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We report the synthesis and crystal structures of three new copper(II) Schiff-base complexes. The complexes have been characterized by elemental analysis and Fourier transform infrared (FT-IR) and UV–visible spectroscopies. The X-ray diffraction (XRD) analysis reveals that complexes 1 and 3 crystallize in a monoclinic space group C2/c and 2 in a triclinic space group P1̅, each adopting a square planar geometry around the metal center. We use a density functional theory method to explore the quantum chemical properties of these complexes. The calculation proceeds with the three-dimensional (3D) crystal structure characterization of the complexes in which the calculated IR and UV–vis values are comparable to the experimental results. Charge distribution and molecular orbital analyses enabled quantum chemical property prediction of these complexes. We study the drug-likeness properties and binding potentials of the synthesized complexes. The in silico outcome showed that they could serve as permeability-glycoprotein (P-gp) and different cytochrome P450 substrates. Our calculations showed that the complexes significantly bind to cytochrome P450 3A4.
Tunde L. Yusuf; Segun D. Oladipo; Sizwe Zamisa; Hezekiel M. Kumalo; Isiaka A. Lawal; Monsurat M. Lawal; Nonhlangabezo Mabuba. Design of New Schiff-Base Copper(II) Complexes: Synthesis, Crystal Structures, DFT Study, and Binding Potency toward Cytochrome P450 3A4. ACS Omega 2021, 6, 13704 -13718.
AMA StyleTunde L. Yusuf, Segun D. Oladipo, Sizwe Zamisa, Hezekiel M. Kumalo, Isiaka A. Lawal, Monsurat M. Lawal, Nonhlangabezo Mabuba. Design of New Schiff-Base Copper(II) Complexes: Synthesis, Crystal Structures, DFT Study, and Binding Potency toward Cytochrome P450 3A4. ACS Omega. 2021; 6 (21):13704-13718.
Chicago/Turabian StyleTunde L. Yusuf; Segun D. Oladipo; Sizwe Zamisa; Hezekiel M. Kumalo; Isiaka A. Lawal; Monsurat M. Lawal; Nonhlangabezo Mabuba. 2021. "Design of New Schiff-Base Copper(II) Complexes: Synthesis, Crystal Structures, DFT Study, and Binding Potency toward Cytochrome P450 3A4." ACS Omega 6, no. 21: 13704-13718.
The application of gold as drug candidate dated back to 2500 BC and its relevance in medicine became more appealing following 1985 FDA approval of ingested Auranofin for the treatment of rheumatoid arthritis. In this study, we have provided a density functional theory (DFT) study of some gold(III)-dithiocarbamate complexes with characteristic anticancer potentials. DFT calculation of the reactivity and selectivity properties of these complexes with an enzyme template of thioredoxin reductase (TrxR) was carried out. The investigation proceeds with theoretical characterization of the selected compounds through spectroscopic analyses. IR and UV–vis analyses were carried out and the calculated values are comparable to experimental results. NMR assignment was determined for the gold compounds and the estimated theoretical chemical shift values agree with available experimental data from literature. The obtained DFT-based chemical parameters proved to be significant in evaluating the selectivity, reactivity and stability of the gold(III) complexes as potential anticancer moieties, specifically against TrxR. Calculated binding free energy gave similar order with the available in vitro inhibition profile of these gold(III)-dithiocarbamate complexes against TrxR. The outcome of this DFT study could serve as a useful guide towards future design of new and potent anticancer drug candidate. The investigated chemical reactivity properties could be considered and applied to a wide range of bioactive compounds and enzyme—inhibitor systems.
Monsurat M. Lawal; Isiaka Lawal; Michael J. Klink; Gideon Femi Tolufashe; Umar Ndagi; Hezekiel M. Kumalo. Density functional theory study of gold(III)-dithiocarbamate complexes with characteristic anticancer potentials. Journal of Inorganic Biochemistry 2020, 206, 111044 .
AMA StyleMonsurat M. Lawal, Isiaka Lawal, Michael J. Klink, Gideon Femi Tolufashe, Umar Ndagi, Hezekiel M. Kumalo. Density functional theory study of gold(III)-dithiocarbamate complexes with characteristic anticancer potentials. Journal of Inorganic Biochemistry. 2020; 206 ():111044.
Chicago/Turabian StyleMonsurat M. Lawal; Isiaka Lawal; Michael J. Klink; Gideon Femi Tolufashe; Umar Ndagi; Hezekiel M. Kumalo. 2020. "Density functional theory study of gold(III)-dithiocarbamate complexes with characteristic anticancer potentials." Journal of Inorganic Biochemistry 206, no. : 111044.
