Surface enhanced infra-red spectroscopy with modified silver nanoparticles (AgNPs) for detection of quaternary ammonium cationic surfactants

A novel surface enhanced infra-red spectroscopy (SEIRS) method with silver nanoparticles (AgNPs) assisted by single drop microextraction (SDME) was developed for detection of total mixed quaternary ammonium cationic surfactants (QACS) in water samples.

Application of Diester Gemini Quaternary Ammonium Salt as Paper Softening Agent

Quaternary ammonium cationic surfactants have very important application in the papermaking industry, which is a series of important paper softening agents. In order to obtain an environment-friendly paper softening agent, a novel diester gemini quaternary ammonium salt cationic surfactant has been prepared. Dodecyldimethyl amine, epichlorohydrin and adipic acid were used as raw materials to synthesize the surfactant, and Fourier transform infrared spectroscopy was used to characterize the groups in reaction product. Moreover, the softening effect of the diester gemini quaternary ammonium salt cationic surfactant was studied in detail.

Petroleum quaternary ammonium surfactants mixture synthesized from light naphtha as corrosion inhibitors for carbon steel in 1 m HCl

A quaternary ammonium cationic surfactants mixture was synthesized from light naphtha, petroleum fraction. The mixture was analyzed by Fourier transform infrared spectroscopy and UV/Visible spectroscopy and was evaluated as a corrosion inhibitor for carbon steel in 1 m HCl, by gravimetry, potentiodynamic polarization and electrochemical impedance spectroscopy. The results showed that inhibiting efficiency increased with inhibitor concentration and temperature, and was independent of pH (in the range of 0–4) and immersion time; its optimal value was up to 84% for 560 mg/l at 25°C. Experimental data showed that the cationic surfactants mixture acts as a mixed (anodic and cathodic) inhibitor and conformed to the Langmuir adsorption isotherm. Scanning electron microscopy images revealed the inhibiting capacity of the mixture against carbon steel acid corrosion.