Mazen Khaled Nazal

Imidazolines containing single-, twin- and triple-tailed hydrophobes and hydrophilic pendants (CH2CH2NH)nH as inhibitors of mild steel corrosion in CO2–0.5 M NaCl

Inhibition of mild steel corrosion in CO2–0.5 M NaCl (40 °C, 1 atm; 120 °C, 10 bar) by a new series of imidazolines having single-, twin- and triple-tailed phenyl substituents at C(2) and N(1) pendants of CH2CH2NH2 and (CH2CH2NH)2CH2CH2NH2 have been examined. Imidazolines containing twin-tailed (3,5-dioctyloxyphenyl) hydrophobes outperformed their single- and triple-tailed counterparts as well as two commercial imidazolines. The triamine pendant imparted better inhibition at higher temperature and pressure. The XPS study confirmed the presence of an imidazoline film covering the metal surface. The imidazolines prefer to be adsorbed on the metal surface rather than micellization.

Synergistic effect of tri-n-butyl phosphate (TBP) or tri-n-octyl phosphine oxide (TOPO) with didodecylphosphoric acid (HDDPA) on extraction of uranium(VI) and thorium(IV) ions

Importance of removal of radioactive elements from wastewater was the motivation behind this work. Synergistic solvent extraction of U(VI) and Th(IV) ions from perchlorate solution using didodecylphosphoric acid (HDDPA) incorporated with tri-n-butyl phosphate (TBP) or tri-n-octylphosphine oxide (TOPO) as a synergists have been studied for the first time. The effects of HDDPA concentration, synergist’s concentration, pH values and temperature on the extraction process have been studied. The thermodynamic parameters of the extraction process for these ions were calculated. It was found that the synergistic contribution of TOPO is higher than TBP in the extraction of Th(IV) and U(VI).

Adsorption isotherms and kinetics for dibenzothiophene on activated carbon and carbon nanotube doped with nickel oxide nanoparticles

Activated carbon (AC) and multiwall carbon nanotubes (CNT) doped with 1, 5 and 10% Ni in the form of nickel oxide nanoparticles were prepared using the wetness impregnation method. These percentages were denoted by the endings NI1, NI5 and NI10 in the notations ACNI1, ACNI5, ACNI10 and CNTNI1, CNTNI5, CNTNIL10, respectively. The physicochemical properties for these adsorbents were characterized using N 2 adsorption–desorption surface area analyzer, thermal gravimetric analysis (TGA), scanning electron microscopy, energy-dispersive X-ray spectroscopy, field-emission transmission electron microscopy, X-ray diffraction and X-ray photoelectron spectrometre. Adsorption isotherms were obtained and desulphurization kinetics were carried out on solutions of dibenzothiophene (DBT) and thiophene in a model fuel. The efficiencies of DBT and thiophene removal were reported. The adsorption isotherms fitted the Langmuir and Freundlich models. The highest adsorption capacity for DBT was 74± 5 mg g−1 on ACNI5; the maximum adsorption capacities of the other adsorbents followed the trend ACNI1 > ACNI10 > AC > CNTNI5 > CNTNI1 > CNTNI10 > CNT. The adsorption rates for DBT and thiophene followed pseudo-second-order kinetics. The selective removal by these adsorbents of DBT relative to thiophene and naphthalene was evaluated. The adsorbents’ reusability and the effect of the percentage of aromatic compounds on their adsorption capacity were also reported.

Proton conducting blend membranes: physical, morphological and electronic properties

Blend membranes of sulfonated poly(ether ether ketone) (SPEEK) and sulfonated polyetherimide (SPEI) have been prepared and investigated as a potential polymer electrolyte membrane (PEM) for direct methanol fuel cell (DMFC). Polymers were dissolved in N-methyl-2-pyrrolidone (NMP) in different mixing ratios and membranes were casted using a semi-automatic casting machine on a pre-cleaned glass plate. The influence of SPEI percentage on ion exchange capacity (IEC), water uptake, methanol permeability and proton exchange capacity have been investigated. Blend membranes showed slightly better IEC, water uptake and methanol crossover properties as compare to pure SPEEK; but proton conductivity was slightly lower than that of pure SPEEK membrane. Membrane morphology was investigated by FESEM, TGA and AFM. Overall, a homogeneous surface was observed for most of the blend membranes, with minor phase separation at higher SPEI contents samples. AFM image of the membrane surface shows nanoscale surface roughness.

Synthesis of silver sulfide modified carbon materials for adsorptive removal of dibenzothiophene in n-hexane

ABSTRACT Carbon nanotube (CNT) and graphene oxide (GO) as common nanostructures were modified with silver sulfide (Ag2S) using chemical vapor deposition. The raw and modified materials were tested for the removal of Dibenzothiophene (DBT) from a model fuel in batch mode adsorption experiments. The maximum adsorption capacities of DBT were 52.18 and 49.65 mg g−1, using CNT-Ag2S and GO-Ag2S, respectively. The adsorption isotherm was modeled using Freundlich, Langmuir and Temkin models using linear and non-linear regression. The squared correlation coefficient (R2) and HYBRID error function were used to determine the best adsorption model. IR spectroscopy was used to study the DBT adsorption mechanism, and it was found that the DBT molecules lie flat on the surface of the developed adsorbents. Significant improvement was achieved in the adsorption of DBT using CNT-Ag2S and GO-Ag2S, where the maximum adsorption capacity increased by 127% and 117% respectively, which indicates a stronger interaction between DBT and the modified adsorbents.

Applications of Nanomaterials in Miniaturized Extraction Techniques

Abstract Nanomaterials have attracted great research activity in almost all areas of separation science due to their fascinating chemical and physical properties (e.g., size, surface area, mechanical and chemical stability, and magnetism). These materials have been widely adopted in sample preparation as a solid or stationary phase prior to chromatographic analysis. A growing trend has been observed in their applications in miniaturized extraction techniques because of their large surface areas, ease of functionalization, and excellent affinity towards certain classes of target analytes. In this chapter, we cover applications of nanomaterials in three famous miniaturized solid-phase extraction approaches, namely, porous membrane protected micro-solid-phase extraction, solid-phase microextraction, and dispersive solid-phase microextraction.

Preparation and Performance Evaluation of SPEEK/Polyaniline Composite Membrane for Direct Methanol Fuel Cell

Abstract Polymer composites comprising sulfonated poly(ether ether ketone) (SPEEK) and 10 to 50 wt% of Poly(trimellitic anhydride chloride-co-4,4′-methylenedianiline) (PTCMA) were prepared by solution casting. The effects of PTCMA concentrations on morphological, thermal and transport properties (water uptake, methanol permeability, ion exchange capacity and proton conductivity) were investigated. A morphological analysis revealed an homogenous dense microstructure for all the composites. Also, transport property tests revealed that the water uptake, methanol permeability and ion exchange capacity were enhanced by the addition of PTCMA whereas proton conductivity deteriorated. As shown by a thermogravimetric analysis, the difference between the thermal properties of the pure SPEEK and the composites was insignificant. Overall, the composites were observed to display a better global performance in terms of transport properties than pure SPEEK.