Sulfamethoxazole (SMZ), Carbamazepine (CBZ) and Ketoprofen (KET) adsorption using graphene-oxide (GO) functionalized ionic liquids (IL) was investigated. Ionic liquid 1-hexyl 3-decahexyl imidazolium was synthesized and characterized using high resolution-mass spectrometry (HR-MS) and nuclear magnetic resonance (1H and 13C NMR). GO and GO–IL were synthesized and characterized using thermal gravimetric analysis (TGA), X-ray diffraction (XRD), Raman, Fourier-transform infrared spectroscopy (FT-IR), scanning electron microscopy (SEM), surface area and porosity analysis and Zeta potential. Computational, isotherm, kinetics and regeneration studies were carried out to determine the adsorption capacity, adsorption mechanism and the reusability of the material for the adsorption of SMZ, CBZ and KET. Density functional theory (DFT) and ONIOM (QM/MM) approach were applied to describe the nature of the interaction, energetics, charge distribution and pH effect during the sorption of the pharmaceutical compounds on the adsorbents at the molecular level. Effects of solution pH, contact time, adsorbent dosage, and energetics on the selected pharmaceuticals were also investigated experimentally. pH plays significant role on the adsorption of SMZ and KET but has no significant effect on the adsorption of CBZ on both GO and GO–IL. Pseudo-second order and Langmuir best explained the kinetics and the adsorption isotherm, respectively. GO–IL showed superior adsorption efficiency for the selected pharmaceuticals when compared to the GO.
Isiaka Ayobamidele Lawal; Monsurat M. Lawal; Samson O. Akpotu; Hussein Kehinde Okoro; Michael Klink; Patrick Ndungu. Noncovalent Graphene Oxide Functionalized with Ionic Liquid: Theoretical, Isotherm, Kinetics, and Regeneration Studies on the Adsorption of Pharmaceuticals. Industrial & Engineering Chemistry Research 2020, 59, 4945 -4957.
AMA StyleIsiaka Ayobamidele Lawal, Monsurat M. Lawal, Samson O. Akpotu, Hussein Kehinde Okoro, Michael Klink, Patrick Ndungu. Noncovalent Graphene Oxide Functionalized with Ionic Liquid: Theoretical, Isotherm, Kinetics, and Regeneration Studies on the Adsorption of Pharmaceuticals. Industrial & Engineering Chemistry Research. 2020; 59 (11):4945-4957.
Chicago/Turabian StyleIsiaka Ayobamidele Lawal; Monsurat M. Lawal; Samson O. Akpotu; Hussein Kehinde Okoro; Michael Klink; Patrick Ndungu. 2020. "Noncovalent Graphene Oxide Functionalized with Ionic Liquid: Theoretical, Isotherm, Kinetics, and Regeneration Studies on the Adsorption of Pharmaceuticals." Industrial & Engineering Chemistry Research 59, no. 11: 4945-4957.
Water pollution by pharmaceuticals is a global issue and its remediation is important. To overcome this, we synthesised super hydrophobic nanoporous 3-dimensional ordered nanomaterials with multi-functional binding chemistry for highly efficient adsorption of estrogen (17β-estradiol). Graphene oxide (GO) was synthesised via Tours method and methoxylether polyethylene glycol (mPEG) was covalently introduced onto GO surface via facile amidation mild process to give GO-mPEG. GO-mPEG was anchored on nanoporous SBA-15 and homogenously reduced in-situ to SBA-rGO-mPEG. XRD analysis confirmed successful synthesis of SBA-15 and cross-linked GO/rGO-mPEG on SBA-15 surface. Image analysis revealed the architecture of SBA-15 as porous 3-dimensional silica network and presence of interwoven/crosslinked thin-films of GO-mPEG on SBA-15 surface. EDX mapping/elemental analysis showed expected elements were present. FTIR and textural analysis revealed the presence of different functional groups and high surface area as well as porosity, respectively. Optimal molar ratio experiments showed that 0.5SBA-rGO-mPEG had the highest sorption capacity. The relatively large surface area, 3-dimensional nanoprous silica structure and excess of polyamide/amido-carbonic functional groups on nanocomposites were suited for adsorption of 17β-estradiol. Equilibrium time was 30 min and effect of pH on adsorption was negligible. Sorption kinetic process of SBA-rGO-mPEG suited the pseudo-second-order model and equilibrium data fitted both Freundlich and Langmuir models. Qm values of 57.1, 78.5, 102.6 and 192.3 mg/g was recorded for SBA-GO, 0.1SBA-rGO-mPEG, 0.25SBA-rGO-mPEG and 0.5SBA-rGO-mPEG, respectively. H-bond, hydrophobic and π−π interactions were the sorption mechanism of SBA-rGO-mPEG after detailed analysis of data. Adsorbents was regenerated/re-used after 4 cycles with high remediation from environmental/real water samples.
