Emad Ali Soliman

In this study, novel proton exchange membranes (PEMs) based on a composite of sulfonated polyacrylonitrile (SPAN), sulfonated polyglycidyl methacrylate (SPGMA), or sulfonated poly(acrylonitrile-co-glycidyl methacrylate) (SP(AN-co-GMA))/polyvinyl chloride (PVC) were developed to be used for direct methanol fuel cells (DMFCs). After polymerization and sulfonation of the prepared polymers, the polyelectrolyte membranes were prepared by the casting and solvent evaporation technique for sulfonated homo- or co-polymers with polyvinyl chloride (PVC) composites. The resulting membranes were characterized by Fourier infrared and Raman spectral analyses, X-ray diffractometry, and scanning electron microscopy. The findings of this study reveal that both the thermal stability and ion exchange capacity of the composite membranes based on sulfonated copolymers were higher than that of their corresponding composites based on sulfonated homopolymers. In this context, the weight loss percentage of the prepared composite polyelectrolyte membranes did not exceed 12% of their initial weights. The IEC of all the composite membranes ranged from 0.18 to 0.48 meq/g. Thus, the IEC value increased with the increasing proportion of the glycidyl methacrylate comonomer. Moreover, the prepared PEMs based on SP(AN-co-GMA)/PVC composites showed lower methanol permeability (8.7 × 10⁻⁷ cm²/s) than that of the Nafion membranes (3.39 × 10⁻⁶ cm²/s). Therefore, these prepared PEMs are a good candidate for DMFCs applications.

In this study, chemically cross-linked PVA/PAMPS membranes have been prepared to be used in direct methanol fuel cells (DMFCs). The structural properties of the resultant membrane were characterized by use FTIR and SEM. Additionally, their thermal stability was assessed using TGA. Moreover, the mechanical properties and methanol and water uptake of membrane was studied. The obtained FTIR of PVA/PAMPS membranes revealed a noticeable increase in the intensity of adsorption peaks appearing at 1062 and 1220 cm⁻¹, which correspond to sulfonic groups with the increasing proportion of PAMPS. The thermograms of these polyelectrolyte membranes showed that their thermal stability was lower than that of PVA membrane, and total weight loss gradually decreased with increasing the PAMPS. Additionally, the functional properties and efficiency of these polyelectrolyte membranes were significantly improved with increasing PAMPS proportion in these blends. The IEC of polymer blend membrane prepared using PVA/PAMPS ratio of 1:1 was 2.64 meq/g. The same membrane recorded also a methanol permeability coefficient of 2.5 × 10⁻⁸ cm²/s and thus, its efficiency factor was 4 × 10⁵ greater than that previously reported for the commercial polyelectrolyte membrane, Nafion^® (2.6 × 10⁵). No significant increase in this efficiency factor was observed with a further amount of PAMPS. These results proved that the PVA:PAMPS ratio of 1:1 represents the optimum mass ratio to develop the cost-effective and efficient PVA/PAMPS blend membranes for DMFCs applications.

Global demand for non-conventional heavy and extra-heavy oil has been marginal until the end of twentieth century because of their composition complexity and high viscosity that cause many operational difficulties in the production with decline of their economic viability. However, growing energy demands in the beginning of the twenty-first century motivate many countries to handle such non-conventional resources. Heavy extra-heavy crudes usually have higher pour points due to high content of high molecular weight components, such as waxes, asphaltenes, and resins. The structural changes for these components cause abrupt rise in oil viscosity and simultaneous deposition of wax and asphaltene on the inner walls of pipelines. This can cause clogging of pipes accompanying oil flowability reduction with extra burden on the pumping system and consequently increases its power requirement and cost. This chapter presents technological challenges in transportation, describing the different mitigation strategies that have been developed to improve the low-temperature flow properties of heavy crude oils (heating, dilution, oil-in-water emulsion, and upgrading and core annular flow).

Immobilized Cu²⁺ ions affinity cellophane–poly(glycidyl methacrylate) (PGMA)‐grafted membranes have been prepared through three steps. The first step was introducing of epoxy groups to its chemical structure through grafting process with PGMA. Factors affecting the grafting process have been studied and grafting percentage (GP) up to 233% has been obtained. The second step was converting the introduced epoxy groups to sulfonic ones. It was found that maximum amount of sulfonic groups (2.7 mmol/g) was obtained with minimum GP (46.08%). The third and last step was the immobilization of Cu²⁺ ions into sulfonated grafted membranes obtained from the previous step. Maximum amount of immobilized Cu²⁺ ions was found to be 60.9 ppm per gram of polymer. The verification of the grafting and sulfonation steps has been performed through characterization of the obtained membranes using FTIR, TGA, and EDAX analysis. Finally, Cu²⁺‐immobilized membranes have been evaluated in separation of β‐galactosidase (β‐Gal) enzyme from its mixture with bovine serum albumin (BSA) in different pH medium. Maximum protein adsorption, for both proteins, has been obtained at pH range 4–4.5; as 90 and 45% for β‐Gal and BSA, respectively. The results showed high affinity toward β‐Gal separation although BSA concentration (0.5%) is 20‐folds of β‐Gal (0.025%). © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2009