http://111.93.178.142:25000/jspui/handle/123456789/3017 2026-04-20T18:28:18Z 2026-04-20T18:28:18Z J.T. Pilusa, C.P. Mokgohloa L.E. Macevele http://111.93.178.142:25000/jspui/handle/123456789/3050 2026-04-15T12:14:58Z 2026-04-15T00:00:00Z

Title: Application of Chitosan-based Zirconia Hybrid Composite Functionalized with Multi-Walled Carbon Nanotubes for Efficient Removal of Humic Acid from Water Samples Authors: J.T. Pilusa, C.P. Mokgohloa; L.E. Macevele Abstract: Humic acid (HA) is abundant in soil and aquatic systems and can hinder wastewater treatment by affecting the removal of heavy metals and other contaminants. Herein, this study presents chitosan-zirconia (CTS-ZrO2) composites doped with functionalized multi-walled carbon nanotubes (f-MWCNTs) for HA adsorption. The composites were characterized using TGA, BET, EDX, XRD, FTIR and SEM. Batch experiments assessed the effects of pH (2-8), adsorbent dosage (1-5 g L-1), initial HA concentration (10-50 mg L-1), contact time (5-240 min), temperature (25-40 ºC), ionic strength, reusability and binary systems. The CT-ZrO2-f-MWCNTs composite exhibited a maximum adsorption capacity of 32.89 mg g-1 at pH 3, dosage of 2 g L-1, initial HA concentration of 10 mg L-1 and 25 ºC, achieving 99.04% removal within 30 min. The adsorbent remained effective after five cycles and isotherm studies indicated that adsorption followed the Langmuir Type II model, suggesting multilayer adsorption. Description: Vol38,No.1,p249

2026-04-15T00:00:00Z Kingsley Michieka http://111.93.178.142:25000/jspui/handle/123456789/3049 2026-04-15T12:09:12Z 2026-04-15T00:00:00Z

Title: Cationic Iron Half-Sandwich Complexes of Aminopyridines: Synthesis and Characterisation Authors: Kingsley Michieka Abstract: The reaction of [(η5 -C5H5)Fe(CO)2] + , with the aminopyridine ligands lead to formation of cationic organometallic complexes of the general formula [(η5 -C5H5)Fe(CO)2L]+ (where L = 2-Apy, 3-Apy, 4-Apy and Apy = aminopyridine). These ligands have the ability to coordinate to a metal center in monodentate fashion via the pyridine ring or amine nitrogen atoms, can form chelate complexes with one metal center or bridge two metal ions. Spectroscopic data (FTIR, 1H and 13C NMR and elemental analysis) collected for the five metal complexes is consistent with monodenate coordination mode through the pyridyl nitrogen in complexes 2, 3 and 4 atoms and amine nitrogen in complexes 1 and 4. Description: Vol37, No1,p243

2026-04-15T00:00:00Z Leila Amiri-Zirtol http://111.93.178.142:25000/jspui/handle/123456789/3048 2026-04-15T12:05:36Z 2026-04-15T00:00:00Z

Title: Fe3O4@SiO2@(CH2)3@4-(2-Aminoethyl)morpholine as a Reusable Magnetic Organocatalyst for Synthesis of Pyrano[3,2‑c]chromene Derivatives Along with Docking Study Authors: Leila Amiri-Zirtol Abstract: Pyrano[3,2-c]chromene derivatives, as an important category of heterocyclic compounds, have received much attention due to their various biological activities. Different synthetic methods using various catalysts have been reported for the synthesis of these compounds. Here, a green, magnetically separable catalyst functionalized with nitrogen-containing groups was used for the synthesis of a series of pyrano[3,2-c]chromene derivatives. The target compounds were synthesized by employing the catalytic activity of the previously synthesized composite under environmentally friendly and mild conditions. The reaction proceeded efficiently in a water/ethanol mixture within a short time and resulted in high product yields. A multicomponent reaction was used to synthesize pyrano[3,2-c]chromene derivatives from malononitrile, 4-hydroxycoumarin and various aldehydes. The purity of the final compounds was checked by melting point determination and comparison with literature values. Since pyrano[3,2-c]chromene derivatives are proposed as potential inhibitors of DNA topoisomerases, especially TOPII, in the second part of this study, a computational study was performed targeting the DNA-TOPII complex. The results revealed that some of the synthesized compounds are known to inhibit topoisomerases, supporting their role as promising anticancer agents. Description: Vol38, No.1,p234

2026-04-15T00:00:00Z N.D. Shooto, P.M. Thabede http://111.93.178.142:25000/jspui/handle/123456789/3047 2026-04-15T11:58:27Z 2026-04-15T00:00:00Z

Title: Adsorption of Ammonium Ions from Water using Activated Carbon Derived from Garlic Waste Authors: N.D. Shooto, P.M. Thabede Abstract: Water contaminated with ammonium (NH4 + ) is associated with many adverse effects on humans, aquatic organisms and the environment. The removal of NH4 + from aquatic sources is essential to support life. This study used modified garlic basal plate waste to remove NH4 + from polluted water. Garlic waste was carbonized at 450 ºC and chemically activated with NaOH and H3PO4. After activation, the samples were characterized using SEM, EDX, TEM, XRD, FTIR and Raman spectroscopy. The SEM images showed that the inner surface was exposed and was heterogeneous and, porous with cavities of different sizes and shapes. The elemental constituents of the materials are carbon (C), oxygen (O) and heteroatoms in trace amounts. FTIR analysis showed that the materials have many functional groups, such as –OH (3250 cm–1 ), –CH (2916 cm–1 ), –C=C and –NH2 groups (1658 cm–1 ), –OH (1425 cm–1 ) and –CO (1000 cm–1 ). Equilibrium studies indicated that the data fit the nonlinear Freundlich model, suggesting that the uptake represents multilayer adsorption due to different active sites on the adsorbent with unequal energy levels. The Freundlich constant (n) values were between 4.276 and 5.902, indicating that the uptake was favourable. The contact time effect showed three different phases of adsorption: a strong uptake, a steady state of adsorption and a plateau. The data for the contact time corresponded to the pseudo-second order kinetic model. The Hº values ranged from (-1.27 to -5.04 KJ/mol), indicating that the uptake was dominated by physical adsorption, but to some extent other mechanisms were partially involved in the uptake. The values of Sº and Gº were also negative, indicating that the adsorption was spontaneous and only partially random. The optimal conditions for the uptake of NH4 + using a working standard with an initial concentration of 100 mg/L were a solution pH of 10 and a temperature of 298 K. Under these conditions, the adsorption capacities for untreated carbon from garlic basal plate (CGBP), a Description: Vol38,No.1,p223

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