Influence of series of long-chain cationic surfactants on the quality characteristics of nano silica induced zinc phosphated mild steel

Mild steel panels were zinc phosphated employing environmentally safe nano silica as an accelerator and a series of four cationic surfactants as additives. The four cationic surfactants chosen were decyltriethyl ammonium bromide (C10TEAB), dodecyltriethyl ammonium bromide (C12TEAB), hexadecyltriethyl ammonium bromide (C16TEAB), and octadecyltriethyl ammonium bromide (C18TEAB). The length of the alkyl chain of the surfactant compounds influenced the quality of the coatings. The corrosion resistance of the coated panels was assessed using a salt spray test. The hydrophobicity of the coatings increased as the hydrocarbon chain length of the surfactants extended from C10 to C18. Porosity, adhesion, and roughness tests were used to examine the surface properties of the coated panels. The coating weight and thickness of the resultant coatings on the base metal were used to quantify coating quality. The results of the tests revealed that the presence of C16TEAB additive outperformed all other components in terms of coating efficiency, coating thickness, and corrosion inhibition performance. The optimal quantity of C18TEAB deposited had a maximum coating weight of 0.0430 g/mm2 that enhanced durability, appearance, and barrier qualities.

Synthesis and properties of ester functionalized cationic Gemini surfactants with amide groups

In this paper, a novel series of ester-functionalized cationic Gemini surfactants with amide groups (abbreviated as C m -(BAE)-C m (m = 12, 14, 16)) were synthesized and their surface tension as well as the thermodynamic surface parameters were determined with conductivity and fluorescence measurements, respectively. The structures of these Gemini surfactants were characterized by FT-IR, 1H NMR, and MS. The Krafft points of the three surfactants are below 0 °C, indicating better water solubility. The critical micelle concentration (CMC) of these surfactants decreases with the increase in the length of hydrophobic chain. The micellization process of these surfactants was found to be entropy-driven. The polar functional ester groups in the spacer form hydrogen bonds with water molecules, which increases the solubility of these Gemini surfactants in aqueous systems, facilitates the aggregation of their monomers and improves the stability of their micelles.