Samson O. Akpotu; Isiaka Lawal; Brenda Moodley; Augustine E. Ofomaja. Covalently linked graphene oxide/reduced graphene oxide-methoxylether polyethylene glycol functionalised silica for scavenging of estrogen: Adsorption performance and mechanism. Chemosphere 2019, 246, 125729 .
AMA StyleSamson O. Akpotu, Isiaka Lawal, Brenda Moodley, Augustine E. Ofomaja. Covalently linked graphene oxide/reduced graphene oxide-methoxylether polyethylene glycol functionalised silica for scavenging of estrogen: Adsorption performance and mechanism. Chemosphere. 2019; 246 ():125729.
Chicago/Turabian StyleSamson O. Akpotu; Isiaka Lawal; Brenda Moodley; Augustine E. Ofomaja. 2019. "Covalently linked graphene oxide/reduced graphene oxide-methoxylether polyethylene glycol functionalised silica for scavenging of estrogen: Adsorption performance and mechanism." Chemosphere 246, no. : 125729.
Montmorillonite clay has a wide range of applications, one of which includes the binding of mycotoxins in foods and feeds through adsorption. T-2 toxin, produced by some Fusarium, Myrothecium, and Stachybotrys species, causes dystrophy in the brain, heart, and kidney. Various formulations that include lemongrass essential oil-modified montmorillonite clay (LGEO-MMT), lemongrass powder (LGP), montmorillonite clay washed with 1 mM NaCl (Na-MMT), montmorillonite clay (MMT), and lemongrass powder mixed with montmorillonite clay (LGP-MMT) were applied to maize at concentrations of 8% and 12% and stored for a period of one month at 30 °C. Unmodified montmorillonite clay and LGP served as the negative controls alongside untreated maize. Fourier Transform Infrared (FTIR) spectra of the various treatments showed the major functional groups as Si-O and -OH. All treatment formulations were effective in the decontamination of T-2 toxin in maize. Accordingly, it was revealed that the inclusion of Na-MMT in maize at a concentration of 8% was most effective in decontaminating T-2 toxin by 66% in maize followed by LGP-MMT at 12% inclusion level recording a 56% decontamination of T-2 toxin in maize (p = 0.05). Montmorillonite clay can be effectively modified with plant extracts for the decontamination of T-2 toxin.
Bunmi K. Olopade; Solomon U. Oranusi; Obinna C. Nwinyi; Isiaka A. Lawal; Sefater Gbashi; Patrick B. Njobeh. Decontamination of T-2 Toxin in Maize by Modified Montmorillonite Clay. Toxins 2019, 11, 616 .
AMA StyleBunmi K. Olopade, Solomon U. Oranusi, Obinna C. Nwinyi, Isiaka A. Lawal, Sefater Gbashi, Patrick B. Njobeh. Decontamination of T-2 Toxin in Maize by Modified Montmorillonite Clay. Toxins. 2019; 11 (11):616.
Chicago/Turabian StyleBunmi K. Olopade; Solomon U. Oranusi; Obinna C. Nwinyi; Isiaka A. Lawal; Sefater Gbashi; Patrick B. Njobeh. 2019. "Decontamination of T-2 Toxin in Maize by Modified Montmorillonite Clay." Toxins 11, no. 11: 616.
