Counterion-coupled gemini (Cocogem) surfactants based on dodecylisopropylol amine and dicarboxylic acids: synthesis, characterization and evaluation as biocide against SRB

Abstract

New cocogem surfactants were synthesized by interaction of dodecylisopropylol amine with dicarboxylic (oxalic, succinic, adipic, sebacic, tartaric, maleic, fumaric, isophthalic) acids. By tensiometric method, the surface activity of aqueous solutions of the synthesized cocogem surfactants at the border with air was studied and, by conductometric method, the specific electrical conductivity of these solutions was determined. The degree of counterion binding (β), critical micelle concentration (CMC), effectiveness of surface tension reduction (π_CMC), surface excess concentration (Γ_max), area per molecule at the interface (A_min), changes of Gibbs free energies of adsorption (ΔG_ad) and micellization (ΔG_mic) have been calculated. The character of change of the colloidal-chemical indices depending on spacer-group nature and length has been clarified. So, with an elongation of the spacer group and when passing from cis-form to trans-form, the value of CMC decreases. The obtained cocogem surfactants exhibit a considerable bactericidal effectiveness against sulfate-reducing bacteria. The bactericide properties of the cocogem surfactants containing in the spacer chain a saturated hydrocarbon fragment and benzene ring are stronger than for the others.

Keywords:

• Adsorption
• cocogem surfactant
• micellization
• surface tension

Acknowledgements

The publication was prepared with the support of the “RUDN University Program 5–100”. The authors thank the Institute of Petrochemical Processes of National Academy of Sciences of Azerbaijan for supporting this research.

Disclosure statement

No potential conflict of interest was reported by the authors.