Novel Gemini Cationic Surfactants: Thermodynamic, Antimicrobial Susceptibility, and Corrosion Inhibition Behavior against Acidithiobacillus ferrooxidans

Two novel triazine-based quaternary ammonium salt Gemini surfactants as potential corrosion inhibitors for carbon steel in a sulfate-reducing bacteria solution: Experimental and theoretical studies

In this paper, two triazine ring-containing quaternary ammonium salt Gemini surfactants (C12-2-C12 and C14-2-C14) were synthesized. The minimum inhibitory concentrations against sulfate-reducing bacteria (SRB) of C12-2-C12, C14-2-C14 and dodecyl dimethyl benzyl ammonium chloride (1227) were determined using the double-dilution method. The performance of C12-2-C12 and C14-2-C14 in inhibiting carbon steel corrosion in the presence of SRB was examined, with 1227 serving as a control sample. The corrosion inhibition properties were assessed through static weight loss, electrochemical testing, and surface analysis. The interface adsorption behaviour of the corrosion inhibitor was explored via molecular dynamics simulations. Results indicate that the minimum inhibitory concentrations (MIC) of C12-2-C12 (0.021 mM) and C14-2-C14 (0.005 mM) are lower than that of 1227 (0.300 mM). The results of static weightlessness measurement reveal that the corrosion inhibition effects of the three surfactants on carbon steel soaked in SRB solution follow the order of C14-2-C14 > C12-2-C12 > 1227, with inhibition rates of 93.23 %, 88.45 %, and 76.49 % at a concentration of 0.2 mM, respectively. The adsorption behavior of these surfactants (1227, C12-2-C12, and C14-2-C14) on carbon steel surface in the presence of SRB conforms the Langmuir isotherm adsorption model. The outcomes of electrochemical experiments align with the static weight loss data. Furthermore, surface analysis results suggest that the surfactants can adsorb onto the carbon steel surface to form a protective film, thereby inhibiting SRB-induced corrosion.

Preparation of zwitterionic ionic surfactants-based sulphonyl for steel protections: Experimental and theoretical insights

Designating an organic inhibitor with a specific chemical structure that actively participates in steel protection by increasing adsorption on the steel surface. Based on that, we synthesized three zwitterionic surfactants based on azomethine with different hydrophobic chain lengths labeled ZWSO, ZWSD, and ZWSH. The presence of azomethine group, electrons, and heteroatoms in the zwitterionic surfactant’s amphipathic structure helped to improve C-steel protection. Their inhibitory activity toward steel corrosion was investigated utilizing electrochemical impedance spectroscopy (EIS), gravimetrical, and potentiodynamic polarization techniques. Importantly, the surfactant tail influenced corrosion inhibition performance; as surfactant tail length increased, so did inhibition efficiency due to increased adsorption affinity. The inhibition efficiencies of ZWSO, ZWSD, and ZWSH are 87.15, 89.82, and 91.36%, respectively. Tafel data clarified that ZWSO, ZWSD, and ZWSH inhibitors behave as mixed-type inhibitors following the modified Langmuir isotherm. The inhibitors can adsorb physiochemically on the steel surface with ∆G ads ranges from −38.48 to −44.6 kJ mol−1. The SEM confirms that the morphology of C-steel becomes smoother because of inhibitor adsorption. The DFT and MCs output data supported the experimental performance of the tested ZWSO, ZWSD, and ZWSH inhibitors and especially their dependence on surfactant tail length.

Suppression of steel corrosion via some gemini cationic surfactant-based Schiff base: experimental and theoretical investigations

Steel is involved extensively in engineering vast constructing units in many industries and can undergo to corrosion by some chemical and/or electrochemical reactions with the environment. Therefore, designating an organic inhibitor with a specific chemical structure will participate in steel protection via enhancing their adsorption on the steel surface. Three gemini cationic surfactants based on azomethine with different hydrophobic tails labeled GSBI8, GSBI12, and GSBI16 have been designated and evaluated as corrosion inhibitors utilizing electrochemical impedance spectroscopy (EIS), gravimetrical and potentiodynamic polarization techniques. Importantly, the surfactant tail regulated the corrosion inhibition performance; with increasing the surfactant tail length, their inhibition efficiency enhanced because of their higher adsorption affinity. The inhibition efficiency of GSBI8, GSBI12, and GSBI16 reached 95.52, 96.72, and 97.1% respectively (EIS measurements). The Tafel examination clarified that GSBI8, GSBI12, and GSBI16 inhibitors behave as mixed type inhibitors following the modified Langmuir isotherm. The inhibitors adsorption on C-steel was confirmed by SEM surface examination. Finally, the DFT and MCs point of views investigation supported the experimental performance of the tested GSBI8, GSBI12, and GSBI16 inhibitors and specially their dependence on surfactant tail length.

Cationic gemini surfactant properties, its potential as a promising bioapplication candidate, and strategies for improving its biocompatibility: A review

Gemini surfactants consist of two cationic monomers of a surfactant linked together with a spacer. The specific structure of a cationic gemini surfactant is the reason for both its high surface activity and its ability to decrease the surface tension of water. The high surface activity and unique structure of gemini surfactants result in outstanding properties, including antibacterial and antifungal activity, anticorrosion properties, unique aggregation behaviour, the ability to form various structures reversibly in response to environmental conditions, and interactions with biomacromolecules such as DNA and proteins. These properties can be tailored by selecting the optimal structure of a gemini surfactant in terms of the nature and length of its alkyl substituents, spacer, and head group. Additionally, regarding their properties, comparison with their monomeric counterparts demonstrates that gemini surfactants have higher performance efficacy at lower concentrations. Hence, less material is needed, and the toxicity is lower. However, there are some limitations regarding their biocompatibility that have led researchers to develop amino acid-based and sugar-based gemini surfactants. Owing to their remarkable properties, cationic gemini surfactants are promising candidates for bioapplications such as drug delivery systems, gene carriers, and biomaterial surface modification.