Gemini surfactants

Journal of Surfactants and Detergents (Impact Factor: 1.35). 09/1998; 1(4):547-554. DOI: 10.1007/s11743-998-0057-8

ABSTRACT The literature, including patents, describing the emerging area of gemini surfactants is reviewed. The differences in structure/property
relationships between gemini and comparable conventional surfactants are described and discussed in terms of their predicted
performance properties. Supportive performance data are enumerated.

  • [Show abstract] [Hide abstract]
    ABSTRACT: Using surface tension and fluorescence methods, the surface and solution properties of two cationic gemini surfactants {pentanediyl-1,5-bis(dimethylcetylammonium bromide) and hexanediyl-1,6-bis(dimethylcetylammonium bromide)} (referred to as 16-5-16 and 16-6-16) have been studied in the presence and absence of primary linear alkanols. Parameters studied include the critical micelle concentration (CMC), C 20 (the surfactant concentration required to reduce the surface tension of the solvent by 20 mN·m−1), Г max (maximum surface excess), and A min (minimum surface area per molecule). These parameters indicate mixed micelle formation and, therefore, surfactant-additive interaction parameters in mixed micelles and mixed monolayers, as well as activity coefficients, were calculated. A synergistic effect was observed in all instances and was found to be correlated with the chain length of the alkanols. The CMC values of 16-s-16 (s = 5, 6) decrease with increasing alkanol concentration and the extent of this effect follows the sequence: 1-octanol (C8OH) > 1-heptanol (C7OH) > hexan-1-ol (C6OH) > 1-pentanol (C5OH) > butanol (C4OH). The micelle aggregation number (N agg) of mixed micelles has been obtained using the steady state fluorescence quenching method. The micropolarity of gemini/alkanol systems has been evaluated from the ratio of intensity of peaks (I 1/I 3) of the pyrene fluorescence emission spectra. Results are interpreted on the basis of the structure of mixed micelles and monolayers.
    Journal of Solution Chemistry 12/2013; 42(12). · 1.08 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Three anionic surfactants of the monododecyl diaryl disulfonate type (MDDADS-n, n = 0, 1, 2) were synthesized. The structural characters of MDDADS-n surfactants were verified by electrospray ionization/mass spectrometry. The effect of the spacer group on the surface activity, salinity and hardness tolerance and mimic oil washing efficiency were investigated. The results showed that the critical micelle concentration (CMC), surface tension at CMC, C20 and the minimum area per molecule of the anionic surfactants increased when the spacer group length increased. There was less effect on mimic oil washing efficiency of MDDADS-n when the spacer group changed; meanwhile, they displayed higher mimic oil washing efficiency in salt solution (NaCl or CaCl2) than that of sodium dodecylbenzenesulfonate (SDBS); all MDDADS-n surfactants showed much lower sensitivity to water hardness than SDBS, what would be beneficial to enhancing oil recovery in a high salinity oil field.
    Journal of Surfactants and Detergents 01/2013; · 1.35 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: New dimeric surfactants [16-s-16, s: (CH2)4; CH2–COO–(CH2)2–OCO–CH2; CH2–COO–ISO–OCO–CH2 (ISO = d-isorbide) and CH2–CONH–(CH2)2–NHCO–CH2] were synthesized and characterized (I–IV, respectively). The micellization behavior of dimeric surfactants with various spacers was studied by conductance/steady-state fluorescence quenching (SSFQ) measurement and compared with the conventional surfactant (cetyltrimethylammoniumbromide, CTAB). The critical micelle concentration (CMC) values of several surfactants were found to be nearly the same by both techniques. Conductance measurements were used exclusively to obtain CMC and degree of dissociation (α) values at various temperatures, while SSFQ measurements were used to obtain a few CMC values (for comparison) and an aggregation number (N agg). A decrease in CMC and N agg values and an increase in α were observed for dimeric surfactants when compared with CTAB. CMC decreases and then increases with a continuous increase in temperature (U-shaped behavior). The temperature of minimum CMC, T m, was distinctly different for CTAB and the dimeric surfactants. T m values were dependent on the nature of the spacer. The temperature dependence of CMC and α value was used to calculate the thermodynamic parameters of micelle formation for two classes of surfactant (conventional and dimeric). Enthalpy-entropy compensation plots exhibited fair linearity except for IV. Compensation lines for spacers containing ester groups are parallel to one another. Micro-polarity and apparent dielectric constant (ε a) data suggest that the micellar environment felt by pyrene is similar to that of an alkanol with a 3–4 carbon chain.
    Journal of Surfactants and Detergents 09/2013; · 1.35 Impact Factor


Available from