Waste from biomass was used to prepare a low–cost biochar–clay hybrid adsorbent. The hybrid adsorbent was synthesised by combining Kaolin with biomass (Vitex doniana), thereafter, modified with Deep Eutectic Solvent (DES). The materials were characterised using scanning electron microscopy (SEM), X-ray diffraction (XRD), Fourier transform infrared spectrometry (FTIR), Thermal gravimetric analysis (TGA), and Brunauer–Emmett–Teller (BET), also, pHpzc of the materials were studied. The resultant adsorbents were used for both column and batch adsorption of organic pollutants; dye (Acid Blue 74; AB74) and pharmaceuticals (ciprofloxacin; CIP and acetaminophen; ACTE). Column adsorption capacity, effect of pollutant concentration and effect of flow rate were studied, also, the column was modelled using Thomas, Yoon-Nelson and Adams-Bohart model. Furthermore, batch adsorption experiments were performed, effect of change in pH, time, dose and concentration were studied. Batch adsorption data were fitted with isotherm and kinetic models. The experiment showed tremendous increase in adsorption capacity when the hybrid adsorbent (HYD) was modified with DES (HYD–DES). Acid Blue 74 on HYD–DES has the highest column sorption capacity followed by ciprofloxacin and acetaminophen. Adsorption was favoured at pH range of 2–10 for both AB74 and ACTE as there is no significant changes in the % removal performance, while adsorption was best at pH 6 and above for CIP. AB74 and CIP are best described by Langmuir isotherm, whereas ACTE adsorption was best explained by Freundlich isotherm equilibrium. The DES modified HYD has shown it can be effectively utilised as possible adsorbent for adsorbing organic dyes and pharmaceuticals.
Isiaka A. Lawal; Michael Klink; Patrick Ndungu. Deep eutectic solvent as an efficient modifier of low-cost adsorbent for the removal of pharmaceuticals and dye. Environmental Research 2019, 179, 108837 .
AMA StyleIsiaka A. Lawal, Michael Klink, Patrick Ndungu. Deep eutectic solvent as an efficient modifier of low-cost adsorbent for the removal of pharmaceuticals and dye. Environmental Research. 2019; 179 ():108837.
Chicago/Turabian StyleIsiaka A. Lawal; Michael Klink; Patrick Ndungu. 2019. "Deep eutectic solvent as an efficient modifier of low-cost adsorbent for the removal of pharmaceuticals and dye." Environmental Research 179, no. : 108837.
The silver-zinc oxide (Ag-ZnO) polyamide thin film composite (PA-TFC) membrane was prepared by interfacial polymerization. The Ag-ZnO/PA-TFC membrane was characterized by attenuated total reflectance fourier-transform infrared spectroscopy (ATR-FTIR) for polyamide functional groups and contact angle for surface hydrophilicity. The Ag-ZnO/PA-TFC membrane was further characterized by Scanning Electron Microscopy (SEM) and Atomic Force Microscopy (AFM) for morphology and surface roughness, respectively. The performance of the fabricated membrane was investigated using pure water flux, permeability, rejection, flux recovery, and fouling resistance using low molecular weight organic pollutants, 2-chlorophenol (2-CP) and 2,4-dichlorophenol (2,4-DCP). The results were compared to the neat (PA-TFC) membrane. It was observed that incorporation of Ag-ZnO nanocomposites into the PA-TFC membrane improved hydrophilicity, permeation, rejection, and fouling resistance properties of the membrane. The contact angle decreased from 62.8° to 54° for PA-TFC and the Ag-ZnO/PA-TFC membrane, respectively. The presence of Ag-ZnO enhanced permeability of the membrane from 0.9 (Lm−2h−1bar−1) to 1.9 (Lm−2h−1bar−1). Modification of the membrane with Ag-ZnO further showed an enhanced rejection of 2-CP and 2,4-DCP from 43% to 80% and 58% to 85%, respectively. The 2,4-DCP molecules were rejected more than 2-CP due to enhanced repulsive forces from the extra Cl ion. A high flux recovery of about 95% was achieved for the modified membrane compared to 64% for the neat membrane. The improved flux recovery was an indication of enhanced antifouling propensity.
Kate Kotlhao; Isiaka Lawal; Richard Moutloali; Michael Klink. Antifouling Properties of Silver-Zinc Oxide Polyamide Thin Film Composite Membrane and Rejection of 2-Chlorophenol and 2,4-Dichlorophenol. Membranes 2019, 9, 96 .
AMA StyleKate Kotlhao, Isiaka Lawal, Richard Moutloali, Michael Klink. Antifouling Properties of Silver-Zinc Oxide Polyamide Thin Film Composite Membrane and Rejection of 2-Chlorophenol and 2,4-Dichlorophenol. Membranes. 2019; 9 (8):96.
Chicago/Turabian StyleKate Kotlhao; Isiaka Lawal; Richard Moutloali; Michael Klink. 2019. "Antifouling Properties of Silver-Zinc Oxide Polyamide Thin Film Composite Membrane and Rejection of 2-Chlorophenol and 2,4-Dichlorophenol." Membranes 9, no. 8: 96.
