Synthesis and Biocidal Activity of Some Naphthalene-Based Cationic Surfactants

In this study, different cationic surfactants were prepared by reacting dodecyl bromide with tertiary amines to produce a series of quaternary ammonium salts that were converted subsequently to stannous and cobalt cationic complexes via complexing them with stannous (II) or cobalt (II) ions. Surface properties such as surface- and interfacial-tension, and the emulsifying power of these surfactants were investigated. The surface parameters including critical micelle concentration, maximum surface excess, minimum surface area, tension lowering efficiency and effectiveness were studied. The free energy of micellization and adsorption were calculated. Antimicrobial activity was determined via the inhibition zone diameter of the prepared compounds, which was measured against six strains of a representative group of microorganisms. The antimicrobial activity of some of the prepared surfactants against sulfate reducing bacteria was determined by the dilution method. FTIR spectra, elemental analysis and a H1 NMR spectrum were examined to confirm compound structure and purity. The results obtained indicate that these compounds have good surface properties and good biocidal effect on broad spectrum of micro organisms

Synthesis and evaluation of some derivatives of polysiloxanes

Silicone surfactants have been widely used in our daily life and many industrial fields on the basis of their unusual properties. Only in the past decades has the use of silicone as a hydrophobic building block for the preparation of surfactants become common. The recent trend to combine silicone, polyoxyalkylene and carbohydrate moieties in the same molecule has resulted in a plethora of new compounds with new properties. In this article, we report the preparation of a series of “glycopolysiloxanes” surfactants with different molecular weights. They were structurally characterized by IR, 1H NMR and MS. Specifically, the critical micelle concentration (cmc), effectiveness of surface tension reduction (πcmc), maximum surface excess (Γmax), minimum surface area (Amin) and standard free energies of micellization (ΔG°mic) and adsorption (ΔG°ads) have been determined from aqueous surface tension measurements using Du-Nouy Tensiometer (KRUSS K6 type 4851) with a platinum ring. All the surfactants have good surface properties and have low cmc. The bacteriostatic power of these polymers was tested and compared under the same conditions in aqueous solution against common strains of Gram positive bacteria and strains of Gram negative bacteria

Preparation and evaluation of some amide ether carboxylate surfactants

A homologous series of new mild surfactants, namely: Alkyl amide ether carboxylates surfactants (AEC) RCO–NHCH2CH2O (CH2CH2O)6CH2COONa, were synthesized by esterification, amidation, ethoxylation and carboxymethylation reaction steps of fatty acids (Lauric, Myristic, palmitic, stearic, oleic or linoleic). The chemical structures of the prepared compounds were confirmed using different spectroscopic techniques, FTIR spectroscopy, mass spectra and HNMR. The surface properties including surface and interfacial tensions, foaming height, emulsification power, calcium ion stability, stability to hydrolysis and critical micelle concentration (cmc) were determined. The study of their surface properties showed their stability in hard water and in acidic and alkaline media. These compounds have high calcium ion stability. The low foaming power could have an application in the dyeing auxiliary industry. The lower values of the interfacial tension values indicate the ability of using these surfactants in several applications as corrosion inhibitors and biocides. The data revealed various advantages and potentials as a main surfactant as well as co- surfactants

Evaluation of some vanillin-modified polyoxyethylene surfactants as additives for water based mud

Water-based drilling fluids are increasingly being used for oil and gas exploration and are generally considered to be more environmentally acceptable than oil-based or synthetic-based fluids. In this study, new types of vanillin-modified polyoxyethylene surfactants were evaluated as additives in water-based mud. Their rheological properties in water-based mud were investigated which included the apparent viscosity, the plastic viscosity, the yield point, the gel strength, the thixotropy as well as the filtration properties. Also, the effect of high temperature on the rheology of the formulated water based mud was studied. The tested ethoxylated non-ionic surfactants showed good results when utilized in the formulation of water-based mud

Surface parameters, biodegradability and antimicrobial activity of some amide ether carboxylates surfactants

In the present investigation, a series of amide ether carboxylates surfactants RCO-NHCH2CH2O (CH2CH2O)6CH2COONa (AEC), with different alkyl chain lengths from (C12 to C18) and (C18=, C18==) were synthesized. The surface parameters particularly effectiveness (Πcmc), efficiency (PC20), maximum surface excess (Γmax) and minimum area per molecule (Amin) values were investigated. In addition, the standard free energies of micellization (ΔGmic0) and adsorption (ΔGads0) were calculated for the prepared surfactants in aqueous solution. The prepared surfactants were tested for their biodegradability in the water of the River Nile according to the Die-away test method. Their antimicrobial activity against strains of bacteria, yeast and fungi were also investigated