Influence of the length of the spacer group on the performance of the sulfate-based Gemini surfactants

PurposeA series of sulfate-based Gemini anionic surfactants were synthesized via etherification, ring opening and sulfation reactions using epichlorohydrin, fatty alcohol, ethylene glycol and chlorosulfonic acid as the main raw materials. Orthogonal experiments for 1,8-bisalkoxymethylene-3,6-dioxin-1,8-octane disulfate were performed on the sulfation reaction to determine the optimal reaction conditions.Design/methodology/approachA series of sulfate-based Gemini anionic surfactants were synthesized via etherification, ring opening and sulfation reactions using epichlorohydrin, fatty alcohol, ethylene glycol and chlorosulfonic acid as the main raw materials. Orthogonal experiments for 1,8-bisalkoxymethylene-3,6-dioxin-1,8-octane disulfate were performed on the sulfation reaction to determine the optimal reaction conditions. The structures of the intermediate and final products were characterized by FT-IR (Fourier transform infrared spectroscopy analysis), 1H-NMR (proton nuclear magnetic resonance spectroscopy) methods. The thermal performance of surfactants was analyzed using thermogravimetric analysis (TGA). The thermogravimetric results showed that the sulfate-based Gemini surfactants had good heat resistance (the thermal decomposition temperature of which was in the range of 140∼170?). The Krafft point, surface tension, foaming, Hydrophile–Lipophile Balance Number (HLB), emulsifying, wetting, and lime-soap dispersing performance were measured by visual observation, hanging drop method, aqueous surfactant solution method and Borghetti–Bergman method, respectively. The results have shown that all the sulfate-based Gemini surfactants had good water solubility and lime-soap dispersing ability. When spacer group was -(CH2)2-, with the increase of the carbon chain length from C12 to C14, the micellar concentration critical micelle concentration and surface tension (CMC) gradually increased from 8.25 × 10–4 mol/L to 8.75 × 10–4 mol/L and 27.5 mN/m to 30.9 mN/m, respectively. Also, the sulfate-based Gemini surfactants with the different length of the spacer group had a different effect on their performance on foaming properties and foam properties, HLB and emulsifying ability and wetting ability. FindingsIn view of the important role of the spacer group and the general use of anionic surfactants in oil fields, this article considers the preparation of a series of sulfate-based Gemini surfactants by changing the spacer group and the chain length of the hydrophobic group and evaluating their surface activity, and finally its Kraffi, on the foam properties, HLB value, emulsifying performance, lime soap dispersing ability etc.Originality/valueSulfate-based Gemini surfactants have broad application prospects in the fields of oil and gas exploitation, environmental protection, chemistry and daily chemical industry and so on.

Lime Soap as Bacteria Reducer

Some people in South Kalimantan have used river water to fulfill their daily needs include washing the utensils. Wash the cutlery use river water can cause disease transmission. Squeezed lime has an antibacterial effect in inhibiting bacterial growth. Antibacterial dishwashing soap is effective in reducing pathogenic bacteria. This research is to know the difference of bacterial amount on the variation of contact time with soap. Know the difference of bacteria on the variation of concentration of lime soap and soap without lime. The study used the experimental method with pretest and posttest with control design. The independent variables are a lime soap with a concentration of 40%, 50%, 60% and variable of contact time 30 second, 60 second and 90 seconds. The dependent variable is the number of bacteria on the dinnerware of a dinner plate. The data obtained in this study is the data of measurement of the number of bacteria on the dinner plate. Data analyzed by Kruskal-Wallis test. MPN coliform examination of river water showed results >2400 CFU/ml sample. There were no significant differences in treatment with contact time variation of 30 seconds, 60 seconds and 90 seconds. The significance value is 0.796 (> 0.05). There were significant differences in the treatment of lime soap with concentration variations of 40%, 50%, 60%, and soap without lime. The value of significance is 0,000 (<0.05).