A series of N-alkyl pyridinium aldoxime surfactants was synthesized by the reaction of pyridinium aldoxime with long chain alkyl halides (decyl, dodecyl, tetradecyl and hexadecyl bromide). The chemical structure of the synthesized compounds was confirmed by elemental analysis and FTIR spectra. Surface tension was measured in aqueous solutions for different concentrations at 25 °C. Various surface properties of the synthesized surfactants were evaluated, particularly the critical micelle concentration (CMC), effectiveness (πCMC), efficiency (PC20) as well as the maximum surface excess (Γmax) and minimum surface area (Amin). Also, the micellization and adsorption at liquid/air interfaces were investigated. The synthesized cationic surfactants were evaluated for their biocidal activity. Good antibacterial and antifungal activities were recorded against Gram-positive bacteria (Bacillus subtilis ATCC 6633, Micrococcus luteus ATCC 25922), followed by Gram-negative bacteria (Escherichia coli ATCC 23282, Pseudomonas aeruginosa ATCC 10145), yeast (Candida albicans IMRU 3669) and filamentous fungus (Aspergillus niger ATCC 16404).
DISPERSANTS, usually blended with several surfactants and a solvent, are used to enhance oil spill dispersion as small droplets in water column. Although there is growing acceptance of dispersants as a counter measure to marine oil spill around the world, the two major issues with the dispersants are their toxicity to marine life and dispersion effectiveness (DE) for crude oil. To develop more efficient and less toxic dispersants, three dispersants of hexaglycerol esters (hexaglycerol laurate, hexaglycerol myristate and hexaglycerol palmitate) non-ionic surfactants were prepared. Salinity at different temperatures of the three dispersants was investigated. They had high (DE) for studied crude oil. Emulsion stability was also examined and it was found that all the prepared surfactants were able to form stable emulsions and their stability was very high, extending for months.
Two series of cationic gemini surfactants, alkanediyl‐α,ω‐bis[N,N‐dimethyl alkyl (octyl or dodecyl)ammonium] dibromide (R‐s‐R; s = 6, 10, 12 and R = 8 and 12) were prepared and evaluated as additives for water‐based mud. The chemical structures of the prepared surfactants were confirmed using FTIR and mass spectroscopy. Surface activity of these compounds has been studied and their surface properties including surface tension, emulsification power, critical micelle concentration, effectiveness, maximum surface excess and minimum surface area were determined. The results showed that the prepared compounds have significant surface activity, especially those of longer hydrophobic chain length. The prepared cationic gemini surfactants were evaluated as viscosifiers and filter loss additives for water‐based mud formulated from local Na‐montmorillonite clay. XRD analysis was carried out to the Na‐montmorillonite clay to determine the interaction of the surfactants with inter layers of the clay structure. Rheological properties, gel strength, thixotropy, filtration properties and the effect of temperature on rheological properties of the water‐based mud were studied. The results indicated that the gemini surfactants have a positive effect on the rheological and filtration properties of the Na‐montmorillonite clay according to American Petroleum Institute specifications.
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