No abstract

No abstract

No abstract

No abstract

Asphaltene aggregations of heavy crude oils provoke their destabilization and affect their viscosity significantly during their production, transportation, and refining. This problem was produced from phase separation and asphaltene particle growth. Recently, ionic liquids (ILs) have attracted more attention as a green solvent to solve these problems. In the present work, new ILs based on the imidazolium cation and organic salt anions such as oleate, abietate, and m-alkyl phenoxy were prepared at room temperature and characterized by nuclear magnetic resonance (NMR) and thermal analyses. These ILs were evaluated as asphaltene dispersants for Arabic heavy crude oil. The molecular interactions between the prepared ILs and asphaltenes were proven from zeta potential and asphaltene particle size variations. The effect of IL concentrations on asphaltene dispersion and viscosity values of crude oils is investigated at different temperatures. The ability of the prepared ILs to reduce the viscosity of the crude oil was investigated and arranged in the order of ILs that contained hydrophenancerene groups more than that contained alkyl groups or phenoxygroups as the anion.

In this study, an easy, rapid and eco-friendly method was used successfully to synthesize the magnetite nanoparticles (MNPs). In order to fine-tune the synthesized MNPs for the collection of heavy crude oil spills, the particles’ surface was modified with green hydrophobic biocomponents that were extracted from Anthemis pseudocotula (AP). The surface modified reaction carried with that of the MNPs in the presence of n-hexane extract (APH) resulted in the formation of APH-MNPs, while in the presence of chloroform extract (APC), resulted in APC-MNPs formation. The as-formed MNPs were thoroughly characterized using transmittance electron microscopy, X-ray powder diffraction, vibrating sample magnetometer and thermogravimetric analysis. The efficiency of the surface-modified MNPs for the collection of oil spills in the presence of an external magnetic field was evaluated by taking different ratios of MNPs:crude oil. From the analysis of the results, we found that the APH-MNPs particles have higher efficiency in the collection of heavy crude oil than the corresponding APC-MNPs.

Super adsorbent polymers can be considered to be a very efficient solution for wastewater treatment. In general, their adsorption capacities depend on the type and amount of the functional groups present on the surface of the polymers, while their economic value is affected by their cost. Therefore, this study aims to understand the effect of multi-functionalization of cheap Arabic gum on the adsorption capability toward heavy metals. Graft copolymers of polyacrylonitrile (PAN) onto Arabic gum (AG) were prepared in aqueous solution using (KMnO4/HNO3) as a redox initiator. Chemical modification of the graft copolymer was carried out by reaction with hydrazine hydrochloride followed by hydrolysis in the basic medium. The modified graft product was characterized by various techniques, such as Fourier transform infrared spectroscopy (FTIR), elemental analysis, scanning electron microscope (SEM), and X-ray powder diffraction (XRD). The modified graft copolymer was used to adsorb Pb2+, Cd2+ and Cu2+ from their aqueous solutions using batch extraction. Different parameters influence the uptake behavior, including contact time, pH, and the initial concentration of the metal ions; all of these were investigated. The kinetics were investigated using the pseudo first order and pseudo second order, and the equilibrium data were analyzed using the Langmuir and Freundlich model. The modified graft product showed the superadsorbent capacity to obtain maximum values (Qmax) 1017, 413 and 396 mg/g for Pb2+, Cd2+ and Cu2+, respectively. Acid treatment with 0.2 M HNO3 resulted in 96%, 99% and 99% metal recovery for the Pb2+, Cd2+ and Cu2+, respectively. This indicates the recyclability of product for further usage upon drying between treatments.

Silver nanoparticles (Ag NP) have been attracted much attention in recent years in biomedical applications due to their antimicrobial activity, but their drawbacks include toxicity and instability to aqueous hydrochloric acid solutions. Ag NPs have now been successfully prepared by a simple and "green" synthesis method by reducing Ag + ions in the presence of modified poly(vinyl alcohol) thiol (PVA-SH) in aqueous acidic solution. In this respect, Ag NPs were stabilized by coating different types of citrate-reduced Ag NPs with different weight ratios (1-3 Wt. %) of PVSH derivatives. The as-prepared Ag NPs were characterized using UV-Visible, high resolution transmission electron microscopy/ energy dispersive X-ray spectroscopy (TEM/EDS), dynamic light scattering (DLS) and X-ray powder diffraction (XRD) combined with Rietveld analysis. The changes in size, shape, and hydrodynamic diameter of Ag NPs after different duration exposure to synthetic stomach fluid (SSF) and1 M HCl were determined using TEM, XRD and UV-Visible analyses. The data indicated that these Ag NPs possessed high stability to SSF for more than 90 days, which was not previously reported in the literature.