Amphoteric Surfactants: Synthesis, Surface, Antimicrobial Activities, and Corrosion Inhibition for Aluminum in Acidic Solution

Abstract—

A new amphoteric surface-active agents, namely, sodium salt of 2-hydroxy-3-(trimethyl azanyl) propoxy-3-(alkanoyl oxy)-1-oxopropane-2-sulfonate were synthesized, and their chemical structures were confirmed spectroscopically. Surface tension measurements of those surface-active compounds were used to assess some surface parameters such as critical micelle concentration (cmc), the surface tension at the cmc (γ_cmc), effectiveness (π_cmc) and efficiency of adsorption. Results revealed that cmc and γ_cmc decreased as the number of carbon atoms in a hydrocarbon chain increased from 5.62 × 10^–3 to 1.78 × 10^–3 mol/l and from 33.6 to 44.4 mN/m, respectively. Values of ∆G_ads were lower than those of ∆G_mic, which facilitated the adsorption of the molecules of the surfactants on the air–water interface. The prepared surfactants showed good results for antimicrobial activity. Also, the weight loss and the potentiodynamic polarization methods were used to study the effect of the new synthesized surfactants as corrosion inhibitors for aluminum in 1 M of HCl. The obtained data showed that the prepared surfactants acted as good corrosion inhibitors for aluminum in 1 M HCl.