Montmorillonite clay due to its abundance and environmental friendliness has several industrial applications among which are the adsorption of mycotoxins in foods and feed. The mycotoxin; zearalenone (ZEA) is oestrogenic and has been implicated in hormonal and reproductive issues for both man and animals. Thus, nanoformulations from Montmorillonite clay and Cymbopogoncitratus (lemongrass) extracts were developed for the reduction of the toxin in millet. The various formulations include: Montmorillonite clay to which extract of Cymbopogoncitratus(lemon grass essential oil)has been incorporated (Mont-LGEO), Montmorillonite clay mixed with C. citratus(lemon grass)powder (Mont-LGP) and Montmorillonite clay washed with NaCl (Mont-Na). Pure Montmorillonite clay (Mont) and C. citratus (lemon grass) powder (LGP) served as the controls for the treatment. Each of these compositions were applied to millet samples at a concentration of 8 % and 12% and stored for 4 weeks. XRD patterns for compositions containing Montmorillonite clay revealed major peaks at 2-Theta value of 20.06° representing Montmorillonite and 26.56° and 68.53°representing quartz. The level of ZEA in all treated samples was quantified after 4 weeks using the Liquid Chromatography tandem mass spectrophotometer LC-MS/MS. All the compositions were effective in the decontamination of zearalenone. Furthermore, C. citratus powder was the most effective in the decontamination of zearalenone in the cereal after 4 weeks.
B. K Olopade; S. Oranusi; O. C. Nwinyi; P. B. Njobeh; Isiaka Lawal. Characterization of Nanoformulations from Montmorillonite clay for the decontamination of zearalenonein cereals using X-ray Diffraction Technique. Journal of Physics: Conference Series 2019, 1299, 012107 .
AMA StyleB. K Olopade, S. Oranusi, O. C. Nwinyi, P. B. Njobeh, Isiaka Lawal. Characterization of Nanoformulations from Montmorillonite clay for the decontamination of zearalenonein cereals using X-ray Diffraction Technique. Journal of Physics: Conference Series. 2019; 1299 (1):012107.
Chicago/Turabian StyleB. K Olopade; S. Oranusi; O. C. Nwinyi; P. B. Njobeh; Isiaka Lawal. 2019. "Characterization of Nanoformulations from Montmorillonite clay for the decontamination of zearalenonein cereals using X-ray Diffraction Technique." Journal of Physics: Conference Series 1299, no. 1: 012107.
The importance of improving adsorbent's adsorption efficiency in organic pollutants has been reported by many researchers. Surfactant-based modified adsorbents were a tasteful choice. As a result, the use of surfactants as a modifier for removing organic pollutants has shown to play a very big role in enhancing the adsorption efficiency of different materials. Ionic liquids are receiving extensive interest as green multipurpose compounds, primarily as a replacement for traditional chemicals that are used in many chemical processes. This work gives a brief bibliometric analysis of application of ionic liquid from 1930 to 2017, documents were collected from Scopus database and keywords from the abstracts and titles were analyzed using VOSviewer software. Furthermore, the work presents a review of conventionally known surfactants and the recent likelihood of ionic liquids for modifying adsorbents for adsorption of organic pollutants. Over the period of years between 1930 and 2017, 13,144 documents were published on the application of ionic liquids. VOSviewer software further confirms that adsorption is one of the leading areas in applications of ionic liquids. Review also showed that ionic liquid is a good modifier of adsorbents.
Isiaka A. Lawal; Michael Klink; Patrick Ndungu; Brenda Moodley. Brief bibliometric analysis of “ionic liquid” applications and its review as a substitute for common adsorbent modifier for the adsorption of organic pollutants. Environmental Research 2019, 175, 34 -51.
AMA StyleIsiaka A. Lawal, Michael Klink, Patrick Ndungu, Brenda Moodley. Brief bibliometric analysis of “ionic liquid” applications and its review as a substitute for common adsorbent modifier for the adsorption of organic pollutants. Environmental Research. 2019; 175 ():34-51.
Chicago/Turabian StyleIsiaka A. Lawal; Michael Klink; Patrick Ndungu; Brenda Moodley. 2019. "Brief bibliometric analysis of “ionic liquid” applications and its review as a substitute for common adsorbent modifier for the adsorption of organic pollutants." Environmental Research 175, no. : 34-51.
