Volume 45, Issue 4

Sulfonation with SO 3 of an oleic methyl ester has led to a mixture of sulfonates with potential properties as a surfactant, an emulsifier or even a wetting agent that can be used in detergent formulations. For the first time, the products from the sulfonation reaction with SO 3 are identified.

The adsorption of sodium dodecyl sulfate (SDS) on alumina was studied by using the surfactant ion-selective electrode. The adsorbance could be calculated from the potential and concentration response characteristics of surfactant ion-selective electrode to get surfactant adsorption isotherm. Further experiment results show that the adsorbance was greatly influenced by pH of the solution. It is demonstrated that surfactant ion-selective electrode could be utilized to measure surfactant concentrations in solution after adsorption equilibrium without solid-liquid separation.

The foaming power and foam stability of three commercial alkyl polyglycosides (APG), Glucopon 215, 600 and 650, have been studied using a modified Ross Miles method. The effects of APG concentration (0.1–4.0 g/L) and temperature (30–60°C) on foam level have been analysed, determining the volume of air in the foam and the foaming power at different times (0–300 s). Furthermore, the foaminess was determined over time until 300 s, registering values from 0.95 or 0.96 to 0.98 or 0.99. Finally, different binary mixtures of surfactants have been assayed at 40°C. To prepare these mixtures Glucopon 650 was mixed with one of the following surfactants: two commercial fatty alcohol ethoxylates, Findet 1214N/23 and Findet 10/18, and a control foaming surfactant, Triton CF:32.

The production of normal paraffin from Gas to Liquids (GTL) plants provides LAB producers with a more cost-effective feedstock than normal paraffin extracted from kerosene. Test results to date demonstrate that the performance of GTL Normal Paraffin, and LAB and LAS derived from it, however, is equal to that of kerosene derived normal paraffin. Recent work has particularly focussed on the environmental performance of LAS produced from GTL Normal Paraffin. Detailed GC and NMR analyses confirm that there is little, if any, significant difference in the analytical “profiles” of the kerosene and GTL Normal Paraffin derived LAS samples. It is therefore not surprising that there is no difference in the biodegradability of kerosene and GTL Normal Paraffin derived LAS samples. All samples achieved > 60% mineralisation after 28 days (OECD 301B); all these data were consistent with previous biodegradability data for LAS from European Chemical Bureau (ECB) and Human & Environmental Risk Assessment (HERA) databases. Similarly, there is no difference in the ecotoxicity of kerosene and GTL Normal Paraffin derived LAS samples. Test results to fish (LC 50 ), invertebrates (EC 50 ) and algae (EC 50 ) lay in the range 1–10 mg/l, 1–10 mg/l and 10–100 mg/l respectively; again these data are entirely consistent with previous ecotoxicity data for LAS from ECB and HERA databases.

The biodegradation of triethylene glycol monododecyl ether (C12EO3) was studied under the conditions of the Organization for Economic Co-operation and Development (OECD) Screening Test. Primary biodegradation of C12EO3 and concentration profiles of its metabolites were measured by the high performance liquid chromatography with fluorimetric detection (HPLC-FD) after derivatisation with 1-naphthoyl chloride. High performance liquid chromatography – electrospray mass spectrometry (HPLC-MS) was used for the identification and analysis of C12EO3 and its metabolites.

Studies of solubilization of organic contaminants by surfactants are complicated by the fact that the effective surfactant concentration is decreased by partitioning into the organic phase. This paper introduces an experimental setup for surfactant solubilization where the partitioning loss of surfactants is minimized. Using this setup, two anionic (sodium dodecyl sulphate and Spolapon AOS 146) and one nonionic surfactant (Novanik 0633 A) were compared. When comparing solubilization efficacies expressed as multiples of the critical micelle concentration, the two anionic surfactants were able to solubilize a higher amount of polychlorinated biphenyls. For lower surfactant concentrations, solubilization efficacies were similar for all surfactants. However, it is necessary to take into account that the critical micelle concentration of the nonionic surfactant is considerably lower.

The kinetics of the oxidation of β-alanine (Ala) by N-bromophthalimide (NBP) has been studied in the presence of cationic surfactant, cetyltrimethylammonium bromide (CTAB) at 313 K. The oxidation kinetics exhibits first order kinetics with respect to [Oxidant], fractional order of [Ala] and inverse fractional order of [H + ] on the rate of reaction. The rate of reaction decreases with decreasing dielectric constant of the medium. The rate constant increases with increasing CTAB and then constant. Increasing [Hg(OAc) 2 ] and inorganic salts i.e. [Cl − ] and [Br − ] increased the rate of reaction, whereas a change in ionic strength of the medium had no effect on oxidation velocity. Methyl Cyanide as the main oxidation product has been identified. Thermodynamic and activation parameters have been evaluated. The rate constants, binding constants with surfactant (CTAB) and the index of cooperativity have also been evaluated.