability of the biochar nanosheets after exfoliation. This work shows that nanosheet forms of biochars can generate a high energy density and offer a long cycle life with minimum self-discharge, making them suitable for supercapacitor applications.
  • Thumbnail Image
    Item
    Nanomaterial-based biosorbents: Adsorbent for efficient removal of selected organic pollutants from industrial wastewater
    (2022) Okoro HK; Pandey S; Ogunkunle CO; Ngila CJ; Zvinowanda C; Jimoh I; Lawal IA; Orosun MM; Adeniyi AG
    The contamination of the environment by organic pollutants is a major risk factor, particularly for developing countries. Selected organic pollutants (SOPs) like the phenolic compounds, polyaromatic hydrocarbons (PAHs), pesticides, and herbicides pose serious environmental and health issues owing to their toxic characteristics and poor degradability. Apart from their potential mutagenicity, carcinogenicity, tetragenicity and high body accumulation, these pollutants have become an increase concern worldwide. Biosorption is a promising alternative strategy for removing organic pollutants during water purification processes. Biosorbents have several advantages such as simplicity of operation, good sorption capacity, high recoverability and modifiability. As a result, the focus and novelty of this review is on recent trends in the use of biosorbents, with a particular emphasis on the removal of SOPs from wastewater. It also cover use of bacteria biosorbents, fungal, algae and chitosan/chitin biosorbents. Apart from that, we have also reviewed various classes of SOPs, their levels in the environment, classification and available characteristics techniques suitable for the adsorption experiments of these nanocomposites materials. In addition, we have provided comprehensive explanations and conclusions on possible future application of biosorbents and the mechanism of adsorption of these materials for removal of these SOPs from wastewater during water purification processes.