The removal of phenol and crystal violet dye using carbon nanotubes (CNTs) modified with deep eutectic solvent (DES) was investigated. DES (mixture of methyltriphenylphosphonium bromide and glycerol) was prepared and characterized by nuclear magnetic resonance (1H and 13C NMR). The DES was thereafter used to modify CNTs to form CNT–DES. The modified CNTs and CNTs only were characterized using FT–IR, scanning electron microscopy (SEM), and X-ray diffraction (XRD) and used in the adsorption study of phenol (PHE) and crystal violet dye (CRV). The effects of adsorbates concentration, solution pH and contact time were investigated in order to determine optimal experimental conditions. Adsorption data was better described by the pseudo-second-order kinetics and Freundlich isotherm for both CRV and PHE on CNTs and CNT–DES. Computational modelling was used to explain the possible adsorption interactions of CNT and CNT–DES with CRV and PHE, respectively. The modified moiety was better than CNT only for the adsorption of these compounds, which is in agreement with experimental outcome.
Isiaka Lawal; Monsurat M. Lawal; Mayowa A. Azeez; Patrick Ndungu. Theoretical and experimental adsorption studies of phenol and crystal violet dye on carbon nanotube functionalized with deep eutectic solvent. Journal of Molecular Liquids 2019, 288, 110895 .
AMA StyleIsiaka Lawal, Monsurat M. Lawal, Mayowa A. Azeez, Patrick Ndungu. Theoretical and experimental adsorption studies of phenol and crystal violet dye on carbon nanotube functionalized with deep eutectic solvent. Journal of Molecular Liquids. 2019; 288 ():110895.
Chicago/Turabian StyleIsiaka Lawal; Monsurat M. Lawal; Mayowa A. Azeez; Patrick Ndungu. 2019. "Theoretical and experimental adsorption studies of phenol and crystal violet dye on carbon nanotube functionalized with deep eutectic solvent." Journal of Molecular Liquids 288, no. : 110895.
Bunmi K. Olopade; Solomon U. Oranusi; Obinna C. Nwinyi; Patrick B. Njobeh; Isiaka A. Lawal. Modification of montmorillonite clay with Cymbopogon citratus for the decontamination of zearalenone in millet. AIMS Agriculture and Food 2019, 4, 643 -657.
AMA StyleBunmi K. Olopade, Solomon U. Oranusi, Obinna C. Nwinyi, Patrick B. Njobeh, Isiaka A. Lawal. Modification of montmorillonite clay with Cymbopogon citratus for the decontamination of zearalenone in millet. AIMS Agriculture and Food. 2019; 4 (3):643-657.
Chicago/Turabian StyleBunmi K. Olopade; Solomon U. Oranusi; Obinna C. Nwinyi; Patrick B. Njobeh; Isiaka A. Lawal. 2019. "Modification of montmorillonite clay with Cymbopogon citratus for the decontamination of zearalenone in millet." AIMS Agriculture and Food 4, no. 3: 643-657.
Serious concern has been raised over the use of organic compounds due to their adverse effects on the environment. Dyes which are part of these organic compounds have been reported to cause acute and chronic effect on both plants and animals. Therefore, this study aimed at investigating the mechanism of remediating dyes in an aqueous medium on deep eutectic solvent modified CNT/ZnCo2O4 hybrid nanostructure. A CNT/ZnCo2O4 hybrid nanostructure was synthesized. Deep eutectic solvent (DES) was also synthesized and used in the modification of CNT/ZnCo2O4. The DES modified CNT/ZnCo2O4 and unmodified CNT/ZnCo2O4 were characterized using Fourier-Transform Infrared Spectroscopy (FT-IR), X-Ray Diffraction (XRD) and Transmission Electron Microscopy (TEM). Thereafter, the modified and the unmodified were used for eosin Y dye adsorption. The investigation into the effects of adsorbate concentration, contact time and solution pH were done to determine experimental optimal conditions. Adsorption of eosin Y dye is favored at pH range 2-7. Sorption efficiency of DES modified CNT/ZnCo2O4 is far better than the unmodified CNT/ZnCo2O4. Adsorption data was better explained by the pseudo-second-order kinetics and Langmuir isotherm for eosin Y dye on both DES modified CNT/ZnCo2O4 and unmodified CNT/ZnCo2O4. Desorption experiment showed that DES modified CNT/ZnCo2O4 is reusable for at least five cycles. Therefore, DES modified CNT/ZnCo2O4 can be effectively used as potential adsorbents for the removal of organic dyes from wastewater.
Isiaka A. Lawal; Tarekegn Heliso Dolla; Karin Pruessner; Patrick Ndungu. Synthesis and characterization of deep eutectic solvent functionalized CNT/ZnCo2O4 nanostructure: Kinetics, isotherm and regenerative studies on Eosin Y adsorption. Journal of Environmental Chemical Engineering 2018, 7, 102877 .
