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.

κ-carrageenan is useful for its superior gelling, hydrogel, and thickening properties. The purpose of the study was to maximize the hydrogel properties and water-absorbing capacity of κ-carrageenan by blending it with starch from potato peels to be used as safe and biodegradable water-absorbent children’s toys. The prepared materials were analyzed using FTIR and Raman spectroscopy to analyze the functional groups. Results showed that there was a shift in the characteristic peaks of starch and κ-carrageenan, which indicated their proper reaction during blend formation. In addition, samples show a peak at 1220 cm⁻¹ corresponding to the ester sulfate groups, and at 1670 cm⁻¹ due to the carbonyl group contained in D-galactose. SEM micrographs showed the presence of rough surface topology after blending the two polymers, with the appearance of small pores. In addition, the presence of surface cracks indicates the biodegradability of the prepared membranes that would result after enzymatic treatment. These results are supported by surface roughness results that show the surface of the κ-carrageenan/starch membranes became rougher after enzymatic treatment. The hydrophilicity of the prepared membranes was evaluated from contact angle (CA) measurements and the swelling ratio. The swelling ratio of the prepared membranes increased gradually as the starch ratio increased, reaching 150%, while the water-uptake capacity increased from 48 ± 4% for plain κ-carrageenan to 150 ± 5% for 1:2 κ-carrageenan/starch blends. The amylase enzyme showed an effective ability to degrade both the plain κ-carrageenan and κ-carrageenan/starch membranes, and release glucose units for up to 236 and 563, respectively. According to these results, these blends could be effectively used in making safe and biodegradable molded toys with superior water-absorbing capabilities.

Bioethanol-derived biomass is a green sustainable source of energy that is highly recommended as an efficient alternative to the replacement of fossil fuels. However, this type of bioethanol production is always expensive with very low bioethanol concentration. Therefore, this work aims to represent a facile and green approach for bioethanol production with high concentration and purity as well as reasonable cost from corn stover (CS). The goal of this study is to characterize CS and its treated samples with maleic acid (CSM) using various characterization analyses, such as proximate and ultimate analysis, HHV, TGA, FTIR, SEM, and CHNS. The bioethanol production stages: Pretreatment, enzymatic degradation, fermentation, and finally bioethanol separation and purification via the pervaporation process, which have been investigated and optimized are associated with the economic analysis. The optimum operating condition of the pretreatment process was 2% maleic acid, 1:20 solid-to-liquid ratio at 45 psi, 120 °C, and 1 h of operation in the autoclave. This process contributes to 53 and 45% lignin and hemicellulose removal, 98% cellulose recovery, and a glucose yield of 741 mg/dL. The yeast isolate succeeded in the production of 1230 mg/dL of bioethanol. This isolated yeast strain was close to Pichia nakasei with a similarity of 98%, and its amplified 18S rRNA gene sequence was deposited in GenBank with the accession number MZ675535. Poly (MMA-co-MA) membrane was synthesized, characterized, and its efficiency for increasing the bioethanol concentration was evaluated using the integrated pervaporation technique. The techno-economic analysis is presented in detail to evaluate the process profitability, which achieves a considerable profit for the whole duration of the project without any losses as it reaches a net profit of USD 1 million in 2023, reaching USD 2.1 million in 2047 for a company with a capacity of 32 thousand tons per year. The sequential strategy offers a promising approach for efficient bioethanol production under mild and environmentally friendly conditions that enable its implication industrially.

The bioconversion of environmental wastes into energy is gaining much interest in most developing and developed countries. The current study is concerned with the proper exploitation of some industrial wastes. Cellulosic fiber waste was selected as a raw material for producing bioethanol as an alternative energy source. A combination of physical, chemical, and enzymatic hydrolysis treatments was applied to maximize the concentration of glucose that could be fermented with yeast into bioethanol. The results showed that the maximum production of 13.9 mg/mL of glucose was achieved when 5% cellulosic fiber waste was treated with 40% HCl, autoclaved, and followed with enzymatic hydrolysis. Using SEM and FTIR analysis, the instrumental characterization of the waste fiber treatment confirmed the effectiveness of the degradation by turning the long threads of the fibers into small pieces, in addition to the appearance of new functional groups and peak shifting. A potent yeast strain isolated from rotten grapes was identified as Starmerella bacillaris STDF-G4 (accession number OP872748), which was used to ferment the obtained glucose units into bioethanol under optimized conditions. The maximum production of 3.16 mg/mL of bioethanol was recorded when 7% of the yeast strain was anaerobically incubated at 30 °C in a broth culture with the pH adjusted to 5. The optimized conditions were scaled up from flasks to a fermentation bioreactor to maximize the bioethanol concentration. The obtained data showed the ability of the yeast strain to produce 4.13 mg/mL of bioethanol after the first 6 h of incubation and double the amount after 36 h of incubation to reach 8.6 mg/mL, indicating the efficiency of the bioreactor in reducing the time and significantly increasing the product.

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.