Volume 47, Issue 1

Cleavable surfactants are of great interest for numerous reasons. These are amphiphiles in which a weak linkage has been deliberately inserted, normally, but not always, between the hydrophobic tail and the polar head group. Surfactant may degrade by chemical means, e.g., induced by acid, alkali, ultraviolet (UV) light, heat, or ozone. Acid- and alkali-labile surfactants have also attracted the attention in recent years. The main purpose for development of novel cleavable surfactants is to improve the biodegradation characteristics and the rate of biodegradation has consequently been studied for several of the surfactants. Alkali labile linkages that have been used for the purpose include normal ester bonds, betaine esters, and carbonates. This review deals the development of monomeric and gemini type cleavable surfactants.

Removal of industrially important Tartrazine dye from aqueous solution was carried with virgin and variously activated coal samples at room temperature. The morphological study indicated that the number of coal particles was increased when the coal was evacuated at 200°C while aggregated form was observed at 400°C evacuation temperature. The coal particles were again formed at 600°C evacuation temperature. The coal, which was evacuated at 400°C, adsorbed less Tartrazine than the coal samples which were evacuated at 200 and 600°C. This might be caused by the aggregation of the coal particles at 400°C (because of the plastic range of coal swelling), which results in a decrease of the coal surface area. The obtained adsorption data were also fitted to Langmuir and Freundlich isotherms, which followed both Langmuir and Freundlich isotherms models.

Φ-Sulfo Fatty Methyl Esters sulfonates (Φ-MES) were obtained via sulfoxidation of fatty acid methyl esters (FAME) with SO 2 , O 2 , and ultraviolet light of appropriate wavelength. Expectedly, these products may be used as linear alkylbenzene sulfonate (LAS) and alkyl ether sulfate (AES) partners, either in heavy-duty or in hand dishwashing liquids. Φ-MES are new anionic surfactants that can be regarded as potential components for detergent formulations and body care products as well. In this work we summarize the most relevant results of our research started fifteen years ago, on the synthesis, separation and analysis of Φ-sulfo fatty methyl ester sulfonates known as Φ-MES, and we update our last findings. We have to point out that we are for the time being, the only research group in the world to have published our research on Φ-MES. This paper describes the optimum batch conditions for the sulfoxidation of FAME and a reaction mechanism is proposed. The paper depicts an improved workup for the separation of reaction products from non reacted methyl ester and the GC-MS analysis of Φ-sulfo fatty methyl ester sulfonate is shown. Finally, an interpretation of conversion and selectivity of sulfoxydation reaction is given.

In the presence of an acid-binding agent loaded on alumina, 3-dehydroabietylamino-2-hydroxypropyl trimethyl ammonium chloride (DHAHPTMA) was synthesized with dehydroabietylamine (DHA) and 3-chloro-2-hydroxypropyl trimethyl ammonium chloride (CTA) as starting material. The structure of DHAHPTMA was characterized by FT-IR and 1 H-NMR, and the content of DHAHPTMA in product was determined by Ion Chromatography (IC). The antibacterial activity of DHAHPTMA was evaluated according to its minimum inhibitory concentrations (MICs) against Staphylococcus aureus (S. aureus), Staphylococcus epidermidis (S. epidermidis), gas bacillus, Klebsiella pneumoniae, Escherichia coli (E. coli), Pseusomonas aeruginosa (P. aeruginosa) and Salmonella. Results of IC showed that the mass content of DHAHPTMA in the product was higher than 97%. The experimental results also indicated that the MICs of DHAHPTMA against S. aureus, S. epidermidis and E. coli were lower than that of Bromo-Geramium against theses bacteria.

A slow stirring method to measure log P values of water-soluble surfactants is described. Aqueous surfactant solution is equilibrated with octanol. A surface tension technique is used to determine the decrease in concentration in the aqueous phase. Interference from octanol, which is surface active, is prevented by evaporation and redissolution of the sample. For industrial surfactants this method gives a log P value that is effectively weighted according to the surface activity of the components. The test can be used to screen surfactants for a possible risk of bioaccumulation as it is generally accepted that substances with log P < 3 are unlikely to bioaccumulate. The apparent log P of an alkane sulfonate was 1.5 when a 1 g/L aqueous solution was equilibrated with an equal volume of octanol. Due to ion pair formation in the octanol phase the apparent log P decreased with concentration. As a result, the tendency to partition into octanol is likely to be less at environmentally relevant concentrations.

Sodium salts of fatty alcohol polyoxyethylene ether sulfonates with different length of hydrophobic chain (C n E 3 SO 3 , n +; 14, 16, 18) were synthesized from sodium isethionate, then the structure was verified by IR. The temperature resistance, calcium-tolerant stability and salt tolerance were evaluated by pyrogenetic decomposition, phase separation and middle phase emulsion respectively. In addition the mixture of C n E 3 SO 3 and heavy alkylbenzene sulfonate (HABS) was studied. The results showed that: (1) C n E 3 SO 3 was very stable at 150°C especially in neutral, weak acid and weak alkaline conditions; (2) C n E 3 SO 3 performed a good salt tolerance and have a rank of C 18 E 3 SO 3 > C 16 E 3 SO 3 > C 14 E 3 SO 3 ; (3) the calcium-tolerant stability of C n E 3 SO 3 reached 8700 mg/L, 9500 mg/L and 10000 mg/L respectively; (4) C n E 3 SO 3 was very good for improving the salt tolerance of mixture of C n E 3 SO 3 and HABS. C 18 E 3 SO 3 was the best in mixtures of Daqing crude oil/water containing C 18 E 3 SO 3 and HABS in a ratio of ω(C 18 E 3 SO 3 ):ω(HABS) = 3:7 and showed the strongest synergistic effect. The interfacial tension in the system Daqing crude oil/water reached a minimum in the order of 10 –3 mN/m and was always below 10 –2 mN/m for c NaCl from 0 to 15000 mg/L.

A fullerenol sensor utilizing fluorescence quenching of a labeled protein was developed for rapid detection and quantification of ionic (cetyltriammonium bromide (CTAB), sodium dodecyl sulphate, (SDS)) and non-ionic (Tween 20 and Triton X-100) surfactants in solution. The sensor is based on the competitive adsorption of the surfactants and the fluorescently labeled protein to fullerenols – hydroxylated buckminsterfullerenes. The fluorescence quenching between fullerenols and the fluorochrome-labeled protein was detected and related to the replacement of the labeled protein by the surfactants. The non-ionic surfactants could be measured at sub to low micromolar concentrations whereas significantly higher concentration of ionic surfactants was required to efficiently cover the fullerenol surface. The combination of the novel fullerenol sensor with existing micro titer plate fluorometric instrumentation can find use as a versatile and rapid probe for tracing various types of surface active molecules.