AMA StyleIsiaka A. Lawal, Tarekegn Heliso Dolla, Karin Pruessner, Patrick Ndungu. Synthesis and characterization of deep eutectic solvent functionalized CNT/ZnCo2O4 nanostructure: Kinetics, isotherm and regenerative studies on Eosin Y adsorption. Journal of Environmental Chemical Engineering. 2018; 7 (1):102877.
Chicago/Turabian StyleIsiaka A. Lawal; Tarekegn Heliso Dolla; Karin Pruessner; Patrick Ndungu. 2018. "Synthesis and characterization of deep eutectic solvent functionalized CNT/ZnCo2O4 nanostructure: Kinetics, isotherm and regenerative studies on Eosin Y adsorption." Journal of Environmental Chemical Engineering 7, no. 1: 102877.
The adsorption of sulfamethoxazole (SMZ) and ketoprofen (KET) using carbon nanotubes (CNTs) and CNTs modified with ionic liquids (ILs) was investigated. Two ionic liquids (1-benzyl, 3-hexyl imidazolium, IL1 and 1-benzyl, 3-decahexyl imidazolium, IL2) were synthesized, and characterized by nuclear magnetic resonance (1H and 13C NMR) and high resolution-mass spectrometry (HR-MS). CNTs and modified CNTs were characterized using FT-IR, X-ray diffraction (XRD), surface area and porosity analysis, thermal gravimetric analysis (TGA), Zeta potential, Raman and scanning electron microscopy (SEM). Kinetics, isotherm and computational studies were carried out to determine the efficiency and adsorption mechanism of SMZ and KET on modified CNTs. A density functional theory (DFT) method was applied to shed more light on the interactions between the pharmaceutical compounds and the adsorbents at the molecular level. The effects of adsorbent dosage, concentration, solution pH, energetics and contact time of SMZ and KET on the adsorption process were investigated. The adsorption of SMZ and KET on CNTs and modified CNTs were pH dependent, and adsorption was best described by pseudo-second-order kinetics and the Freundlich adsorption isotherm. Ionic liquid modified CNTs showed improved adsorption capacities compared to the unmodified ones for both SMZ and KET, which is in line with the computational results showing performance order; CNT+KET/SMZ < CNT–ILs+SMZ < CNT–ILs+KET.
Isiaka A. Lawal; Monsurat M. Lawal; Samson O. Akpotu; Mayowa A. Azeez; Patrick Ndungu; Brenda Moodley. Theoretical and experimental adsorption studies of sulfamethoxazole and ketoprofen on synthesized ionic liquids modified CNTs. Ecotoxicology and Environmental Safety 2018, 161, 542 -552.
AMA StyleIsiaka A. Lawal, Monsurat M. Lawal, Samson O. Akpotu, Mayowa A. Azeez, Patrick Ndungu, Brenda Moodley. Theoretical and experimental adsorption studies of sulfamethoxazole and ketoprofen on synthesized ionic liquids modified CNTs. Ecotoxicology and Environmental Safety. 2018; 161 ():542-552.
Chicago/Turabian StyleIsiaka A. Lawal; Monsurat M. Lawal; Samson O. Akpotu; Mayowa A. Azeez; Patrick Ndungu; Brenda Moodley. 2018. "Theoretical and experimental adsorption studies of sulfamethoxazole and ketoprofen on synthesized ionic liquids modified CNTs." Ecotoxicology and Environmental Safety 161, no. : 542-552.
This study evaluates the batch and column adsorption of four pharmaceuticals, tetracycline (TC), sulfamethoxazole (SMZ), nalidixic acid (NAD) and chloramphenicol (CHL) on ionic liquid modified montmorillonite (Mt‒IL). 1-methyl, 3-decahexyl imidazolium ionic liquid modified montmorillonite was used in batch and column adsorption experiments. Investigation of the effects of variation in pH and contact time conducted, and the data were fitted into kinetics and isotherm models. All the pharmaceuticals investigated adsorbed maximally between pH range 3 and 10. The maximum adsorption capacities (qe) of TC, SMZ, NAD and CHL were 765.7, 504.1, 150.4 and 30.9 mg g-1, respectively, onto Mt‒IL in the batch studies. The equilibrium experimental data were best explained by Freundlich model. Pseudo-second-order kinetic model explained all the pharmaceuticals adsorbed onto Mt‒IL. While in column studies, the exchange zone depth, adsorption capacity, and the required time for the pharmaceuticals to move via the height of the adsorbent in the column and adsorption rates were investigated by Yoon-Nelson, Thomas and Adams-Bohart model. Column adsorption capacities at fixed rate of flow (5.0 mL min-1) and varying concentrations (50 – 200 mg L-1) ranges from 482 to 1501 mg g-1 for the pharmaceuticals studied.
