Alkyl polyglycosides (APGs) of different hydrocarbon chain lengths were prepared using an indirect method involving the condensation of fatty alcohol with dextrose. The chemical structures of the prepared compounds were confirmed using different spectroscopic techniques, primarily Fourier transform infrared spectroscopy, nuclear magnetic resonance and mass spectroscopy. The surface properties of the solutions containing different concentrations of the prepared APGs were determined at different temperatures. The results of the spectroscopic analysis demonstrate that these materials were prepared through the correct techniques, producing pure materials. The results of the critical micelle concentration (CMC) determination demonstrate that the surface properties of these compounds depend mainly on the nature of their hydrophobic component.

A diversity of solution has been used and utilized to minimize cold flow properties problems caused by paraffins crystallization during production and/or transportation of waxy crude oils. Herein, a novel series of nanohybrids of poly­(methyl methacrylate)-graphene oxide (PMMA-GO) as pour point depressants was prepared successfully by dispersing the inorganic nanosheets of GO on the organic, PMMA, matrix via in situ free radical polymerization. The prepared PMMA-GO nanohybrids were characterized by FT-IR and Raman spectroscopy, XRD, HRTEM, SEM, and GPC chromatography. The thermal stability of PMMA-GO nanohybrids was also studied by both TGA and DSC. The results showed that the pour point and the apparent viscosity of waxy crude oil were reduced significantly upon addition of PMMA-GO nanohybrid, and the long-term stability of the PMMA-GO nanohybrid was superior to that of a conventional PMMA material. The significant effect of this PMMA-GO nanohybrid as pour point depressant and flow improver on waxy crude oil problem is carrying new technology to minimization of the permeability during the charge and transportation process. The effect of oil soluble PMMA-GO nanohybrid on the pour point/rheological properties is discussed, and a beneficiation mechanism is suggested.

Surface tension as a function of concentration and temperature was measured for solutions of N-acyl sarcosinates, RCON(CH 3 )CH 2 COONa. From the intersection points in the (γ-log c) curves, the critical micelle concentration (CMC) was determined at 20, 35, 50, and 65°C. Structural effects on the CMC, maximum surface excess, and the minimum area per molecule at the aqueous solution/air interface are discussed. The free energy, enthalpy, and entropy of micellization and adsorption of surfactant solutions also were investigated. JAOCS 74, 43-47 (1997).

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.

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