In this study, manganese dioxide (MnO₂) nanoparticles (NPs) were synthesized via the hydrothermal method and utilized for the adsorption of Janus green dye (JG) from aqueous solutions. The effects of MnO₂ NPs on kinetics and diffusion were also analyzed. The synthesized NPs were characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD), energy-dispersive X-ray analysis (EDX), and Fourier-transform infrared spectroscopy (FT-IR), with XRD confirming the nanoparticle size of 6.23 nm. The adsorption kinetics were investigated using three models: pseudo-first-order (PFO), pseudo-second-order (PSO), and the intraparticle diffusion model. The PSO model provided the best fit (R² = 0.999), indicating that the adsorption process is chemical in nature. Kinetic analysis revealed that the MnO₂ surface exhibited faster adsorption kinetics during the film diffusion step (rate constant 0.2776) compared to intraparticle diffusion (0.0042) at 298.15 K. Thermodynamic parameters, including enthalpy change (∆H*), entropy change (∆S*), and Gibbs free energy change (∆G*) of activation, were calculated from the Eyring equation to be 37.48 kJ/mol and -144.69 J/mol, respectively. The positive ∆G* value (80.62 kJ/mol) suggests that the adsorption process is energy-intensive, requiring higher energy to form chemical bonds between JG and MnO₂ nanoparticles. KEY WORDS: Hydrothermal method, Janus green dye, Manganese dioxide nanoparticles, Kinetic behavior, Intraparticle diffusion model Bull. Chem. Soc. Ethiop. 2025, 39(8), 1509-1523. DOI: https://dx.doi.org/10.4314/bcse.v39i8.5
Polyvinal alcohol was Cynoethylated , complex compound with Iodin in presence of Cu++ ions were preparated and their ultra violet (U.V) and infra red( IR) spectra were investigated. The prepared derivative and complexes were evaluated as antibacterial and antifungal agents following the standard dilution method. MIC(minimum inhibitory concentration) for each polymer using ten types of gram + ve and gram _ ve bacteria were determinated in addition to three types of fungi. The results obtainded showed that MIC, s were around 0.0011 × 103 molar for different polymetric derivatives tried.
The purpose of this study was to develop poloxamer-based in-situ gel of chloramphenicol aiming to increase bioavailability and prolong corneal contact time, controlling drug release, and enhancing ocular bioavailability. The in-situ gel was prepared using different concentrations of poloxamer 407 combined with hydroxypropyl methyl cellulose (HPMC) or carbapol 940 to achieve gelation temperature about physiological temperature and improve rheological behavior and gelling properties of poloxamer gel. The prepared formulations were evaluated for their appearance, pH, and sol-gel transition temperature. The formulations F2, F3, and F5 have a gelation temperature within the accepted range 35-370C an
... Show Morethis work, a simple method was used to prepare the MnO2 nanoparticles. These nanoparticles then were characterized by several techniques, such as X-ray diffraction, Fourier transform infrared spectroscopy, scanning electron microscopy (SEM) and atomic force microscope (AFM). The results showed that the diffraction peak of MnO2 nanoparticles was similar to that of standard data. The images of AFM and SEM indicated that the MnO2 nanorods were growing from the MnO2 nano spherical shape. PVA-pentaerythritol/MnO2 nanocomposite films were fabricated by evaporating casting method. The dielectric constant and loss tangent of P-Ery/MnO2 films were measured between 10 kHz and 1 MHz using LCR. As the content of MnO2 increased, the dielectric constant
... Show MoreThe thermodynamic constanting of “crude and partially purified” Paraxonase(PON) was evaluated in the sera of “healthy and ectopic” pregnant women in order to characterize the reaction of PON with diethyl para-nitro phenyl phosphate as substrate.This study was performed on (17) women with ectopic pregnancy (EP) whose age between (25-55) years and (25) normal pregnant women with a mean age of (25 -55) years as a control group . Samples were collected from the Medical City, AL-Yarmook and Fatema AL-Zahraa hospitals during the period from Sep.2011 to April 2012.The study included the evaluation of “paraxonase activity, specific activity and total protein” in the (crude and partially purified) sera of EP pa
... Show MoreIn this research, a novel synthesis of CaONPs has been developed via an environmentally friendly, green method. Garlic extract (Allium sativum) was used as a green-reducing and stabilizing agent for CaONPs. The average particle size of CaONPs was approximately 24.42 nm. The synthesized CaONPs were identified by using Fourier transform infrared (FT-IR) spectroscopy, U.V.-vis spectrum, X-ray diffraction (XRD), Field Emission-Scanning Electron Microscopy (FE-SEM), Transmission Electron Microscopy, transmission electron microscopy (TEM), Energy Dispersive X-ray spectroscopy (EDX), Atomic Force Microscopy (AFM), and zeta potential (Zp) analysis. The current study highlights the notable applications for CaONPs. First, an antimicrobial assay revea
... Show MoreDuring the last few years, the greener additives prepared from bio-raw materials with low-cost and multifunctional applications have attracted considerable attention in the field of lubricant industry. In the present work, copolymers derived from sunflower and linseed oils with decyl methacrylate were synthesized by a thermal method using benzoyl peroxide (BPO) as a radical initiator. Direct polymerization of fatty acid double bonds in the presence of a free radical initiator results in the development of environmentally friendly copolymeric additives (Co-1 and Co-2). Fourier Transform Infrared (FTIR) and Proton Nuclear Magnetic Resonance (1H-NMR) were used to characterize the resulting copolymers. Thermal decomposition of copolymers was de
... Show More