Isiaka A. Lawal; Brenda Moodley. Fixed-Bed and Batch Adsorption of Pharmaceuticals from Aqueous Solutions on Ionic Liquid-Modified Montmorillonite. Chemical Engineering & Technology 2018, 41, 983 -993.
AMA StyleIsiaka A. Lawal, Brenda Moodley. Fixed-Bed and Batch Adsorption of Pharmaceuticals from Aqueous Solutions on Ionic Liquid-Modified Montmorillonite. Chemical Engineering & Technology. 2018; 41 (5):983-993.
Chicago/Turabian StyleIsiaka A. Lawal; Brenda Moodley. 2018. "Fixed-Bed and Batch Adsorption of Pharmaceuticals from Aqueous Solutions on Ionic Liquid-Modified Montmorillonite." Chemical Engineering & Technology 41, no. 5: 983-993.
Isiaka Lawal; Darren Chetty; Samson O. Akpotu; Brenda Moodley. Sorption of Congo red and reactive blue on biomass and activated carbon derived from biomass modified by ionic liquid. Environmental Nanotechnology, Monitoring & Management 2017, 8, 83 -91.
AMA StyleIsiaka Lawal, Darren Chetty, Samson O. Akpotu, Brenda Moodley. Sorption of Congo red and reactive blue on biomass and activated carbon derived from biomass modified by ionic liquid. Environmental Nanotechnology, Monitoring & Management. 2017; 8 ():83-91.
Chicago/Turabian StyleIsiaka Lawal; Darren Chetty; Samson O. Akpotu; Brenda Moodley. 2017. "Sorption of Congo red and reactive blue on biomass and activated carbon derived from biomass modified by ionic liquid." Environmental Nanotechnology, Monitoring & Management 8, no. : 83-91.
Isiaka A. Lawal; Brenda Moodley. Column, kinetic and isotherm studies of PAH (phenanthrene) and dye (acid red) on kaolin modified with 1-hexyl, 3-decahexyl imidazolium ionic liquid. Journal of Environmental Chemical Engineering 2016, 4, 2774 -2784.
AMA StyleIsiaka A. Lawal, Brenda Moodley. Column, kinetic and isotherm studies of PAH (phenanthrene) and dye (acid red) on kaolin modified with 1-hexyl, 3-decahexyl imidazolium ionic liquid. Journal of Environmental Chemical Engineering. 2016; 4 (3):2774-2784.
Chicago/Turabian StyleIsiaka A. Lawal; Brenda Moodley. 2016. "Column, kinetic and isotherm studies of PAH (phenanthrene) and dye (acid red) on kaolin modified with 1-hexyl, 3-decahexyl imidazolium ionic liquid." Journal of Environmental Chemical Engineering 4, no. 3: 2774-2784.
Isiaka A. Lawal; Brenda Moodley. Sorption mechansim of pharmaceuticals from aqueous medium on ionic liquid modified biomass. Journal of Chemical Technology & Biotechnology 2016, 92, 808 -818.
AMA StyleIsiaka A. Lawal, Brenda Moodley. Sorption mechansim of pharmaceuticals from aqueous medium on ionic liquid modified biomass. Journal of Chemical Technology & Biotechnology. 2016; 92 (4):808-818.
Chicago/Turabian StyleIsiaka A. Lawal; Brenda Moodley. 2016. "Sorption mechansim of pharmaceuticals from aqueous medium on ionic liquid modified biomass." Journal of Chemical Technology & Biotechnology 92, no. 4: 808-818.
The removal of amaranth dye using montmorillonite modified with an ionic liquid (IL) was investigated.
Isiaka A. Lawal; Brenda Moodley. Synthesis, characterisation and application of imidazolium based ionic liquid modified montmorillonite sorbents for the removal of amaranth dye. RSC Advances 2015, 5, 61913 -61924.
AMA StyleIsiaka A. Lawal, Brenda Moodley. Synthesis, characterisation and application of imidazolium based ionic liquid modified montmorillonite sorbents for the removal of amaranth dye. RSC Advances. 2015; 5 (76):61913-61924.
Chicago/Turabian StyleIsiaka A. Lawal; Brenda Moodley. 2015. "Synthesis, characterisation and application of imidazolium based ionic liquid modified montmorillonite sorbents for the removal of amaranth dye." RSC Advances 5, no. 76: 61913-61924.